Commit 9757a5ae authored by Sean Christopherson's avatar Sean Christopherson
Browse files

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: default avatarManali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-44-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent c3d6a721

arch/x86/kvm/vmx/vmx.c

+1 −0
Original line number Diff line number Diff line
@@ -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);