From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Subject: Re: [FYI PATCH] Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
Date: Fri, 25 Mar 2022 20:22:37 +0000 [thread overview]
Message-ID: <Yj4kjRSuBDfupRqW@google.com> (raw)
In-Reply-To: <78e3f054-829e-b00d-6c65-9ae622f301df@redhat.com>
On Fri, Mar 25, 2022, Paolo Bonzini wrote:
> On 3/25/22 00:57, Sean Christopherson wrote:
> > Can I have 1-2 weeks to try and root cause and fix the underlying issue before
> > sending reverts to Linus? I really don't want to paper over a TLB flushing bug
> > or an off-by-one bug, and I really, really don't want to end up with another
> > scenario where KVM zaps everything just because.
>
> Well, too late... I didn't want to send a pull request that was broken,
Ah, I didn't see that it was in the initial pull request, thought it was only in
kvm/next. I'll send a full patch.
> Mingwei provided a convincing reason for the breakage.
No, the side effects are completely benign, and arguably desirable. The issue is
that KVM loses a pending TLB flush if there are multiple roots.
next prev parent reply other threads:[~2022-03-25 20:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-18 16:48 [FYI PATCH] Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()" Paolo Bonzini
2022-03-21 9:13 ` Paolo Bonzini
2022-03-24 23:57 ` Sean Christopherson
2022-03-25 10:38 ` Vitaly Kuznetsov
2022-03-25 11:21 ` Paolo Bonzini
2022-03-25 20:22 ` Sean Christopherson [this message]
2022-03-25 15:03 ` Vitaly Kuznetsov
2022-03-25 20:18 ` Sean Christopherson
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