Re: [Qemu-devel] [PATCH] pc: compat: remove PCLMULQDQ from Westmere on pc-*-1.4 and older

["Andreas Färber" <afaerber@suse.de>]

Am 09.08.2013 19:24, schrieb Eduardo Habkost:
> On Fri, Aug 09, 2013 at 04:47:53PM +0200, Andreas Färber wrote:
>> Am 09.08.2013 16:11, schrieb Eduardo Habkost:
>>> commit 41cb383f42d0cb51d8e3e25e3ecebc954dd4196f made a guest-visible
>>> change by adding the PCLMULQDQ bit to Westmere without adding
>>> compatibility code to keep the ABI older machine-types. This patch fixes
>>> it by adding the missing compat code.
>>>
>>> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
>>> ---
>>> Bug detected by the virt-test CPUID-dump comparison test case, available at:
>>>   https://github.com/autotest/virt-test/pull/714
>>> ---
>>>  hw/i386/pc_piix.c | 1 +
>>>  hw/i386/pc_q35.c  | 1 +
>>>  2 files changed, 2 insertions(+)
>>>
>>> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
>>> index ab25458..2817092 100644
>>> --- a/hw/i386/pc_piix.c
>>> +++ b/hw/i386/pc_piix.c
>>> @@ -259,6 +259,7 @@ static void pc_init_pci_1_4(QEMUMachineInitArgs *args)
>>>  {
>>>      has_pvpanic = false;
>>>      x86_cpu_compat_set_features("n270", FEAT_1_ECX, 0, CPUID_EXT_MOVBE);
>>> +    x86_cpu_compat_set_features("Westmere", FEAT_1_ECX, 0, CPUID_EXT_PCLMULQDQ);
>>>      pc_init_pci_1_5(args);
>>>  }
>>>  
>>> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
>>> index 2f35d12..25c6b33 100644
>>> --- a/hw/i386/pc_q35.c
>>> +++ b/hw/i386/pc_q35.c
>>> @@ -227,6 +227,7 @@ static void pc_q35_init_1_4(QEMUMachineInitArgs *args)
>>>  {
>>>      has_pvpanic = false;
>>>      x86_cpu_compat_set_features("n270", FEAT_1_ECX, 0, CPUID_EXT_MOVBE);
>>> +    x86_cpu_compat_set_features("Westmere", FEAT_1_ECX, 0, CPUID_EXT_PCLMULQDQ);
>>>      pc_q35_init_1_5(args);
>>>  }
>>>  
>>
>> Looks good to me, still need to test, and I should probably add
>>
>> Cc: qemu-stable@nongnu.org
>>
>> for 1.5.3 then.
> 
> The patch doesn't apply cleanly on stable-1.5, but I will send a version
> for qemu-stable as well.

It's not required to apply cleanly to a specific stable- branch. :)
We need a commit id to reference in the backported version.

Thanks, applied to qom-cpu, pull coming later today.
https://github.com/afaerber/qemu-cpu/commits/qom-cpu

Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg