Re: [PATCH v4] KVM: x86: Restrict saved GPA writes to hardware write faults

[Sean Christopherson <seanjc@google.com>]

On Thu, Sep 17, 2026, Kyle Zeng wrote:
> @@ -2036,6 +2037,7 @@ static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm)
>  	unsigned long i;
>  
>  	dst->active = true;
> +	dst_kvm->arch.has_protected_page_tables = true;
>  	dst->asid = src->asid;
>  	dst->handle = src->handle;
>  	dst->pages_locked = src->pages_locked;

Hrm, I think in the sev_migrate_from() case, we should clear the flag in the source
to be consistent with the other fields:

	src->asid = 0;
	src->active = false;
	src->handle = 0;
	src->pages_locked = 0;
	src->es_active = false;

And with the vCPU tracking:

		memset(&src_svm->sev_es, 0, sizeof(src_svm->sev_es));
		src_svm->vmcb->control.ghcb_gpa = INVALID_PAGE;
		src_svm->vmcb->control.vmsa_pa = INVALID_PAGE;
		src_vcpu->arch.guest_state_protected = false;

I can't imagine it will ever matter, but it leaving the flag set looks wrong,
being consistent costs nothing in practice.

No need for a v5, I'll fixup when applying.