From: Paolo Bonzini <pbonzini@redhat.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: mtosatti@redhat.com, Avi Kivity <avi@redhat.com>,
kvm@vger.kernel.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 3/3] apic: always update the in-kernel status after loading
Date: Fri, 02 Nov 2012 15:53:36 +0100 [thread overview]
Message-ID: <5093DE70.6030007@redhat.com> (raw)
In-Reply-To: <50901AAE.4010802@web.de>
Il 30/10/2012 19:21, Jan Kiszka ha scritto:
> > > Aren't we still dependent on the order of processing? If the APIC is
> > > restored after the device, won't we get the same problem?
> >
> > Strictly speaking yes, but CPUs and APICs are always the first devices
> > to be saved.
> Hmm, thinking about this again: Why is the MSI event injected at all
> during restore, specifically while the device models are in transitional
> state. Can you explain this?
Because the (virtio-serial) port was connected on the source and
disconnected on the destination, or vice versa.
In my simplified reproducer, I'm really using different command-lines on
the source and destination, but it is not necessary. For example, if
you have a socket backend, the destination will usually be disconnected
at the time the machine loads.
One alternative fix is a vm_clock timer that expires immediately. It
would fix both MSI and INTx, on the other hand I thought it was an APIC
bug because the QEMU APIC works nicely.
> Does the same pattern then also apply on INTx injection?
Yes.
Paolo
next prev parent reply other threads:[~2012-11-02 14:53 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-30 12:16 [Qemu-devel] [PATCH uq/master 0/3] Fix MSI injection at load time Paolo Bonzini
2012-10-30 12:16 ` [Qemu-devel] [PATCH 1/3] kvm: move KVM_GET_LAPIC/KVM_SET_LAPIC to hw/kvm/apic.c Paolo Bonzini
2012-10-30 18:13 ` Jan Kiszka
2012-10-30 12:16 ` [Qemu-devel] [PATCH 2/3] apic: add get/put methods Paolo Bonzini
2012-10-30 18:17 ` Jan Kiszka
2012-10-30 12:16 ` [Qemu-devel] [PATCH 3/3] apic: always update the in-kernel status after loading Paolo Bonzini
2012-10-30 12:38 ` Avi Kivity
2012-10-30 14:16 ` Paolo Bonzini
2012-10-30 18:21 ` Jan Kiszka
2012-11-02 14:53 ` Paolo Bonzini [this message]
2012-11-02 14:59 ` Jan Kiszka
2012-11-02 15:07 ` Gerd Hoffmann
2012-11-02 15:13 ` Paolo Bonzini
2012-11-02 15:17 ` Gerd Hoffmann
2012-11-02 15:21 ` Paolo Bonzini
2012-10-30 18:17 ` Jan Kiszka
2012-10-30 12:16 ` [Qemu-devel] [PATCH 4/3] ioapic: change pre_save/post_load methods to get/put Paolo Bonzini
2012-10-30 18:18 ` Jan Kiszka
2012-10-30 12:16 ` [Qemu-devel] [PATCH 5/3] ioapic: unify reset callbacks Paolo Bonzini
2012-10-30 16:47 ` [Qemu-devel] [PATCH uq/master 0/3] Fix MSI injection at load time Paolo Bonzini
2012-10-30 18:22 ` Jan Kiszka
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