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 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.

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
>>