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| author | Jim Mattson <jmattson@google.com> | 2026-05-27 10:43:44 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-05-27 11:21:41 -0700 |
| commit | be7fd7c3e8bcfd3a1804567ce5cf9ca3b254c1ba (patch) | |
| tree | 0c28b16947a05e25899f6ca775925a5ebe7c76dd | |
| parent | cf7d65d1d6f50daadfe7c475f0c2b1bfdc288b56 (diff) | |
| download | linux-be7fd7c3e8bcfd3a1804567ce5cf9ca3b254c1ba.tar.gz linux-be7fd7c3e8bcfd3a1804567ce5cf9ca3b254c1ba.zip | |
KVM: x86: Prioritize CPUID faulting over CPUID VM-exits in nested VMX
Per the Intel SDM, "Certain exceptions have priority over VM exits. These
include invalid-opcode exceptions, faults based on privilege level, and
general-protection exceptions that are based on checking I/O permission
bits in the task-state segment (TSS)."
Ensure that when L2 executes CPUID at CPL > 0 while L1 has enabled CPUID
faulting, KVM intercepts the exit in L0 and queues #GP rather than
forwarding the CPUID VM-exit to L1.
Empirical testing confirms that this #GP has higher precedence than a CPUID
VM-exit on Granite Rapids (F/M/S 6/0xad/1).
Fixes: db2336a80489 ("KVM: x86: virtualize cpuid faulting")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260513224608.1859737-1-jmattson%40google.com?part=3
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260527174347.2356165-3-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index a78ce0080963..30dcabc899a2 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -6552,6 +6552,8 @@ static bool nested_vmx_l0_wants_exit(struct kvm_vcpu *vcpu, nested_evmcs_l2_tlb_flush_enabled(vcpu) && kvm_hv_is_tlb_flush_hcall(vcpu); #endif + case EXIT_REASON_CPUID: + return !kvm_is_cpuid_allowed(vcpu); default: break; } |