Re: [PATCH V3] x86, amd_ucode: Skip microcode updates for final levels

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 11/08/15 16:14, Aravind Gopalakrishnan wrote:
> On 8/11/2015 9:53 AM, Jan Beulich wrote:
>>>>> On 03.08.15 at 21:34, <aravind.gopalakrishnan@amd.com> wrote:
>>> --- a/xen/arch/x86/microcode_amd.c
>>> +++ b/xen/arch/x86/microcode_amd.c
>>> @@ -347,6 +347,43 @@ static int container_fast_forward(const void
>>> *data, size_t size_left, size_t *of
>>>       return 0;
>>>   }
>>>   +/*
>>> + * The 'final_levels' of patch ids have been obtained empirically.
>>> + * Refer bug https://bugzilla.suse.com/show_bug.cgi?id=913996
>>> + * for details of the issue. The short version is that people
>>> + * using certain Fam10h systems noticed system hang issues when
>>> + * trying to update microcode levels beyond the patch IDs below.
>>> + * From internal discussions, we gathered that OS/hypervisor
>>> + * cannot reliably perform microcode updates beyond these levels
>>> + * due to hardware issues. Therefore, we need to abort microcode
>>> + * update process if we hit any of these levels.
>>> + */
>>> +static unsigned int final_levels[] = {
>> const
>
> Okay, will fix this.
>
>>> +    0x01000098,
>>> +    0x0100009f,
>>> +    0x010000af
>>> +};
>>> +
>>> +static bool_t check_final_patch_levels(int cpu)
>> unsigned int
>>
>
> I can change this too, but- Any specific reason for this?
> The other sanity checker or verification functions like
> verify_patch_size() or microcode_fits() return a bool_t too..

"int cpu" is the issue (I am guessing), not the return type.

~Andrew