[PATCH 01/13] KVM: nSVM: don't sync back tlb_ctl on nested VM exit

From: Maxim Levitsky
Date: Thu Nov 17 2022 - 09:34:46 EST


The CPU doesn't change TLB_CTL value as stated in the PRM (15.16.2):

"The VMRUN instruction reads, but does not change, the
value of the TLB_CONTROL field"

Therefore the KVM shoudn't do that either.

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index b258d6988f5dde..43cc4a5d22e012 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -989,7 +989,6 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
vmcb12->control.next_rip = vmcb02->control.next_rip;

vmcb12->control.int_ctl = svm->nested.ctl.int_ctl;
- vmcb12->control.tlb_ctl = svm->nested.ctl.tlb_ctl;
vmcb12->control.event_inj = svm->nested.ctl.event_inj;
vmcb12->control.event_inj_err = svm->nested.ctl.event_inj_err;

--
2.34.3