Commit f99b0522 authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Paolo Bonzini
Browse files

KVM: SNP: Fix LBR Virtualization for SNP guest 



SEV-ES and thus SNP guest mandates LBR Virtualization to be _always_ ON.
Although commit b7e4be0a ("KVM: SEV-ES: Delegate LBR virtualization
to the processor") did the correct change for SEV-ES guests, it missed
the SNP. Fix it.

Reported-by: default avatarSrikanth Aithal <sraithal@amd.com>
Fixes: b7e4be0a ("KVM: SEV-ES: Delegate LBR virtualization to the processor")
Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Message-ID: <20240605114810.1304-1-ravi.bangoria@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ab978c62

arch/x86/kvm/svm/sev.c

+8 −0
Original line number Diff line number Diff line
@@ -2402,6 +2402,14 @@ static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp) 
		}



		svm->vcpu.arch.guest_state_protected = true;

		/*

		 * SEV-ES (and thus SNP) guest mandates LBR Virtualization to

		 * be _always_ ON. Enable it only after setting

		 * guest_state_protected because KVM_SET_MSRS allows dynamic

		 * toggling of LBRV (for performance reason) on write access to

		 * MSR_IA32_DEBUGCTLMSR when guest_state_protected is not set.

		 */

		svm_enable_lbrv(vcpu);

	}



	return 0;