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Fri, 18 Sep 2026 06:59:46 -0700 (PDT) Date: Fri, 18 Sep 2026 06:59:45 -0700 In-Reply-To: <20260918033658.21842-1-kylebot@openai.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260918033658.21842-1-kylebot@openai.com> Message-ID: Subject: Re: [PATCH v4] KVM: x86: Restrict saved GPA writes to hardware write faults From: Sean Christopherson To: Kyle Zeng Cc: kvm@vger.kernel.org, Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Oleg Boiko Content-Type: text/plain; charset="us-ascii" 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.