Commit Graph

61 Commits

Author SHA1 Message Date
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
Juergen Gross
a1c42ddedf kvm: rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS
KVM_MAX_VCPU_ID is not specifying the highest allowed vcpu-id, but the
number of allowed vcpu-ids. This has already led to confusion, so
rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS to make its semantics more
clear

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210913135745.13944-3-jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30 04:27:05 -04:00
Aneesh Kumar K.V
dbf77fed8b powerpc: rename powerpc_debugfs_root to arch_debugfs_dir
No functional change in this patch. arch_debugfs_dir is the generic kernel
name declared in linux/debugfs.h for arch-specific debugfs directory.
Architectures like x86/s390 already use the name. Rename powerpc
specific powerpc_debugfs_root to arch_debugfs_dir.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com
2021-08-13 22:04:26 +10:00
Cédric Le Goater
f5af0a9787 KVM: PPC: Book3S HV: XIVE: Add support for automatic save-restore
On P10, the feature doing an automatic "save & restore" of a VCPU
interrupt context is set by default in OPAL. When a VP context is
pulled out, the state of the interrupt registers are saved by the XIVE
interrupt controller under the internal NVP structure representing the
VP. This saves a costly store/load in guest entries and exits.

If OPAL advertises the "save & restore" feature in the device tree,
it should also have set the 'H' bit in the CAM line. Check that when
vCPUs are connected to their ICP in KVM before going any further.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210720134209.256133-3-clg@kaod.org
2021-08-10 23:15:02 +10:00
Cédric Le Goater
b68c6646cc KVM: PPC: Book3S HV: XIVE: Add a 'flags' field
Use it to hold platform specific features. P9 DD2 introduced
single-escalation support. P10 will add others.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210720134209.256133-2-clg@kaod.org
2021-08-10 23:15:01 +10:00
Cédric Le Goater
51be9e51a8 KVM: PPC: Book3S HV: XIVE: Fix mapping of passthrough interrupts
PCI MSI interrupt numbers are now mapped in a PCI-MSI domain but the
underlying calls handling the passthrough of the interrupt in the
guest need a number in the XIVE IRQ domain.

Use the IRQ data mapped in the XIVE IRQ domain and not the one in the
PCI-MSI domain.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-16-clg@kaod.org
2021-08-10 23:14:59 +10:00
Cédric Le Goater
e5e78b1511 KVM: PPC: Book3S HV: XIVE: Change interface of passthrough interrupt routines
The routine kvmppc_set_passthru_irq() calls kvmppc_xive_set_mapped()
and kvmppc_xive_clr_mapped() with an IRQ descriptor. Use directly the
host IRQ number to remove a useless conversion.

Add some debug.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210701132750.1475580-15-clg@kaod.org
2021-08-10 23:14:59 +10:00
Linus Torvalds
21edf50948 Updates for the interrupt subsystem:
Core changes:
 
   - Cleanup and simplification of common code to invoke the low level
     interrupt flow handlers when this invocation requires irqdomain
     resolution. Add the necessary core infrastructure.
 
   - Provide a proper interface for modular PMU drivers to set the
     interrupt affinity.
 
   - Add a request flag which allows to exclude interrupts from spurious
     interrupt detection. Useful especially for IPI handlers which always
     return IRQ_HANDLED which turns the spurious interrupt detection into a
     pointless waste of CPU cycles.
 
 Driver changes:
 
   - Bulk convert interrupt chip drivers to the new irqdomain low level flow
     handler invocation mechanism.
 
   - Add device tree bindings for the Renesas R-Car M3-W+ SoC
 
   - Enable modular build of the Qualcomm PDC driver
 
   - The usual small fixes and improvements.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmDbIg8THHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYobZNEAC2wTq3Ishk026va7g5mbQVSvAQyf8G
 0msmgJ48lJWVL9a6JUogNcCO7sZCTcAy4CYbuHI6kz1fGZZnNWSCrtEz0rFNAdWE
 WVR2k8ExR2R73vJm+K50WUMMj8YsefRnIFXWlJdTp+pksr3TZ7Lo70taGUK/6tMo
 aL0dqvnf7Vb3LG0iIkaHWLF4HnyK/UGqB+121rlL4UhI1/g+3EUxNWNcY5eg/dmc
 Ym73U1uDsjydp3/3jm8v8NYNtwCDGpujZZc/88RFLjP6PMpF1S9JUvDEt+LHJi0a
 cdS3RreB78HYXpLg5NtDFJwIegRMLSitvCGPBjHvWBzbifkMsA2zWIb6Cs8VkYys
 vuPoEGZ0ol+SWvcnSh5Xy36nyr4iGIBhQql47UAaqelSxsYPjvCCSD4yJV3k8hnC
 ZuDscOekXUMn75qZR0quNdi1SkgKpGZxK73QFbuW3Apl5EgArVai6kq0rbl6zlx6
 ACy0SEcevhOcpU6WpqDgrmUBgFr+M8zina8edRELgiFEuWT6pYxKwrN3pT4U5djO
 e5V3YuNzzwzvtUoXN4AiTlT8gwRiGfgeiEvHpvZBXPNvk5ffS6XzPiV81ZMWiBkb
 ReoCbqME3PKoxj1VAHJvVXHbcjiPIJeCRdV+5vQSNh1SPSQOmEdWyJtNUDrSkoym
 QkKKY5jrOhPhlQ==
 =FIKh
 -----END PGP SIGNATURE-----

Merge tag 'irq-core-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Updates for the interrupt subsystem:

  Core changes:

   - Cleanup and simplification of common code to invoke the low level
     interrupt flow handlers when this invocation requires irqdomain
     resolution. Add the necessary core infrastructure.

   - Provide a proper interface for modular PMU drivers to set the
     interrupt affinity.

   - Add a request flag which allows to exclude interrupts from spurious
     interrupt detection. Useful especially for IPI handlers which
     always return IRQ_HANDLED which turns the spurious interrupt
     detection into a pointless waste of CPU cycles.

  Driver changes:

   - Bulk convert interrupt chip drivers to the new irqdomain low level
     flow handler invocation mechanism.

   - Add device tree bindings for the Renesas R-Car M3-W+ SoC

   - Enable modular build of the Qualcomm PDC driver

   - The usual small fixes and improvements"

* tag 'irq-core-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
  dt-bindings: interrupt-controller: arm,gic-v3: Describe GICv3 optional properties
  irqchip: gic-pm: Remove redundant error log of clock bulk
  irqchip/sun4i: Remove unnecessary oom message
  irqchip/irq-imx-gpcv2: Remove unnecessary oom message
  irqchip/imgpdc: Remove unnecessary oom message
  irqchip/gic-v3-its: Remove unnecessary oom message
  irqchip/gic-v2m: Remove unnecessary oom message
  irqchip/exynos-combiner: Remove unnecessary oom message
  irqchip: Bulk conversion to generic_handle_domain_irq()
  genirq: Move non-irqdomain handle_domain_irq() handling into ARM's handle_IRQ()
  genirq: Add generic_handle_domain_irq() helper
  irqchip/nvic: Convert from handle_IRQ() to handle_domain_irq()
  irqdesc: Fix __handle_domain_irq() comment
  genirq: Use irq_resolve_mapping() to implement __handle_domain_irq() and co
  irqdomain: Introduce irq_resolve_mapping()
  irqdomain: Protect the linear revmap with RCU
  irqdomain: Cache irq_data instead of a virq number in the revmap
  irqdomain: Use struct_size() helper when allocating irqdomain
  irqdomain: Make normal and nomap irqdomains exclusive
  powerpc: Move the use of irq_domain_add_nomap() behind a config option
  ...
2021-06-29 12:25:04 -07:00
Nicholas Piggin
dcbac73a5b KVM: PPC: Book3S HV: Remove virt mode checks from real mode handlers
Now that the P7/8 path no longer supports radix, real-mode handlers
do not need to deal with being called in virt mode.

This change effectively reverts commit acde25726b ("KVM: PPC: Book3S
HV: Add radix checks in real-mode hypercall handlers").

It removes a few more real-mode tests in rm hcall handlers, which
allows the indirect ops for the xive module to be removed from the
built-in xics rm handlers.

kvmppc_h_random is renamed to kvmppc_rm_h_random to be a bit more
descriptive and consistent with other rm handlers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-25-npiggin@gmail.com
2021-06-10 22:12:14 +10:00
Nicholas Piggin
9dc2babc18 KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
In the interest of minimising the amount of code that is run in
"real-mode", don't handle hcalls in real mode in the P9 path. This
requires some new handlers for H_CEDE and xics-on-xive to be added
before xive is pulled or cede logic is checked.

This introduces a change in radix guest behaviour where radix guests
that execute 'sc 1' in userspace now get a privilege fault whereas
previously the 'sc 1' would be reflected as a syscall interrupt to the
guest kernel. That reflection is only required for hash guests that run
PR KVM.

Background:

In POWER8 and earlier processors, it is very expensive to exit from the
HV real mode context of a guest hypervisor interrupt, and switch to host
virtual mode. On those processors, guest->HV interrupts reach the
hypervisor with the MMU off because the MMU is loaded with guest context
(LPCR, SDR1, SLB), and the other threads in the sub-core need to be
pulled out of the guest too. Then the primary must save off guest state,
invalidate SLB and ERAT, and load up host state before the MMU can be
enabled to run in host virtual mode (~= regular Linux mode).

Hash guests also require a lot of hcalls to run due to the nature of the
MMU architecture and paravirtualisation design. The XICS interrupt
controller requires hcalls to run.

So KVM traditionally tries hard to avoid the full exit, by handling
hcalls and other interrupts in real mode as much as possible.

By contrast, POWER9 has independent MMU context per-thread, and in radix
mode the hypervisor is in host virtual memory mode when the HV interrupt
is taken. Radix guests do not require significant hcalls to manage their
translations, and xive guests don't need hcalls to handle interrupts. So
it's much less important for performance to handle hcalls in real mode on
POWER9.

One caveat is that the TCE hcalls are performance critical, real-mode
variants introduced for POWER8 in order to achieve 10GbE performance.
Real mode TCE hcalls were found to be less important on POWER9, which
was able to drive 40GBe networking without them (using the virt mode
hcalls) but performance is still important. These hcalls will benefit
from subsequent guest entry/exit optimisation including possibly a
faster "partial exit" that does not entirely switch to host context to
handle the hcall.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-14-npiggin@gmail.com
2021-06-10 22:12:13 +10:00
Nicholas Piggin
023c3c96ca KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C
This is more symmetric with kvmppc_xive_push_vcpu, and has the advantage
that it runs with the MMU on.

The extra test added to the asm will go away with a future change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-9-npiggin@gmail.com
2021-06-10 22:12:12 +10:00
Marc Zyngier
13a9a5d17d powerpc: Add missing linux/{of.h,irqdomain.h} include directives
A bunch of PPC files are missing the inclusion of linux/of.h and
linux/irqdomain.h, relying on transitive inclusion from another
file.

As we are about to break this dependency, make sure these dependencies
are explicit.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10 13:09:16 +01:00
Jiapeng Chong
c9df3f809c powerpc/xive: Assign boolean values to a bool variable
Fix the following coccicheck warnings:

./arch/powerpc/kvm/book3s_xive.c:1856:2-17: WARNING: Assignment of 0/1
to bool variable.

./arch/powerpc/kvm/book3s_xive.c:1854:2-17: WARNING: Assignment of 0/1
to bool variable.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1612680192-43116-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-02-11 23:35:06 +11:00
Linus Torvalds
8a5be36b93 powerpc updates for 5.11
- Switch to the generic C VDSO, as well as some cleanups of our VDSO
    setup/handling code.
 
  - Support for KUAP (Kernel User Access Prevention) on systems using the hashed
    page table MMU, using memory protection keys.
 
  - Better handling of PowerVM SMT8 systems where all threads of a core do not
    share an L2, allowing the scheduler to make better scheduling decisions.
 
  - Further improvements to our machine check handling.
 
  - Show registers when unwinding interrupt frames during stack traces.
 
  - Improvements to our pseries (PowerVM) partition migration code.
 
  - Several series from Christophe refactoring and cleaning up various parts of
    the 32-bit code.
 
  - Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Ard
   Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling, Cédric Le Goater,
   Christophe Leroy, Christophe Lombard, Colin Ian King, Daniel Axtens, David
   Hildenbrand, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geert
   Uytterhoeven, Giuseppe Sacco, Greg Kurz, Harish, Jan Kratochvil, Jordan
   Niethe, Kaixu Xia, Laurent Dufour, Leonardo Bras, Madhavan Srinivasan, Mahesh
   Salgaonkar, Mathieu Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov,
   Oliver O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
   Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej Siewior ,
   Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe Kleine-König,
   Vincent Stehlé, Youling Tang, Zhang Xiaoxu.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAl/bURITHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgEzBEAC1Vwibcog2P9rkJPb0q3UGWSYSx25V
 h/LwwxtM9Tm14j/LZsSgkOgIsfMaWEBIw/8D4efQ7AX9aFo+R0c2DdQMx1MG5MXz
 gZk58+l3LwId6h9+OrwurpEW+ZmURLAtGMSyFdkeiZ3/XTnkbf1XnewC0QWQe56a
 EGLmjx1MFl45jspoy7UIUXsXoNJIfflEKhrgUzSUh8X2eLmvB9ws6A4BXxbVzyZl
 lZv3+uWimU2pFgdkB9jOCxoG4zFEr2o5ovLHG7zCCVo5JoXmTPQ5cMVBraH206ms
 +5vCmu4qI8uP5UlZW/mZfhrtDiMdHdQqqFOaQwVlOmoUbU6L6E6rxm3iVnov2Bbi
 iUgxoeJDxAb2cM2EWFK6oWVgr7+NkwvXM1IG8xtprhHrCdnC9r+psQr/dswb3LSg
 MJ7u/RCq3uixy2kWP8E0NEHw7ngQZ/ZKPqzfnmIWOC7tYUxgaL02I8Ff9/ZXAI2J
 CnmqFYOjrimHkcwXGOtKkXNvfU0DiL97qpK2AQNWElE8+bUUmpw+ltUrsdSycYmv
 Afc4WIcVrTA+a9laSLgjdZbolbNSa3p+cMIYdPrVx9g+xqygbxIKv+EDGNv1WHfD
 GU1gmohMY+ZkMOvFRMi8LAsEm0DH/etWE0py/8uyxDYKnGyD1Ur6452DStkmgGb2
 azmcaOyLdb+HXA==
 =Ga3K
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Switch to the generic C VDSO, as well as some cleanups of our VDSO
   setup/handling code.

 - Support for KUAP (Kernel User Access Prevention) on systems using the
   hashed page table MMU, using memory protection keys.

 - Better handling of PowerVM SMT8 systems where all threads of a core
   do not share an L2, allowing the scheduler to make better scheduling
   decisions.

 - Further improvements to our machine check handling.

 - Show registers when unwinding interrupt frames during stack traces.

 - Improvements to our pseries (PowerVM) partition migration code.

 - Several series from Christophe refactoring and cleaning up various
   parts of the 32-bit code.

 - Other smaller features, fixes & cleanups.

Thanks to: Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh
Kumar K.V, Ard Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling,
Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King,
Daniel Axtens, David Hildenbrand, Frederic Barrat, Ganesh Goudar,
Gautham R. Shenoy, Geert Uytterhoeven, Giuseppe Sacco, Greg Kurz,
Harish, Jan Kratochvil, Jordan Niethe, Kaixu Xia, Laurent Dufour,
Leonardo Bras, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov, Oliver
O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej
Siewior , Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe
Kleine-König, Vincent Stehlé, Youling Tang, and Zhang Xiaoxu.

* tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (304 commits)
  powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug
  powerpc: Add config fragment for disabling -Werror
  powerpc/configs: Add ppc64le_allnoconfig target
  powerpc/powernv: Rate limit opal-elog read failure message
  powerpc/pseries/memhotplug: Quieten some DLPAR operations
  powerpc/ps3: use dma_mapping_error()
  powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10
  powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
  powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range()
  KVM: PPC: Book3S HV: Fix mask size for emulated msgsndp
  KVM: PPC: fix comparison to bool warning
  KVM: PPC: Book3S: Assign boolean values to a bool variable
  powerpc: Inline setup_kup()
  powerpc/64s: Mark the kuap/kuep functions non __init
  KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering
  powerpc/xive: Improve error reporting of OPAL calls
  powerpc/xive: Simplify xive_do_source_eoi()
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG
  ...
2020-12-17 13:34:25 -08:00
Cédric Le Goater
b5277d18c6 powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW
This flag was used to support the PHB4 LSIs on P9 DD1 and we have
stopped supporting this CPU when DD2 came out. See skiboot commit:

  https://github.com/open-power/skiboot/commit/0b0d15e3c170

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-10-clg@kaod.org
2020-12-11 09:53:10 +11:00
Cédric Le Goater
4f1c3f7b08 powerpc/xive: Rename XIVE_IRQ_NO_EOI to show its a flag
This is a simple cleanup to identify easily all flags of the XIVE
interrupt structure. The interrupts flagged with XIVE_IRQ_FLAG_NO_EOI
are the escalations used to wake up vCPUs in KVM. They are handled
very differently from the rest.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-3-clg@kaod.org
2020-12-11 09:34:07 +11:00
Cédric Le Goater
9898367500 KVM: PPC: Book3S HV: XIVE: Show detailed configuration in debug output
This is useful to track allocation of the HW resources on per guest
basis. Making sure IPIs are local to the chip of the vCPUs reduces
rerouting between interrupt controllers and gives better performance
in case of pinning. Checking the distribution of VP structures on the
chips also helps in reducing PowerBUS traffic.

[ clg: resurrected show_sources and reworked ouput ]

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-2-clg@kaod.org
2020-12-11 09:34:07 +11:00
Greg Kurz
f54db39fbe KVM: PPC: Book3S HV: XIVE: Fix vCPU id sanity check
Commit 062cfab706 ("KVM: PPC: Book3S HV: XIVE: Make VP block size
configurable") updated kvmppc_xive_vcpu_id_valid() in a way that
allows userspace to trigger an assertion in skiboot and crash the host:

[  696.186248988,3] XIVE[ IC 08  ] eq_blk != vp_blk (0 vs. 1) for target 0x4300008c/0
[  696.186314757,0] Assert fail: hw/xive.c:2370:0
[  696.186342458,0] Aborting!
xive-kvCPU 0043 Backtrace:
 S: 0000000031e2b8f0 R: 0000000030013840   .backtrace+0x48
 S: 0000000031e2b990 R: 000000003001b2d0   ._abort+0x4c
 S: 0000000031e2ba10 R: 000000003001b34c   .assert_fail+0x34
 S: 0000000031e2ba90 R: 0000000030058984   .xive_eq_for_target.part.20+0xb0
 S: 0000000031e2bb40 R: 0000000030059fdc   .xive_setup_silent_gather+0x2c
 S: 0000000031e2bc20 R: 000000003005a334   .opal_xive_set_vp_info+0x124
 S: 0000000031e2bd20 R: 00000000300051a4   opal_entry+0x134
 --- OPAL call token: 0x8a caller R1: 0xc000001f28563850 ---

XIVE maintains the interrupt context state of non-dispatched vCPUs in
an internal VP structure. We allocate a bunch of those on startup to
accommodate all possible vCPUs. Each VP has an id, that we derive from
the vCPU id for efficiency:

static inline u32 kvmppc_xive_vp(struct kvmppc_xive *xive, u32 server)
{
	return xive->vp_base + kvmppc_pack_vcpu_id(xive->kvm, server);
}

The KVM XIVE device used to allocate KVM_MAX_VCPUS VPs. This was
limitting the number of concurrent VMs because the VP space is
limited on the HW. Since most of the time, VMs run with a lot less
vCPUs, commit 062cfab706 ("KVM: PPC: Book3S HV: XIVE: Make VP
block size configurable") gave the possibility for userspace to
tune the size of the VP block through the KVM_DEV_XIVE_NR_SERVERS
attribute.

The check in kvmppc_pack_vcpu_id() was changed from

	cpu < KVM_MAX_VCPUS * xive->kvm->arch.emul_smt_mode

to

	cpu < xive->nr_servers * xive->kvm->arch.emul_smt_mode

The previous check was based on the fact that the VP block had
KVM_MAX_VCPUS entries and that kvmppc_pack_vcpu_id() guarantees
that packed vCPU ids are below KVM_MAX_VCPUS. We've changed the
size of the VP block, but kvmppc_pack_vcpu_id() has nothing to
do with it and it certainly doesn't ensure that the packed vCPU
ids are below xive->nr_servers. kvmppc_xive_vcpu_id_valid() might
thus return true when the VM was configured with a non-standard
VSMT mode, even if the packed vCPU id is higher than what we
expect. We end up using an unallocated VP id, which confuses
OPAL. The assert in OPAL is probably abusive and should be
converted to a regular error that the kernel can handle, but
we shouldn't really use broken VP ids in the first place.

Fix kvmppc_xive_vcpu_id_valid() so that it checks the packed
vCPU id is below xive->nr_servers, which is explicitly what we
want.

Fixes: 062cfab706 ("KVM: PPC: Book3S HV: XIVE: Make VP block size configurable")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/160673876747.695514.1809676603724514920.stgit@bahia.lan
2020-12-01 21:45:51 +11:00
Greg Kurz
6a3163212f KVM: PPC: Book3S HV: XIVE: Fix typo in comment
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156219139988.578018.1046848908285019838.stgit@bahia.lan
2020-01-23 21:31:23 +11:00
Greg Kurz
efe5ddcae4 KVM: PPC: Book3S HV: XIVE: Allow userspace to set the # of VPs
Add a new attribute to both XIVE and XICS-on-XIVE KVM devices so that
userspace can tell how many interrupt servers it needs. If a VM needs
less than the current default of KVM_MAX_VCPUS (2048), we can allocate
less VPs in OPAL. Combined with a core stride (VSMT) that matches the
number of guest threads per core, this may substantially increases the
number of VMs that can run concurrently with an in-kernel XIVE device.

Since the legacy XIVE KVM device is exposed to userspace through the
XICS KVM API, a new attribute group is added to it for this purpose.
While here, fix the syntax of the existing KVM_DEV_XICS_GRP_SOURCES
in the XICS documentation.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
062cfab706 KVM: PPC: Book3S HV: XIVE: Make VP block size configurable
The XIVE VP is an internal structure which allow the XIVE interrupt
controller to maintain the interrupt context state of vCPUs non
dispatched on HW threads.

When a guest is started, the XIVE KVM device allocates a block of
XIVE VPs in OPAL, enough to accommodate the highest possible vCPU
id KVM_MAX_VCPU_ID (16384) packed down to KVM_MAX_VCPUS (2048).
With a guest's core stride of 8 and a threading mode of 1 (QEMU's
default), a VM must run at least 256 vCPUs to actually need such a
range of VPs.

A POWER9 system has a limited XIVE VP space : 512k and KVM is
currently wasting this HW resource with large VP allocations,
especially since a typical VM likely runs with a lot less vCPUs.

Make the size of the VP block configurable. Add an nr_servers
field to the XIVE structure and a function to set it for this
purpose.

Split VP allocation out of the device create function. Since the
VP block isn't used before the first vCPU connects to the XIVE KVM
device, allocation is now performed by kvmppc_xive_connect_vcpu().
This gives the opportunity to set nr_servers in between:

          kvmppc_xive_create() / kvmppc_xive_native_create()
                               .
                               .
                     kvmppc_xive_set_nr_servers()
                               .
                               .
    kvmppc_xive_connect_vcpu() / kvmppc_xive_native_connect_vcpu()

The connect_vcpu() functions check that the vCPU id is below nr_servers
and if it is the first vCPU they allocate the VP block. This is protected
against a concurrent update of nr_servers by kvmppc_xive_set_nr_servers()
with the xive->lock mutex.

Also, the block is allocated once for the device lifetime: nr_servers
should stay constant otherwise connect_vcpu() could generate a boggus
VP id and likely crash OPAL. It is thus forbidden to update nr_servers
once the block is allocated.

If the VP allocation fail, return ENOSPC which seems more appropriate to
report the depletion of system wide HW resource than ENOMEM or ENXIO.

A VM using a stride of 8 and 1 thread per core with 32 vCPUs would hence
only need 256 VPs instead of 2048. If the stride is set to match the number
of threads per core, this goes further down to 32.

This will be exposed to userspace by a subsequent patch.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
8db29ea239 KVM: PPC: Book3S HV: XIVE: Compute the VP id in a common helper
Reduce code duplication by consolidating the checking of vCPU ids and VP
ids to a common helper used by both legacy and native XIVE KVM devices.
And explain the magic with a comment.

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
8a4e7597ba KVM: PPC: Book3S HV: XIVE: Show VP id in debugfs
Print out the VP id of each connected vCPU, this allow to see:
- the VP block base in which OPAL encodes information that may be
  useful when debugging
- the packed vCPU id which may differ from the raw vCPU id if the
  latter is >= KVM_MAX_VCPUS (2048)

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:02 +11:00
Greg Kurz
e7d71c9430 KVM: PPC: Book3S HV: XIVE: Set kvm->arch.xive when VPs are allocated
If we cannot allocate the XIVE VPs in OPAL, the creation of a XIVE or
XICS-on-XIVE device is aborted as expected, but we leave kvm->arch.xive
set forever since the release method isn't called in this case. Any
subsequent tentative to create a XIVE or XICS-on-XIVE for this VM will
thus always fail (DoS). This is a problem for QEMU since it destroys
and re-creates these devices when the VM is reset: the VM would be
restricted to using the much slower emulated XIVE or XICS forever.

As an alternative to adding rollback, do not assign kvm->arch.xive before
making sure the XIVE VPs are allocated in OPAL.

Cc: stable@vger.kernel.org # v5.2
Fixes: 5422e95103 ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method")
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-22 16:29:01 +11:00
Greg Kurz
12ade69c1e KVM: PPC: Book3S HV: XIVE: Ensure VP isn't already in use
Connecting a vCPU to a XIVE KVM device means establishing a 1:1
association between a vCPU id and the offset (VP id) of a VP
structure within a fixed size block of VPs. We currently try to
enforce the 1:1 relationship by checking that a vCPU with the
same id isn't already connected. This is good but unfortunately
not enough because we don't map VP ids to raw vCPU ids but to
packed vCPU ids, and the packing function kvmppc_pack_vcpu_id()
isn't bijective by design. We got away with it because QEMU passes
vCPU ids that fit well in the packing pattern. But nothing prevents
userspace to come up with a forged vCPU id resulting in a packed id
collision which causes the KVM device to associate two vCPUs to the
same VP. This greatly confuses the irq layer and ultimately crashes
the kernel, as shown below.

Example: a guest with 1 guest thread per core, a core stride of
8 and 300 vCPUs has vCPU ids 0,8,16...2392. If QEMU is patched to
inject at some point an invalid vCPU id 348, which is the packed
version of itself and 2392, we get:

genirq: Flags mismatch irq 199. 00010000 (kvm-2-2392) vs. 00010000 (kvm-2-348)
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38
Call Trace:
[c000003f7f9937e0] [c000000000c0110c] dump_stack+0xb0/0xf4 (unreliable)
[c000003f7f993820] [c0000000001cb480] __setup_irq+0xa70/0xad0
[c000003f7f9938d0] [c0000000001cb75c] request_threaded_irq+0x13c/0x260
[c000003f7f993940] [c00800000d44e7ac] kvmppc_xive_attach_escalation+0x104/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
xive-kvm: Failed to request escalation interrupt for queue 0 of VCPU 2392
------------[ cut here ]------------
remove_proc_entry: removing non-empty directory 'irq/199', leaking at least 'kvm-2-348'
WARNING: CPU: 24 PID: 88176 at /home/greg/Work/linux/kernel-kvm-ppc/fs/proc/generic.c:684 remove_proc_entry+0x1ec/0x200
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ #38
NIP:  c00000000053b0cc LR: c00000000053b0c8 CTR: c0000000000ba3b0
REGS: c000003f7f9934b0 TRAP: 0700   Not tainted  (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 48228222  XER: 20040000
CFAR: c000000000131a50 IRQMASK: 0
GPR00: c00000000053b0c8 c000003f7f993740 c0000000015ec500 0000000000000057
GPR04: 0000000000000001 0000000000000000 000049fb98484262 0000000000001bcf
GPR08: 0000000000000007 0000000000000007 0000000000000001 9000000000001033
GPR12: 0000000000008000 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 c000003f863758b0 c000003f86375870 0000000000000006
GPR24: c000003f86375a30 0000000000000007 c0002039373d9020 c0000000014c4a48
GPR28: 0000000000000001 c000003fe62a4f6b c00020394b2e9fab c000003fe62a4ec0
NIP [c00000000053b0cc] remove_proc_entry+0x1ec/0x200
LR [c00000000053b0c8] remove_proc_entry+0x1e8/0x200
Call Trace:
[c000003f7f993740] [c00000000053b0c8] remove_proc_entry+0x1e8/0x200 (unreliable)
[c000003f7f9937e0] [c0000000001d3654] unregister_irq_proc+0x114/0x150
[c000003f7f993880] [c0000000001c6284] free_desc+0x54/0xb0
[c000003f7f9938c0] [c0000000001c65ec] irq_free_descs+0xac/0x100
[c000003f7f993910] [c0000000001d1ff8] irq_dispose_mapping+0x68/0x80
[c000003f7f993940] [c00800000d44e8a4] kvmppc_xive_attach_escalation+0x1fc/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
Instruction dump:
2c230000 41820008 3923ff78 e8e900a0 3c82ff69 3c62ff8d 7fa6eb78 7fc5f378
3884f080 3863b948 4bbf6925 60000000 <0fe00000> 4bffff7c fba10088 4bbf6e41
---[ end trace b925b67a74a1d8d1 ]---
BUG: Kernel NULL pointer dereference at 0x00000010
Faulting instruction address: 0xc00800000d44fc04
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Tainted: G        W         5.3.0-xive-nr-servers-5.3-gku+ #38
NIP:  c00800000d44fc04 LR: c00800000d44fc00 CTR: c0000000001cd970
REGS: c000003f7f9938e0 TRAP: 0300   Tainted: G        W          (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24228882  XER: 20040000
CFAR: c0000000001cd9ac DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
GPR00: c00800000d44fc00 c000003f7f993b70 c00800000d468300 0000000000000000
GPR04: 00000000000000c7 0000000000000000 0000000000000000 c000003ffacd06d8
GPR08: 0000000000000000 c000003ffacd0738 0000000000000000 fffffffffffffffd
GPR12: 0000000000000040 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 00007ffffe0d9a80 000000012f4f5df0 000000012ef8c9f8
GPR24: 0000000000000001 0000000000000000 c000003fe4501ed0 c000003f8b1d0000
GPR28: c0000033314689c0 c000003fe4501c00 c000003fe4501e70 c000003fe4501e90
NIP [c00800000d44fc04] kvmppc_xive_cleanup_vcpu+0xfc/0x210 [kvm]
LR [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm]
Call Trace:
[c000003f7f993b70] [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm] (unreliable)
[c000003f7f993bd0] [c00800000d450bd4] kvmppc_xive_release+0xdc/0x1b0 [kvm]
[c000003f7f993c30] [c00800000d436a98] kvm_device_release+0xb0/0x110 [kvm]
[c000003f7f993c70] [c00000000046730c] __fput+0xec/0x320
[c000003f7f993cd0] [c000000000164ae0] task_work_run+0x150/0x1c0
[c000003f7f993d30] [c000000000025034] do_notify_resume+0x304/0x440
[c000003f7f993e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74
Instruction dump:
3bff0008 7fbfd040 419e0054 847e0004 2fa30000 419effec e93d0000 8929203c
2f890000 419effb8 4800821d e8410018 <e9230010> e9490008 9b2a0039 7c0004ac
---[ end trace b925b67a74a1d8d2 ]---

Kernel panic - not syncing: Fatal exception

This affects both XIVE and XICS-on-XIVE devices since the beginning.

Check the VP id instead of the vCPU id when a new vCPU is connected.
The allocation of the XIVE CPU structure in kvmppc_xive_connect_vcpu()
is moved after the check to avoid the need for rollback.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-10-15 16:09:11 +11:00
Paul Mackerras
da15c03b04 powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race
Testing has revealed the existence of a race condition where a XIVE
interrupt being shut down can be in one of the XIVE interrupt queues
(of which there are up to 8 per CPU, one for each priority) at the
point where free_irq() is called.  If this happens, can return an
interrupt number which has been shut down.  This can lead to various
symptoms:

- irq_to_desc(irq) can be NULL.  In this case, no end-of-interrupt
  function gets called, resulting in the CPU's elevated interrupt
  priority (numerically lowered CPPR) never gets reset.  That then
  means that the CPU stops processing interrupts, causing device
  timeouts and other errors in various device drivers.

- The irq descriptor or related data structures can be in the process
  of being freed as the interrupt code is using them.  This typically
  leads to crashes due to bad pointer dereferences.

This race is basically what commit 62e0468650 ("genirq: Add optional
hardware synchronization for shutdown", 2019-06-28) is intended to
fix, given a get_irqchip_state() method for the interrupt controller
being used.  It works by polling the interrupt controller when an
interrupt is being freed until the controller says it is not pending.

With XIVE, the PQ bits of the interrupt source indicate the state of
the interrupt source, and in particular the P bit goes from 0 to 1 at
the point where the hardware writes an entry into the interrupt queue
that this interrupt is directed towards.  Normally, the code will then
process the interrupt and do an end-of-interrupt (EOI) operation which
will reset PQ to 00 (assuming another interrupt hasn't been generated
in the meantime).  However, there are situations where the code resets
P even though a queue entry exists (for example, by setting PQ to 01,
which disables the interrupt source), and also situations where the
code leaves P at 1 after removing the queue entry (for example, this
is done for escalation interrupts so they cannot fire again until
they are explicitly re-enabled).

The code already has a 'saved_p' flag for the interrupt source which
indicates that a queue entry exists, although it isn't maintained
consistently.  This patch adds a 'stale_p' flag to indicate that
P has been left at 1 after processing a queue entry, and adds code
to set and clear saved_p and stale_p as necessary to maintain a
consistent indication of whether a queue entry may or may not exist.

With this, we can implement xive_get_irqchip_state() by looking at
stale_p, saved_p and the ESB PQ bits for the interrupt.

There is some additional code to handle escalation interrupts
properly; because they are enabled and disabled in KVM assembly code,
which does not have access to the xive_irq_data struct for the
escalation interrupt.  Hence, stale_p may be incorrect when the
escalation interrupt is freed in kvmppc_xive_{,native_}cleanup_vcpu().
Fortunately, we can fix it up by looking at vcpu->arch.xive_esc_on,
with some careful attention to barriers in order to ensure the correct
result if xive_esc_irq() races with kvmppc_xive_cleanup_vcpu().

Finally, this adds code to make noise on the console (pr_crit and
WARN_ON(1)) if we find an interrupt queue entry for an interrupt
which does not have a descriptor.  While this won't catch the race
reliably, if it does get triggered it will be an indication that
the race is occurring and needs to be debugged.

Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190813100648.GE9567@blackberry
2019-08-16 14:16:59 +10:00
Paul Mackerras
8d4ba9c931 KVM: PPC: Book3S HV: Don't push XIVE context when not using XIVE device
At present, when running a guest on POWER9 using HV KVM but not using
an in-kernel interrupt controller (XICS or XIVE), for example if QEMU
is run with the kernel_irqchip=off option, the guest entry code goes
ahead and tries to load the guest context into the XIVE hardware, even
though no context has been set up.

To fix this, we check that the "CAM word" is non-zero before pushing
it to the hardware.  The CAM word is initialized to a non-zero value
in kvmppc_xive_connect_vcpu() and kvmppc_xive_native_connect_vcpu(),
and is now cleared in kvmppc_xive_{,native_}cleanup_vcpu.

Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.12+
Reported-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190813100100.GC9567@blackberry
2019-08-16 14:16:08 +10:00
Cédric Le Goater
237aed48c6 KVM: PPC: Book3S HV: XIVE: Free escalation interrupts before disabling the VP
When a vCPU is brought done, the XIVE VP (Virtual Processor) is first
disabled and then the event notification queues are freed. When freeing
the queues, we check for possible escalation interrupts and free them
also.

But when a XIVE VP is disabled, the underlying XIVE ENDs also are
disabled in OPAL. When an END (Event Notification Descriptor) is
disabled, its ESB pages (ESn and ESe) are disabled and loads return all
1s. Which means that any access on the ESB page of the escalation
interrupt will return invalid values.

When an interrupt is freed, the shutdown handler computes a 'saved_p'
field from the value returned by a load in xive_do_source_set_mask().
This value is incorrect for escalation interrupts for the reason
described above.

This has no impact on Linux/KVM today because we don't make use of it
but we will introduce in future changes a xive_get_irqchip_state()
handler. This handler will use the 'saved_p' field to return the state
of an interrupt and 'saved_p' being incorrect, softlockup will occur.

Fix the vCPU cleanup sequence by first freeing the escalation interrupts
if any, then disable the XIVE VP and last free the queues.

Fixes: 90c73795af ("KVM: PPC: Book3S HV: Add a new KVM device for the XIVE native exploitation mode")
Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190806172538.5087-1-clg@kaod.org
2019-08-16 14:03:27 +10:00
Cédric Le Goater
9798f4ea71 KVM: PPC: Book3S HV: XIVE: fix rollback when kvmppc_xive_create fails
The XIVE device structure is now allocated in kvmppc_xive_get_device()
and kfree'd in kvmppc_core_destroy_vm(). In case of an OPAL error when
allocating the XIVE VPs, the kfree() call in kvmppc_xive_*create()
will result in a double free and corrupt the host memory.

Fixes: 5422e95103 ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6ea6998b-a890-2511-01d1-747d7621eb19@kaod.org
2019-07-19 13:41:12 +10:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Cédric Le Goater
ef97402040 KVM: PPC: Book3S HV: XIVE: Do not clear IRQ data of passthrough interrupts
The passthrough interrupts are defined at the host level and their IRQ
data should not be cleared unless specifically deconfigured (shutdown)
by the host. They differ from the IPI interrupts which are allocated
by the XIVE KVM device and reserved to the guest usage only.

This fixes a host crash when destroying a VM in which a PCI adapter
was passed-through. In this case, the interrupt is cleared and freed
by the KVM device and then shutdown by vfio at the host level.

[ 1007.360265] BUG: Kernel NULL pointer dereference at 0x00000d00
[ 1007.360285] Faulting instruction address: 0xc00000000009da34
[ 1007.360296] Oops: Kernel access of bad area, sig: 7 [#1]
[ 1007.360303] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
[ 1007.360314] Modules linked in: vhost_net vhost iptable_mangle ipt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc kvm_hv kvm xt_tcpudp iptable_filter squashfs fuse binfmt_misc vmx_crypto ib_iser rdma_cm iw_cm ib_cm libiscsi scsi_transport_iscsi nfsd ip_tables x_tables autofs4 btrfs zstd_decompress zstd_compress lzo_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq multipath mlx5_ib ib_uverbs ib_core crc32c_vpmsum mlx5_core
[ 1007.360425] CPU: 9 PID: 15576 Comm: CPU 18/KVM Kdump: loaded Not tainted 5.1.0-gad7e7d0ef #4
[ 1007.360454] NIP:  c00000000009da34 LR: c00000000009e50c CTR: c00000000009e5d0
[ 1007.360482] REGS: c000007f24ccf330 TRAP: 0300   Not tainted  (5.1.0-gad7e7d0ef)
[ 1007.360500] MSR:  900000000280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 24002484  XER: 00000000
[ 1007.360532] CFAR: c00000000009da10 DAR: 0000000000000d00 DSISR: 00080000 IRQMASK: 1
[ 1007.360532] GPR00: c00000000009e62c c000007f24ccf5c0 c000000001510600 c000007fe7f947c0
[ 1007.360532] GPR04: 0000000000000d00 0000000000000000 0000000000000000 c000005eff02d200
[ 1007.360532] GPR08: 0000000000400000 0000000000000000 0000000000000000 fffffffffffffffd
[ 1007.360532] GPR12: c00000000009e5d0 c000007fffff7b00 0000000000000031 000000012c345718
[ 1007.360532] GPR16: 0000000000000000 0000000000000008 0000000000418004 0000000000040100
[ 1007.360532] GPR20: 0000000000000000 0000000008430000 00000000003c0000 0000000000000027
[ 1007.360532] GPR24: 00000000000000ff 0000000000000000 00000000000000ff c000007faa90d98c
[ 1007.360532] GPR28: c000007faa90da40 00000000000fe040 ffffffffffffffff c000007fe7f947c0
[ 1007.360689] NIP [c00000000009da34] xive_esb_read+0x34/0x120
[ 1007.360706] LR [c00000000009e50c] xive_do_source_set_mask.part.0+0x2c/0x50
[ 1007.360732] Call Trace:
[ 1007.360738] [c000007f24ccf5c0] [c000000000a6383c] snooze_loop+0x15c/0x270 (unreliable)
[ 1007.360775] [c000007f24ccf5f0] [c00000000009e62c] xive_irq_shutdown+0x5c/0xe0
[ 1007.360795] [c000007f24ccf630] [c00000000019e4a0] irq_shutdown+0x60/0xe0
[ 1007.360813] [c000007f24ccf660] [c000000000198c44] __free_irq+0x3a4/0x420
[ 1007.360831] [c000007f24ccf700] [c000000000198dc8] free_irq+0x78/0xe0
[ 1007.360849] [c000007f24ccf730] [c00000000096c5a8] vfio_msi_set_vector_signal+0xa8/0x350
[ 1007.360878] [c000007f24ccf7f0] [c00000000096c938] vfio_msi_set_block+0xe8/0x1e0
[ 1007.360899] [c000007f24ccf850] [c00000000096cae0] vfio_msi_disable+0xb0/0x110
[ 1007.360912] [c000007f24ccf8a0] [c00000000096cd04] vfio_pci_set_msi_trigger+0x1c4/0x3d0
[ 1007.360922] [c000007f24ccf910] [c00000000096d910] vfio_pci_set_irqs_ioctl+0xa0/0x170
[ 1007.360941] [c000007f24ccf930] [c00000000096b400] vfio_pci_disable+0x80/0x5e0
[ 1007.360963] [c000007f24ccfa10] [c00000000096b9bc] vfio_pci_release+0x5c/0x90
[ 1007.360991] [c000007f24ccfa40] [c000000000963a9c] vfio_device_fops_release+0x3c/0x70
[ 1007.361012] [c000007f24ccfa70] [c0000000003b5668] __fput+0xc8/0x2b0
[ 1007.361040] [c000007f24ccfac0] [c0000000001409b0] task_work_run+0x140/0x1b0
[ 1007.361059] [c000007f24ccfb20] [c000000000118f8c] do_exit+0x3ac/0xd00
[ 1007.361076] [c000007f24ccfc00] [c0000000001199b0] do_group_exit+0x60/0x100
[ 1007.361094] [c000007f24ccfc40] [c00000000012b514] get_signal+0x1a4/0x8f0
[ 1007.361112] [c000007f24ccfd30] [c000000000021cc8] do_notify_resume+0x1a8/0x430
[ 1007.361141] [c000007f24ccfe20] [c00000000000e444] ret_from_except_lite+0x70/0x74
[ 1007.361159] Instruction dump:
[ 1007.361175] 38422c00 e9230000 712a0004 41820010 548a2036 7d442378 78840020 71290020
[ 1007.361194] 4082004c e9230010 7c892214 7c0004ac <e9240000> 0c090000 4c00012c 792a0022

Cc: stable@vger.kernel.org # v4.12+
Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30 13:54:21 +10:00
Cédric Le Goater
7e10b9a6da KVM: PPC: Book3S HV: XIVE: Introduce a new mutex for the XIVE device
The XICS-on-XIVE KVM device needs to allocate XIVE event queues when a
priority is used by the OS. This is referred as EQ provisioning and it
is done under the hood when :

  1. a CPU is hot-plugged in the VM
  2. the "set-xive" is called at VM startup
  3. sources are restored at VM restore

The kvm->lock mutex is used to protect the different XIVE structures
being modified but in some contexts, kvm->lock is taken under the
vcpu->mutex which is not permitted by the KVM locking rules.

Introduce a new mutex 'lock' for the KVM devices for them to
synchronize accesses to the XIVE device structures.

Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-30 13:53:33 +10:00
Paul Mackerras
c395fe1d8e KVM: PPC: Book3S HV: Avoid touching arch.mmu_ready in XIVE release functions
Currently, kvmppc_xive_release() and kvmppc_xive_native_release() clear
kvm->arch.mmu_ready and call kick_all_cpus_sync() as a way of ensuring
that no vcpus are executing in the guest.  However, future patches will
change the mutex associated with kvm->arch.mmu_ready to a new mutex that
nests inside the vcpu mutexes, making it difficult to continue to use
this method.

In fact, taking the vcpu mutex for a vcpu excludes execution of that
vcpu, and we already take the vcpu mutex around the call to
kvmppc_xive_[native_]cleanup_vcpu().  Once the cleanup function is
done and we release the vcpu mutex, the vcpu can execute once again,
but because we have cleared vcpu->arch.xive_vcpu, vcpu->arch.irq_type,
vcpu->arch.xive_esc_vaddr and vcpu->arch.xive_esc_raddr, that vcpu will
not be going into XIVE code any more.  Thus, once we have cleaned up
all of the vcpus, we are safe to clean up the rest of the XIVE state,
and we don't need to use kvm->arch.mmu_ready to hold off vcpu execution.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-05-29 13:44:36 +10:00
Paul Mackerras
0caecf5b00 KVM: PPC: Book3S HV: XIVE: Clear escalation interrupt pointers on device close
This adds code to ensure that after a XIVE or XICS-on-XIVE KVM device
is closed, KVM will not try to enable or disable any of the escalation
interrupts for the VCPUs.  We don't have to worry about races between
clearing the pointers and use of the pointers by the XIVE context
push/pull code, because the callers hold the vcpu->mutex, which is
also taken by the KVM_RUN code.  Therefore the vcpu cannot be entering
or exiting the guest concurrently.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:41:01 +10:00
Paul Mackerras
6f868405fa KVM: PPC: Book3S HV: XIVE: Prevent races when releasing device
Now that we have the possibility of a XIVE or XICS-on-XIVE device being
released while the VM is still running, we need to be careful about
races and potential use-after-free bugs.  Although the kvmppc_xive
struct is not freed, but kept around for re-use, the kvmppc_xive_vcpu
structs are freed, and they are used extensively in both the XIVE native
and XICS-on-XIVE code.

There are various ways in which XIVE code gets invoked:

- VCPU entry and exit, which do push and pull operations on the XIVE hardware
- one_reg get and set functions (vcpu->mutex is held)
- XICS hypercalls (but only inside guest execution, not from
  kvmppc_pseries_do_hcall)
- device creation calls (kvm->lock is held)
- device callbacks - get/set attribute, mmap, pagefault, release/destroy
- set_mapped/clr_mapped calls (kvm->lock is held)
- connect_vcpu calls
- debugfs file read callbacks

Inside a device release function, we know that userspace cannot have an
open file descriptor referring to the device, nor can it have any mmapped
regions from the device.  Therefore the device callbacks are excluded,
as are the connect_vcpu calls (since they need a fd for the device).
Further, since the caller holds the kvm->lock mutex, no other device
creation calls or set/clr_mapped calls can be executing concurrently.

To exclude VCPU execution and XICS hypercalls, we temporarily set
kvm->arch.mmu_ready to 0.  This forces any VCPU task that is trying to
enter the guest to take the kvm->lock mutex, which is held by the caller
of the release function.  Then, sending an IPI to all other CPUs forces
any VCPU currently executing in the guest to exit.

Finally, we take the vcpu->mutex for each VCPU around the process of
cleaning up and freeing its XIVE data structures, in order to exclude
any one_reg get/set calls.

To exclude the debugfs read callbacks, we just need to ensure that
debugfs_remove is called before freeing any data structures.  Once it
returns we know that no CPU can be executing the callbacks (for our
kvmppc_xive instance).

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:41:01 +10:00
Cédric Le Goater
5422e95103 KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method
When a P9 sPAPR VM boots, the CAS negotiation process determines which
interrupt mode to use (XICS legacy or XIVE native) and invokes a
machine reset to activate the chosen mode.

We introduce 'release' methods for the XICS-on-XIVE and the XIVE
native KVM devices which are called when the file descriptor of the
device is closed after the TIMA and ESB pages have been unmapped.
They perform the necessary cleanups : clear the vCPU interrupt
presenters that could be attached and then destroy the device. The
'release' methods replace the 'destroy' methods as 'destroy' is not
called anymore once 'release' is. Compatibility with older QEMU is
nevertheless maintained.

This is not considered as a safe operation as the vCPUs are still
running and could be referencing the KVM device through their
presenters. To protect the system from any breakage, the kvmppc_xive
objects representing both KVM devices are now stored in an array under
the VM. Allocation is performed on first usage and memory is freed
only when the VM exits.

[paulus@ozlabs.org - Moved freeing of xive structures to book3s.c,
 put it under #ifdef CONFIG_KVM_XICS.]

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:40:39 +10:00
Cédric Le Goater
232b984b7d KVM: PPC: Book3S HV: XIVE: Add passthrough support
The KVM XICS-over-XIVE device and the proposed KVM XIVE native device
implement an IRQ space for the guest using the generic IPI interrupts
of the XIVE IC controller. These interrupts are allocated at the OPAL
level and "mapped" into the guest IRQ number space in the range 0-0x1FFF.
Interrupt management is performed in the XIVE way: using loads and
stores on the addresses of the XIVE IPI interrupt ESB pages.

Both KVM devices share the same internal structure caching information
on the interrupts, among which the xive_irq_data struct containing the
addresses of the IPI ESB pages and an extra one in case of pass-through.
The later contains the addresses of the ESB pages of the underlying HW
controller interrupts, PHB4 in all cases for now.

A guest, when running in the XICS legacy interrupt mode, lets the KVM
XICS-over-XIVE device "handle" interrupt management, that is to
perform the loads and stores on the addresses of the ESB pages of the
guest interrupts. However, when running in XIVE native exploitation
mode, the KVM XIVE native device exposes the interrupt ESB pages to
the guest and lets the guest perform directly the loads and stores.

The VMA exposing the ESB pages make use of a custom VM fault handler
which role is to populate the VMA with appropriate pages. When a fault
occurs, the guest IRQ number is deduced from the offset, and the ESB
pages of associated XIVE IPI interrupt are inserted in the VMA (using
the internal structure caching information on the interrupts).

Supporting device passthrough in the guest running in XIVE native
exploitation mode adds some extra refinements because the ESB pages
of a different HW controller (PHB4) need to be exposed to the guest
along with the initial IPI ESB pages of the XIVE IC controller. But
the overall mechanic is the same.

When the device HW irqs are mapped into or unmapped from the guest
IRQ number space, the passthru_irq helpers, kvmppc_xive_set_mapped()
and kvmppc_xive_clr_mapped(), are called to record or clear the
passthrough interrupt information and to perform the switch.

The approach taken by this patch is to clear the ESB pages of the
guest IRQ number being mapped and let the VM fault handler repopulate.
The handler will insert the ESB page corresponding to the HW interrupt
of the device being passed-through or the initial IPI ESB page if the
device is being removed.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
13ce3297c5 KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration
These controls will be used by the H_INT_SET_QUEUE_CONFIG and
H_INT_GET_QUEUE_CONFIG hcalls from QEMU to configure the underlying
Event Queue in the XIVE IC. They will also be used to restore the
configuration of the XIVE EQs and to capture the internal run-time
state of the EQs. Both 'get' and 'set' rely on an OPAL call to access
the EQ toggle bit and EQ index which are updated by the XIVE IC when
event notifications are enqueued in the EQ.

The value of the guest physical address of the event queue is saved in
the XIVE internal xive_q structure for later use. That is when
migration needs to mark the EQ pages dirty to capture a consistent
memory state of the VM.

To be noted that H_INT_SET_QUEUE_CONFIG does not require the extra
OPAL call setting the EQ toggle bit and EQ index to configure the EQ,
but restoring the EQ state will.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
e8676ce50e KVM: PPC: Book3S HV: XIVE: Add a control to configure a source
This control will be used by the H_INT_SET_SOURCE_CONFIG hcall from
QEMU to configure the target of a source and also to restore the
configuration of a source when migrating the VM.

The XIVE source interrupt structure is extended with the value of the
Effective Interrupt Source Number. The EISN is the interrupt number
pushed in the event queue that the guest OS will use to dispatch
events internally. Caching the EISN value in KVM eases the test when
checking if a reconfiguration is indeed needed.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
4131f83c3d KVM: PPC: Book3S HV: XIVE: add a control to initialize a source
The XIVE KVM device maintains a list of interrupt sources for the VM
which are allocated in the pool of generic interrupts (IPIs) of the
main XIVE IC controller. These are used for the CPU IPIs as well as
for virtual device interrupts. The IRQ number space is defined by
QEMU.

The XIVE device reuses the source structures of the XICS-on-XIVE
device for the source blocks (2-level tree) and for the source
interrupts. Under XIVE native, the source interrupt caches mostly
configuration information and is less used than under the XICS-on-XIVE
device in which hcalls are still necessary at run-time.

When a source is initialized in KVM, an IPI interrupt source is simply
allocated at the OPAL level and then MASKED. KVM only needs to know
about its type: LSI or MSI.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Cédric Le Goater
eacc56bb9d KVM: PPC: Book3S HV: XIVE: Introduce a new capability KVM_CAP_PPC_IRQ_XIVE
The user interface exposes a new capability KVM_CAP_PPC_IRQ_XIVE to
let QEMU connect the vCPU presenters to the XIVE KVM device if
required. The capability is not advertised for now as the full support
for the XIVE native exploitation mode is not yet available. When this
is case, the capability will be advertised on PowerNV Hypervisors
only. Nested guests (pseries KVM Hypervisor) are not supported.

Internally, the interface to the new KVM device is protected with a
new interrupt mode: KVMPPC_IRQ_XIVE.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-30 19:35:16 +10:00
Yangtao Li
0f6ddf34be KVM: PPC: Book3S HV: Change to use DEFINE_SHOW_ATTRIBUTE macro
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-14 15:39:47 +11:00
Paul Mackerras
95a6432ce9 KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests
This creates an alternative guest entry/exit path which is used for
radix guests on POWER9 systems when we have indep_threads_mode=Y.  In
these circumstances there is exactly one vcpu per vcore and there is
no coordination required between vcpus or vcores; the vcpu can enter
the guest without needing to synchronize with anything else.

The new fast path is implemented almost entirely in C in book3s_hv.c
and runs with the MMU on until the guest is entered.  On guest exit
we use the existing path until the point where we are committed to
exiting the guest (as distinct from handling an interrupt in the
low-level code and returning to the guest) and we have pulled the
guest context from the XIVE.  At that point we check a flag in the
stack frame to see whether we came in via the old path and the new
path; if we came in via the new path then we go back to C code to do
the rest of the process of saving the guest context and restoring the
host context.

The C code is split into separate functions for handling the
OS-accessible state and the hypervisor state, with the idea that the
latter can be replaced by a hypercall when we implement nested
virtualization.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[mpe: Fix CONFIG_ALTIVEC=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-09 16:04:27 +11:00
Finn Thain
3cc97bea60 treewide: correct "differenciate" and "instanciate" typos
Also add these typos to spelling.txt so checkpatch.pl will look for them.

Link: http://lkml.kernel.org/r/88af06b9de34d870cb0afc46cfd24e0458be2575.1529471371.git.fthain@telegraphics.com.au
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-23 18:48:43 -07:00
Sam Bobroff
1e175d2e07 KVM: PPC: Book3S HV: Pack VCORE IDs to access full VCPU ID space
It is not currently possible to create the full number of possible
VCPUs (KVM_MAX_VCPUS) on Power9 with KVM-HV when the guest uses fewer
threads per core than its core stride (or "VSMT mode"). This is
because the VCORE ID and XIVE offsets grow beyond KVM_MAX_VCPUS
even though the VCPU ID is less than KVM_MAX_VCPU_ID.

To address this, "pack" the VCORE ID and XIVE offsets by using
knowledge of the way the VCPU IDs will be used when there are fewer
guest threads per core than the core stride. The primary thread of
each core will always be used first. Then, if the guest uses more than
one thread per core, these secondary threads will sequentially follow
the primary in each core.

So, the only way an ID above KVM_MAX_VCPUS can be seen, is if the
VCPUs are being spaced apart, so at least half of each core is empty,
and IDs between KVM_MAX_VCPUS and (KVM_MAX_VCPUS * 2) can be mapped
into the second half of each core (4..7, in an 8-thread core).

Similarly, if IDs above KVM_MAX_VCPUS * 2 are seen, at least 3/4 of
each core is being left empty, and we can map down into the second and
third quarters of each core (2, 3 and 5, 6 in an 8-thread core).

Lastly, if IDs above KVM_MAX_VCPUS * 4 are seen, only the primary
threads are being used and 7/8 of the core is empty, allowing use of
the 1, 5, 3 and 7 thread slots.

(Strides less than 8 are handled similarly.)

This allows the VCORE ID or offset to be calculated quickly from the
VCPU ID or XIVE server numbers, without access to the VCPU structure.

[paulus@ozlabs.org - tidied up comment a little, changed some WARN_ONCE
 to pr_devel, wrapped line, fixed id check.]

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-07-26 13:23:52 +10:00
Ingo Molnar
ed7158bae4 treewide/trivial: Remove ';;$' typo noise
On lkml suggestions were made to split up such trivial typo fixes into per subsystem
patches:

  --- a/arch/x86/boot/compressed/eboot.c
  +++ b/arch/x86/boot/compressed/eboot.c
  @@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
          struct efi_uga_draw_protocol *uga = NULL, *first_uga;
          efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
          unsigned long nr_ugas;
  -       u32 *handles = (u32 *)uga_handle;;
  +       u32 *handles = (u32 *)uga_handle;
          efi_status_t status = EFI_INVALID_PARAMETER;
          int i;

This patch is the result of the following script:

  $ sed -i 's/;;$/;/g' $(git grep -E ';;$'  | grep "\.[ch]:"  | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq)

... followed by manual review to make sure it's all good.

Splitting this up is just crazy talk, let's get over with this and just do it.

Reported-by: Pavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-22 10:59:33 +01:00
Linus Torvalds
15303ba5d1 KVM changes for 4.16
ARM:
 - Include icache invalidation optimizations, improving VM startup time
 
 - Support for forwarded level-triggered interrupts, improving
   performance for timers and passthrough platform devices
 
 - A small fix for power-management notifiers, and some cosmetic changes
 
 PPC:
 - Add MMIO emulation for vector loads and stores
 
 - Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
   requiring the complex thread synchronization of older CPU versions
 
 - Improve the handling of escalation interrupts with the XIVE interrupt
   controller
 
 - Support decrement register migration
 
 - Various cleanups and bugfixes.
 
 s390:
 - Cornelia Huck passed maintainership to Janosch Frank
 
 - Exitless interrupts for emulated devices
 
 - Cleanup of cpuflag handling
 
 - kvm_stat counter improvements
 
 - VSIE improvements
 
 - mm cleanup
 
 x86:
 - Hypervisor part of SEV
 
 - UMIP, RDPID, and MSR_SMI_COUNT emulation
 
 - Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
 
 - Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
   features
 
 - Show vcpu id in its anonymous inode name
 
 - Many fixes and cleanups
 
 - Per-VCPU MSR bitmaps (already merged through x86/pti branch)
 
 - Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
 -----BEGIN PGP SIGNATURE-----
 
 iQEcBAABCAAGBQJafvMtAAoJEED/6hsPKofo6YcH/Rzf2RmshrWaC3q82yfIV0Qz
 Z8N8yJHSaSdc3Jo6cmiVj0zelwAxdQcyjwlT7vxt5SL2yML+/Q0st9Hc3EgGGXPm
 Il99eJEl+2MYpZgYZqV8ff3mHS5s5Jms+7BITAeh6Rgt+DyNbykEAvzt+MCHK9cP
 xtsIZQlvRF7HIrpOlaRzOPp3sK2/MDZJ1RBE7wYItK3CUAmsHim/LVYKzZkRTij3
 /9b4LP1yMMbziG+Yxt1o682EwJB5YIat6fmDG9uFeEVI5rWWN7WFubqs8gCjYy/p
 FX+BjpOdgTRnX+1m9GIj0Jlc/HKMXryDfSZS07Zy4FbGEwSiI5SfKECub4mDhuE=
 =C/uD
 -----END PGP SIGNATURE-----

Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:

   - icache invalidation optimizations, improving VM startup time

   - support for forwarded level-triggered interrupts, improving
     performance for timers and passthrough platform devices

   - a small fix for power-management notifiers, and some cosmetic
     changes

  PPC:

   - add MMIO emulation for vector loads and stores

   - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
     requiring the complex thread synchronization of older CPU versions

   - improve the handling of escalation interrupts with the XIVE
     interrupt controller

   - support decrement register migration

   - various cleanups and bugfixes.

  s390:

   - Cornelia Huck passed maintainership to Janosch Frank

   - exitless interrupts for emulated devices

   - cleanup of cpuflag handling

   - kvm_stat counter improvements

   - VSIE improvements

   - mm cleanup

  x86:

   - hypervisor part of SEV

   - UMIP, RDPID, and MSR_SMI_COUNT emulation

   - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit

   - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
     AVX512 features

   - show vcpu id in its anonymous inode name

   - many fixes and cleanups

   - per-VCPU MSR bitmaps (already merged through x86/pti branch)

   - stable KVM clock when nesting on Hyper-V (merged through
     x86/hyperv)"

* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
  KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
  KVM: PPC: Book3S HV: Branch inside feature section
  KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
  KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
  KVM: PPC: Book3S PR: Fix broken select due to misspelling
  KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
  KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
  KVM: PPC: Book3S HV: Drop locks before reading guest memory
  kvm: x86: remove efer_reload entry in kvm_vcpu_stat
  KVM: x86: AMD Processor Topology Information
  x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
  kvm: embed vcpu id to dentry of vcpu anon inode
  kvm: Map PFN-type memory regions as writable (if possible)
  x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
  KVM: arm/arm64: Fixup userspace irqchip static key optimization
  KVM: arm/arm64: Fix userspace_irqchip_in_use counting
  KVM: arm/arm64: Fix incorrect timer_is_pending logic
  MAINTAINERS: update KVM/s390 maintainers
  MAINTAINERS: add Halil as additional vfio-ccw maintainer
  MAINTAINERS: add David as a reviewer for KVM/s390
  ...
2018-02-10 13:16:35 -08:00
Radim Krčmář
d2b9b2079e PPC KVM update for 4.16
- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs
   without requiring the complex thread synchronization that earlier
   CPU versions required.
 
 - A series from Ben Herrenschmidt to improve the handling of
   escalation interrupts with the XIVE interrupt controller.
 
 - Provide for the decrementer register to be copied across on
   migration.
 
 - Various minor cleanups and bugfixes.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJaYXViAAoJEJ2a6ncsY3GfDhgIAIDVBZH/Ftq7eJiUSxDpqyCQ
 DF/x7fNKzK/J33pu+3ntOI2gZsldExAy7vH2M27I4qLIkbI5y3vu4v8l3CDlS1LK
 9dKi72zg7baozoVF5mGUNm0B1sSvZiIQlC/kaami2aPTF1GcrJ561GthzfZwxENX
 TSLqOA4LkeUZh2tUsvbcUrPi6v+E4Em2lgacQcx2ioMblWz56sZu79VsUbSSw/a3
 P8+pIv7EbHw+TrOZMehjCbZkOdBeZ3IRLJsdlIAfe7y4vWME/5b9uVnQS/+XQj/B
 6f3rQrduGvF2P6GMjsm8gDkgE5oZ1zbKlgO4i5WApnu80MMLFlfEUN+GWuGJ95Q=
 =OjGs
 -----END PGP SIGNATURE-----

Merge tag 'kvm-ppc-next-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

PPC KVM update for 4.16

- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs
  without requiring the complex thread synchronization that earlier
  CPU versions required.

- A series from Ben Herrenschmidt to improve the handling of
  escalation interrupts with the XIVE interrupt controller.

- Provide for the decrementer register to be copied across on
  migration.

- Various minor cleanups and bugfixes.
2018-02-01 16:13:07 +01:00
Linus Torvalds
40b9672a2f Merge branch 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull asm/uaccess.h whack-a-mole from Al Viro:
 "It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop
  cropping up..."

* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h
  riscv: use linux/uaccess.h, not asm/uaccess.h...
  ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h
2018-01-31 19:18:12 -08:00
Benjamin Herrenschmidt
9b9b13a6d1 KVM: PPC: Book3S HV: Keep XIVE escalation interrupt masked unless ceded
This works on top of the single escalation support. When in single
escalation, with this change, we will keep the escalation interrupt
disabled unless the VCPU is in H_CEDE (idle). In any other case, we
know the VCPU will be rescheduled and thus there is no need to take
escalation interrupts in the host whenever a guest interrupt fires.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-19 12:10:21 +11:00