Re: [PATCH v3 5/5] sev/i386: Enable an SEV-ES guest based on SEV policy

[Tom Lendacky <thomas.lendacky@amd.com>]

On 9/17/20 11:07 AM, Tom Lendacky wrote:
> On 9/17/20 10:34 AM, Dr. David Alan Gilbert wrote:
>> * Tom Lendacky (thomas.lendacky@amd.com) wrote:
>>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>>
>>> Update the sev_es_enabled() function return value to be based on the SEV
>>> policy that has been specified. SEV-ES is enabled if SEV is enabled and
>>> the SEV-ES policy bit is set in the policy object.
>>>
>>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>>> ---
>>>   target/i386/sev.c | 4 +++-
>>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/target/i386/sev.c b/target/i386/sev.c
>>> index 6ddefc65fa..bcaadaa2f9 100644
>>> --- a/target/i386/sev.c
>>> +++ b/target/i386/sev.c
>>> @@ -70,6 +70,8 @@ struct SevGuestState {
>>>   #define DEFAULT_GUEST_POLICY    0x1 /* disable debug */
>>>   #define DEFAULT_SEV_DEVICE      "/dev/sev"
>>> +#define GUEST_POLICY_SEV_ES_BIT (1 << 2)
>>> +
>>
>> I'm surprised that all the policy bits aren't defined in a header 
>> somewhere.
> 
> I have another version to be issued with changes to use QemuUUID, so I can 
> look at moving the bits to a header.

Hmmm... and they already are defined in target/i386/sev_i386.h. I guess I 
was looking for sev.h and didn't notice sev_i386.h. So I'll update to use 
the values in sev_i386.h.

Thanks,
Tom

> 
> Thanks,
> Tom
> 
>>
>> But other than that,
>>
>>
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>>
>>>   /* SEV Information Block GUID = 00f771de-1a7e-4fcb-890e-68c77e2fb44e */
>>>   #define SEV_INFO_BLOCK_GUID \
>>>       "\xde\x71\xf7\x00\x7e\x1a\xcb\x4f\x89\x0e\x68\xc7\x7e\x2f\xb4\x4e"
>>> @@ -375,7 +377,7 @@ sev_enabled(void)
>>>   bool
>>>   sev_es_enabled(void)
>>>   {
>>> -    return false;
>>> +    return sev_enabled() && (sev_guest->policy & 
>>> GUEST_POLICY_SEV_ES_BIT);
>>>   }
>>>   uint64_t
>>> -- 
>>> 2.28.0
>>>