Commit 723d5fb0 authored by Emanuele Giuseppe Esposito's avatar Emanuele Giuseppe Esposito Committed by Paolo Bonzini
Browse files

kvm: svm: Add IA32_FLUSH_CMD guest support 



Expose IA32_FLUSH_CMD to the guest if the guest CPUID enumerates
support for this MSR. As with IA32_PRED_CMD, permission for
unintercepted writes to this MSR will be granted to the guest after
the first non-zero write.

Signed-off-by: default avatarEmanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20230201132905.549148-3-eesposit@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a807b78a

arch/x86/kvm/svm/svm.c

+30 −13
Original line number Diff line number Diff line
@@ -2869,6 +2869,28 @@ static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data) 
	return 0;

}



static int svm_set_msr_ia32_cmd(struct kvm_vcpu *vcpu, struct msr_data *msr,

				bool guest_has_feat, u64 cmd,

				int x86_feature_bit)

{

	struct vcpu_svm *svm = to_svm(vcpu);



	if (!msr->host_initiated && !guest_has_feat)

		return 1;



	if (!(msr->data & ~cmd))

		return 1;

	if (!boot_cpu_has(x86_feature_bit))

		return 1;

	if (!msr->data)

		return 0;



	wrmsrl(msr->index, cmd);

	set_msr_interception(vcpu, svm->msrpm, msr->index, 0, 1);



	return 0;

}



static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)

{

	struct vcpu_svm *svm = to_svm(vcpu);
@@ -2943,19 +2965,14 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) 
		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SPEC_CTRL, 1, 1);

		break;

	case MSR_IA32_PRED_CMD:

		if (!msr->host_initiated &&

		    !guest_has_pred_cmd_msr(vcpu))

			return 1;



		if (data & ~PRED_CMD_IBPB)

			return 1;

		if (!boot_cpu_has(X86_FEATURE_IBPB))

			return 1;

		if (!data)

		r = svm_set_msr_ia32_cmd(vcpu, msr,

					 guest_has_pred_cmd_msr(vcpu),

					 PRED_CMD_IBPB, X86_FEATURE_IBPB);

		break;



		wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);

		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);

	case MSR_IA32_FLUSH_CMD:

		r = svm_set_msr_ia32_cmd(vcpu, msr,

					 guest_cpuid_has(vcpu, X86_FEATURE_FLUSH_L1D),

					 L1D_FLUSH, X86_FEATURE_FLUSH_L1D);

		break;

	case MSR_AMD64_VIRT_SPEC_CTRL:

		if (!msr->host_initiated &&