[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-ppc] broken incoming migration

From: Alexey Kardashevskiy
Subject: Re: [Qemu-ppc] broken incoming migration
Date: Thu, 30 May 2013 17:49:27 +1000
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6

Forgot some cc:.

On 05/30/2013 05:44 PM, Alexey Kardashevskiy wrote:
> Hi!
> I found the migration broken on pseries platform, specifically, this patch
> broke it:
> f1c72795af573b24a7da5eb52375c9aba8a37972
> migration: do not sent zero pages in bulk stage
> The idea is not to send zero pages to the destination guest which is
> expected to have 100% empty RAM.
> However on pseries plaftorm the guest always has some stuff in the RAM as a
> part of initialization (device tree, system firmware and rtas (?)) so it is
> not completely empty. As the source guest cannot detect this, it skips some
> pages during migration and we get a broken destination guest. Bug.
> While the idea is ok in general, I do not see any easy way to fix it as
> neither QEMUMachine::init nor QEMUMachine::reset callbacks has information
> about whether we are about to receive a migration or not (-incoming
> parameter) and we cannot move device-tree and system firmware
> initialization anywhere else.
> ram_bulk_stage is static and cannot be disabled from the platform
> initialization code.
> So what would the community suggest? Thanks!


reply via email to

[Prev in Thread] Current Thread [Next in Thread]