[RESEND,05/30] KVM: x86: nSVM: expose clean bit support to the guest

Commit Message

Maxim Levitsky Feb. 7, 2022, 3:54 p.m. UTC

KVM already honours few clean bits thus it makes sense
to let the nested guest know about it.

Note that KVM also doesn't check if the hardware supports
clean bits, and therefore nested KVM was
already setting clean bits and L0 KVM
was already honouring them.


Signed-off-by: Maxim Levitsky <[e-mail]>
---
 arch/x86/kvm/svm/svm.c | 1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 71bfa52121622..8013be9edf27c 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4663,6 +4663,7 @@  static __init void svm_set_cpu_caps(void)
 	/* CPUID 0x80000001 and 0x8000000A (SVM features) */
 	if (nested) {
 		kvm_cpu_cap_set(X86_FEATURE_SVM);
+		kvm_cpu_cap_set(X86_FEATURE_VMCBCLEAN);
 
 		if (nrips)
 			kvm_cpu_cap_set(X86_FEATURE_NRIPS);