diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-12-05 16:17:19 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-01-08 11:52:22 -0800 |
| commit | 9757a5aebcd6ca808d5b80831649438a017478ad (patch) | |
| tree | 6908e79ec1afb05df4c9bf552cb05ed28de89dc8 | |
| parent | c3d6a7210a4de909683a36779f5b8567f79a3688 (diff) | |
KVM: VMX: Initialize vmcs01.VM_EXIT_MSR_STORE_ADDR with list address
Initialize vmcs01.VM_EXIT_MSR_STORE_ADDR to point at the vCPU's
msr_autostore list in anticipation of utilizing the auto-store
functionality, and to harden KVM against stray reads to pfn 0 (or, in
theory, a random pfn if the underlying CPU uses a complex scheme for
encoding VMCS data). The MSR auto lists are supposed to be ignored if the
associated COUNT VMCS field is '0', but leaving the ADDR field
zero-initialized in memory is an unnecessary risk (albeit a minuscule risk)
given that the cost is a single VMWRITE during vCPU creation.
Tested-by: Manali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-44-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3f64d4b1b19c..6a17cb90eaf4 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4933,6 +4933,7 @@ static void init_vmcs(struct vcpu_vmx *vmx) vmcs_write64(VM_FUNCTION_CONTROL, 0); vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0); + vmcs_write64(VM_EXIT_MSR_STORE_ADDR, __pa(vmx->msr_autostore.val)); vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0); vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val)); vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0); |