From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Mingwei Zhang <mizhang@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: x86/mmu: fix potential races when walking host page table
Date: Fri, 29 Apr 2022 14:35:43 +0000 [thread overview]
Message-ID: <Ymv3vwBEgCH0CMPH@google.com> (raw)
In-Reply-To: <4b0936bf-fd3e-950a-81af-fd393475553f@redhat.com>
On Fri, Apr 29, 2022, Paolo Bonzini wrote:
> > +out:
> > + local_irq_restore(flags);
> > + return level;
> > +}
> > +EXPORT_SYMBOL_GPL(kvm_lookup_address_level_in_mm);
>
> Exporting is not needed.
>
> Thanks for writing the walk code though. I'll adapt it and integrate the
> patch.
But why are we fixing this only in KVM? I liked the idea of stealing perf's
implementation because it was a seemlingly perfect fit and wouldn't introduce
new code (ignoring wrappers, etc...).
We _know_ that at least one subsystem is misusing lookup_address_in_pgd() and
given that its wrappers are exported, I highly doubt KVM is the only offender.
It really feels like we're passing the buck here by burying the fix in KVM.
next prev parent reply other threads:[~2022-04-29 14:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 3:17 [PATCH] KVM: x86/mmu: fix potential races when walking host page table Mingwei Zhang
2022-04-29 9:10 ` Paolo Bonzini
2022-04-29 14:35 ` Sean Christopherson [this message]
2022-04-29 14:45 ` Paolo Bonzini
2022-04-29 15:47 ` Sean Christopherson
2022-04-29 15:33 ` Sean Christopherson
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