Re: [PATCH 6.1] KVM: x86/mmu: Fix an sign-extension bug with mmu_seq that hangs vCPUs

[Greg Kroah-Hartman]

On Thu, Aug 24, 2023 at 06:46:59AM -0700, Sean Christopherson wrote:
> On Thu, Aug 24, 2023, Greg Kroah-Hartman wrote:
> > On Wed, Aug 23, 2023 at 06:01:04PM -0700, Sean Christopherson wrote:
> > > Note, upstream commit ba6e3fe25543 ("KVM: x86/mmu: Grab mmu_invalidate_seq
> > > in kvm_faultin_pfn()") unknowingly fixed the bug in v6.3 when refactoring
> > > how KVM tracks the sequence counter snapshot.
> > > 
> > > Reported-by: Brian Rak <brak@xxxxxxxxx>
> > > Reported-by: Amaan Cheval <amaan.cheval@xxxxxxxxx>
> > > Reported-by: Eric Wheeler <kvm@xxxxxxxxxxxxxxxxxx>
> > > Closes: https://lore.kernel.org/all/f023d927-52aa-7e08-2ee5-59a2fbc65953@xxxxxxxxxxxxxxx
> > > Fixes: a955cad84cda ("KVM: x86/mmu: Retry page fault if root is invalidated by memslot update")
> > > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> > 
> > What is the git commit id of this change in Linus's tree?
> 
> There is none.  Commit ba6e3fe25543 (landed in v6.3) unknowingly fixed the bug as
> part of a completely unrelated refactoring.

Ah, missed that in the text here, thanks!

greg k-h