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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	kvm@vger.kernel.org, "Xiao Guangrong" <guangrong.xiao@gmail.com>
Subject: Re: [PATCH v2 11/27] KVM: x86/mmu: Zap only the relevant pages when removing a memslot
Date: Tue, 20 Aug 2019 14:02:45 -0700	[thread overview]
Message-ID: <20190820210245.GC15808@linux.intel.com> (raw)
In-Reply-To: <20190820144204.161f49e0@x1.home>

On Tue, Aug 20, 2019 at 02:42:04PM -0600, Alex Williamson wrote:
> On Tue, 20 Aug 2019 13:03:19 -0700
> Sean Christopherson <sean.j.christopherson@intel.com> wrote:
> > All that being said, it doesn't explain why gfns like 0xfec00 and 0xfee00
> > were sensitive to (lack of) zapping.  My theory is that zapping what were
> > effectively random-but-interesting shadow pages cleaned things up enough
> > to avoid noticeable badness.
> > 
> > 
> > Alex,
> > 
> > Can you please test the attached patch?  It implements a very slimmed down
> > version of kvm_mmu_zap_all() to zap only shadow pages that can hold sptes
> > pointing at the memslot being removed, which was the original intent of
> > kvm_mmu_invalidate_zap_pages_in_memslot().  I apologize in advance if it
> > crashes the host.  I'm hopeful it's correct, but given how broken the
> > previous version was, I'm not exactly confident.
> 
> It doesn't crash the host, but the guest is not happy, failing to boot
> the desktop in one case and triggering errors in the guest w/o even
> running test programs in another case.  Seems like it might be worse
> than previous.  Thanks,

Hrm, I'm back to being completely flummoxed.

Would you be able to generate a trace of all events/kvmmmu, using the
latest patch?  I'd like to rule out a stupid code bug if it's not too
much trouble.

  reply	other threads:[~2019-08-20 21:02 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-05 20:54 [PATCH v2 00/27] KVM: x86/mmu: Remove fast invalidate mechanism Sean Christopherson
2019-02-05 20:54 ` [PATCH v2 01/27] KVM: Call kvm_arch_memslots_updated() before updating memslots Sean Christopherson
2019-02-06  9:12   ` Cornelia Huck
2019-02-12 12:36 ` [PATCH v2 00/27] KVM: x86/mmu: Remove fast invalidate mechanism Paolo Bonzini
     [not found] ` <20190205210137.1377-11-sean.j.christopherson@intel.com>
2019-08-13 16:04   ` [PATCH v2 11/27] KVM: x86/mmu: Zap only the relevant pages when removing a memslot Alex Williamson
2019-08-13 17:04     ` Sean Christopherson
2019-08-13 17:57       ` Alex Williamson
2019-08-13 19:33         ` Alex Williamson
2019-08-13 20:19           ` Sean Christopherson
2019-08-13 20:37             ` Paolo Bonzini
2019-08-13 21:14               ` Alex Williamson
2019-08-13 21:15                 ` Paolo Bonzini
2019-08-13 22:10                   ` Alex Williamson
2019-08-15 14:46                 ` Sean Christopherson
2019-08-15 15:23             ` Alex Williamson
2019-08-15 16:00               ` Sean Christopherson
2019-08-15 18:16                 ` Alex Williamson
2019-08-15 19:25                   ` Sean Christopherson
2019-08-15 20:11                     ` Alex Williamson
2019-08-19 16:03               ` Paolo Bonzini
2019-08-20 20:03                 ` Sean Christopherson
2019-08-20 20:42                   ` Alex Williamson
2019-08-20 21:02                     ` Sean Christopherson [this message]
2019-08-21 19:08                       ` Alex Williamson
2019-08-21 19:35                         ` Alex Williamson
2019-08-21 20:30                           ` Sean Christopherson
2019-08-23  2:25                             ` Sean Christopherson
2019-08-23 22:05                               ` Alex Williamson
2019-08-21 20:10                         ` Sean Christopherson
2019-08-26  7:36                           ` Tian, Kevin
2019-08-26 14:56                           ` Sean Christopherson
2020-06-26 17:32                   ` Sean Christopherson
2022-10-20 18:31                     ` Alexander Graf
2022-10-20 20:37                       ` Sean Christopherson
2022-10-20 21:06                         ` Alexander Graf
2022-10-21 19:40                           ` Sean Christopherson
2022-10-24  6:12                             ` Alexander Graf
2022-10-24 15:55                               ` Sean Christopherson

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