From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: kvm <kvm@vger.kernel.org>, qemu-devel <qemu-devel@nongnu.org>
Subject: Re: qemu vs. kvm: When to flush the coalesced mmio buffer?
Date: Mon, 03 Jan 2011 14:32:16 +0200 [thread overview]
Message-ID: <4D21C1D0.6060301@redhat.com> (raw)
In-Reply-To: <4D21BCF4.6020904@web.de>
On 01/03/2011 02:11 PM, Jan Kiszka wrote:
> Hi again,
>
> another subtle difference between qemu-kvm and upstream:
>
> When we leave the guest for an IO window (KVM_RUN returns EINTR or
> EAGAIN), we call kvm_flush_coalesced_mmio_buffer in qemu-kvm but not in
> upstream. When version is better? I can't find any rationales in both
> git logs.
We must flush on EINTR, otherwise a live migration can leave some mmios
in the source host and not replay them on the destination host.
(plus, as Gleb says, if you're in userspace you might as well flush)
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-01-03 12:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-03 12:11 qemu vs. kvm: When to flush the coalesced mmio buffer? Jan Kiszka
2011-01-03 12:25 ` [Qemu-devel] " Gleb Natapov
2011-01-03 12:32 ` Avi Kivity [this message]
2011-01-03 12:34 ` Jan Kiszka
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