Re: [PATCH 8/8] KVM: nSVM: read only changed fields of the nested guest data area

From: Paolo Bonzini
Date: Thu Aug 20 2020 - 06:07:20 EST


On 20/08/20 11:13, Maxim Levitsky wrote:
> + u32 clean = nested_vmcb->control.clean;
> +
> + if (svm->nested.vmcb_gpa != vmcb_gpa) {
> + svm->nested.vmcb_gpa = vmcb_gpa;
> + clean = 0;
> + }

You probably should set clean to 0 also if the guest doesn't have the
VMCBCLEAN feature (so, you first need an extra patch to add the
VMCBCLEAN feature to cpufeatures.h). It's probably best to cache the
guest vmcbclean in struct vcpu_svm, too.

Paolo