Re: [PATCH Part2 v6 04/49] x86/sev: set SYSCFG.MFMD

From: Borislav Petkov
Date: Thu Jul 21 2022 - 07:29:18 EST


On Mon, Jun 20, 2022 at 11:02:18PM +0000, Ashish Kalra wrote:
> Subject: [PATCH Part2 v6 04/49] x86/sev: set SYSCFG.MFMD

That subject title needs to be made human readable.

> From: Brijesh Singh <brijesh.singh@xxxxxxx>
>
> SEV-SNP FW >= 1.51 requires that SYSCFG.MFMD must be set.

Because?

Also, commit message needs to be human-readable and not pseudocode.

> @@ -2325,6 +2346,9 @@ static __init int __snp_rmptable_init(void)
> /* Flush the caches to ensure that data is written before SNP is enabled. */
> wbinvd_on_all_cpus();
>
> + /* MFDM must be enabled on all the CPUs prior to enabling SNP. */
> + on_each_cpu(mfdm_enable, NULL, 1);
> +
> /* Enable SNP on all CPUs. */
> on_each_cpu(snp_enable, NULL, 1);

No, not two IPI generating function calls - one and do everything in it.
I.e., what Marc said.

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette