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03bd36a387
529 Commits
Author | SHA1 | Message | Date | |
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Changyuan Lyu
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03bd36a387 |
KVM: Documentation: Enumerate allowed value macros of irq_type
The expression `irq_type[n]` may confuse readers to interpret `n` as the bit position and think of CPU = 1 << 0, SPI = 1 << 1, and PPI = 1 << 2. Since arch/arm64/include/uapi/asm/kvm.h already has macro definitions for the allowed values, this commit uses these symbols to clear up the ambiguity. Signed-off-by: Changyuan Lyu <changyuanl@google.com> Link: https://lore.kernel.org/r/20240623164542.2999626-2-changyuanl@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev> |
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Changyuan Lyu
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dc1d234cdd |
KVM: Documentation: Fix typo BFD
BDF is the acronym for Bus, Device, Function. Signed-off-by: Changyuan Lyu <changyuanl@google.com> Link: https://lore.kernel.org/r/20240623164542.2999626-1-changyuanl@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev> |
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Linus Torvalds
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ff2632d7d0 |
powerpc updates for 6.10
- Enable BPF Kernel Functions (kfuncs) in the powerpc BPF JIT. - Allow per-process DEXCR (Dynamic Execution Control Register) settings via prctl, notably NPHIE which controls hashst/hashchk for ROP protection. - Install powerpc selftests in sub-directories. Note this changes the way run_kselftest.sh needs to be invoked for powerpc selftests. - Change fadump (Firmware Assisted Dump) to better handle memory add/remove. - Add support for passing additional parameters to the fadump kernel. - Add support for updating the kdump image on CPU/memory add/remove events. - Other small features, cleanups and fixes. Thanks to: Andrew Donnellan, Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Benjamin Gray, Bjorn Helgaas, Christian Zigotzky, Christophe Jaillet, Christophe Leroy, Colin Ian King, Cédric Le Goater, Dr. David Alan Gilbert, Erhard Furtner, Frank Li, GUO Zihua, Ganesh Goudar, Geoff Levand, Ghanshyam Agrawal, Greg Kurz, Hari Bathini, Joel Stanley, Justin Stitt, Kunwu Chan, Li Yang, Lidong Zhong, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Matthias Schiffer, Naresh Kamboju, Nathan Chancellor, Nathan Lynch, Naveen N Rao, Nicholas Miehlbradt, Ran Wang, Randy Dunlap, Ritesh Harjani, Sachin Sant, Shirisha Ganta, Shrikanth Hegde, Sourabh Jain, Stephen Rothwell, sundar, Thorsten Blum, Vaibhav Jain, Xiaowei Bao, Yang Li, Zhao Chenhui. -----BEGIN PGP SIGNATURE----- iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAmZHLtwTHG1wZUBlbGxl cm1hbi5pZC5hdQAKCRBR6+o8yOGlgCGdD/0cqQkYl6+E0/K68Y7jnAWF+l0LNFlm /4jZ+zKXPiPhSdaQq4xo2ZjEooUPsm3c+AHidmrAtOMBULvv4pyciu61hrVu4Y2b aAudkBMUc+i/Lfaz7fq1KnN4LDFVm7xZZ+i/ju9tOBLMpOZ3YZ+YoOGA6nqsshJF XuB5h0T+H55he1wBpvyyrsUUyss53Mp3IsajxdwBOsUDDp0fSAg8SLEyhoiK3BsQ EjEa6iEqJSBheqFEXPvqsMuqM3k51CHe/pCOMODjo7P+u/MNrClZUscZKXGB5xq9 Bu3SPxIYfRmU4XE53517faElEPmlxSBrjQGCD1EGEVXGsjn6r7TD6R5voow3SoUq CLTy90KNNrS1cIqeomu6bJ/anzYrViqTdekImA7Vb+Ol8f+uT9l+l1D75eYOKPQ3 N0AHoa4rnWIb5kjCAjHaZ54O+B2q2tPlQqFUmt+BrvZyKS13zjE36stnArxP3MPC Xw6y3huX3AkZiJ4mQYRiBn//xGOLwrRCd/EoTDnoe08yq0Hoor6qIm4uEy2Nu3Kf 0mBsEOxMsmQd6NEq43B/sFgVbbxKhAyxfZ9gHqxDQZcgoxXcMesyj/n4+jM5sRYK zmavLlykM2Tjlh1evs8+e0mCEwDjDn2GRlqstJQTrmnGhbMKi3jvw9I7gGtZVqbS kAflTXzsIXvxBA== =GoCV -----END PGP SIGNATURE----- Merge tag 'powerpc-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Enable BPF Kernel Functions (kfuncs) in the powerpc BPF JIT. - Allow per-process DEXCR (Dynamic Execution Control Register) settings via prctl, notably NPHIE which controls hashst/hashchk for ROP protection. - Install powerpc selftests in sub-directories. Note this changes the way run_kselftest.sh needs to be invoked for powerpc selftests. - Change fadump (Firmware Assisted Dump) to better handle memory add/remove. - Add support for passing additional parameters to the fadump kernel. - Add support for updating the kdump image on CPU/memory add/remove events. - Other small features, cleanups and fixes. Thanks to Andrew Donnellan, Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Benjamin Gray, Bjorn Helgaas, Christian Zigotzky, Christophe Jaillet, Christophe Leroy, Colin Ian King, Cédric Le Goater, Dr. David Alan Gilbert, Erhard Furtner, Frank Li, GUO Zihua, Ganesh Goudar, Geoff Levand, Ghanshyam Agrawal, Greg Kurz, Hari Bathini, Joel Stanley, Justin Stitt, Kunwu Chan, Li Yang, Lidong Zhong, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Matthias Schiffer, Naresh Kamboju, Nathan Chancellor, Nathan Lynch, Naveen N Rao, Nicholas Miehlbradt, Ran Wang, Randy Dunlap, Ritesh Harjani, Sachin Sant, Shirisha Ganta, Shrikanth Hegde, Sourabh Jain, Stephen Rothwell, sundar, Thorsten Blum, Vaibhav Jain, Xiaowei Bao, Yang Li, and Zhao Chenhui. * tag 'powerpc-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (85 commits) powerpc/fadump: Fix section mismatch warning powerpc/85xx: fix compile error without CONFIG_CRASH_DUMP powerpc/fadump: update documentation about bootargs_append powerpc/fadump: pass additional parameters when fadump is active powerpc/fadump: setup additional parameters for dump capture kernel powerpc/pseries/fadump: add support for multiple boot memory regions selftests/powerpc/dexcr: Fix spelling mistake "predicition" -> "prediction" KVM: PPC: Book3S HV nestedv2: Fix an error handling path in gs_msg_ops_kvmhv_nestedv2_config_fill_info() KVM: PPC: Fix documentation for ppc mmu caps KVM: PPC: code cleanup for kvmppc_book3s_irqprio_deliver KVM: PPC: Book3S HV nestedv2: Cancel pending DEC exception powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#" powerpc/code-patching: Use dedicated memory routines for patching powerpc/code-patching: Test patch_instructions() during boot powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region() powerpc: rename SPRN_HID2 define to SPRN_HID2_750FX powerpc: Fix typos powerpc/eeh: Fix spelling of the word "auxillary" and update comment macintosh/ams: Fix unused variable warning powerpc/Makefile: Remove bits related to the previous use of -mcmodel=large ... |
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Paolo Bonzini
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f4bc1373d5 |
KVM cleanups for 6.10:
- Misc cleanups extracted from the "exit on missing userspace mapping" series, which has been put on hold in anticipation of a "KVM Userfault" approach, which should provide a superset of functionality. - Remove kvm_make_all_cpus_request_except(), which got added to hack around an AVIC bug, and then became dead code when a more robust fix came along. - Fix a goof in the KVM_CREATE_GUEST_MEMFD documentation. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmY+oHQACgkQOlYIJqCj N/3c/w//dmgqxFGpPoCvZ2+pVarrbpsMdfO5skaMF0EN1a0Rb0oJcVYj7z1zqsjQ 4DCCANxVrcEGVBZG5I8nhk1lDlGS7zOTOBBovgVDNj7wL9p/fzOhR6UlLKG5QMMn 0nWY9raC8ubcrtKgOm/qOtSgZrL9rEWh3QUK1FRPKaF12r1CLPmJIvVvpCm8t//f YZrqpHj/JqXbc8V8toBHqvi3DaMIOA2gWRvjfwSWfCL+x7ZPYny3Q+nw9fl2fSR6 f6w1lB6VhyDudzscu4l7U4y5wI0LMmYhJ5p5tvQBB5qtbAJ7vpIUxxYh4CT/YdbH WLQCIBr2wR0Mkl0g4FwNlnnt6a5Sa6V4nVKfzkl37L0Ucyu+SpP8t6YO4nb/dJmb Sicx3qqeHC7N9Y9VVKzK3Kb33KVaBFawvzjIcc+GFXMDFZ35b33vWhYzTl3sJpLY hjfGpYTB1zHSj6f7a9mW7d15E/lyfqMKCzewZWnko0hISM8Jm1LxU3PMFJa8TR2/ yB6IUDDJnEk6fSwUwaCluAJv3kfnhs/S3fMFw+5cYkcmgW7yaE+K9nJ3aEkx5l7x 9sXjAtc7zbAwEuJZ+5C1+CgwWGKsfLKtXbjqMYAIAYep5oa+UrJ4L77aZyTV1mSD oRJs0LmNmachV5nxKFHAaijVc6vmZNhcD9ygbM5qeLGoGby+W8g= =dgM4 -----END PGP SIGNATURE----- Merge tag 'kvm-x86-generic-6.10' of https://github.com/kvm-x86/linux into HEAD KVM cleanups for 6.10: - Misc cleanups extracted from the "exit on missing userspace mapping" series, which has been put on hold in anticipation of a "KVM Userfault" approach, which should provide a superset of functionality. - Remove kvm_make_all_cpus_request_except(), which got added to hack around an AVIC bug, and then became dead code when a more robust fix came along. - Fix a goof in the KVM_CREATE_GUEST_MEMFD documentation. |
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Paolo Bonzini
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e5f62e27b1 |
KVM/arm64 updates for Linux 6.10
- Move a lot of state that was previously stored on a per vcpu basis into a per-CPU area, because it is only pertinent to the host while the vcpu is loaded. This results in better state tracking, and a smaller vcpu structure. - Add full handling of the ERET/ERETAA/ERETAB instructions in nested virtualisation. The last two instructions also require emulating part of the pointer authentication extension. As a result, the trap handling of pointer authentication has been greattly simplified. - Turn the global (and not very scalable) LPI translation cache into a per-ITS, scalable cache, making non directly injected LPIs much cheaper to make visible to the vcpu. - A batch of pKVM patches, mostly fixes and cleanups, as the upstreaming process seems to be resuming. Fingers crossed! - Allocate PPIs and SGIs outside of the vcpu structure, allowing for smaller EL2 mapping and some flexibility in implementing more or less than 32 private IRQs. - Purge stale mpidr_data if a vcpu is created after the MPIDR map has been created. - Preserve vcpu-specific ID registers across a vcpu reset. - Various minor cleanups and improvements. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAmY/PT4ACgkQI9DQutE9 ekNwSA/7BTro0n5gP5/SfSFJeEedigpmHQJtHJk9og0LBzjXZTvYqKpI5J1HnpWE AFsDf3aDRPaSCvI+S14LkkK+TmGtVEXUg8YGytQo08IcO2x6xBT/YjpkVOHy23kq SGgNMPNUH2sycb7hTcz9Z/V0vBeYwFzYEAhmpvtROvmaRd8ZIyt+ofcclwUZZAQ2 SolOXR2d+ynCh8ZCOexqyZ67keikW1NXtW5aNWWFc6S6qhmcWdaWJGDcSyHauFac +YuHjPETJYh7TNpwYTmKclRh1fk/CgA/e+r71Hlgdkg+DGCyVnEZBQxqMi6GTzNC dzy3qhTtRT61SR54q55yMVIC3o6uRSkht+xNg1Nd+UghiqGKAtoYhvGjduodONW2 1Eas6O+vHipu98HgFnkJRPlnF1HR3VunPDwpzIWIZjK0fIXEfrWqCR3nHFaxShOR dniTEPfELguxOtbl3jCZ+KHCIXueysczXFlqQjSDkg/P1l0jKBgpkZzMPY2mpP1y TgjipfSL5gr1GPdbrmh4WznQtn5IYWduKIrdEmSBuru05OmBaCO4geXPUwL4coHd O8TBnXYBTN/z3lORZMSOj9uK8hgU1UWmnOIkdJ4YBBAL8DSS+O+KtCRkHQP0ghl+ whl0q1SWTu4LtOQzN5CUrhq9Tge11erEt888VyJbBJmv8x6qJjE= =CEfD -----END PGP SIGNATURE----- Merge tag 'kvmarm-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 6.10 - Move a lot of state that was previously stored on a per vcpu basis into a per-CPU area, because it is only pertinent to the host while the vcpu is loaded. This results in better state tracking, and a smaller vcpu structure. - Add full handling of the ERET/ERETAA/ERETAB instructions in nested virtualisation. The last two instructions also require emulating part of the pointer authentication extension. As a result, the trap handling of pointer authentication has been greattly simplified. - Turn the global (and not very scalable) LPI translation cache into a per-ITS, scalable cache, making non directly injected LPIs much cheaper to make visible to the vcpu. - A batch of pKVM patches, mostly fixes and cleanups, as the upstreaming process seems to be resuming. Fingers crossed! - Allocate PPIs and SGIs outside of the vcpu structure, allowing for smaller EL2 mapping and some flexibility in implementing more or less than 32 private IRQs. - Purge stale mpidr_data if a vcpu is created after the MPIDR map has been created. - Preserve vcpu-specific ID registers across a vcpu reset. - Various minor cleanups and improvements. |
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Michael Roth
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4af663c2f6 |
KVM: SEV: Allow per-guest configuration of GHCB protocol version
The GHCB protocol version may be different from one guest to the next. Add a field to track it for each KVM instance and extend KVM_SEV_INIT2 to allow it to be configured by userspace. Now that all SEV-ES support for GHCB protocol version 2 is in place, go ahead and default to it when creating SEV-ES guests through the new KVM_SEV_INIT2 interface. Keep the older KVM_SEV_ES_INIT interface restricted to GHCB protocol version 1. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Message-ID: <20240501071048.2208265-5-michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Joel Stanley
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651d61bc8b |
KVM: PPC: Fix documentation for ppc mmu caps
The documentation mentions KVM_CAP_PPC_RADIX_MMU, but the defines in the
kvm headers spell it KVM_CAP_PPC_MMU_RADIX. Similarly with
KVM_CAP_PPC_MMU_HASH_V3.
Fixes:
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Carlos López
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2098acaf24 |
KVM: fix documentation for KVM_CREATE_GUEST_MEMFD
The KVM_CREATE_GUEST_MEMFD ioctl returns a file descriptor, and is
documented as such in the description. However, the "Returns" field
in the documentation states that the ioctl returns 0 on success.
Update this to match the description.
Signed-off-by: Carlos López <clopez@suse.de>
Fixes:
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Marc Zyngier
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8540bd1b99 |
Merge branch kvm-arm64/pkvm-6.10 into kvmarm-master/next
* kvm-arm64/pkvm-6.10: (25 commits) : . : At last, a bunch of pKVM patches, courtesy of Fuad Tabba. : From the cover letter: : : "This series is a bit of a bombay-mix of patches we've been : carrying. There's no one overarching theme, but they do improve : the code by fixing existing bugs in pKVM, refactoring code to : make it more readable and easier to re-use for pKVM, or adding : functionality to the existing pKVM code upstream." : . KVM: arm64: Force injection of a data abort on NISV MMIO exit KVM: arm64: Restrict supported capabilities for protected VMs KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap() KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst KVM: arm64: Rename firmware pseudo-register documentation file KVM: arm64: Reformat/beautify PTP hypercall documentation KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit KVM: arm64: Introduce and use predicates that check for protected VMs KVM: arm64: Add is_pkvm_initialized() helper KVM: arm64: Simplify vgic-v3 hypercalls KVM: arm64: Move setting the page as dirty out of the critical section KVM: arm64: Change kvm_handle_mmio_return() return polarity KVM: arm64: Fix comment for __pkvm_vcpu_init_traps() KVM: arm64: Prevent kmemleak from accessing .hyp.data KVM: arm64: Do not map the host fpsimd state to hyp in pKVM KVM: arm64: Rename __tlb_switch_to_{guest,host}() in VHE KVM: arm64: Support TLB invalidation in guest context KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE KVM: arm64: Check for PTE validity when checking for executable/cacheable KVM: arm64: Avoid BUG-ing from the host abort path ... Signed-off-by: Marc Zyngier <maz@kernel.org> |
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Marc Zyngier
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3b467b1658 |
KVM: arm64: Force injection of a data abort on NISV MMIO exit
If a vcpu exits for a data abort with an invalid syndrome, the expectations are that userspace has a chance to save the day if it has requested to see such exits. However, this is completely futile in the case of a protected VM, as none of the state is available. In this particular case, inject a data abort directly into the vcpu, consistent with what userspace could do. This also helps with pKVM, which discards all syndrome information when forwarding data aborts that are not known to be MMIO. Finally, document this tweak to the API. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-31-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org> |
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Will Deacon
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4dc8c9de38 |
KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst
KVM/arm64 makes use of the SMCCC "Vendor Specific Hypervisor Service Call Range" to expose KVM-specific hypercalls to guests in a discoverable and extensible fashion. Document the existence of this interface and the discovery hypercall. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-28-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org> |
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Will Deacon
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af725804f9 |
KVM: arm64: Rename firmware pseudo-register documentation file
In preparation for describing the guest view of KVM/arm64 hypercalls in hypercalls.rst, move the existing contents of the file concerning the firmware pseudo-registers elsewhere. Cc: Raghavendra Rao Ananta <rananta@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-27-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org> |
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Will Deacon
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5a08146d9b |
KVM: arm64: Reformat/beautify PTP hypercall documentation
The PTP hypercall documentation doesn't produce the best-looking table when formatting in HTML as all of the return value definitions end up on the same line. Reformat the PTP hypercall documentation to follow the formatting used by hypercalls.rst. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20240423150538.2103045-26-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org> |
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Paolo Bonzini
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4f5defae70 |
KVM: SEV: introduce KVM_SEV_INIT2 operation
The idea that no parameter would ever be necessary when enabling SEV or SEV-ES for a VM was decidedly optimistic. In fact, in some sense it's already a parameter whether SEV or SEV-ES is desired. Another possible source of variability is the desired set of VMSA features, as that affects the measurement of the VM's initial state and cannot be changed arbitrarily by the hypervisor. Create a new sub-operation for KVM_MEMORY_ENCRYPT_OP that can take a struct, and put the new op to work by including the VMSA features as a field of the struct. The existing KVM_SEV_INIT and KVM_SEV_ES_INIT use the full set of supported VMSA features for backwards compatibility. The struct also includes the usual bells and whistles for future extensibility: a flags field that must be zero for now, and some padding at the end. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20240404121327.3107131-13-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Paolo Bonzini
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26c44aa9e0 |
KVM: SEV: define VM types for SEV and SEV-ES
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20240404121327.3107131-11-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Paolo Bonzini
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ac5c48027b |
KVM: SEV: publish supported VMSA features
Compute the set of features to be stored in the VMSA when KVM is initialized; move it from there into kvm_sev_info when SEV is initialized, and then into the initial VMSA. The new variable can then be used to return the set of supported features to userspace, via the KVM_GET_DEVICE_ATTR ioctl. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com> Message-ID: <20240404121327.3107131-6-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Paolo Bonzini
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c20722c412 |
Documentation: kvm/sev: clarify usage of KVM_MEMORY_ENCRYPT_OP
Explain that it operates on the VM file descriptor, and also clarify how
detection of SEV operates on old kernels predating commit
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Paolo Bonzini
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19cebbab99 |
Documentation: kvm/sev: separate description of firmware
The description of firmware is included part under the "SEV Key Management" header, part under the KVM_SEV_INIT ioctl. Put these two bits together and and rename "SEV Key Management" to what it actually is, namely a description of the KVM_MEMORY_ENCRYPT_OP API. Reviewed-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Paolo Bonzini
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c822a075ab |
Guest-side KVM async #PF ABI cleanup for 6.9
Delete kvm_vcpu_pv_apf_data.enabled to fix a goof in KVM's async #PF ABI where the enabled field pushes the size of "struct kvm_vcpu_pv_apf_data" from 64 to 68 bytes, i.e. beyond a single cache line. The enabled field is purely a guest-side flag that Linux-as-a-guest uses to track whether or not the guest has enabled async #PF support. The actual flag that is passed to the host, i.e. to KVM proper, is a single bit in a synthetic MSR, MSR_KVM_ASYNC_PF_EN, i.e. is in a location completely unrelated to the shared kvm_vcpu_pv_apf_data structure. Simply drop the the field and use a dedicated guest-side per-CPU variable to fix the ABI, as opposed to fixing the documentation to match reality. KVM has never consumed kvm_vcpu_pv_apf_data.enabled, so the odds of the ABI change breaking anything are extremely low. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmXZBsMACgkQOlYIJqCj N/1H5g/8CgK81MpaTI4CsCf0rwD4orhmghAnJmllJHi676dteUm7gYzbDE8wajym rS7gtJwqe6cnK7hJt7SH31sfDEhYds43wD7o6VrLewjWCgaZ7YilYb+qJhzGOUt5 OxQwzZu/57hOhXFFS7P7ZamgkiQu05IYLuK5BSWQbsuMLaGkA+uWoNKopr5588VW MQhR4jVCQSEdgYakgpy+TjWVi4/usiHHCFhcGV54ErKAKL/nCjyUOrgApINTzawQ Czh3ZAKMo6UanHOB6lZACc3MdSOTooDnIItzWOFDMJSLW376tmC70OGI42qi3ht6 CB5zoUN9p4WyQkb7BluJ40PTmpNPEQQVglmU0bjVAKuGmDZ6YgkQ1OWAap6mH+q1 JOzuFgXMXP+aCYXfeZYHedmPsqW+BJ4dd9vOtnoFE7sgCMye26gFb45wbuTWPFpX LcjykG6YUJJI/LcIc3i68onHPn7RI9XXOIVCyAh39zclCPkIKrlI8RKMlg2yBIdv pkLYHUsXRJ+02GHd7YQGFe6ph1rHs3P5LsNoUh8cLetGharww2fqpuAVDwftMvAg MG3zgA6BGv4bpHDNjGPEh+3g36d9C6hOheek2Wgjwy7zF6JxQme4UsXzecqETT5o j7LxLfjUaPzAvfTlGA9jZYO3X7tqpJomj1YxQQEd2p/36nGR+3k= =3ujw -----END PGP SIGNATURE----- Merge tag 'kvm-x86-asyncpf_abi-6.9' of https://github.com/kvm-x86/linux into HEAD Guest-side KVM async #PF ABI cleanup for 6.9 Delete kvm_vcpu_pv_apf_data.enabled to fix a goof in KVM's async #PF ABI where the enabled field pushes the size of "struct kvm_vcpu_pv_apf_data" from 64 to 68 bytes, i.e. beyond a single cache line. The enabled field is purely a guest-side flag that Linux-as-a-guest uses to track whether or not the guest has enabled async #PF support. The actual flag that is passed to the host, i.e. to KVM proper, is a single bit in a synthetic MSR, MSR_KVM_ASYNC_PF_EN, i.e. is in a location completely unrelated to the shared kvm_vcpu_pv_apf_data structure. Simply drop the the field and use a dedicated guest-side per-CPU variable to fix the ABI, as opposed to fixing the documentation to match reality. KVM has never consumed kvm_vcpu_pv_apf_data.enabled, so the odds of the ABI change breaking anything are extremely low. |
||
Linus Torvalds
|
4f712ee0cb |
S390:
* Changes to FPU handling came in via the main s390 pull request * Only deliver to the guest the SCLP events that userspace has requested. * More virtual vs physical address fixes (only a cleanup since virtual and physical address spaces are currently the same). * Fix selftests undefined behavior. x86: * Fix a restriction that the guest can't program a PMU event whose encoding matches an architectural event that isn't included in the guest CPUID. The enumeration of an architectural event only says that if a CPU supports an architectural event, then the event can be programmed *using the architectural encoding*. The enumeration does NOT say anything about the encoding when the CPU doesn't report support the event *in general*. It might support it, and it might support it using the same encoding that made it into the architectural PMU spec. * Fix a variety of bugs in KVM's emulation of RDPMC (more details on individual commits) and add a selftest to verify KVM correctly emulates RDMPC, counter availability, and a variety of other PMC-related behaviors that depend on guest CPUID and therefore are easier to validate with selftests than with custom guests (aka kvm-unit-tests). * Zero out PMU state on AMD if the virtual PMU is disabled, it does not cause any bug but it wastes time in various cases where KVM would check if a PMC event needs to be synthesized. * Optimize triggering of emulated events, with a nice ~10% performance improvement in VM-Exit microbenchmarks when a vPMU is exposed to the guest. * Tighten the check for "PMI in guest" to reduce false positives if an NMI arrives in the host while KVM is handling an IRQ VM-Exit. * Fix a bug where KVM would report stale/bogus exit qualification information when exiting to userspace with an internal error exit code. * Add a VMX flag in /proc/cpuinfo to report 5-level EPT support. * Rework TDP MMU root unload, free, and alloc to run with mmu_lock held for read, e.g. to avoid serializing vCPUs when userspace deletes a memslot. * Tear down TDP MMU page tables at 4KiB granularity (used to be 1GiB). KVM doesn't support yielding in the middle of processing a zap, and 1GiB granularity resulted in multi-millisecond lags that are quite impolite for CONFIG_PREEMPT kernels. * Allocate write-tracking metadata on-demand to avoid the memory overhead when a kernel is built with i915 virtualization support but the workloads use neither shadow paging nor i915 virtualization. * Explicitly initialize a variety of on-stack variables in the emulator that triggered KMSAN false positives. * Fix the debugregs ABI for 32-bit KVM. * Rework the "force immediate exit" code so that vendor code ultimately decides how and when to force the exit, which allowed some optimization for both Intel and AMD. * Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if vCPU creation ultimately failed, causing extra unnecessary work. * Cleanup the logic for checking if the currently loaded vCPU is in-kernel. * Harden against underflowing the active mmu_notifier invalidation count, so that "bad" invalidations (usually due to bugs elsehwere in the kernel) are detected earlier and are less likely to hang the kernel. x86 Xen emulation: * Overlay pages can now be cached based on host virtual address, instead of guest physical addresses. This removes the need to reconfigure and invalidate the cache if the guest changes the gpa but the underlying host virtual address remains the same. * When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation. * Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior). * Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs. RISC-V: * Support exception and interrupt handling in selftests * New self test for RISC-V architectural timer (Sstc extension) * New extension support (Ztso, Zacas) * Support userspace emulation of random number seed CSRs. ARM: * Infrastructure for building KVM's trap configuration based on the architectural features (or lack thereof) advertised in the VM's ID registers * Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to x86's WC) at stage-2, improving the performance of interacting with assigned devices that can tolerate it * Conversion of KVM's representation of LPIs to an xarray, utilized to address serialization some of the serialization on the LPI injection path * Support for _architectural_ VHE-only systems, advertised through the absence of FEAT_E2H0 in the CPU's ID register * Miscellaneous cleanups, fixes, and spelling corrections to KVM and selftests LoongArch: * Set reserved bits as zero in CPUCFG. * Start SW timer only when vcpu is blocking. * Do not restart SW timer when it is expired. * Remove unnecessary CSR register saving during enter guest. * Misc cleanups and fixes as usual. Generic: * cleanup Kconfig by removing CONFIG_HAVE_KVM, which was basically always true on all architectures except MIPS (where Kconfig determines the available depending on CPU capabilities). It is replaced either by an architecture-dependent symbol for MIPS, and IS_ENABLED(CONFIG_KVM) everywhere else. * Factor common "select" statements in common code instead of requiring each architecture to specify it * Remove thoroughly obsolete APIs from the uapi headers. * Move architecture-dependent stuff to uapi/asm/kvm.h * Always flush the async page fault workqueue when a work item is being removed, especially during vCPU destruction, to ensure that there are no workers running in KVM code when all references to KVM-the-module are gone, i.e. to prevent a very unlikely use-after-free if kvm.ko is unloaded. * Grab a reference to the VM's mm_struct in the async #PF worker itself instead of gifting the worker a reference, so that there's no need to remember to *conditionally* clean up after the worker. Selftests: * Reduce boilerplate especially when utilize selftest TAP infrastructure. * Add basic smoke tests for SEV and SEV-ES, along with a pile of library support for handling private/encrypted/protected memory. * Fix benign bugs where tests neglect to close() guest_memfd files. -----BEGIN PGP SIGNATURE----- iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmX0iP8UHHBib256aW5p QHJlZGhhdC5jb20ACgkQv/vSX3jHroND7wf+JZoNvwZ+bmwWe/4jn/YwNoYi/C5z eypn8M1gsWEccpCpqPBwznVm9T29rF4uOlcMvqLEkHfTpaL1EKUUjP1lXPz/ileP 6a2RdOGxAhyTiFC9fjy+wkkjtLbn1kZf6YsS0hjphP9+w0chNbdn0w81dFVnXryd j7XYI8R/bFAthNsJOuZXSEjCfIHxvTTG74OrTf1B1FEBB+arPmrgUeJftMVhffQK Sowgg8L/Ii/x6fgV5NZQVSIyVf1rp8z7c6UaHT4Fwb0+RAMW8p9pYv9Qp1YkKp8y 5j0V9UzOHP7FRaYimZ5BtwQoqiZXYylQ+VuU/Y2f4X85cvlLzSqxaEMAPA== =mqOV -----END PGP SIGNATURE----- Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm Pull kvm updates from Paolo Bonzini: "S390: - Changes to FPU handling came in via the main s390 pull request - Only deliver to the guest the SCLP events that userspace has requested - More virtual vs physical address fixes (only a cleanup since virtual and physical address spaces are currently the same) - Fix selftests undefined behavior x86: - Fix a restriction that the guest can't program a PMU event whose encoding matches an architectural event that isn't included in the guest CPUID. The enumeration of an architectural event only says that if a CPU supports an architectural event, then the event can be programmed *using the architectural encoding*. The enumeration does NOT say anything about the encoding when the CPU doesn't report support the event *in general*. It might support it, and it might support it using the same encoding that made it into the architectural PMU spec - Fix a variety of bugs in KVM's emulation of RDPMC (more details on individual commits) and add a selftest to verify KVM correctly emulates RDMPC, counter availability, and a variety of other PMC-related behaviors that depend on guest CPUID and therefore are easier to validate with selftests than with custom guests (aka kvm-unit-tests) - Zero out PMU state on AMD if the virtual PMU is disabled, it does not cause any bug but it wastes time in various cases where KVM would check if a PMC event needs to be synthesized - Optimize triggering of emulated events, with a nice ~10% performance improvement in VM-Exit microbenchmarks when a vPMU is exposed to the guest - Tighten the check for "PMI in guest" to reduce false positives if an NMI arrives in the host while KVM is handling an IRQ VM-Exit - Fix a bug where KVM would report stale/bogus exit qualification information when exiting to userspace with an internal error exit code - Add a VMX flag in /proc/cpuinfo to report 5-level EPT support - Rework TDP MMU root unload, free, and alloc to run with mmu_lock held for read, e.g. to avoid serializing vCPUs when userspace deletes a memslot - Tear down TDP MMU page tables at 4KiB granularity (used to be 1GiB). KVM doesn't support yielding in the middle of processing a zap, and 1GiB granularity resulted in multi-millisecond lags that are quite impolite for CONFIG_PREEMPT kernels - Allocate write-tracking metadata on-demand to avoid the memory overhead when a kernel is built with i915 virtualization support but the workloads use neither shadow paging nor i915 virtualization - Explicitly initialize a variety of on-stack variables in the emulator that triggered KMSAN false positives - Fix the debugregs ABI for 32-bit KVM - Rework the "force immediate exit" code so that vendor code ultimately decides how and when to force the exit, which allowed some optimization for both Intel and AMD - Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if vCPU creation ultimately failed, causing extra unnecessary work - Cleanup the logic for checking if the currently loaded vCPU is in-kernel - Harden against underflowing the active mmu_notifier invalidation count, so that "bad" invalidations (usually due to bugs elsehwere in the kernel) are detected earlier and are less likely to hang the kernel x86 Xen emulation: - Overlay pages can now be cached based on host virtual address, instead of guest physical addresses. This removes the need to reconfigure and invalidate the cache if the guest changes the gpa but the underlying host virtual address remains the same - When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation - Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior) - Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs RISC-V: - Support exception and interrupt handling in selftests - New self test for RISC-V architectural timer (Sstc extension) - New extension support (Ztso, Zacas) - Support userspace emulation of random number seed CSRs ARM: - Infrastructure for building KVM's trap configuration based on the architectural features (or lack thereof) advertised in the VM's ID registers - Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to x86's WC) at stage-2, improving the performance of interacting with assigned devices that can tolerate it - Conversion of KVM's representation of LPIs to an xarray, utilized to address serialization some of the serialization on the LPI injection path - Support for _architectural_ VHE-only systems, advertised through the absence of FEAT_E2H0 in the CPU's ID register - Miscellaneous cleanups, fixes, and spelling corrections to KVM and selftests LoongArch: - Set reserved bits as zero in CPUCFG - Start SW timer only when vcpu is blocking - Do not restart SW timer when it is expired - Remove unnecessary CSR register saving during enter guest - Misc cleanups and fixes as usual Generic: - Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically always true on all architectures except MIPS (where Kconfig determines the available depending on CPU capabilities). It is replaced either by an architecture-dependent symbol for MIPS, and IS_ENABLED(CONFIG_KVM) everywhere else - Factor common "select" statements in common code instead of requiring each architecture to specify it - Remove thoroughly obsolete APIs from the uapi headers - Move architecture-dependent stuff to uapi/asm/kvm.h - Always flush the async page fault workqueue when a work item is being removed, especially during vCPU destruction, to ensure that there are no workers running in KVM code when all references to KVM-the-module are gone, i.e. to prevent a very unlikely use-after-free if kvm.ko is unloaded - Grab a reference to the VM's mm_struct in the async #PF worker itself instead of gifting the worker a reference, so that there's no need to remember to *conditionally* clean up after the worker Selftests: - Reduce boilerplate especially when utilize selftest TAP infrastructure - Add basic smoke tests for SEV and SEV-ES, along with a pile of library support for handling private/encrypted/protected memory - Fix benign bugs where tests neglect to close() guest_memfd files" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits) selftests: kvm: remove meaningless assignments in Makefiles KVM: riscv: selftests: Add Zacas extension to get-reg-list test RISC-V: KVM: Allow Zacas extension for Guest/VM KVM: riscv: selftests: Add Ztso extension to get-reg-list test RISC-V: KVM: Allow Ztso extension for Guest/VM RISC-V: KVM: Forward SEED CSR access to user space KVM: riscv: selftests: Add sstc timer test KVM: riscv: selftests: Change vcpu_has_ext to a common function KVM: riscv: selftests: Add guest helper to get vcpu id KVM: riscv: selftests: Add exception handling support LoongArch: KVM: Remove unnecessary CSR register saving during enter guest LoongArch: KVM: Do not restart SW timer when it is expired LoongArch: KVM: Start SW timer only when vcpu is blocking LoongArch: KVM: Set reserved bits as zero in CPUCFG KVM: selftests: Explicitly close guest_memfd files in some gmem tests KVM: x86/xen: fix recursive deadlock in timer injection KVM: pfncache: simplify locking and make more self-contained KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled KVM: x86/xen: improve accuracy of Xen timers ... |
||
Linus Torvalds
|
38b334fc76 |
- Add the x86 part of the SEV-SNP host support. This will allow the
kernel to be used as a KVM hypervisor capable of running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP is the ultimate goal of the AMD confidential computing side, providing the most comprehensive confidential computing environment up to date. This is the x86 part and there is a KVM part which did not get ready in time for the merge window so latter will be forthcoming in the next cycle. - Rework the early code's position-dependent SEV variable references in order to allow building the kernel with clang and -fPIE/-fPIC and -mcmodel=kernel - The usual set of fixes, cleanups and improvements all over the place -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmXvH0wACgkQEsHwGGHe VUrzmA//VS/n6dhHRnm/nAGngr4PeegkgV1OhyKYFfiZ272rT6P9QvblQrgcY0dc Ij1DOhEKlke51pTHvMOQ33B3P4Fuc0mx3dpCLY0up5V26kzQiKCjRKEkC4U1bcw8 W4GqMejaR89bE14bYibmwpSib9T/uVsV65eM3xf1iF5UvsnoUaTziymDoy+nb43a B1pdd5vcl4mBNqXeEvt0qjg+xkMLpWUI9tJDB8mbMl/cnIFGgMZzBaY8oktHSROK QpuUnKegOgp1RXpfLbNjmZ2Q4Rkk4MNazzDzWq3EIxaRjXL3Qp507ePK7yeA2qa0 J3jCBQc9E2j7lfrIkUgNIzOWhMAXM2YH5bvH6UrIcMi1qsWJYDmkp2MF1nUedjdf Wj16/pJbeEw1aKKIywJGwsmViSQju158vY3SzXG83U/A/Iz7zZRHFmC/ALoxZptY Bi7VhfcOSpz98PE3axnG8CvvxRDWMfzBr2FY1VmQbg6VBNo1Xl1aP/IH1I8iQNKg /laBYl/qP+1286TygF1lthYROb1lfEIJprgi2xfO6jVYUqPb7/zq2sm78qZRfm7l 25PN/oHnuidfVfI/H3hzcGubjOG9Zwra8WWYBB2EEmelf21rT0OLqq+eS4T6pxFb GNVfc0AzG77UmqbrpkAMuPqL7LrGaSee4NdU3hkEdSphlx1/YTo= =c1ps -----END PGP SIGNATURE----- Merge tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV updates from Borislav Petkov: - Add the x86 part of the SEV-SNP host support. This will allow the kernel to be used as a KVM hypervisor capable of running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP is the ultimate goal of the AMD confidential computing side, providing the most comprehensive confidential computing environment up to date. This is the x86 part and there is a KVM part which did not get ready in time for the merge window so latter will be forthcoming in the next cycle. - Rework the early code's position-dependent SEV variable references in order to allow building the kernel with clang and -fPIE/-fPIC and -mcmodel=kernel - The usual set of fixes, cleanups and improvements all over the place * tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/sev: Disable KMSAN for memory encryption TUs x86/sev: Dump SEV_STATUS crypto: ccp - Have it depend on AMD_IOMMU iommu/amd: Fix failure return from snp_lookup_rmpentry() x86/sev: Fix position dependent variable references in startup code crypto: ccp: Make snp_range_list static x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT Documentation: virt: Fix up pre-formatted text block for SEV ioctls crypto: ccp: Add the SNP_SET_CONFIG command crypto: ccp: Add the SNP_COMMIT command crypto: ccp: Add the SNP_PLATFORM_STATUS command x86/cpufeatures: Enable/unmask SEV-SNP CPU feature KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown crypto: ccp: Handle legacy SEV commands when SNP is enabled crypto: ccp: Handle non-volatile INIT_EX data when SNP is enabled crypto: ccp: Handle the legacy TMR allocation when SNP is enabled x86/sev: Introduce an SNP leaked pages list crypto: ccp: Provide an API to issue SEV and SNP commands ... |
||
Paolo Bonzini
|
e9a2bba476 |
KVM Xen and pfncache changes for 6.9:
- Rip out the half-baked support for using gfn_to_pfn caches to manage pages that are "mapped" into guests via physical addresses. - Add support for using gfn_to_pfn caches with only a host virtual address, i.e. to bypass the "gfn" stage of the cache. The primary use case is overlay pages, where the guest may change the gfn used to reference the overlay page, but the backing hva+pfn remains the same. - Add an ioctl() to allow mapping Xen's shared_info page using an hva instead of a gpa, so that userspace doesn't need to reconfigure and invalidate the cache/mapping if the guest changes the gpa (but userspace keeps the resolved hva the same). - When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation. - Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior). - Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs. - Extend gfn_to_pfn_cache's mutex to cover (de)activation (in addition to refresh), and drop a now-redundant acquisition of xen_lock (that was protecting the shared_info cache) to fix a deadlock due to recursively acquiring xen_lock. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmXrblYACgkQOlYIJqCj N/3K4Q/+KZ8lrnNXvdHNCQdosA5DDXpqUcRzhlTUp82fncpdJ0LqrSMzMots2Eh9 KC0jSPo8EkivF+Epug0+bpQBEaLXzTWhRcS1grePCDz2lBnxoHFSWjvaK2p14KlC LvxCJZjxyfLKHwKHpSndvO9hVFElCY3mvvE9KRcKeQAmrz1cz+DDMKelo1MuV8D+ GfymhYc+UXpY41+6hQdznx+WoGoXKRameo3iGYuBoJjvKOyl4Wxkx9WSXIxxxuqG kHxjiWTR/jF1ITJl6PeMrFcGl3cuGKM/UfTOM6W2h6Wi3mhLpXveoVLnqR1kipIj btSzSVHL7C4WTPwOcyhwPzap+dJmm31c6N0uPScT7r9yhs+q5BDj26vcVcyPZUHo efIwmsnO2eQvuw+f8C6QqWCPaxvw46N0zxzwgc5uA3jvAC93y0l4v+xlAQsC0wzV 0+BwU00cutH/3t3c/WPD5QcmRLH726VoFuTlaDufpoMU7gBVJ8rzjcusxR+5BKT+ GJcAgZxZhEgvnzmTKd4Ec/mt+xZ2Erd+kV3MKCHvDPyj8jqy8FQ4DAWKGBR+h3WR rqAs2k8NPHyh3i1a3FL1opmxEGsRS+Cnc6Bi77cj9DxTr22JkgDJEuFR+Ues1z6/ SpE889kt3w5zTo34+lNxNPlIKmO0ICwwhDL6pxJTWU7iWQnKypU= =GliW -----END PGP SIGNATURE----- Merge tag 'kvm-x86-xen-6.9' of https://github.com/kvm-x86/linux into HEAD KVM Xen and pfncache changes for 6.9: - Rip out the half-baked support for using gfn_to_pfn caches to manage pages that are "mapped" into guests via physical addresses. - Add support for using gfn_to_pfn caches with only a host virtual address, i.e. to bypass the "gfn" stage of the cache. The primary use case is overlay pages, where the guest may change the gfn used to reference the overlay page, but the backing hva+pfn remains the same. - Add an ioctl() to allow mapping Xen's shared_info page using an hva instead of a gpa, so that userspace doesn't need to reconfigure and invalidate the cache/mapping if the guest changes the gpa (but userspace keeps the resolved hva the same). - When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation. - Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior). - Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs. - Extend gfn_to_pfn_cache's mutex to cover (de)activation (in addition to refresh), and drop a now-redundant acquisition of xen_lock (that was protecting the shared_info cache) to fix a deadlock due to recursively acquiring xen_lock. |
||
Linus Torvalds
|
137e0ec05a |
KVM GUEST_MEMFD fixes for 6.8:
- Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to avoid creating an inconsistent ABI (KVM_MEM_GUEST_MEMFD is not writable from userspace, so there would be no way to write to a read-only guest_memfd). - Update documentation for KVM_SW_PROTECTED_VM to make it abundantly clear that such VMs are purely for development and testing. - Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan is to support confidential VMs with deterministic private memory (SNP and TDX) only in the TDP MMU. - Fix a bug in a GUEST_MEMFD dirty logging test that caused false passes. x86 fixes: - Fix missing marking of a guest page as dirty when emulating an atomic access. - Check for mmu_notifier invalidation events before faulting in the pfn, and before acquiring mmu_lock, to avoid unnecessary work and lock contention with preemptible kernels (including CONFIG_PREEMPT_DYNAMIC in non-preemptible mode). - Disable AMD DebugSwap by default, it breaks VMSA signing and will be re-enabled with a better VM creation API in 6.10. - Do the cache flush of converted pages in svm_register_enc_region() before dropping kvm->lock, to avoid a race with unregistering of the same region and the consequent use-after-free issue. -----BEGIN PGP SIGNATURE----- iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmXskdYUHHBib256aW5p QHJlZGhhdC5jb20ACgkQv/vSX3jHroN1TAf/SUGf4QuYG7nnfgWDR+goFO6Gx7NE pJr3kAwv6d2f+qTlURfGjnX929pgZDLgoTkXTNeZquN6LjgownxMjBIpymVobvAD AKvqJS/ECpryuehXbeqlxJxJn+TrxJ5r4QeNILMHc3AOZoiUqM6xl3zFfXWDNWVo IazwT8P3d8wxiHAxv1eG6OVWHxbcg31068FVKRX3f/bWPbVwROJrPkCopmz2BJvU 6KYdYcn2rkpDTEM3ouDC/6gxJ9vpSY3+nW7Q7dNtGtOH2+BddfSA6I0rphCQWCNs uXOxd5bDrC+KmkiULTPostuvwBgIm1k9wC2kW9A4P2VEf6Ay+ZHEdAOBJQ== =+MT/ -----END PGP SIGNATURE----- Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm Pull kvm fixes from Paolo Bonzini: "KVM GUEST_MEMFD fixes for 6.8: - Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to avoid creating an inconsistent ABI (KVM_MEM_GUEST_MEMFD is not writable from userspace, so there would be no way to write to a read-only guest_memfd). - Update documentation for KVM_SW_PROTECTED_VM to make it abundantly clear that such VMs are purely for development and testing. - Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan is to support confidential VMs with deterministic private memory (SNP and TDX) only in the TDP MMU. - Fix a bug in a GUEST_MEMFD dirty logging test that caused false passes. x86 fixes: - Fix missing marking of a guest page as dirty when emulating an atomic access. - Check for mmu_notifier invalidation events before faulting in the pfn, and before acquiring mmu_lock, to avoid unnecessary work and lock contention with preemptible kernels (including CONFIG_PREEMPT_DYNAMIC in non-preemptible mode). - Disable AMD DebugSwap by default, it breaks VMSA signing and will be re-enabled with a better VM creation API in 6.10. - Do the cache flush of converted pages in svm_register_enc_region() before dropping kvm->lock, to avoid a race with unregistering of the same region and the consequent use-after-free issue" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: SEV: disable SEV-ES DebugSwap by default KVM: x86/mmu: Retry fault before acquiring mmu_lock if mapping is changing KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region() KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive KVM: selftests: Create GUEST_MEMFD for relevant invalid flags testcases KVM: x86/mmu: Restrict KVM_SW_PROTECTED_VM to the TDP MMU KVM: x86: Update KVM_SW_PROTECTED_VM docs to make it clear they're a WIP KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY KVM: x86: Mark target gfn of emulated atomic instruction as dirty |
||
Michael Kelley
|
04ed680e76 |
Documentation: hyperv: Add overview of PCI pass-thru device support
Add documentation topic for PCI pass-thru devices in Linux guests on Hyper-V and for the associated PCI controller driver (pci-hyperv.c). Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Link: https://lore.kernel.org/r/20240222200710.305259-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20240222200710.305259-1-mhklinux@outlook.com> |
||
Sean Christopherson
|
422692098c |
KVM: x86: Update KVM_SW_PROTECTED_VM docs to make it clear they're a WIP
Rewrite the help message for KVM_SW_PROTECTED_VM to make it clear that
software-protected VMs are a development and testing vehicle for
guest_memfd(), and that attempting to use KVM_SW_PROTECTED_VM for anything
remotely resembling a "real" VM will fail. E.g. any memory accesses from
KVM will incorrectly access shared memory, nested TDP is wildly broken,
and so on and so forth.
Update KVM's API documentation with similar warnings to discourage anyone
from attempting to run anything but selftests with KVM_X86_SW_PROTECTED_VM.
Fixes:
|
||
Paul Durrant
|
3991f35805 |
KVM: x86/xen: allow vcpu_info to be mapped by fixed HVA
If the guest does not explicitly set the GPA of vcpu_info structure in memory then, for guests with 32 vCPUs or fewer, the vcpu_info embedded in the shared_info page may be used. As described in a previous commit, the shared_info page is an overlay at a fixed HVA within the VMM, so in this case it also more optimal to activate the vcpu_info cache with a fixed HVA to avoid unnecessary invalidation if the guest memory layout is modified. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lore.kernel.org/r/20240215152916.1158-14-paul@xen.org [sean: use kvm_gpc_is_{gpa,hva}_active()] Signed-off-by: Sean Christopherson <seanjc@google.com> |
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Paul Durrant
|
b9220d3279 |
KVM: x86/xen: allow shared_info to be mapped by fixed HVA
The shared_info page is not guest memory as such. It is a dedicated page allocated by the VMM and overlaid onto guest memory in a GFN chosen by the guest and specified in the XENMEM_add_to_physmap hypercall. The guest may even request that shared_info be moved from one GFN to another by re-issuing that hypercall, but the HVA is never going to change. Because the shared_info page is an overlay the memory slots need to be updated in response to the hypercall. However, memory slot adjustment is not atomic and, whilst all vCPUs are paused, there is still the possibility that events may be delivered (which requires the shared_info page to be updated) whilst the shared_info GPA is absent. The HVA is never absent though, so it makes much more sense to use that as the basis for the kernel's mapping. Hence add a new KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA attribute type for this purpose and a KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA flag to advertize its availability. Don't actually advertize it yet though. That will be done in a subsequent patch, which will also add tests for the new attribute type. Also update the KVM API documentation with the new attribute and also fix it up to consistently refer to 'shared_info' (with the underscore). Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lore.kernel.org/r/20240215152916.1158-13-paul@xen.org [sean: store "hva" as a user pointer, use kvm_gpc_is_{gpa,hva}_active()] Signed-off-by: Sean Christopherson <seanjc@google.com> |
||
Xiaoyao Li
|
df01f0a116 |
KVM: x86: Improve documentation of MSR_KVM_ASYNC_PF_EN
Fix some incorrect statement of MSR_KVM_ASYNC_PF_EN documentation and state clearly the token in 'struct kvm_vcpu_pv_apf_data' of 'page ready' event is matchted with the token in CR2 in 'page not present' event. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20231025055914.1201792-3-xiaoyao.li@intel.com Signed-off-by: Sean Christopherson <seanjc@google.com> |
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Xiaoyao Li
|
ccb2280ec2 |
x86/kvm: Use separate percpu variable to track the enabling of asyncpf
Refer to commit |
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Michael Roth
|
1bfca8d280 |
Documentation: virt: Fix up pre-formatted text block for SEV ioctls
A missing newline after "::" resulted in the htmldocs build failing to
recognize the start of a pre-formatted block of text, resulting in
kernel/linux/Documentation/virt/coco/sev-guest.rst:75: WARNING: Inline emphasis start-string without end-string.
kernel/linux/Documentation/virt/coco/sev-guest.rst:78: WARNING: Inline emphasis start-string without end-string.
kernel/linux/Documentation/virt/coco/sev-guest.rst:81: WARNING: Inline emphasis start-string without end-string.
kernel/linux/Documentation/virt/coco/sev-guest.rst:83: WARNING: Definition list ends without a blank line; unexpected unindent.
Fix it.
Fixes:
|
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Brijesh Singh
|
cb645fe478 |
crypto: ccp: Add the SNP_SET_CONFIG command
The SEV-SNP firmware provides the SNP_CONFIG command used to set various system-wide configuration values for SNP guests, such as the reported TCB version used when signing guest attestation reports. Add an interface to set this via userspace. [ mdr: Squash in doc patch from Dionna, drop extended request/ certificate handling and simplify this to a simple wrapper around SNP_CONFIG fw cmd. ] Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Co-developed-by: Alexey Kardashevskiy <aik@amd.com> Signed-off-by: Alexey Kardashevskiy <aik@amd.com> Co-developed-by: Dionna Glaze <dionnaglaze@google.com> Signed-off-by: Dionna Glaze <dionnaglaze@google.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240126041126.1927228-26-michael.roth@amd.com |
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Tom Lendacky
|
fad133c79a |
crypto: ccp: Add the SNP_COMMIT command
The SNP_COMMIT command is used to commit the currently installed version of the SEV firmware. Once committed, the firmware cannot be replaced with a previous firmware version (cannot be rolled back). This command will also update the reported TCB to match that of the currently installed firmware. [ mdr: Note the reported TCB update in the documentation/commit. ] Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240126041126.1927228-25-michael.roth@amd.com |
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Brijesh Singh
|
f5db8841eb |
crypto: ccp: Add the SNP_PLATFORM_STATUS command
This command is used to query the SNP platform status. See the SEV-SNP spec for more details. Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240126041126.1927228-24-michael.roth@amd.com |
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Paolo Bonzini
|
7f26fea9bc |
KVM x86 MMU changes for 6.8:
- Fix a relatively benign off-by-one error when splitting huge pages during CLEAR_DIRTY_LOG. - Fix a bug where KVM could incorrectly test-and-clear dirty bits in non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with a non-huge SPTE. - Relax the TDP MMU's lockdep assertions related to holding mmu_lock for read versus write so that KVM doesn't pass "bool shared" all over the place just to have precise assertions in paths that don't actually care about whether the caller is a reader or a writer. -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEEMHr+pfEFOIzK+KY1YJEiAU0MEvkFAmWW/W4SHHNlYW5qY0Bn b29nbGUuY29tAAoJEGCRIgFNDBL5pAQP/27OuHVhtcao9m8GAsm55tMEIDh2n6Ih Yb74SOQhprbaGWyx/J6QdKABzcQX86L3CvCMSy6Ssoz2FeDM8Qs2a80/0jkK0qtI TPXnOsvxh/MgEsC55LOSJZeWM+xwEqaTA2wuPAbvAcJLdAZsSLQQV1XwH6nl4l0l LhcdkUeAKqQ8DbeBvTDyz80zuWaKhQMm5DJOBM6HbqaAdmMpw/hPDtu9b654jC2R Z6Rs5590OFrR13cBAvgCBayvb54pjW9dbm8lfZ4Grcq1I+C0I7Y5jF+DYFjKuTUi N7t+3HrpAM54DWwD95qkTO73g8tMSvwKGKq+OhylZrbPjeqgyYApcUvbxgKmhgGu hBRoAS9D2goJQtFv4TehpAiJIoR6YGX5cCyIIFI50EfsWkifED/b7zUBf2jg0UnV Z7IzvGLQtMAHj6daDcgXxaLVAXQ3v4aQK7DiPuCIiFGcXvedgcGIFjZH4NaVvK2D Y9ygO8PSbN0MbGUSkaS8Urrxmx7l1tv05cardxjSVxnKEx01nYugB0vTM0/o7gSq Bs2gnf+UJrazeabqFuVBYzzuHH7QyjsiQQ0HWoQiq04v8+C5VldwQKk+g8vxLXG1 iYNXW7qgueLxYxRNleLiyfw1HIyspR09d6e67n2729Xxtay0cvL8dC68AhEenb+N fZ2lKFhnZ2Vs =3f2t -----END PGP SIGNATURE----- Merge tag 'kvm-x86-mmu-6.8' of https://github.com/kvm-x86/linux into HEAD KVM x86 MMU changes for 6.8: - Fix a relatively benign off-by-one error when splitting huge pages during CLEAR_DIRTY_LOG. - Fix a bug where KVM could incorrectly test-and-clear dirty bits in non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with a non-huge SPTE. - Relax the TDP MMU's lockdep assertions related to holding mmu_lock for read versus write so that KVM doesn't pass "bool shared" all over the place just to have precise assertions in paths that don't actually care about whether the caller is a reader or a writer. |
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Paolo Bonzini
|
3115d2de39 |
KVM Xen change for 6.8:
To workaround Xen guests that don't expect Xen PV clocks to be marked as being based on a stable TSC, add a Xen config knob to allow userspace to opt out of KVM setting the "TSC stable" bit in Xen PV clocks. Note, the "TSC stable" bit was added to the PVCLOCK ABI by KVM without an ack from Xen, i.e. KVM isn't entirely blameless for the buggy guest behavior. -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEEMHr+pfEFOIzK+KY1YJEiAU0MEvkFAmWXASsSHHNlYW5qY0Bn b29nbGUuY29tAAoJEGCRIgFNDBL5R54P/iQPQBs4dJmNkPiA6uSq1O5/8hN4P59z aapJNgDiny/D9/zPbOxGWR31W7lvCgiES/lp3KcHZmwbeAwJpdT6a0cJWGRlGuov gccK8AoYcnwSU98sPisnFv7dJ66ogJfXVkPKKaWo+zVW53XUq2XpIie4eWaOweBt QsXpTGYpGajv1Bf/MgRtNtlkVAo1w8XL1L0NWRugzCk2CAYezz8IT1874GNZoJbd GJfVP+76FdNw+4/CxiaBwxP0gHfBIiAsJzGqbmMPhGG2xJn+KGs5FTEf37Pta8cl aMHAq6/JAoabJfP39MexVkopMaFlPbDwIWfkLWf6wSP86KHei+t9kLC0E4/R2NJ+ GKlrBB6Gj+gzFR4fZ75hIwS/4REMt6zVCbS7uSRrCduqrlEFcY5ED2NesoL9wZrB WMDIxIGIVDdRxc9WLypKmBj7KTgL0qXBxnsAcPiDRf1sk6SGajkesWxA1C1Nzo/H yNfqq0gjdPZVB2RIGN6DpWQFu3d+ZQnG2ToKIBW7OkvJ5USYiDSo4VozhESgYHRZ UJDhJ73QYESynClP6ST+9cxNof3FXCEPDeKr5NcmjVZxlJcdeUDNRqv0LUxQ56BI FvHMHtSs4WLYHZZVzsdh+Yhnc9rEGfoL0NwDPBCcOXjuNMvNQmuzSldc/VDGm/qt sCtxYMms5n7u =3v8F -----END PGP SIGNATURE----- Merge tag 'kvm-x86-xen-6.8' of https://github.com/kvm-x86/linux into HEAD KVM Xen change for 6.8: To workaround Xen guests that don't expect Xen PV clocks to be marked as being based on a stable TSC, add a Xen config knob to allow userspace to opt out of KVM setting the "TSC stable" bit in Xen PV clocks. Note, the "TSC stable" bit was added to the PVCLOCK ABI by KVM without an ack from Xen, i.e. KVM isn't entirely blameless for the buggy guest behavior. |
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Paolo Bonzini
|
a5d3df8ae1 |
KVM: remove deprecated UAPIs
The deprecated interfaces were removed 15 years ago. KVM's device assignment was deprecated in 4.2 and removed 6.5 years ago; the only interest might be in compiling ancient versions of QEMU, but QEMU has been using its own imported copy of the kernel headers since June 2011. So again we go into archaeology territory; just remove the cruft. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Paul Durrant
|
6d72283526 |
KVM x86/xen: add an override for PVCLOCK_TSC_STABLE_BIT
Unless explicitly told to do so (by passing 'clocksource=tsc' and 'tsc=stable:socket', and then jumping through some hoops concerning potential CPU hotplug) Xen will never use TSC as its clocksource. Hence, by default, a Xen guest will not see PVCLOCK_TSC_STABLE_BIT set in either the primary or secondary pvclock memory areas. This has led to bugs in some guest kernels which only become evident if PVCLOCK_TSC_STABLE_BIT *is* set in the pvclocks. Hence, to support such guests, give the VMM a new Xen HVM config flag to tell KVM to forcibly clear the bit in the Xen pvclocks. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lore.kernel.org/r/20231102162128.2353459-1-paul@xen.org Signed-off-by: Sean Christopherson <seanjc@google.com> |
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Paolo Bonzini
|
250ce1b4d2 |
KVM: x86/mmu: always take tdp_mmu_pages_lock
It is cheap to take tdp_mmu_pages_lock in all write-side critical sections. We already do it all the time when zapping with read_lock(), so it is not a problem to do it from the kvm_tdp_mmu_zap_all() path (aka kvm_arch_flush_shadow_all(), aka VM destruction and MMU notifier release). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20231125083400.1399197-4-pbonzini@redhat.com Signed-off-by: Sean Christopherson <seanjc@google.com> |
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Sean Christopherson
|
89ea60c2c7 |
KVM: x86: Add support for "protected VMs" that can utilize private memory
Add a new x86 VM type, KVM_X86_SW_PROTECTED_VM, to serve as a development and testing vehicle for Confidential (CoCo) VMs, and potentially to even become a "real" product in the distant future, e.g. a la pKVM. The private memory support in KVM x86 is aimed at AMD's SEV-SNP and Intel's TDX, but those technologies are extremely complex (understatement), difficult to debug, don't support running as nested guests, and require hardware that's isn't universally accessible. I.e. relying SEV-SNP or TDX for maintaining guest private memory isn't a realistic option. At the very least, KVM_X86_SW_PROTECTED_VM will enable a variety of selftests for guest_memfd and private memory support without requiring unique hardware. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20231027182217.3615211-24-seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Chao Peng
|
8dd2eee9d5 |
KVM: x86/mmu: Handle page fault for private memory
Add support for resolving page faults on guest private memory for VMs that differentiate between "shared" and "private" memory. For such VMs, KVM_MEM_GUEST_MEMFD memslots can include both fd-based private memory and hva-based shared memory, and KVM needs to map in the "correct" variant, i.e. KVM needs to map the gfn shared/private as appropriate based on the current state of the gfn's KVM_MEMORY_ATTRIBUTE_PRIVATE flag. For AMD's SEV-SNP and Intel's TDX, the guest effectively gets to request shared vs. private via a bit in the guest page tables, i.e. what the guest wants may conflict with the current memory attributes. To support such "implicit" conversion requests, exit to user with KVM_EXIT_MEMORY_FAULT to forward the request to userspace. Add a new flag for memory faults, KVM_MEMORY_EXIT_FLAG_PRIVATE, to communicate whether the guest wants to map memory as shared vs. private. Like KVM_MEMORY_ATTRIBUTE_PRIVATE, use bit 3 for flagging private memory so that KVM can use bits 0-2 for capturing RWX behavior if/when userspace needs such information, e.g. a likely user of KVM_EXIT_MEMORY_FAULT is to exit on missing mappings when handling guest page fault VM-Exits. In that case, userspace will want to know RWX information in order to correctly/precisely resolve the fault. Note, private memory *must* be backed by guest_memfd, i.e. shared mappings always come from the host userspace page tables, and private mappings always come from a guest_memfd instance. Co-developed-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Message-Id: <20231027182217.3615211-21-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Sean Christopherson
|
a7800aa80e |
KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory
Introduce an ioctl(), KVM_CREATE_GUEST_MEMFD, to allow creating file-based memory that is tied to a specific KVM virtual machine and whose primary purpose is to serve guest memory. A guest-first memory subsystem allows for optimizations and enhancements that are kludgy or outright infeasible to implement/support in a generic memory subsystem. With guest_memfd, guest protections and mapping sizes are fully decoupled from host userspace mappings. E.g. KVM currently doesn't support mapping memory as writable in the guest without it also being writable in host userspace, as KVM's ABI uses VMA protections to define the allow guest protection. Userspace can fudge this by establishing two mappings, a writable mapping for the guest and readable one for itself, but that’s suboptimal on multiple fronts. Similarly, KVM currently requires the guest mapping size to be a strict subset of the host userspace mapping size, e.g. KVM doesn’t support creating a 1GiB guest mapping unless userspace also has a 1GiB guest mapping. Decoupling the mappings sizes would allow userspace to precisely map only what is needed without impacting guest performance, e.g. to harden against unintentional accesses to guest memory. Decoupling guest and userspace mappings may also allow for a cleaner alternative to high-granularity mappings for HugeTLB, which has reached a bit of an impasse and is unlikely to ever be merged. A guest-first memory subsystem also provides clearer line of sight to things like a dedicated memory pool (for slice-of-hardware VMs) and elimination of "struct page" (for offload setups where userspace _never_ needs to mmap() guest memory). More immediately, being able to map memory into KVM guests without mapping said memory into the host is critical for Confidential VMs (CoCo VMs), the initial use case for guest_memfd. While AMD's SEV and Intel's TDX prevent untrusted software from reading guest private data by encrypting guest memory with a key that isn't usable by the untrusted host, projects such as Protected KVM (pKVM) provide confidentiality and integrity *without* relying on memory encryption. And with SEV-SNP and TDX, accessing guest private memory can be fatal to the host, i.e. KVM must be prevent host userspace from accessing guest memory irrespective of hardware behavior. Attempt #1 to support CoCo VMs was to add a VMA flag to mark memory as being mappable only by KVM (or a similarly enlightened kernel subsystem). That approach was abandoned largely due to it needing to play games with PROT_NONE to prevent userspace from accessing guest memory. Attempt #2 to was to usurp PG_hwpoison to prevent the host from mapping guest private memory into userspace, but that approach failed to meet several requirements for software-based CoCo VMs, e.g. pKVM, as the kernel wouldn't easily be able to enforce a 1:1 page:guest association, let alone a 1:1 pfn:gfn mapping. And using PG_hwpoison does not work for memory that isn't backed by 'struct page', e.g. if devices gain support for exposing encrypted memory regions to guests. Attempt #3 was to extend the memfd() syscall and wrap shmem to provide dedicated file-based guest memory. That approach made it as far as v10 before feedback from Hugh Dickins and Christian Brauner (and others) led to it demise. Hugh's objection was that piggybacking shmem made no sense for KVM's use case as KVM didn't actually *want* the features provided by shmem. I.e. KVM was using memfd() and shmem to avoid having to manage memory directly, not because memfd() and shmem were the optimal solution, e.g. things like read/write/mmap in shmem were dead weight. Christian pointed out flaws with implementing a partial overlay (wrapping only _some_ of shmem), e.g. poking at inode_operations or super_operations would show shmem stuff, but address_space_operations and file_operations would show KVM's overlay. Paraphrashing heavily, Christian suggested KVM stop being lazy and create a proper API. Link: https://lore.kernel.org/all/20201020061859.18385-1-kirill.shutemov@linux.intel.com Link: https://lore.kernel.org/all/20210416154106.23721-1-kirill.shutemov@linux.intel.com Link: https://lore.kernel.org/all/20210824005248.200037-1-seanjc@google.com Link: https://lore.kernel.org/all/20211111141352.26311-1-chao.p.peng@linux.intel.com Link: https://lore.kernel.org/all/20221202061347.1070246-1-chao.p.peng@linux.intel.com Link: https://lore.kernel.org/all/ff5c5b97-acdf-9745-ebe5-c6609dd6322e@google.com Link: https://lore.kernel.org/all/20230418-anfallen-irdisch-6993a61be10b@brauner Link: https://lore.kernel.org/all/ZEM5Zq8oo+xnApW9@google.com Link: https://lore.kernel.org/linux-mm/20230306191944.GA15773@monkey Link: https://lore.kernel.org/linux-mm/ZII1p8ZHlHaQ3dDl@casper.infradead.org Cc: Fuad Tabba <tabba@google.com> Cc: Vishal Annapurve <vannapurve@google.com> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Maciej Szmigiero <mail@maciej.szmigiero.name> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: Quentin Perret <qperret@google.com> Cc: Michael Roth <michael.roth@amd.com> Cc: Wang <wei.w.wang@intel.com> Cc: Liam Merwick <liam.merwick@oracle.com> Cc: Isaku Yamahata <isaku.yamahata@gmail.com> Co-developed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Co-developed-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Co-developed-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Co-developed-by: Ackerley Tng <ackerleytng@google.com> Signed-off-by: Ackerley Tng <ackerleytng@google.com> Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Co-developed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Co-developed-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20231027182217.3615211-17-seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Chao Peng
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5a475554db |
KVM: Introduce per-page memory attributes
In confidential computing usages, whether a page is private or shared is necessary information for KVM to perform operations like page fault handling, page zapping etc. There are other potential use cases for per-page memory attributes, e.g. to make memory read-only (or no-exec, or exec-only, etc.) without having to modify memslots. Introduce the KVM_SET_MEMORY_ATTRIBUTES ioctl, advertised by KVM_CAP_MEMORY_ATTRIBUTES, to allow userspace to set the per-page memory attributes to a guest memory range. Use an xarray to store the per-page attributes internally, with a naive, not fully optimized implementation, i.e. prioritize correctness over performance for the initial implementation. Use bit 3 for the PRIVATE attribute so that KVM can use bits 0-2 for RWX attributes/protections in the future, e.g. to give userspace fine-grained control over read, write, and execute protections for guest memory. Provide arch hooks for handling attribute changes before and after common code sets the new attributes, e.g. x86 will use the "pre" hook to zap all relevant mappings, and the "post" hook to track whether or not hugepages can be used to map the range. To simplify the implementation wrap the entire sequence with kvm_mmu_invalidate_{begin,end}() even though the operation isn't strictly guaranteed to be an invalidation. For the initial use case, x86 *will* always invalidate memory, and preventing arch code from creating new mappings while the attributes are in flux makes it much easier to reason about the correctness of consuming attributes. It's possible that future usages may not require an invalidation, e.g. if KVM ends up supporting RWX protections and userspace grants _more_ protections, but again opt for simplicity and punt optimizations to if/when they are needed. Suggested-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/all/Y2WB48kD0J4VGynX@google.com Cc: Fuad Tabba <tabba@google.com> Cc: Xu Yilun <yilun.xu@intel.com> Cc: Mickaël Salaün <mic@digikod.net> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20231027182217.3615211-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Chao Peng
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16f95f3b95 |
KVM: Add KVM_EXIT_MEMORY_FAULT exit to report faults to userspace
Add a new KVM exit type to allow userspace to handle memory faults that KVM cannot resolve, but that userspace *may* be able to handle (without terminating the guest). KVM will initially use KVM_EXIT_MEMORY_FAULT to report implicit conversions between private and shared memory. With guest private memory, there will be two kind of memory conversions: - explicit conversion: happens when the guest explicitly calls into KVM to map a range (as private or shared) - implicit conversion: happens when the guest attempts to access a gfn that is configured in the "wrong" state (private vs. shared) On x86 (first architecture to support guest private memory), explicit conversions will be reported via KVM_EXIT_HYPERCALL+KVM_HC_MAP_GPA_RANGE, but reporting KVM_EXIT_HYPERCALL for implicit conversions is undesriable as there is (obviously) no hypercall, and there is no guarantee that the guest actually intends to convert between private and shared, i.e. what KVM thinks is an implicit conversion "request" could actually be the result of a guest code bug. KVM_EXIT_MEMORY_FAULT will be used to report memory faults that appear to be implicit conversions. Note! To allow for future possibilities where KVM reports KVM_EXIT_MEMORY_FAULT and fills run->memory_fault on _any_ unresolved fault, KVM returns "-EFAULT" (-1 with errno == EFAULT from userspace's perspective), not '0'! Due to historical baggage within KVM, exiting to userspace with '0' from deep callstacks, e.g. in emulation paths, is infeasible as doing so would require a near-complete overhaul of KVM, whereas KVM already propagates -errno return codes to userspace even when the -errno originated in a low level helper. Report the gpa+size instead of a single gfn even though the initial usage is expected to always report single pages. It's entirely possible, likely even, that KVM will someday support sub-page granularity faults, e.g. Intel's sub-page protection feature allows for additional protections at 128-byte granularity. Link: https://lore.kernel.org/all/20230908222905.1321305-5-amoorthy@google.com Link: https://lore.kernel.org/all/ZQ3AmLO2SYv3DszH@google.com Cc: Anish Moorthy <amoorthy@google.com> Cc: David Matlack <dmatlack@google.com> Suggested-by: Sean Christopherson <seanjc@google.com> Co-developed-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20231027182217.3615211-10-seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Sean Christopherson
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bb58b90b1a |
KVM: Introduce KVM_SET_USER_MEMORY_REGION2
Introduce a "version 2" of KVM_SET_USER_MEMORY_REGION so that additional information can be supplied without setting userspace up to fail. The padding in the new kvm_userspace_memory_region2 structure will be used to pass a file descriptor in addition to the userspace_addr, i.e. allow userspace to point at a file descriptor and map memory into a guest that is NOT mapped into host userspace. Alternatively, KVM could simply add "struct kvm_userspace_memory_region2" without a new ioctl(), but as Paolo pointed out, adding a new ioctl() makes detection of bad flags a bit more robust, e.g. if the new fd field is guarded only by a flag and not a new ioctl(), then a userspace bug (setting a "bad" flag) would generate out-of-bounds access instead of an -EINVAL error. Cc: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Message-Id: <20231027182217.3615211-9-seanjc@google.com> Acked-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Paolo Bonzini
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45b890f768 |
KVM/arm64 updates for 6.7
- Generalized infrastructure for 'writable' ID registers, effectively allowing userspace to opt-out of certain vCPU features for its guest - Optimization for vSGI injection, opportunistically compressing MPIDR to vCPU mapping into a table - Improvements to KVM's PMU emulation, allowing userspace to select the number of PMCs available to a VM - Guest support for memory operation instructions (FEAT_MOPS) - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing bugs and getting rid of useless code - Changes to the way the SMCCC filter is constructed, avoiding wasted memory allocations when not in use - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing the overhead of errata mitigations - Miscellaneous kernel and selftest fixes -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQSNXHjWXuzMZutrKNKivnWIJHzdFgUCZUFJRgAKCRCivnWIJHzd FtgYAP9cMsc1Mhlw3jNQnTc6q0cbTulD/SoEDPUat1dXMqjs+gEAnskwQTrTX834 fgGQeCAyp7Gmar+KeP64H0xm8kPSpAw= =R4M7 -----END PGP SIGNATURE----- Merge tag 'kvmarm-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.7 - Generalized infrastructure for 'writable' ID registers, effectively allowing userspace to opt-out of certain vCPU features for its guest - Optimization for vSGI injection, opportunistically compressing MPIDR to vCPU mapping into a table - Improvements to KVM's PMU emulation, allowing userspace to select the number of PMCs available to a VM - Guest support for memory operation instructions (FEAT_MOPS) - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing bugs and getting rid of useless code - Changes to the way the SMCCC filter is constructed, avoiding wasted memory allocations when not in use - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing the overhead of errata mitigations - Miscellaneous kernel and selftest fixes |
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Paolo Bonzini
|
fadaf574a7 |
KVM x86 Documentation updates for 6.7:
- Fix various typos, notably a confusing reference to the non-existent "struct kvm_vcpu_event" (the actual structure is kvm_vcpu_events, plural). - Update x86's kvm_mmu_page documentation to bring it closer to the code (this raced with the removal of async zapping and so the documentation is already stale; my bad). - Document the behavior of x86 PMU filters on fixed counters. -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEEMHr+pfEFOIzK+KY1YJEiAU0MEvkFAmU8D4kSHHNlYW5qY0Bn b29nbGUuY29tAAoJEGCRIgFNDBL5D4wQAKp05OrsZS2ABGu6DEDG/WnSrEjq6gKZ /jACooXABBxb5c83iVrDlx+VJY/gxJoT5lrpE9YU9Y1ZhVk1CK09ADalW3OelmkG L9NA3QB7iHrVwqQhTbKvLguLNNDiCyQd2dyzMGVWf+aUERvGN2D6mZvB/PeBvLHV rJ4tNmOVtx+Ge4OabHxf94mnGU2ioVCXinwh36DjVkC+Cavq+CHpHdD5NSBcn9Ax /nmAf4p6o3utIXAk/7iEPiiFoq6WTj6NwCqhCXpB50/DcAi15lzXhtp0lLaTVD20 wvepeNsk451HXE5MYsUwhAndBTBr3/N1+aBaLTTtK3TPnUf40M+UY5FDXG7Bs3kQ k5pSFobodUrd4vfXyu+Vpl6Q6VBpPo74aklmYr2VwfLPAzi8k1zazaBYij/fueQa Xrl2Y3gT3Pl2KUnKK7BX4l0TYSWM0E3zdCDs6sLdOAsDeEPo0sW3ZQHG8nAXY/EH eWp7AAMjooPshCjASslaZDn5lxQSIoauhwfWOoD4xMTIGpSTw8EUJK1GoUgx2Un8 pirNWNIJuv1DwdKti4uJnGwQhwol7pIa0thbx4JS+oSe16buR2yYSeXXwEKviImy nB0fmdwslpbkjfpjPfSDcHl+XF6HwPszQ6f6WXiNsmv3n2tG701F8lhD1y/fKmo2 x3zpc+DpKUw4 =W12P -----END PGP SIGNATURE----- Merge tag 'kvm-x86-docs-6.7' of https://github.com/kvm-x86/linux into HEAD KVM x86 Documentation updates for 6.7: - Fix various typos, notably a confusing reference to the non-existent "struct kvm_vcpu_event" (the actual structure is kvm_vcpu_events, plural). - Update x86's kvm_mmu_page documentation to bring it closer to the code (this raced with the removal of async zapping and so the documentation is already stale; my bad). - Document the behavior of x86 PMU filters on fixed counters. |
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Oliver Upton
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a87a36436c |
Merge branch kvm-arm64/writable-id-regs into kvmarm/next
* kvm-arm64/writable-id-regs: : Writable ID registers, courtesy of Jing Zhang : : This series significantly expands the architectural feature set that : userspace can manipulate via the ID registers. A new ioctl is defined : that makes the mutable fields in the ID registers discoverable to : userspace. KVM: selftests: Avoid using forced target for generating arm64 headers tools headers arm64: Fix references to top srcdir in Makefile KVM: arm64: selftests: Test for setting ID register from usersapce tools headers arm64: Update sysreg.h with kernel sources KVM: selftests: Generate sysreg-defs.h and add to include path perf build: Generate arm64's sysreg-defs.h and add to include path tools: arm64: Add a Makefile for generating sysreg-defs.h KVM: arm64: Document vCPU feature selection UAPIs KVM: arm64: Allow userspace to change ID_AA64ZFR0_EL1 KVM: arm64: Allow userspace to change ID_AA64PFR0_EL1 KVM: arm64: Allow userspace to change ID_AA64MMFR{0-2}_EL1 KVM: arm64: Allow userspace to change ID_AA64ISAR{0-2}_EL1 KVM: arm64: Bump up the default KVM sanitised debug version to v8p8 KVM: arm64: Reject attempts to set invalid debug arch version KVM: arm64: Advertise selected DebugVer in DBGDIDR.Version KVM: arm64: Use guest ID register values for the sake of emulation KVM: arm64: Document KVM_ARM_GET_REG_WRITABLE_MASKS KVM: arm64: Allow userspace to get the writable masks for feature ID registers Signed-off-by: Oliver Upton <oliver.upton@linux.dev> |
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Oliver Upton
|
dafa493dd0 |
KVM: arm64: Document vCPU feature selection UAPIs
KVM/arm64 has a couple schemes for handling vCPU feature selection now, which is a lot to put on userspace. Add some documentation about how these interact and provide some recommendations for how to use the writable ID register scheme. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231003230408.3405722-11-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev> |
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Jing Zhang
|
6656cda0f3 |
KVM: arm64: Document KVM_ARM_GET_REG_WRITABLE_MASKS
Add some basic documentation on how to get feature ID register writable masks from userspace. Signed-off-by: Jing Zhang <jingzhangos@google.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231003230408.3405722-3-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev> |
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Tianrui Zhao
|
6f0257a032 |
LoongArch: KVM: Supplement kvm document about LoongArch-specific part
Supplement kvm document about LoongArch-specific part, such as add api introduction for GET/SET_ONE_REG, GET/SET_FPU, GET/SET_MP_STATE, etc. Reviewed-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> |