<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/arch/arm64/include/uapi/asm/kvm.h, branch linus/master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/arch/arm64/include/uapi/asm/kvm.h?h=linus%2Fmaster</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/arch/arm64/include/uapi/asm/kvm.h?h=linus%2Fmaster'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2022-05-26T21:20:14Z</updated>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2022-05-26T21:20:14Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-05-26T21:20:14Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=bf9095424d027e942e1d1ee74977e17b7df8e455'/>
<id>urn:sha1:bf9095424d027e942e1d1ee74977e17b7df8e455</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "S390:

   - ultravisor communication device driver

   - fix TEID on terminating storage key ops

  RISC-V:

   - Added Sv57x4 support for G-stage page table

   - Added range based local HFENCE functions

   - Added remote HFENCE functions based on VCPU requests

   - Added ISA extension registers in ONE_REG interface

   - Updated KVM RISC-V maintainers entry to cover selftests support

  ARM:

   - 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

  x86:

   - New ioctls to get/set TSC frequency for a whole VM

   - Allow userspace to opt out of hypercall patching

   - Only do MSR filtering for MSRs accessed by rdmsr/wrmsr

  AMD SEV improvements:

   - Add KVM_EXIT_SHUTDOWN metadata for SEV-ES

   - V_TSC_AUX support

  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"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (199 commits)
  KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest
  KVM: selftests: x86: Sync the new name of the test case to .gitignore
  Documentation: kvm: reorder ARM-specific section about KVM_SYSTEM_EVENT_SUSPEND
  x86, kvm: use correct GFP flags for preemption disabled
  KVM: LAPIC: Drop pending LAPIC timer injection when canceling the timer
  x86/kvm: Alloc dummy async #PF token outside of raw spinlock
  KVM: x86: avoid calling x86 emulator without a decoded instruction
  KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak
  x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave)
  s390/uv_uapi: depend on CONFIG_S390
  KVM: selftests: x86: Fix test failure on arch lbr capable platforms
  KVM: LAPIC: Trace LAPIC timer expiration on every vmentry
  KVM: s390: selftest: Test suppression indication on key prot exception
  KVM: s390: Don't indicate suppression on dirtying, failing memop
  selftests: drivers/s390x: Add uvdevice tests
  drivers/s390/char: Add Ultravisor io device
  MAINTAINERS: Update KVM RISC-V entry to cover selftests support
  RISC-V: KVM: Introduce ISA extension register
  RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
  RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
  ...
</content>
</entry>
<entry>
<title>KVM: arm64: Hide KVM_REG_ARM_*_BMAP_BIT_COUNT from userspace</title>
<updated>2022-05-15T10:36:24Z</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2022-05-15T10:36:24Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=2cde51f1e10f260076899bf41add74ed4a6de034'/>
<id>urn:sha1:2cde51f1e10f260076899bf41add74ed4a6de034</id>
<content type='text'>
These constants will change over time, and userspace has no
business knowing about them. Hide them behind __KERNEL__.

Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
</content>
</entry>
<entry>
<title>KVM: arm64: Add vendor hypervisor firmware register</title>
<updated>2022-05-03T20:30:19Z</updated>
<author>
<name>Raghavendra Rao Ananta</name>
<email>rananta@google.com</email>
</author>
<published>2022-05-02T23:38:48Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=b22216e1a617ca55b41337cd1e057ebc784a65d4'/>
<id>urn:sha1:b22216e1a617ca55b41337cd1e057ebc784a65d4</id>
<content type='text'>
Introduce the firmware register to hold the vendor specific
hypervisor service calls (owner value 6) as a bitmap. The
bitmap represents the features that'll be enabled for the
guest, as configured by the user-space. Currently, this
includes support for KVM-vendor features along with
reading the UID, represented by bit-0, and Precision Time
Protocol (PTP), represented by bit-1.

Signed-off-by: Raghavendra Rao Ananta &lt;rananta@google.com&gt;
Reviewed-by: Gavin Shan &lt;gshan@redhat.com&gt;
[maz: tidy-up bitmap values]
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220502233853.1233742-5-rananta@google.com
</content>
</entry>
<entry>
<title>KVM: arm64: Add standard hypervisor firmware register</title>
<updated>2022-05-03T20:30:19Z</updated>
<author>
<name>Raghavendra Rao Ananta</name>
<email>rananta@google.com</email>
</author>
<published>2022-05-02T23:38:47Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=428fd6788d4d0e0d390de9fb4486be3c1187310d'/>
<id>urn:sha1:428fd6788d4d0e0d390de9fb4486be3c1187310d</id>
<content type='text'>
Introduce the firmware register to hold the standard hypervisor
service calls (owner value 5) as a bitmap. The bitmap represents
the features that'll be enabled for the guest, as configured by
the user-space. Currently, this includes support only for
Paravirtualized time, represented by bit-0.

Signed-off-by: Raghavendra Rao Ananta &lt;rananta@google.com&gt;
Reviewed-by: Gavin Shan &lt;gshan@redhat.com&gt;
[maz: tidy-up bitmap values]
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220502233853.1233742-4-rananta@google.com
</content>
</entry>
<entry>
<title>KVM: arm64: Setup a framework for hypercall bitmap firmware registers</title>
<updated>2022-05-03T20:30:19Z</updated>
<author>
<name>Raghavendra Rao Ananta</name>
<email>rananta@google.com</email>
</author>
<published>2022-05-02T23:38:46Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=05714cab7d63b189894235cf310fae7d6ffc2e9b'/>
<id>urn:sha1:05714cab7d63b189894235cf310fae7d6ffc2e9b</id>
<content type='text'>
KVM regularly introduces new hypercall services to the guests without
any consent from the userspace. This means, the guests can observe
hypercall services in and out as they migrate across various host
kernel versions. This could be a major problem if the guest
discovered a hypercall, started using it, and after getting migrated
to an older kernel realizes that it's no longer available. Depending
on how the guest handles the change, there's a potential chance that
the guest would just panic.

As a result, there's a need for the userspace to elect the services
that it wishes the guest to discover. It can elect these services
based on the kernels spread across its (migration) fleet. To remedy
this, extend the existing firmware pseudo-registers, such as
KVM_REG_ARM_PSCI_VERSION, but by creating a new COPROC register space
for all the hypercall services available.

These firmware registers are categorized based on the service call
owners, but unlike the existing firmware pseudo-registers, they hold
the features supported in the form of a bitmap.

During the VM initialization, the registers are set to upper-limit of
the features supported by the corresponding registers. It's expected
that the VMMs discover the features provided by each register via
GET_ONE_REG, and write back the desired values using SET_ONE_REG.
KVM allows this modification only until the VM has started.

Some of the standard features are not mapped to any bits of the
registers. But since they can recreate the original problem of
making it available without userspace's consent, they need to
be explicitly added to the case-list in
kvm_hvc_call_default_allowed(). Any function-id that's not enabled
via the bitmap, or not listed in kvm_hvc_call_default_allowed, will
be returned as SMCCC_RET_NOT_SUPPORTED to the guest.

Older userspace code can simply ignore the feature and the
hypercall services will be exposed unconditionally to the guests,
thus ensuring backward compatibility.

In this patch, the framework adds the register only for ARM's standard
secure services (owner value 4). Currently, this includes support only
for ARM True Random Number Generator (TRNG) service, with bit-0 of the
register representing mandatory features of v1.0. Other services are
momentarily added in the upcoming patches.

Signed-off-by: Raghavendra Rao Ananta &lt;rananta@google.com&gt;
Reviewed-by: Gavin Shan &lt;gshan@redhat.com&gt;
[maz: reduced the scope of some helpers, tidy-up bitmap max values,
 dropped error-only fast path]
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220502233853.1233742-3-rananta@google.com
</content>
</entry>
<entry>
<title>KVM: arm64: uapi: Add kvm_debug_exit_arch.hsr_high</title>
<updated>2022-04-29T18:26:27Z</updated>
<author>
<name>Alexandru Elisei</name>
<email>alexandru.elisei@arm.com</email>
</author>
<published>2022-04-25T11:44:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=18f3976fdb5da2ba9572845e6f7dfb58652871ea'/>
<id>urn:sha1:18f3976fdb5da2ba9572845e6f7dfb58652871ea</id>
<content type='text'>
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-&gt;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 &lt;alexandru.elisei@arm.com&gt;
Reviewed-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220425114444.368693-6-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2022-03-24T18:58:57Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-24T18:58:57Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=1ebdbeb03efe89f01f15df038a589077df3d21f5'/>
<id>urn:sha1:1ebdbeb03efe89f01f15df038a589077df3d21f5</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "ARM:
   - 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

  RISC-V:
   - Prevent KVM_COMPAT from being selected

   - Optimize __kvm_riscv_switch_to() implementation

   - RISC-V SBI v0.3 support

  s390:
   - memop selftest

   - fix SCK locking

   - adapter interruptions virtualization for secure guests

   - add Claudio Imbrenda as maintainer

   - first step to do proper storage key checking

  x86:
   - Continue switching kvm_x86_ops to static_call(); introduce
     static_call_cond() and __static_call_ret0 when applicable.

   - Cleanup unused arguments in several functions

   - Synthesize AMD 0x80000021 leaf

   - Fixes and optimization for Hyper-V sparse-bank hypercalls

   - Implement Hyper-V's enlightened MSR bitmap for nested SVM

   - Remove MMU auditing

   - Eager splitting of page tables (new aka "TDP" MMU only) when dirty
     page tracking is enabled

   - Cleanup the implementation of the guest PGD cache

   - Preparation for the implementation of Intel IPI virtualization

   - Fix some segment descriptor checks in the emulator

   - Allow AMD AVIC support on systems with physical APIC ID above 255

   - Better API to disable virtualization quirks

   - Fixes and optimizations for the zapping of page tables:

      - Zap roots in two passes, avoiding RCU read-side critical
        sections that last too long for very large guests backed by 4
        KiB SPTEs.

      - Zap invalid and defunct roots asynchronously via
        concurrency-managed work queue.

      - Allowing yielding when zapping TDP MMU roots in response to the
        root's last reference being put.

      - Batch more TLB flushes with an RCU trick. Whoever frees the
        paging structure now holds RCU as a proxy for all vCPUs running
        in the guest, i.e. to prolongs the grace period on their behalf.
        It then kicks the the vCPUs out of guest mode before doing
        rcu_read_unlock().

  Generic:
   - Introduce __vcalloc and use it for very large allocations that need
     memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
  KVM: use kvcalloc for array allocations
  KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2
  kvm: x86: Require const tsc for RT
  KVM: x86: synthesize CPUID leaf 0x80000021h if useful
  KVM: x86: add support for CPUID leaf 0x80000021
  KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask
  Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
  kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU
  KVM: arm64: fix typos in comments
  KVM: arm64: Generalise VM features into a set of flags
  KVM: s390: selftests: Add error memop tests
  KVM: s390: selftests: Add more copy memop tests
  KVM: s390: selftests: Add named stages for memop test
  KVM: s390: selftests: Add macro as abstraction for MEM_OP
  KVM: s390: selftests: Split memop tests
  KVM: s390x: fix SCK locking
  RISC-V: KVM: Implement SBI HSM suspend call
  RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
  RISC-V: Add SBI HSM suspend related defines
  RISC-V: KVM: Implement SBI v0.3 SRST extension
  ...
</content>
</entry>
<entry>
<title>Merge branch kvm-arm64/psci-1.1 into kvmarm-master/next</title>
<updated>2022-02-25T13:49:48Z</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2022-02-25T13:49:48Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=1a48ce92641d19afd16eb0c23efbf408d0a76911'/>
<id>urn:sha1:1a48ce92641d19afd16eb0c23efbf408d0a76911</id>
<content type='text'>
* kvm-arm64/psci-1.1:
  : .
  : Limited PSCI-1.1 support from Will Deacon:
  :
  : This small series exposes the PSCI SYSTEM_RESET2 call to guests, which
  : allows the propagation of a "reset_type" and a "cookie" back to the VMM.
  : Although Linux guests only ever pass 0 for the type ("SYSTEM_WARM_RESET"),
  : the vendor-defined range can be used by a bootloader to provide additional
  : information about the reset, such as an error code.
  : .
  KVM: arm64: Remove unneeded semicolons
  KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field
  KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest
  KVM: arm64: Bump guest PSCI version to 1.1

Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
</content>
</entry>
<entry>
<title>KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated</title>
<updated>2022-02-24T13:58:52Z</updated>
<author>
<name>James Morse</name>
<email>james.morse@arm.com</email>
</author>
<published>2021-12-10T11:16:18Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=a5905d6af492ee6a4a2205f0d550b3f931b03d03'/>
<id>urn:sha1:a5905d6af492ee6a4a2205f0d550b3f931b03d03</id>
<content type='text'>
KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are
implemented, and to preserve that state during migration through its
firmware register interface.

Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3.

Reviewed-by: Russell King (Oracle) &lt;rmk+kernel@armlinux.org.uk&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
</content>
</entry>
<entry>
<title>KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field</title>
<updated>2022-02-21T16:02:55Z</updated>
<author>
<name>Will Deacon</name>
<email>will@kernel.org</email>
</author>
<published>2022-02-21T15:35:24Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=34739fd95fab3a5efb0422e4f012b685e33598dc'/>
<id>urn:sha1:34739fd95fab3a5efb0422e4f012b685e33598dc</id>
<content type='text'>
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 &lt;maz@kernel.org&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Alexandru Elisei &lt;alexandru.elisei@arm.com&gt;
Cc: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220221153524.15397-4-will@kernel.org
</content>
</entry>
</feed>
