From: Paolo Bonzini <pbonzini@redhat.com>
To: stsp <stsp2@yandex.ru>, Jim Mattson <jmattson@google.com>
Cc: Sean Christopherson <seanjc@google.com>,
kvm@vger.kernel.org, David Woodhouse <dwmw@amazon.co.uk>,
"ntsironis@arrikto.com" <ntsironis@arrikto.com>
Subject: Re: exception vs SIGALRM race (was: Re: guest/host mem out of sync on core2duo?)
Date: Wed, 7 Jul 2021 01:41:13 +0200 [thread overview]
Message-ID: <54270fb7-91ac-f10d-5879-956f42372536@redhat.com> (raw)
In-Reply-To: <eadbc511-3270-8a8e-a2d8-a8eb1fccb8c0@yandex.ru>
On 07/07/21 00:22, stsp wrote:
> I confirm that this works, thanks.
> Sadly the problematic patch was
> CCed to -stable, and is now present
> in all kernels, like ubuntu's 5.8.0-55-generic.
> Since AFAICT it didn't contain the
> important/security fix, I think it
> shouldn't have been CCed to -stable.
>
> Can we revert it from -stable?
> That will mean a relatively quick
> fix for most of current users.
It was a bugfix, see the commit message:
when userspace requests an IRQ window vmexit, an interrupt in the
local APIC can cause kvm_cpu_has_interrupt() to be true and thus
kvm_vcpu_ready_for_interrupt_injection() to return false. When this
happens, vcpu_run does not exit to userspace but the interrupt window
vmexits keep occurring. The VM loops without any hope of making progress.
Thanks for the testing!
Paolo
next prev parent reply other threads:[~2021-07-06 23:41 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-12 22:49 guest/host mem out of sync on core2duo? stsp
2021-06-13 12:36 ` stsp
2021-06-14 17:06 ` Sean Christopherson
2021-06-14 17:32 ` stsp
2021-06-17 14:42 ` Sean Christopherson
2021-06-18 15:59 ` stsp
2021-06-18 21:07 ` Jim Mattson
2021-06-18 21:55 ` stsp
2021-06-18 22:06 ` Jim Mattson
2021-06-18 22:26 ` stsp
2021-06-18 22:32 ` Sean Christopherson
2021-06-19 0:11 ` stsp
2021-06-19 0:54 ` Sean Christopherson
2021-06-19 9:18 ` stsp
2021-06-21 2:34 ` exception vs SIGALRM race (was: Re: guest/host mem out of sync on core2duo?) stsp
2021-06-21 22:33 ` Jim Mattson
2021-06-21 23:32 ` stsp
2021-06-22 0:27 ` stsp
2021-06-28 21:47 ` Jim Mattson
2021-06-28 21:50 ` stsp
2021-06-28 22:00 ` stsp
2021-06-28 22:27 ` Jim Mattson
2021-07-06 16:28 ` Paolo Bonzini
2021-07-06 22:22 ` stsp
2021-07-06 23:41 ` Paolo Bonzini [this message]
2021-06-23 23:38 ` exception vs SIGALRM race (with test-case now!) stsp
2021-06-24 0:11 ` stsp
2021-06-24 0:25 ` stsp
2021-06-24 18:05 ` exception vs SIGALRM race on core2 CPUs (with qemu-based test-case this time!) stsp
2021-06-24 18:07 ` stsp
2021-06-25 23:35 ` exception vs SIGALRM race on core2 CPUs (with fix!) stsp
2021-06-26 0:15 ` Jim Mattson
2021-06-26 0:35 ` stsp
2021-06-26 21:50 ` stsp
2021-06-27 12:13 ` stsp
2021-06-26 14:03 ` exception vs SIGALRM race (another patch) stsp
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