Re: [PATCH v8 20/40] x86/sev: Use SEV-SNP AP creation to start secondary CPUs

Brijesh Singh
2022-01-12T16:17:55Z

On 12/10/21 12:50 PM, Dave Hansen wrote:
> On 12/10/21 7:43 AM, Brijesh Singh wrote:
>> + vmsa->efer = 0x1000; /* Must set SVME bit */
>> + vmsa->cr4 = cr4;
>> + vmsa->cr0 = 0x60000010;
>> + vmsa->dr7 = 0x400;
>> + vmsa->dr6 = 0xffff0ff0;
>> + vmsa->rflags = 0x2;
>> + vmsa->g_pat = 0x0007040600070406ULL;
>> + vmsa->xcr0 = 0x1;
>> + vmsa->mxcsr = 0x1f80;
>> + vmsa->x87_ftw = 0x5555;
>> + vmsa->x87_fcw = 0x0040;
>
> This is a big fat pile of magic numbers. We also have nice macros for a
> non-zero number of these, like:
>
> #define MXCSR_DEFAULT 0x1f80
>
> I understand that this probably _works_ as-is, but it doesn't look very
> friendly if someone else needs to go hack on it.
>

APM documents the default value for the AP following the RESET or INIT,
I will define macros and use them accordingly.

thx