Set the FRED_VIRT_ENABLE bit (bit 4) in the VIRT_EXT field of VMCB to enable
FRED Virtualization for the guest. This enables automatic save/restore of
FRED MSRs. Also toggle this bit when setting CPUIDs, to support booting of
secure guests.

Signed-off-by: Shivansh Dhiman <shivansh.dhiman@amd.com>
---
 arch/x86/kvm/svm/svm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 954df4eae90e..24579c149937 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1144,6 +1144,9 @@ static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event)
 	save->fred_ssp3 = 0;
 	save->fred_config = 0;
 
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_FRED))
+		svm->vmcb->control.virt_ext |= FRED_VIRT_ENABLE_MASK;
+
 	init_sys_seg(&save->ldtr, SEG_TYPE_LDT);
 	init_sys_seg(&save->tr, SEG_TYPE_BUSY_TSS16);
 
@@ -4529,6 +4532,9 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 	if (guest_cpuid_is_intel_compatible(vcpu))
 		guest_cpu_cap_clear(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD);
 
+	if (guest_cpu_cap_has(vcpu, X86_FEATURE_FRED))
+		svm->vmcb->control.virt_ext |= FRED_VIRT_ENABLE_MASK;
+
 	if (sev_guest(vcpu->kvm))
 		sev_vcpu_after_set_cpuid(svm);
 }
-- 
2.43.0