Re: [Qemu-devel] [PATCH] x86: Fix Opteron xlevels

[Alexander Graf <agraf@suse.de>]

On 04/21/2015 04:16 PM, Eduardo Habkost wrote:
> On Tue, Apr 21, 2015 at 04:04:21PM +0200, Alexander Graf wrote:
>> The AMD Opteron family has different xlevel levels depending on the
>> generation. I looked up Gen1, Gen2 and Gen3 hardware and adapted the
>> levels according to real silicon.
>>
>> The reason this came up is that there is a sanity check in KVM making
>> sure that SVM is only used when xlevel is high enough. Using real
>> hardware levels, they now are.
>>
>> Reported-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
>> Signed-off-by: Alexander Graf <agraf@suse.de>
> It needs compatibility properties in HW_COMPAT_2_1.  See commit
> 6b11322e0f724eb0649fdc324a44288b783023ad for reference.

Ah, sure, will do.

>
>> ---
>>   target-i386/cpu.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
>> index 03b33cf..d1b1b8c 100644
>> --- a/target-i386/cpu.c
>> +++ b/target-i386/cpu.c
>> @@ -1234,7 +1234,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
>>               CPUID_EXT2_MTRR | CPUID_EXT2_SYSCALL | CPUID_EXT2_APIC |
>>               CPUID_EXT2_CX8 | CPUID_EXT2_MCE | CPUID_EXT2_PAE | CPUID_EXT2_MSR |
>>               CPUID_EXT2_TSC | CPUID_EXT2_PSE | CPUID_EXT2_DE | CPUID_EXT2_FPU,
>> -        .xlevel = 0x80000008,
>> +        .xlevel = 0x80000018,
> Why did you choose 0x80000018? The highest 0x80000000 leaf we implement
> today is 0x8000000A. SVM info is at 0x8000000A.

Because it's what real hardware exposes ;).


Alex

>
>
>>           .model_id = "AMD Opteron 240 (Gen 1 Class Opteron)",
>>       },
>>       {
>> @@ -1262,7 +1262,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
>>               CPUID_EXT2_DE | CPUID_EXT2_FPU,
>>           .features[FEAT_8000_0001_ECX] =
>>               CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
>> -        .xlevel = 0x80000008,
>> +        .xlevel = 0x80000018,
>>           .model_id = "AMD Opteron 22xx (Gen 2 Class Opteron)",
>>       },
>>       {
>> @@ -1292,7 +1292,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
>>           .features[FEAT_8000_0001_ECX] =
>>               CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A |
>>               CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
>> -        .xlevel = 0x80000008,
>> +        .xlevel = 0x8000001A,
>>           .model_id = "AMD Opteron 23xx (Gen 3 Class Opteron)",
>>       },
>>       {
>> -- 
>> 1.7.12.4
>>
>>