Re: [Qemu-devel] [PATCH 0/4 v4] block, arm: Fix buffered flash writes on VExpress

[Stefan Hajnoczi]

On Wed, Nov 20, 2013 at 09:27:22AM +0000, Peter Maydell wrote:
> On 20 November 2013 09:22, Stefan Hajnoczi <address@hidden> wrote:
> > On Tue, Oct 22, 2013 at 09:35:52AM -0700, Roy Franz wrote:
> >> This patchset fixes buffered flash writes on the VExpress
> >> platform.  Buffered writes should now work properly on platforms whose
> >> flash interface width is different from the device width.  The default
> >> is for the device-width to be set to the interface width, so platforms
> >> that can benefit from this change will need to be updated.  This patchset
> >> updates the configuration for the VExpress platform which requires it.
> >> UEFI firmware uses buffered writes for persistent variable storage,
> >> and this patchset enables this usage on QEMU.
> 
> > Looks okay on quick review.
> >
> > I want to confirm: live migration is not supported?
> 
> I don't know if you meant anything special by putting "live"
> in there, but migration and save/restore is absolutely supposed
> to be supported on the vexpress platform and the pflash
> devices (they're in the x86 PC model too...)

I looked at the patches again and there is no problem.

Originally I thought the device_width field would need to be migrated
but it's purely configuration state - the destination QEMU will receive
it on the command-line.  Therefore we don't need to transfer it during
live migration.

Stefan