From: Sean Christopherson <seanjc@google.com>
To: Yosry Ahmed <yosry@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, Stefan Teodorescu <fane@google.com>
Subject: Re: [PATCH] KVM: SVM: Trigger new ASID allocation in both VMCBs on pCPU switch
Date: Thu, 3 Sep 2026 15:26:28 -0700 [thread overview]
Message-ID: <apn0FM-vNTbOCpkk@google.com> (raw)
In-Reply-To: <CAO9r8zN2AqpGudeej3VshJek6iy7iaTwO4GgmLSVO0++omHUxA@mail.gmail.com>
On Thu, Sep 03, 2026, Yosry Ahmed wrote:
> On Thu, Sep 3, 2026 at 3:18 PM Sean Christopherson <seanjc@google.com> wrote:
> > Keep the change in svm_allocate_nested(). Or just do nothing, I'll happily drop
> > the svm->nested.initialized check when applying.
>
> You'll need to update the changelog too.
>
> Instead of:
>
> Additionally, initialize the tracker pCPU for vmcb02 to -1 on nested
> enablement, so that the new ASID allocation in the scenario above
> happens even if EFER.SVME is disabled in L1 before migrating to the new
> pCPU (so asid_generation in vmcb02 is not reset), but enabled before
> returning to the old pCPU.
>
> Maybe:
>
> Additionally, initialize the tracked pCPU for vmcb02 to -1 on nested
> enablement as hardening, so that a new ASID allocation is always
> triggered when nested is disabled and re-enabled.
>
> Let me know if you still wanna fixup when applying or a v2 :)
LOL, just send a v2.
prev parent reply other threads:[~2026-09-03 22:26 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-03 17:58 [PATCH] KVM: SVM: Trigger new ASID allocation in both VMCBs on pCPU switch Yosry Ahmed
2026-09-03 21:53 ` Sean Christopherson
2026-09-03 22:00 ` Yosry Ahmed
2026-09-03 22:18 ` Sean Christopherson
2026-09-03 22:20 ` Yosry Ahmed
2026-09-03 22:26 ` Sean Christopherson [this message]
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