Commit Graph

39 Commits

Author SHA1 Message Date
Anup Patel
ef8949a986 RISC-V: KVM: Forward SBI experimental and vendor extensions
The SBI experimental extension space is for temporary (or experimental)
stuff whereas SBI vendor extension space is for hardware vendor specific
stuff. Both these SBI extension spaces won't be standardized by the SBI
specification so let's blindly forward such SBI calls to the userspace.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-and-tested-by: Atish Patra <atishp@rivosinc.com>
2022-01-06 15:14:33 +05:30
Jisheng Zhang
637ad6551b RISC-V: KVM: make kvm_riscv_vcpu_fp_clean() static
There are no users outside vcpu_fp.c so make kvm_riscv_vcpu_fp_clean()
static.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:13:58 +05:30
Atish Patra
3e1d86569c RISC-V: KVM: Add SBI HSM extension in KVM
SBI HSM extension allows OS to start/stop harts any time. It also allows
ordered booting of harts instead of random booting.

Implement SBI HSM exntesion and designate the vcpu 0 as the boot vcpu id.
All other non-zero non-booting vcpus should be brought up by the OS
implementing HSM extension. If the guest OS doesn't implement HSM
extension, only single vcpu will be available to OS.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:12:47 +05:30
Atish Patra
5f862df558 RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2
The SBI v0.2 contains some of the improved versions of required v0.1
extensions such as remote fence, timer and IPI.

This patch implements those extensions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:12:15 +05:30
Atish Patra
c62a768597 RISC-V: KVM: Add SBI v0.2 base extension
SBI v0.2 base extension defined to allow backward compatibility and
probing of future extensions. This is also the only mandatory SBI
extension that must be implemented by SBI implementors.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:08:29 +05:30
Atish Patra
a046c2d857 RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file
With SBI v0.2, there may be more SBI extensions in future. It makes more
sense to group related extensions in separate files. Guest kernel will
choose appropriate SBI version dynamically.

Move the existing implementation to a separate file so that it can be
removed in future without much conflict.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:57:16 +05:30
Atish Patra
cf70be9d21 RISC-V: KVM: Mark the existing SBI implementation as v0.1
The existing SBI specification impelementation follows v0.1
specification. The latest specification allows more scalability
and performance improvements.

Rename the existing implementation as v0.1 and provide a way
to allow future extensions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:38:52 +05:30
Sean Christopherson
cc4f602bc4 KVM: RISC-V: Use common KVM implementation of MMU memory caches
Use common KVM's implementation of the MMU memory caches, which for all
intents and purposes is semantically identical to RISC-V's version, the
only difference being that the common implementation will fall back to an
atomic allocation if there's a KVM bug that triggers a cache underflow.

RISC-V appears to have based its MMU code on arm64 before the conversion
to the common caches in commit c1a33aebe9 ("KVM: arm64: Use common KVM
implementation of MMU memory caches"), despite having also copy-pasted
the definition of KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE in kvm_types.h.

Opportunistically drop the superfluous wrapper
kvm_riscv_stage2_flush_cache(), whose name is very, very confusing as
"cache flush" in the context of MMU code almost always refers to flushing
hardware caches, not freeing unused software objects.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:38:50 +05:30
David Woodhouse
3e3aa26fd4 KVM: RISC-V: Use Makefile.kvm for common files
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211121125451.9489-6-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-09 12:59:08 -05:00
Sean Christopherson
91b99ea706 KVM: Rename kvm_vcpu_block() => kvm_vcpu_halt()
Rename kvm_vcpu_block() to kvm_vcpu_halt() in preparation for splitting
the actual "block" sequences into a separate helper (to be named
kvm_vcpu_block()).  x86 will use the standalone block-only path to handle
non-halt cases where the vCPU is not runnable.

Rename block_ns to halt_ns to match the new function name.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:51 -05:00
Sean Christopherson
6a99c6e3f5 KVM: Stop passing kvm_userspace_memory_region to arch memslot hooks
Drop the @mem param from kvm_arch_{prepare,commit}_memory_region() now
that its use has been removed in all architectures.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <aa5ed3e62c27e881d0d8bc0acbc1572bc336dc19.1638817640.git.maciej.szmigiero@oracle.com>
2021-12-08 04:24:25 -05:00
Sean Christopherson
d01495d4cf KVM: RISC-V: Use "new" memslot instead of userspace memory region
Get the slot ID, hva, etc... from the "new" memslot instead of the
userspace memory region when preparing/committing a memory region.  This
will allow a future commit to drop @mem from the prepare/commit hooks
once all architectures convert to using "new".

Opportunistically wait to get the various "new" values until after
filtering out the DELETE case in anticipation of a future commit passing
NULL for @new when deleting a memslot.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <543608ab88a1190e73a958efffafc98d2652c067.1638817640.git.maciej.szmigiero@oracle.com>
2021-12-08 04:24:24 -05:00
Sean Christopherson
537a17b314 KVM: Let/force architectures to deal with arch specific memslot data
Pass the "old" slot to kvm_arch_prepare_memory_region() and force arch
code to handle propagating arch specific data from "new" to "old" when
necessary.  This is a baby step towards dynamically allocating "new" from
the get go, and is a (very) minor performance boost on x86 due to not
unnecessarily copying arch data.

For PPC HV, copy the rmap in the !CREATE and !DELETE paths, i.e. for MOVE
and FLAGS_ONLY.  This is functionally a nop as the previous behavior
would overwrite the pointer for CREATE, and eventually discard/ignore it
for DELETE.

For x86, copy the arch data only for FLAGS_ONLY changes.  Unlike PPC HV,
x86 needs to reallocate arch data in the MOVE case as the size of x86's
allocations depend on the alignment of the memslot's gfn.

Opportunistically tweak kvm_arch_prepare_memory_region()'s param order to
match the "commit" prototype.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
[mss: add missing RISCV kvm_arch_prepare_memory_region() change]
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <67dea5f11bbcfd71e3da5986f11e87f5dd4013f9.1638817639.git.maciej.szmigiero@oracle.com>
2021-12-08 04:24:20 -05:00
Marc Zyngier
46808a4cb8 KVM: Use 'unsigned long' as kvm_for_each_vcpu()'s index
Everywhere we use kvm_for_each_vpcu(), we use an int as the vcpu
index. Unfortunately, we're about to move rework the iterator,
which requires this to be upgrade to an unsigned long.

Let's bite the bullet and repaint all of it in one go.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-7-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:15 -05:00
Marc Zyngier
27592ae8db KVM: Move wiping of the kvm->vcpus array to common code
All architectures have similar loops iterating over the vcpus,
freeing one vcpu at a time, and eventually wiping the reference
off the vcpus array. They are also inconsistently taking
the kvm->lock mutex when wiping the references from the array.

Make this code common, which will simplify further changes.
The locking is dropped altogether, as this should only be called
when there is no further references on the kvm structure.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-2-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:13 -05:00
Sean Christopherson
756e1fc165 KVM: RISC-V: Unmap stage2 mapping when deleting/moving a memslot
Unmap stage2 page tables when a memslot is being deleted or moved.  It's
the architectures' responsibility to ensure existing mappings are removed
when kvm_arch_flush_shadow_memslot() returns.

Fixes: 9d05c1fee8 ("RISC-V: KVM: Implement stage2 page table programming")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-22 10:36:16 +05:30
Linus Torvalds
c46e8ece96 Selftest changes:
* Cleanups for the perf test infrastructure and mapping hugepages
 
 * Avoid contention on mmap_sem when the guests start to run
 
 * Add event channel upcall support to xen_shinfo_test
 
 x86 changes:
 
 * Fixes for Xen emulation
 
 * Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache
 
 * Fixes for migration of 32-bit nested guests on 64-bit hypervisor
 
 * Compilation fixes
 
 * More SEV cleanups
 
 Generic:
 
 * Cap the return value of KVM_CAP_NR_VCPUS to both KVM_CAP_MAX_VCPUS
 and num_online_cpus().  Most architectures were only using one of the two.
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmGV/PAUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroMrogf/eAyilGRQL7lLETn3DTVlgLVv82+z
 giX11HlUhUmATHIDluj/wVQUjVcY6AO4SnvFaudX7B+mibndkw4L19IubP/koQZu
 xnKSJTn+mVANdzz3UdsHl0ujbPdQJaFCIPW6iewbn2GRRZMwA5F3vMK/H09XRApL
 I7kq8CPA6sC0I3TPzPN3ROxigexzYunZmGQ4qQe0GUdtxHrJOYQN++ddmWbQoEIC
 gdFTyF7CUQ+lmJe0b/Y88yhISFAJCEBuKFlg9tOTuxSfwvPX6lUu+pi+utEx9M+O
 ckTSQli/apZ4RVcSzxMIwX/BciYqhqOz5uMG+w4DRlJixtGSHtjiEVxGxw==
 =Iij4
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Selftest changes:

   - Cleanups for the perf test infrastructure and mapping hugepages

   - Avoid contention on mmap_sem when the guests start to run

   - Add event channel upcall support to xen_shinfo_test

  x86 changes:

   - Fixes for Xen emulation

   - Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache

   - Fixes for migration of 32-bit nested guests on 64-bit hypervisor

   - Compilation fixes

   - More SEV cleanups

  Generic:

   - Cap the return value of KVM_CAP_NR_VCPUS to both KVM_CAP_MAX_VCPUS
     and num_online_cpus(). Most architectures were only using one of
     the two"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
  KVM: x86: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: s390: Cap KVM_CAP_NR_VCPUS by num_online_cpus()
  KVM: RISC-V: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: PPC: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: MIPS: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: arm64: Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus()
  KVM: x86: Assume a 64-bit hypercall for guests with protected state
  selftests: KVM: Add /x86_64/sev_migrate_tests to .gitignore
  riscv: kvm: fix non-kernel-doc comment block
  KVM: SEV: Fix typo in and tweak name of cmd_allowed_from_miror()
  KVM: SEV: Drop a redundant setting of sev->asid during initialization
  KVM: SEV: WARN if SEV-ES is marked active but SEV is not
  KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()
  KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
  KVM: Kill kvm_map_gfn() / kvm_unmap_gfn() and gfn_to_pfn_cache
  KVM: nVMX: Use a gfn_to_hva_cache for vmptrld
  KVM: nVMX: Use kvm_read_guest_offset_cached() for nested VMCS check
  KVM: x86/xen: Use sizeof_field() instead of open-coding it
  KVM: nVMX: Use kvm_{read,write}_guest_cached() for shadow_vmcs12
  KVM: x86/xen: Fix get_attr of KVM_XEN_ATTR_TYPE_SHARED_INFO
  ...
2021-11-18 12:05:22 -08:00
Vitaly Kuznetsov
37fd3ce1e6 KVM: RISC-V: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211116163443.88707-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:12:14 -05:00
Randy Dunlap
0e2e641921 riscv: kvm: fix non-kernel-doc comment block
Don't use "/**" to begin a comment block for a non-kernel-doc comment.

Prevents this docs build warning:

vcpu_sbi.c:3: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Copyright (c) 2019 Western Digital Corporation or its affiliates.

Fixes: dea8ee31a0 ("RISC-V: KVM: Add SBI v0.1 support")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: kvm@vger.kernel.org
Cc: kvm-riscv@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Message-Id: <20211107034706.30672-1-rdunlap@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:12:13 -05:00
Mauro Carvalho Chehab
636e36b19d Documentation: update vcpu-requests.rst reference
Changeset 2f5947dfca ("Documentation: move Documentation/virtual to Documentation/virt")
renamed: Documentation/virtual/kvm/vcpu-requests.rst
to: Documentation/virt/kvm/vcpu-requests.rst.

Update its cross-reference accordingly.

Fixes: 2f5947dfca ("Documentation: move Documentation/virtual to Documentation/virt")
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-11-17 06:12:14 -07:00
Bixuan Cui
bbd5ba8db7 RISC-V: KVM: fix boolreturn.cocci warnings
Fix boolreturn.cocci warnings:
./arch/riscv/kvm/mmu.c:603:9-10: WARNING: return of 0/1 in function
'kvm_age_gfn' with return type bool
./arch/riscv/kvm/mmu.c:582:9-10: WARNING: return of 0/1 in function
'kvm_set_spte_gfn' with return type bool
./arch/riscv/kvm/mmu.c:621:9-10: WARNING: return of 0/1 in function
'kvm_test_age_gfn' with return type bool
./arch/riscv/kvm/mmu.c:568:9-10: WARNING: return of 0/1 in function
'kvm_unmap_gfn_range' with return type bool

Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-01 17:35:17 +05:30
ran jianping
7b161d9cab RISC-V: KVM: remove unneeded semicolon
Elimate the following coccinelle check warning:
 ./arch/riscv/kvm/vcpu_sbi.c:169:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_exit.c:397:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_exit.c:687:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_exit.c:645:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu.c:247:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu.c:284:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_timer.c:123:2-3: Unneeded semicolon
 ./arch/riscv/kvm/vcpu_timer.c:170:2-3: Unneeded semicolon

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ran jianping <ran.jianping@zte.com.cn>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-01 17:35:13 +05:30
Anup Patel
7c8de080d4 RISC-V: KVM: Fix GPA passed to __kvm_riscv_hfence_gvma_xyz() functions
The parameter passed to HFENCE.GVMA instruction in rs1 register
is guest physical address right shifted by 2 (i.e. divided by 4).

Unfortunately, we overlooked the semantics of rs1 registers for
HFENCE.GVMA instruction and never right shifted guest physical
address by 2. This issue did not manifest for hypervisors till
now because:
  1) Currently, only __kvm_riscv_hfence_gvma_all() and SBI
     HFENCE calls are used to invalidate TLB.
  2) All H-extension implementations (such as QEMU, Spike,
     Rocket Core FPGA, etc) that we tried till now were
     conservatively flushing everything upon any HFENCE.GVMA
     instruction.

This patch fixes GPA passed to __kvm_riscv_hfence_gvma_vmid_gpa()
and __kvm_riscv_hfence_gvma_gpa() functions.

Fixes: fd7bb4a251 ("RISC-V: KVM: Implement VMID allocator")
Reported-by: Ian Huang <ihuang@ventanamicro.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211026170136.2147619-4-anup.patel@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-31 02:45:43 -04:00
Anup Patel
0a86512dc1 RISC-V: KVM: Factor-out FP virtualization into separate sources
The timer and SBI virtualization is already in separate sources.
In future, we will have vector and AIA virtualization also added
as separate sources.

To align with above described modularity, we factor-out FP
virtualization into separate sources.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211026170136.2147619-3-anup.patel@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-31 02:45:43 -04:00
Lukas Bulwahn
9b4eb77099 riscv: do not select non-existing config ANON_INODES
Commit 99cdc6c18c ("RISC-V: Add initial skeletal KVM support") selects
the config ANON_INODES in config KVM, but the config ANON_INODES is removed
since commit 5dd50aaeb1 ("Make anon_inodes unconditional") in 2018.

Hence, ./scripts/checkkconfigsymbols.py warns on non-existing symbols:

  ANON_INODES
  Referencing files: arch/riscv/kvm/Kconfig

Remove selecting the non-existing config ANON_INODES.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Message-Id: <20211022061514.25946-1-lukas.bulwahn@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22 05:53:37 -04:00
Atish Patra
dea8ee31a0 RISC-V: KVM: Add SBI v0.1 support
The KVM host kernel is running in HS-mode needs so we need to handle
the SBI calls coming from guest kernel running in VS-mode.

This patch adds SBI v0.1 support in KVM RISC-V. Almost all SBI v0.1
calls are implemented in KVM kernel module except GETCHAR and PUTCHART
calls which are forwarded to user space because these calls cannot be
implemented in kernel space. In future, when we implement SBI v0.2 for
Guest, we will forward SBI v0.2 experimental and vendor extension calls
to user space.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:11:30 +05:30
Atish Patra
4d9c5c072f RISC-V: KVM: Implement ONE REG interface for FP registers
Add a KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctl interface for floating
point registers such as F0-F31 and FCSR. This support is added for
both 'F' and 'D' extensions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:09:32 +05:30
Atish Patra
5de52d4a23 RISC-V: KVM: FP lazy save/restore
This patch adds floating point (F and D extension) context save/restore
for guest VCPUs. The FP context is saved and restored lazily only when
kernel enter/exits the in-kernel run loop and not during the KVM world
switch. This way FP save/restore has minimal impact on KVM performance.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:08:23 +05:30
Atish Patra
3a9f66cb25 RISC-V: KVM: Add timer functionality
The RISC-V hypervisor specification doesn't have any virtual timer
feature.

Due to this, the guest VCPU timer will be programmed via SBI calls.
The host will use a separate hrtimer event for each guest VCPU to
provide timer functionality. We inject a virtual timer interrupt to
the guest VCPU whenever the guest VCPU hrtimer event expires.

This patch adds guest VCPU timer implementation along with ONE_REG
interface to access VCPU timer state from user space.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:07:16 +05:30
Anup Patel
9955371cc0 RISC-V: KVM: Implement MMU notifiers
This patch implements MMU notifiers for KVM RISC-V so that Guest
physical address space is in-sync with Host physical address space.

This will allow swapping, page migration, etc to work transparently
with KVM RISC-V.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:03:39 +05:30
Anup Patel
9d05c1fee8 RISC-V: KVM: Implement stage2 page table programming
This patch implements all required functions for programming
the stage2 page table for each Guest/VM.

At high-level, the flow of stage2 related functions is similar
from KVM ARM/ARM64 implementation but the stage2 page table
format is quite different for KVM RISC-V.

[jiangyifei: stage2 dirty log support]
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:02:19 +05:30
Anup Patel
fd7bb4a251 RISC-V: KVM: Implement VMID allocator
We implement a simple VMID allocator for Guests/VMs which:
1. Detects number of VMID bits at boot-time
2. Uses atomic number to track VMID version and increments
   VMID version whenever we run-out of VMIDs
3. Flushes Guest TLBs on all host CPUs whenever we run-out
   of VMIDs
4. Force updates HW Stage2 VMID for each Guest VCPU whenever
   VMID changes using VCPU request KVM_REQ_UPDATE_HGATP

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:01:04 +05:30
Anup Patel
5a5d79acd7 RISC-V: KVM: Handle WFI exits for VCPU
We get illegal instruction trap whenever Guest/VM executes WFI
instruction.

This patch handles WFI trap by blocking the trapped VCPU using
kvm_vcpu_block() API. The blocked VCPU will be automatically
resumed whenever a VCPU interrupt is injected from user-space
or from in-kernel IRQCHIP emulation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:55:01 +05:30
Anup Patel
9f70132651 RISC-V: KVM: Handle MMIO exits for VCPU
We will get stage2 page faults whenever Guest/VM access SW emulated
MMIO device or unmapped Guest RAM.

This patch implements MMIO read/write emulation by extracting MMIO
details from the trapped load/store instruction and forwarding the
MMIO read/write to user-space. The actual MMIO emulation will happen
in user-space and KVM kernel module will only take care of register
updates before resuming the trapped VCPU.

The handling for stage2 page faults for unmapped Guest RAM will be
implemeted by a separate patch later.

[jiangyifei: ioeventfd and in-kernel mmio device support]
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:51:47 +05:30
Anup Patel
34bde9d8b9 RISC-V: KVM: Implement VCPU world-switch
This patch implements the VCPU world-switch for KVM RISC-V.

The KVM RISC-V world-switch (i.e. __kvm_riscv_switch_to()) mostly
switches general purpose registers, SSTATUS, STVEC, SSCRATCH and
HSTATUS CSRs. Other CSRs are switched via vcpu_load() and vcpu_put()
interface in kvm_arch_vcpu_load() and kvm_arch_vcpu_put() functions
respectively.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:49:57 +05:30
Anup Patel
92ad82002c RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls
For KVM RISC-V, we use KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls to access
VCPU config and registers from user-space.

We have three types of VCPU registers:
1. CONFIG - these are VCPU config and capabilities
2. CORE   - these are VCPU general purpose registers
3. CSR    - these are VCPU control and status registers

The CONFIG register available to user-space is ISA. The ISA register is
a read and write register where user-space can only write the desired
VCPU ISA capabilities before running the VCPU.

The CORE registers available to user-space are PC, RA, SP, GP, TP, A0-A7,
T0-T6, S0-S11 and MODE. Most of these are RISC-V general registers except
PC and MODE. The PC register represents program counter whereas the MODE
register represent VCPU privilege mode (i.e. S/U-mode).

The CSRs available to user-space are SSTATUS, SIE, STVEC, SSCRATCH, SEPC,
SCAUSE, STVAL, SIP, and SATP. All of these are read/write registers.

In future, more VCPU register types will be added (such as FP) for the
KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:46:22 +05:30
Anup Patel
cce69aff68 RISC-V: KVM: Implement VCPU interrupts and requests handling
This patch implements VCPU interrupts and requests which are both
asynchronous events.

The VCPU interrupts can be set/unset using KVM_INTERRUPT ioctl from
user-space. In future, the in-kernel IRQCHIP emulation will use
kvm_riscv_vcpu_set_interrupt() and kvm_riscv_vcpu_unset_interrupt()
functions to set/unset VCPU interrupts.

Important VCPU requests implemented by this patch are:
KVM_REQ_SLEEP       - set whenever VCPU itself goes to sleep state
KVM_REQ_VCPU_RESET  - set whenever VCPU reset is requested

The WFI trap-n-emulate (added later) will use KVM_REQ_SLEEP request
and kvm_riscv_vcpu_has_interrupt() function.

The KVM_REQ_VCPU_RESET request will be used by SBI emulation (added
later) to power-up a VCPU in power-off state. The user-space can use
the GET_MPSTATE/SET_MPSTATE ioctls to get/set power state of a VCPU.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:42:43 +05:30
Anup Patel
a33c72faf2 RISC-V: KVM: Implement VCPU create, init and destroy functions
This patch implements VCPU create, init and destroy functions
required by generic KVM module. We don't have much dynamic
resources in struct kvm_vcpu_arch so these functions are quite
simple for KVM RISC-V.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:41:17 +05:30
Anup Patel
99cdc6c18c RISC-V: Add initial skeletal KVM support
This patch adds initial skeletal KVM RISC-V support which has:
1. A simple implementation of arch specific VM functions
   except kvm_vm_ioctl_get_dirty_log() which will implemeted
   in-future as part of stage2 page loging.
2. Stubs of required arch specific VCPU functions except
   kvm_arch_vcpu_ioctl_run() which is semi-complete and
   extended by subsequent patches.
3. Stubs for required arch specific stage2 MMU functions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 15:40:08 +05:30