From: Sean Christopherson <seanjc@google.com>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.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,
syzbot+8112db3ab20e70d50c31@syzkaller.appspotmail.com
Subject: Re: [PATCH] KVM: x86: Forcibly leave nested virt when SMM state is toggled
Date: Wed, 26 Jan 2022 16:08:04 +0000 [thread overview]
Message-ID: <YfFx5LZ2rMMtbDWG@google.com> (raw)
In-Reply-To: <7eb8c6722a522e42f8e8974c084c7cab3098d9fa.camel@redhat.com>
On Wed, Jan 26, 2022, Maxim Levitsky wrote:
> On Tue, 2022-01-25 at 22:03 +0000, Sean Christopherson wrote:
> > Peeking at QEMU source, AFAICT QEMU restores nested state before events,
> > but I don't see how that can possibly work. I assume QEMU does something
> > where it restores the "run" state first and then does a full restore?
>
> Well, according to my testing, nested migration with SMM *is* still quite broken,
> (on both SVM and VMX)
> resulting in various issues up to L1 crash.
>
> When I last tackled SMM, I fixed most issues that
> happen just when the L2 is running and I inject flood of SMIs to L1 - even that
> was crashing things all around, so this might be as well the reason for that.
Heh, that would certainly explain why QEMU's code looks broken. Thanks!
next prev parent reply other threads:[~2022-01-26 16:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-25 22:03 [PATCH] KVM: x86: Forcibly leave nested virt when SMM state is toggled Sean Christopherson
2022-01-26 8:26 ` Maxim Levitsky
2022-01-26 16:08 ` Sean Christopherson [this message]
2022-01-26 11:24 ` Paolo Bonzini
2022-02-17 20:21 ` Tadeusz Struk
2022-02-18 16:58 ` Sean Christopherson
2022-02-18 17:22 ` Tadeusz Struk
2022-02-18 18:14 ` Paolo Bonzini
2022-02-24 18:59 ` Tadeusz Struk
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