Re: [Qemu-devel] [PATCH v2 1.7] pc: get rid of builtin pvpanic for "-M pc-1.5"

[Eric Blake <eblake@redhat.com>]

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On 11/06/2013 03:42 AM, Paolo Bonzini wrote:
> This causes two slight backwards-incompatibilities between "-M pc-1.5"
> and 1.5's "-M pc":
> 
> (1) a fw_cfg file is removed with this patch.  This is only a problem
> if migration stops the virtual machine exactly during fw_cfg enumeration.
> 
> (2) after migration, a VM created without an explicit "-device pvpanic"
> will stop reporting panics to management.
> 
> The first problem only occurs if migration is done at a very, very
> early point (and I'm not sure it can happen in practice for reasonable-size
> VMs, since it will likely take more time to send the RAM to destination,
> than it will take for BIOS to scan fw_cfg).
> 
> The second problem only occurs if the guest panics _and_ has a guest
> driver _and_ management knows to look at the crash event, so it is
> mostly theoretical at this point in time.
> 
> Thus keep the code simple, and pretend it was never broken.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/i386/pc_piix.c    | 7 -------
>  hw/i386/pc_q35.c     | 7 -------
>  hw/misc/pvpanic.c    | 5 -----
>  include/hw/i386/pc.h | 1 -
>  4 files changed, 20 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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