- Add support for the ARMv8.6 WFxT extension
- Guard pages for the EL2 stacks
- Trap and emulate AArch32 ID registers to hide unsupported features
- Ability to select and save/restore the set of hypercalls exposed
to the guest
- Support for PSCI-initiated suspend in collaboration with userspace
- GICv3 register-based LPI invalidation support
- Move host PMU event merging into the vcpu data structure
- GICv3 ITS save/restore fixes
- The usual set of small-scale cleanups and fixes
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Merge tag 'kvmarm-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 5.19
- Add support for the ARMv8.6 WFxT extension
- Guard pages for the EL2 stacks
- Trap and emulate AArch32 ID registers to hide unsupported features
- Ability to select and save/restore the set of hypercalls exposed
to the guest
- Support for PSCI-initiated suspend in collaboration with userspace
- GICv3 register-based LPI invalidation support
- Move host PMU event merging into the vcpu data structure
- GICv3 ITS save/restore fixes
- The usual set of small-scale cleanups and fixes
[Due to the conflict, KVM_SYSTEM_EVENT_SEV_TERM is relocated
from 4 to 6. - Paolo]
- Initial support for the ARMv9 Scalable Matrix Extension (SME). SME
takes the approach used for vectors in SVE and extends this to provide
architectural support for matrix operations. No KVM support yet, SME
is disabled in guests.
- Support for crashkernel reservations above ZONE_DMA via the
'crashkernel=X,high' command line option.
- btrfs search_ioctl() fix for live-lock with sub-page faults.
- arm64 perf updates: support for the Hisilicon "CPA" PMU for monitoring
coherent I/O traffic, support for Arm's CMN-650 and CMN-700
interconnect PMUs, minor driver fixes, kerneldoc cleanup.
- Kselftest updates for SME, BTI, MTE.
- Automatic generation of the system register macros from a 'sysreg'
file describing the register bitfields.
- Update the type of the function argument holding the ESR_ELx register
value to unsigned long to match the architecture register size
(originally 32-bit but extended since ARMv8.0).
- stacktrace cleanups.
- ftrace cleanups.
- Miscellaneous updates, most notably: arm64-specific huge_ptep_get(),
avoid executable mappings in kexec/hibernate code, drop TLB flushing
from get_clear_flush() (and rename it to get_clear_contig()),
ARCH_NR_GPIO bumped to 2048 for ARCH_APPLE.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- Initial support for the ARMv9 Scalable Matrix Extension (SME).
SME takes the approach used for vectors in SVE and extends this to
provide architectural support for matrix operations. No KVM support
yet, SME is disabled in guests.
- Support for crashkernel reservations above ZONE_DMA via the
'crashkernel=X,high' command line option.
- btrfs search_ioctl() fix for live-lock with sub-page faults.
- arm64 perf updates: support for the Hisilicon "CPA" PMU for
monitoring coherent I/O traffic, support for Arm's CMN-650 and
CMN-700 interconnect PMUs, minor driver fixes, kerneldoc cleanup.
- Kselftest updates for SME, BTI, MTE.
- Automatic generation of the system register macros from a 'sysreg'
file describing the register bitfields.
- Update the type of the function argument holding the ESR_ELx register
value to unsigned long to match the architecture register size
(originally 32-bit but extended since ARMv8.0).
- stacktrace cleanups.
- ftrace cleanups.
- Miscellaneous updates, most notably: arm64-specific huge_ptep_get(),
avoid executable mappings in kexec/hibernate code, drop TLB flushing
from get_clear_flush() (and rename it to get_clear_contig()),
ARCH_NR_GPIO bumped to 2048 for ARCH_APPLE.
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (145 commits)
arm64/sysreg: Generate definitions for FAR_ELx
arm64/sysreg: Generate definitions for DACR32_EL2
arm64/sysreg: Generate definitions for CSSELR_EL1
arm64/sysreg: Generate definitions for CPACR_ELx
arm64/sysreg: Generate definitions for CONTEXTIDR_ELx
arm64/sysreg: Generate definitions for CLIDR_EL1
arm64/sve: Move sve_free() into SVE code section
arm64: Kconfig.platforms: Add comments
arm64: Kconfig: Fix indentation and add comments
arm64: mm: avoid writable executable mappings in kexec/hibernate code
arm64: lds: move special code sections out of kernel exec segment
arm64/hugetlb: Implement arm64 specific huge_ptep_get()
arm64/hugetlb: Use ptep_get() to get the pte value of a huge page
arm64: kdump: Do not allocate crash low memory if not needed
arm64/sve: Generate ZCR definitions
arm64/sme: Generate defintions for SVCR
arm64/sme: Generate SMPRI_EL1 definitions
arm64/sme: Automatically generate SMPRIMAP_EL2 definitions
arm64/sme: Automatically generate SMIDR_EL1 defines
arm64/sme: Automatically generate defines for SMCR
...
If user space uses a memop to emulate an instruction and that
memop fails, the execution of the instruction ends.
Instruction execution can end in different ways, one of which is
suppression, which requires that the instruction execute like a no-op.
A writing memop that spans multiple pages and fails due to key
protection may have modified guest memory, as a result, the likely
correct ending is termination. Therefore, do not indicate a
suppressing instruction ending in this case.
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220512131019.2594948-2-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
* kvm-arm64/psci-suspend:
: .
: Add support for PSCI SYSTEM_SUSPEND and allow userspace to
: filter the wake-up events.
:
: Patches courtesy of Oliver.
: .
Documentation: KVM: Fix title level for PSCI_SUSPEND
selftests: KVM: Test SYSTEM_SUSPEND PSCI call
selftests: KVM: Refactor psci_test to make it amenable to new tests
selftests: KVM: Use KVM_SET_MP_STATE to power off vCPU in psci_test
selftests: KVM: Create helper for making SMCCC calls
selftests: KVM: Rename psci_cpu_on_test to psci_test
KVM: arm64: Implement PSCI SYSTEM_SUSPEND
KVM: arm64: Add support for userspace to suspend a vCPU
KVM: arm64: Return a value from check_vcpu_requests()
KVM: arm64: Rename the KVM_REQ_SLEEP handler
KVM: arm64: Track vCPU power state using MP state values
KVM: arm64: Dedupe vCPU power off helpers
KVM: arm64: Don't depend on fallthrough to hide SYSTEM_RESET2
Signed-off-by: Marc Zyngier <maz@kernel.org>
* kvm-arm64/hcall-selection:
: .
: Introduce a new set of virtual sysregs for userspace to
: select the hypercalls it wants to see exposed to the guest.
:
: Patches courtesy of Raghavendra and Oliver.
: .
KVM: arm64: Fix hypercall bitmap writeback when vcpus have already run
KVM: arm64: Hide KVM_REG_ARM_*_BMAP_BIT_COUNT from userspace
Documentation: Fix index.rst after psci.rst renaming
selftests: KVM: aarch64: Add the bitmap firmware registers to get-reg-list
selftests: KVM: aarch64: Introduce hypercall ABI test
selftests: KVM: Create helper for making SMCCC calls
selftests: KVM: Rename psci_cpu_on_test to psci_test
tools: Import ARM SMCCC definitions
Docs: KVM: Add doc for the bitmap firmware registers
Docs: KVM: Rename psci.rst to hypercalls.rst
KVM: arm64: Add vendor hypervisor firmware register
KVM: arm64: Add standard hypervisor firmware register
KVM: arm64: Setup a framework for hypercall bitmap firmware registers
KVM: arm64: Factor out firmware register handling from psci.c
Signed-off-by: Marc Zyngier <maz@kernel.org>
The htmldoc build breaks in a funny way with:
<quote>
Sphinx parallel build error:
docutils.utils.SystemMessage: /home/sfr/next/next/Documentation/virt/kvm/api.rst:6175: (SEVERE/4) Title level inconsistent:
For arm/arm64:
^^^^^^^^^^^^^^
</quote>
Swap the ^^s for a bunch of --s...
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[maz: commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND" describes a PSCI call that allows
software to request that a system be placed in the deepest possible
low-power state. Effectively, software can use this to suspend itself to
RAM.
Unfortunately, there really is no good way to implement a system-wide
PSCI call in KVM. Any precondition checks done in the kernel will need
to be repeated by userspace since there is no good way to protect a
critical section that spans an exit to userspace. SYSTEM_RESET and
SYSTEM_OFF are equally plagued by this issue, although no users have
seemingly cared for the relatively long time these calls have been
supported.
The solution is to just make the whole implementation userspace's
problem. Introduce a new system event, KVM_SYSTEM_EVENT_SUSPEND, that
indicates to userspace a calling vCPU has invoked PSCI SYSTEM_SUSPEND.
Additionally, add a CAP to get buy-in from userspace for this new exit
type.
Only advertise the SYSTEM_SUSPEND PSCI call if userspace has opted in.
If a vCPU calls SYSTEM_SUSPEND, punt straight to userspace. Provide
explicit documentation of userspace's responsibilites for the exit and
point to the PSCI specification to describe the actual PSCI call.
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-8-oupton@google.com
Introduce a new MP state, KVM_MP_STATE_SUSPENDED, which indicates a vCPU
is in a suspended state. In the suspended state the vCPU will block
until a wakeup event (pending interrupt) is recognized.
Add a new system event type, KVM_SYSTEM_EVENT_WAKEUP, to indicate to
userspace that KVM has recognized one such wakeup event. It is the
responsibility of userspace to then make the vCPU runnable, or leave it
suspended until the next wakeup event.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-7-oupton@google.com
Add the documentation for the bitmap firmware registers in
hypercalls.rst and api.rst. This includes the details for
KVM_REG_ARM_STD_BMAP, KVM_REG_ARM_STD_HYP_BMAP, and
KVM_REG_ARM_VENDOR_HYP_BMAP registers.
Since the document is growing to carry other hypercall related
information, make necessary adjustments to present the document
in a generic sense, rather than being PSCI focused.
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
[maz: small scale reformat, move things about, random typo fixes]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220502233853.1233742-7-rananta@google.com
When userspace is debugging a VM, the kvm_debug_exit_arch part of the
kvm_run struct contains arm64 specific debug information: the ESR_EL2
value, encoded in the field "hsr", and the address of the instruction
that caused the exception, encoded in the field "far".
Linux has moved to treating ESR_EL2 as a 64-bit register, but unfortunately
kvm_debug_exit_arch.hsr cannot be changed because that would change the
memory layout of the struct on big endian machines:
Current layout: | Layout with "hsr" extended to 64 bits:
|
offset 0: ESR_EL2[31:0] (hsr) | offset 0: ESR_EL2[61:32] (hsr[61:32])
offset 4: padding | offset 4: ESR_EL2[31:0] (hsr[31:0])
offset 8: FAR_EL2[61:0] (far) | offset 8: FAR_EL2[61:0] (far)
which breaks existing code.
The padding is inserted by the compiler because the "far" field must be
aligned to 8 bytes (each field must be naturally aligned - aapcs64 [1],
page 18), and the struct itself must be aligned to 8 bytes (the struct must
be aligned to the maximum alignment of its fields - aapcs64, page 18),
which means that "hsr" must be aligned to 8 bytes as it is the first field
in the struct.
To avoid changing the struct size and layout for the existing fields, add a
new field, "hsr_high", which replaces the existing padding. "hsr_high" will
be used to hold the ESR_EL2[61:32] bits of the register. The memory layout,
both on big and little endian machine, becomes:
offset 0: ESR_EL2[31:0] (hsr)
offset 4: ESR_EL2[61:32] (hsr_high)
offset 8: FAR_EL2[61:0] (far)
The padding that the compiler inserts for the current struct layout is
unitialized. To prevent an updated userspace running on an old kernel
mistaking the padding for a valid "hsr_high" value, add a new flag,
KVM_DEBUG_ARCH_HSR_HIGH_VALID, to kvm_run->flags to let userspace know that
"hsr_high" holds a valid ESR_EL2[61:32] value.
[1] https://github.com/ARM-software/abi-aa/releases/download/2021Q3/aapcs64.pdf
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425114444.368693-6-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes for (relatively) old bugs, to be merged in both the -rc and next
development trees.
The merge reconciles the ABI fixes for KVM_EXIT_SYSTEM_EVENT between
5.18 and commit c24a950ec7 ("KVM, SEV: Add KVM_EXIT_SHUTDOWN metadata
for SEV-ES", 2022-04-13).
When KVM_EXIT_SYSTEM_EVENT was introduced, it included a flags
member that at the time was unused. Unfortunately this extensibility
mechanism has several issues:
- x86 is not writing the member, so it would not be possible to use it
on x86 except for new events
- the member is not aligned to 64 bits, so the definition of the
uAPI struct is incorrect for 32- on 64-bit userspace. This is a
problem for RISC-V, which supports CONFIG_KVM_COMPAT, but fortunately
usage of flags was only introduced in 5.18.
Since padding has to be introduced, place a new field in there
that tells if the flags field is valid. To allow further extensibility,
in fact, change flags to an array of 16 values, and store how many
of the values are valid. The availability of the new ndata field
is tied to a system capability; all architectures are changed to
fill in the field.
To avoid breaking compilation of userspace that was using the flags
field, provide a userspace-only union to overlap flags with data[0].
The new field is placed at the same offset for both 32- and 64-bit
userspace.
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Message-Id: <20220422103013.34832-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If an SEV-ES guest requests termination, exit to userspace with
KVM_EXIT_SYSTEM_EVENT and a dedicated SEV_TERM type instead of -EINVAL
so that userspace can take appropriate action.
See AMD's GHCB spec section '4.1.13 Termination Request' for more details.
Suggested-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Gonda <pgonda@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Message-Id: <20220407210233.782250-1-pgonda@google.com>
[Add documentatino. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Merge branch for features that did not make it into 5.18:
* New ioctls to get/set TSC frequency for a whole VM
* Allow userspace to opt out of hypercall patching
Nested virtualization improvements for AMD:
* Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
nested vGIF)
* Allow AVIC to co-exist with a nested guest running
* Fixes for LBR virtualizations when a nested guest is running,
and nested LBR virtualization support
* PAUSE filtering for nested hypervisors
Guest support:
* Decoupling of vcpu_is_preempted from PV spinlocks
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add missing line break separator between literal block and description
of KVM_EXIT_RISCV_SBI.
This fixes:
</path/to/linux>/Documentation/virt/kvm/api.rst:6118: WARNING: Literal block ends without a blank line; unexpected unindent.
Fixes: da40d85805 (RISC-V: KVM: Document RISC-V specific parts of KVM API, 2021-09-27)
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Message-Id: <20220403065735.23859-1-bagasdotme@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This sets the default TSC frequency for subsequently created vCPUs.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20220225145304.36166-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
At the end of the patch series adding this batch of event channel
acceleration features, finally add the feature bit which advertises
them and document it all.
For SCHEDOP_poll we need to wake a polling vCPU when a given port
is triggered, even when it's masked — and we want to implement that
in the kernel, for efficiency. So we want the kernel to know that it
has sole ownership of event channel delivery. Thus, we allow
userspace to make the 'promise' by setting the corresponding feature
bit in its KVM_XEN_HVM_CONFIG call. As we implement SCHEDOP_poll
bypass later, we will do so only if that promise has been made by
userspace.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-16-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM handles the VMCALL/VMMCALL instructions very strangely. Even though
both of these instructions really should #UD when executed on the wrong
vendor's hardware (i.e. VMCALL on SVM, VMMCALL on VMX), KVM replaces the
guest's instruction with the appropriate instruction for the vendor.
Nonetheless, older guest kernels without commit c1118b3602 ("x86: kvm:
use alternatives for VMCALL vs. VMMCALL if kernel text is read-only")
do not patch in the appropriate instruction using alternatives, likely
motivating KVM's intervention.
Add a quirk allowing userspace to opt out of hypercall patching. If the
quirk is disabled, KVM synthesizes a #UD in the guest.
Signed-off-by: Oliver Upton <oupton@google.com>
Message-Id: <20220316005538.2282772-2-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220313140522.1307751-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MSR filtering requires an exit to userspace that is hard to implement and
would be very slow in the case of nested VMX vmexit and vmentry MSR
accesses. Document the limitation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It isn't OK to cache the dirty status of a page in internal structures
for an indefinite period of time.
Any time a vCPU exits the run loop to userspace might be its last; the
VMM might do its final check of the dirty log, flush the last remaining
dirty pages to the destination and complete a live migration. If we
have internal 'dirty' state which doesn't get flushed until the vCPU
is finally destroyed on the source after migration is complete, then
we have lost data because that will escape the final copy.
This problem already exists with the use of kvm_vcpu_unmap() to mark
pages dirty in e.g. VMX nesting.
Note that the actual Linux MM already considers the page to be dirty
since we have a writeable mapping of it. This is just about the KVM
dirty logging.
For the nesting-style use cases (KVM_GUEST_USES_PFN) we will need to
track which gfn_to_pfn_caches have been used and explicitly mark the
corresponding pages dirty before returning to userspace. But we would
have needed external tracking of that anyway, rather than walking the
full list of GPCs to find those belonging to this vCPU which are dirty.
So let's rely *solely* on that external tracking, and keep it simple
rather than laying a tempting trap for callers to fall into.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-3-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a section to document all the different ways in which the KVM API sucks.
I am sure there are way more, give people a place to vent so that userspace
authors are aware.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220322110712.222449-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM_CAP_DISABLE_QUIRKS is irrevocably broken. The capability does not
advertise the set of quirks which may be disabled to userspace, so it is
impossible to predict the behavior of KVM. Worse yet,
KVM_CAP_DISABLE_QUIRKS will tolerate any value for cap->args[0], meaning
it fails to reject attempts to set invalid quirk bits.
The only valid workaround for the quirky quirks API is to add a new CAP.
Actually advertise the set of quirks that can be disabled to userspace
so it can predict KVM's behavior. Reject values for cap->args[0] that
contain invalid bits.
Finally, add documentation for the new capability and describe the
existing quirks.
Signed-off-by: Oliver Upton <oupton@google.com>
Message-Id: <20220301060351.442881-5-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Proper emulation of the OSLock feature of the debug architecture
- Scalibility improvements for the MMU lock when dirty logging is on
- New VMID allocator, which will eventually help with SVA in VMs
- Better support for PMUs in heterogenous systems
- PSCI 1.1 support, enabling support for SYSTEM_RESET2
- Implement CONFIG_DEBUG_LIST at EL2
- Make CONFIG_ARM64_ERRATUM_2077057 default y
- Reduce the overhead of VM exit when no interrupt is pending
- Remove traces of 32bit ARM host support from the documentation
- Updated vgic selftests
- Various cleanups, doc updates and spelling fixes
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Merge tag 'kvmarm-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 5.18
- Proper emulation of the OSLock feature of the debug architecture
- Scalibility improvements for the MMU lock when dirty logging is on
- New VMID allocator, which will eventually help with SVA in VMs
- Better support for PMUs in heterogenous systems
- PSCI 1.1 support, enabling support for SYSTEM_RESET2
- Implement CONFIG_DEBUG_LIST at EL2
- Make CONFIG_ARM64_ERRATUM_2077057 default y
- Reduce the overhead of VM exit when no interrupt is pending
- Remove traces of 32bit ARM host support from the documentation
- Updated vgic selftests
- Various cleanups, doc updates and spelling fixes
* kvm-arm64/misc-5.18:
: .
: Misc fixes for KVM/arm64 5.18:
:
: - Drop unused kvm parameter to kvm_psci_version()
:
: - Implement CONFIG_DEBUG_LIST at EL2
:
: - Make CONFIG_ARM64_ERRATUM_2077057 default y
:
: - Only do the interrupt dance if we have exited because of an interrupt
:
: - Remove traces of 32bit ARM host support from the documentation
: .
Documentation: KVM: Update documentation to indicate KVM is arm64-only
KVM: arm64: Only open the interrupt window on exit due to an interrupt
KVM: arm64: Enable Cortex-A510 erratum 2077057 by default
Signed-off-by: Marc Zyngier <maz@kernel.org>
KVM support for 32-bit ARM hosts (KVM/arm) has been removed from the
kernel since commit 541ad0150c ("arm: Remove 32bit KVM host
support"). There still exists some remnants of the old architecture in
the KVM documentation.
Remove all traces of 32-bit host support from the documentation. Note
that AArch32 guests are still supported.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220308172856.2997250-1-oupton@google.com
Add a new capability, KVM_CAP_PMU_CAPABILITY, that takes a bitmask of
settings/features to allow userspace to configure PMU virtualization on
a per-VM basis. For now, support a single flag, KVM_PMU_CAP_DISABLE,
to allow disabling PMU virtualization for a VM even when KVM is configured
with enable_pmu=true a module level.
To keep KVM simple, disallow changing VM's PMU configuration after vCPUs
have been created.
Signed-off-by: David Dunn <daviddunn@google.com>
Message-Id: <20220223225743.2703915-2-daviddunn@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
By request of Nick Piggin:
> Patch 3 requires a KVM_CAP_PPC number allocated. QEMU maintainers are
> happy with it (link in changelog) just waiting on KVM upstreaming. Do
> you have objections to the series going to ppc/kvm tree first, or
> another option is you could take patch 3 alone first (it's relatively
> independent of the other 2) and ppc/kvm gets it from you?
Add KVM_CAP_PPC_AIL_MODE_3 to advertise the capability to set the AIL
resource mode to 3 with the H_SET_MODE hypercall. This capability
differs between processor types and KVM types (PR, HV, Nested HV), and
affects guest-visible behaviour.
QEMU will implement a cap-ail-mode-3 to control this behaviour[1], and
use the KVM CAP if available to determine KVM support[2].
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Clarify that the key argument represents the access key, not the whole
storage key.
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Link: https://lore.kernel.org/r/20220221143657.3712481-1-scgl@linux.ibm.com
Fixes: 5e35d0eb47 ("KVM: s390: Update api documentation for memop ioctl")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
When handling reset and power-off PSCI calls from the guest, we
initialise X0 to PSCI_RET_INTERNAL_FAILURE in case the VMM tries to
re-run the vCPU after issuing the call.
Unfortunately, this also means that the VMM cannot see which PSCI call
was issued and therefore cannot distinguish between PSCI SYSTEM_RESET
and SYSTEM_RESET2 calls, which is necessary in order to determine the
validity of the "reset_type" in X1.
Allocate bit 0 of the previously unused 'flags' field of the
system_event structure so that we can indicate the PSCI call used to
initiate the reset.
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220221153524.15397-4-will@kernel.org
Follow the precedent set by other architectures that support the VCPU
ioctl, KVM_ENABLE_CAP, and advertise the VM extension, KVM_CAP_ENABLE_CAP.
This way, userspace can ensure that KVM_ENABLE_CAP is available on a
vcpu before using it.
Fixes: 5c919412fe ("kvm/x86: Hyper-V synthetic interrupt controller")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Message-Id: <20220214212950.1776943-1-aaronlewis@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Document all currently existing operations, flags and explain under
which circumstances they are available. Document the recently
introduced absolute operations and the storage key protection flag,
as well as the existing SIDA operations.
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-10-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Because KVM_GET_SUPPORTED_CPUID is meant to be passed (by simple-minded
VMMs) to KVM_SET_CPUID2, it cannot include any dynamic xsave states that
have not been enabled. Probing those, for example so that they can be
passed to ARCH_REQ_XCOMP_GUEST_PERM, requires a new ioctl or arch_prctl.
The latter is in fact worse, even though that is what the rest of the
API uses, because it would require supported_xcr0 to be moved from the
KVM module to the kernel just for this use. In addition, the value
would be nonsensical (or an error would have to be returned) until
the KVM module is loaded in.
Therefore, to limit the growth of system ioctls, add a /dev/kvm
variant of KVM_{GET,HAS}_DEVICE_ATTR, and implement it in x86
with just one group (0) and attribute (KVM_X86_XCOMP_GUEST_SUPP).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the api number 134 for KVM_GET_XSAVE2, instead of 42, which has been
used by KVM_GET_XSAVE.
Also, fix the WARNINGs of the underlines being too short.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Message-Id: <20220120045003.315177-1-wei.w.wang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With KVM_CAP_XSAVE, userspace uses a hardcoded 4KB buffer to get/set
xstate data from/to KVM. This doesn't work when dynamic xfeatures
(e.g. AMX) are exposed to the guest as they require a larger buffer
size.
Introduce a new capability (KVM_CAP_XSAVE2). Userspace VMM gets the
required xstate buffer size via KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2).
KVM_SET_XSAVE is extended to work with both legacy and new capabilities
by doing properly-sized memdup_user() based on the guest fpu container.
KVM_GET_XSAVE is kept for backward-compatible reason. Instead,
KVM_GET_XSAVE2 is introduced under KVM_CAP_XSAVE2 as the preferred
interface for getting xstate buffer (4KB or larger size) from KVM
(Link: https://lkml.org/lkml/2021/12/15/510)
Also, update the api doc with the new KVM_GET_XSAVE2 ioctl.
Signed-off-by: Guang Zeng <guang.zeng@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20220105123532.12586-19-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM_GET_SUPPORTED_CPUID should not include any dynamic xstates in
CPUID[0xD] if they have not been requested with prctl. Otherwise
a process which directly passes KVM_GET_SUPPORTED_CPUID to
KVM_SET_CPUID2 would now fail even if it doesn't intend to use a
dynamically enabled feature. Userspace must know that prctl is
required and allocate >4K xstate buffer before setting any dynamic
bit.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20220105123532.12586-5-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This adds basic support for delivering 2 level event channels to a guest.
Initially, it only supports delivery via the IRQ routing table, triggered
by an eventfd. In order to do so, it has a kvm_xen_set_evtchn_fast()
function which will use the pre-mapped shared_info page if it already
exists and is still valid, while the slow path through the irqfd_inject
workqueue will remap the shared_info page if necessary.
It sets the bits in the shared_info page but not the vcpu_info; that is
deferred to __kvm_xen_has_interrupt() which raises the vector to the
appropriate vCPU.
Add a 'verbose' mode to xen_shinfo_test while adding test cases for this.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211210163625.2886-5-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the newly reinstated gfn_to_pfn_cache to maintain a kernel mapping
of the Xen shared_info page so that it can be accessed in atomic context.
Note that we do not participate in dirty tracking for the shared info
page and we do not explicitly mark it dirty every single tim we deliver
an event channel interrupts. We wouldn't want to do that even if we *did*
have a valid vCPU context with which to do so.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211210163625.2886-4-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
They are defined in include/uapi/linux/kvm.h as
KVM_S390_GET_SKEYS_NONE and KVM_S390_SKEYS_MAX, but the
api documetation talks of KVM_S390_GET_KEYS_NONE and
KVM_S390_SKEYS_ALLOC_MAX respectively.
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20211118102522.569660-1-scgl@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
For SEV to work with intra host migration, contents of the SEV info struct
such as the ASID (used to index the encryption key in the AMD SP) and
the list of memory regions need to be transferred to the target VM.
This change adds a commands for a target VMM to get a source SEV VM's sev
info.
Signed-off-by: Peter Gonda <pgonda@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Cc: Marc Orr <marcorr@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <20211021174303.385706-3-pgonda@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handling the migration of TSCs correctly is difficult, in part because
Linux does not provide userspace with the ability to retrieve a (TSC,
realtime) clock pair for a single instant in time. In lieu of a more
convenient facility, KVM can report similar information in the kvm_clock
structure.
Provide userspace with a host TSC & realtime pair iff the realtime clock
is based on the TSC. If userspace provides KVM_SET_CLOCK with a valid
realtime value, advance the KVM clock by the amount of elapsed time. Do
not step the KVM clock backwards, though, as it is a monotonic
oscillator.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210916181538.968978-5-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Document RISC-V specific parts of the KVM API, such as:
- The interrupt numbers passed to the KVM_INTERRUPT ioctl.
- The states supported by the KVM_{GET,SET}_MP_STATE ioctls.
- The registers supported by the KVM_{GET,SET}_ONE_REG interface
and the encoding of those register ids.
- The exit reason KVM_EXIT_RISCV_SBI for SBI calls forwarded to
userspace tool.
CC: Jonathan Corbet <corbet@lwn.net>
CC: linux-doc@vger.kernel.org
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
- Page ownership tracking between host EL1 and EL2
- Rely on userspace page tables to create large stage-2 mappings
- Fix incompatibility between pKVM and kmemleak
- Fix the PMU reset state, and improve the performance of the virtual PMU
- Move over to the generic KVM entry code
- Address PSCI reset issues w.r.t. save/restore
- Preliminary rework for the upcoming pKVM fixed feature
- A bunch of MM cleanups
- a vGIC fix for timer spurious interrupts
- Various cleanups
s390:
- enable interpretation of specification exceptions
- fix a vcpu_idx vs vcpu_id mixup
x86:
- fast (lockless) page fault support for the new MMU
- new MMU now the default
- increased maximum allowed VCPU count
- allow inhibit IRQs on KVM_RUN while debugging guests
- let Hyper-V-enabled guests run with virtualized LAPIC as long as they
do not enable the Hyper-V "AutoEOI" feature
- fixes and optimizations for the toggling of AMD AVIC (virtualized LAPIC)
- tuning for the case when two-dimensional paging (EPT/NPT) is disabled
- bugfixes and cleanups, especially with respect to 1) vCPU reset and
2) choosing a paging mode based on CR0/CR4/EFER
- support for 5-level page table on AMD processors
Generic:
- MMU notifier invalidation callbacks do not take mmu_lock unless necessary
- improved caching of LRU kvm_memory_slot
- support for histogram statistics
- add statistics for halt polling and remote TLB flush requests
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- Page ownership tracking between host EL1 and EL2
- Rely on userspace page tables to create large stage-2 mappings
- Fix incompatibility between pKVM and kmemleak
- Fix the PMU reset state, and improve the performance of the virtual
PMU
- Move over to the generic KVM entry code
- Address PSCI reset issues w.r.t. save/restore
- Preliminary rework for the upcoming pKVM fixed feature
- A bunch of MM cleanups
- a vGIC fix for timer spurious interrupts
- Various cleanups
s390:
- enable interpretation of specification exceptions
- fix a vcpu_idx vs vcpu_id mixup
x86:
- fast (lockless) page fault support for the new MMU
- new MMU now the default
- increased maximum allowed VCPU count
- allow inhibit IRQs on KVM_RUN while debugging guests
- let Hyper-V-enabled guests run with virtualized LAPIC as long as
they do not enable the Hyper-V "AutoEOI" feature
- fixes and optimizations for the toggling of AMD AVIC (virtualized
LAPIC)
- tuning for the case when two-dimensional paging (EPT/NPT) is
disabled
- bugfixes and cleanups, especially with respect to vCPU reset and
choosing a paging mode based on CR0/CR4/EFER
- support for 5-level page table on AMD processors
Generic:
- MMU notifier invalidation callbacks do not take mmu_lock unless
necessary
- improved caching of LRU kvm_memory_slot
- support for histogram statistics
- add statistics for halt polling and remote TLB flush requests"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (210 commits)
KVM: Drop unused kvm_dirty_gfn_invalid()
KVM: x86: Update vCPU's hv_clock before back to guest when tsc_offset is adjusted
KVM: MMU: mark role_regs and role accessors as maybe unused
KVM: MIPS: Remove a "set but not used" variable
x86/kvm: Don't enable IRQ when IRQ enabled in kvm_wait
KVM: stats: Add VM stat for remote tlb flush requests
KVM: Remove unnecessary export of kvm_{inc,dec}_notifier_count()
KVM: x86/mmu: Move lpage_disallowed_link further "down" in kvm_mmu_page
KVM: x86/mmu: Relocate kvm_mmu_page.tdp_mmu_page for better cache locality
Revert "KVM: x86: mmu: Add guest physical address check in translate_gpa()"
KVM: x86/mmu: Remove unused field mmio_cached in struct kvm_mmu_page
kvm: x86: Increase KVM_SOFT_MAX_VCPUS to 710
kvm: x86: Increase MAX_VCPUS to 1024
kvm: x86: Set KVM_MAX_VCPU_ID to 4*KVM_MAX_VCPUS
KVM: VMX: avoid running vmx_handle_exit_irqoff in case of emulation
KVM: x86/mmu: Don't freak out if pml5_root is NULL on 4-level host
KVM: s390: index kvm->arch.idle_mask by vcpu_idx
KVM: s390: Enable specification exception interpretation
KVM: arm64: Trim guest debug exception handling
KVM: SVM: Add 5-level page table support for SVM
...
- A reworking of PDF generation to yield better results for documents
using CJK fonts in particular.
- A new set of translations into traditional Chinese, a dialect for which
I am assured there is a community of interested readers.
- A lot more regular Chinese translation work as well.
...plus the usual assortment of updates, fixes, typo tweaks, etc.
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Merge tag 'docs-5.15' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"Yet another set of documentation changes:
- A reworking of PDF generation to yield better results for documents
using CJK fonts in particular.
- A new set of translations into traditional Chinese, a dialect for
which I am assured there is a community of interested readers.
- A lot more regular Chinese translation work as well.
... plus the usual assortment of updates, fixes, typo tweaks, etc"
* tag 'docs-5.15' of git://git.lwn.net/linux: (55 commits)
docs: sphinx-requirements: Move sphinx_rtd_theme to top
docs: pdfdocs: Enable language-specific font choice of zh_TW translations
docs: pdfdocs: Teach xeCJK about character classes of quotation marks
docs: pdfdocs: Permit AutoFakeSlant for CJK fonts
docs: pdfdocs: One-half spacing for CJK translations
docs: pdfdocs: Add conf.py local to translations for ascii-art alignment
docs: pdfdocs: Preserve inter-phrase space in Korean translations
docs: pdfdocs: Choose Serif font as CJK mainfont if possible
docs: pdfdocs: Add CJK-language-specific font settings
docs: pdfdocs: Refactor config for CJK document
scripts/kernel-doc: Override -Werror from KCFLAGS with KDOC_WERROR
docs/zh_CN: Add zh_CN/accounting/psi.rst
doc: align Italian translation
Documentation/features/vm: riscv supports THP now
docs/zh_CN: add infiniband user_verbs translation
docs/zh_CN: add infiniband user_mad translation
docs/zh_CN: add infiniband tag_matching translation
docs/zh_CN: add infiniband sysfs translation
docs/zh_CN: add infiniband opa_vnic translation
docs/zh_CN: add infiniband ipoib translation
...
KVM_GUESTDBG_BLOCKIRQ will allow KVM to block all interrupts
while running.
This change is mostly intended for more robust single stepping
of the guest and it has the following benefits when enabled:
* Resuming from a breakpoint is much more reliable.
When resuming execution from a breakpoint, with interrupts enabled,
more often than not, KVM would inject an interrupt and make the CPU
jump immediately to the interrupt handler and eventually return to
the breakpoint, to trigger it again.
From the user point of view it looks like the CPU never executed a
single instruction and in some cases that can even prevent forward
progress, for example, when the breakpoint is placed by an automated
script (e.g lx-symbols), which does something in response to the
breakpoint and then continues the guest automatically.
If the script execution takes enough time for another interrupt to
arrive, the guest will be stuck on the same breakpoint RIP forever.
* Normal single stepping is much more predictable, since it won't
land the debugger into an interrupt handler.
* RFLAGS.TF has less chance to be leaked to the guest:
We set that flag behind the guest's back to do single stepping
but if single step lands us into an interrupt/exception handler
it will be leaked to the guest in the form of being pushed
to the stack.
This doesn't completely eliminate this problem as exceptions
can still happen, but at least this reduces the chances
of this happening.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210811122927.900604-6-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add documentations for linear and logarithmic histogram statistics.
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210802165633.1866976-3-jingzhangos@google.com>
[Small changes to the phrasing. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
