linux-kernel - [GIT PULL] KVM changes for Linux 6.19-rc2

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Message-ID: <20251219131131.52272-1-pbonzini@redhat.com>
Date: Fri, 19 Dec 2025 14:11:31 +0100
From: Paolo Bonzini <pbonzini@...hat.com>
To: torvalds@...ux-foundation.org
Cc: linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org
Subject: [GIT PULL] KVM changes for Linux 6.19-rc2

Linus,

The following changes since commit ea1013c1539270e372fc99854bc6e4d94eaeff66:

  Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf (2025-12-17 15:54:58 +1200)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/virt/kvm/kvm.git tags/for-linus

for you to fetch changes up to 0499add8efd72456514c6218c062911ccc922a99:

  Merge tag 'kvm-x86-fixes-6.19-rc1' of https://github.com/kvm-x86/linux into HEAD (2025-12-18 18:38:45 +0100)

----------------------------------------------------------------
x86 fixes.  Everyone else is already in holiday mood apparently.

- Add a missing "break" to fix param parsing in the rseq selftest.

- Apply runtime updates to the _current_ CPUID when userspace is setting
  CPUID, e.g. as part of vCPU hotplug, to fix a false positive and to avoid
  dropping the pending update.

- Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot, as it's not
  supported by KVM and leads to a use-after-free due to KVM failing to unbind
  the memslot from the previously-associated guest_memfd instance.

- Harden against similar KVM_MEM_GUEST_MEMFD goofs, and prepare for supporting
  flags-only changes on KVM_MEM_GUEST_MEMFD memlslots, e.g. for dirty logging.

- Set exit_code[63:32] to -1 (all 0xffs) when synthesizing a nested
  SVM_EXIT_ERR (a.k.a. VMEXIT_INVALID) #VMEXIT, as VMEXIT_INVALID is defined
  as -1ull (a 64-bit value).

- Update SVI when activating APICv to fix a bug where a post-activation EOI
  for an in-service IRQ would effective be lost due to SVI being stale.

- Immediately refresh APICv controls (if necessary) on a nested VM-Exit
  instead of deferring the update via KVM_REQ_APICV_UPDATE, as the request is
  effectively ignored because KVM thinks the vCPU already has the correct
  APICv settings.

----------------------------------------------------------------
Dongli Zhang (2):
      KVM: VMX: Update SVI during runtime APICv activation
      KVM: nVMX: Immediately refresh APICv controls as needed on nested VM-Exit

Gavin Shan (1):
      KVM: selftests: Add missing "break" in rseq_test's param parsing

Paolo Bonzini (1):
      Merge tag 'kvm-x86-fixes-6.19-rc1' of https://github.com/kvm-x86/linux into HEAD

Sean Christopherson (6):
      KVM: x86: Apply runtime updates to current CPUID during KVM_SET_CPUID{,2}
      KVM: selftests: Add a CPUID testcase for KVM_SET_CPUID2 with runtime updates
      KVM: Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot
      KVM: Harden and prepare for modifying existing guest_memfd memslots
      KVM: nSVM: Clear exit_code_hi in VMCB when synthesizing nested VM-Exits
      KVM: nSVM: Set exit_code_hi to -1 when synthesizing SVM_EXIT_ERR (failed VMRUN)

 arch/x86/kvm/cpuid.c                         | 11 +++++++++--
 arch/x86/kvm/svm/nested.c                    |  4 ++--
 arch/x86/kvm/svm/svm.c                       |  2 ++
 arch/x86/kvm/svm/svm.h                       |  7 ++++---
 arch/x86/kvm/vmx/nested.c                    |  3 ++-
 arch/x86/kvm/vmx/vmx.c                       |  9 ---------
 arch/x86/kvm/x86.c                           |  7 +++++++
 tools/testing/selftests/kvm/rseq_test.c      |  1 +
 tools/testing/selftests/kvm/x86/cpuid_test.c | 15 +++++++++++++++
 virt/kvm/kvm_main.c                          | 17 ++++++++++++++++-
 10 files changed, 58 insertions(+), 18 deletions(-)