Re: [PATCH Part1 RFC v3 05/22] x86/sev: Add support for hypervisor feature VMGEXIT

[Borislav Petkov]

On Wed, Jun 02, 2021 at 09:03:59AM -0500, Brijesh Singh wrote:
> diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
> index 70f181f20d92..94957c5bdb51 100644
> --- a/arch/x86/kernel/sev-shared.c
> +++ b/arch/x86/kernel/sev-shared.c

I'm guessing this is in sev-shared.c because it is going to be used by
both stages?

> @@ -20,6 +20,7 @@
>   * out when the .bss section is later cleared.
>   */
>  static u16 ghcb_version __section(".data");

State what this is:

/* Bitmap of SEV features supported by the hypervisor */

> +static u64 hv_features __section(".data");

Also, I'm assuming that bitmap remains immutable during the guest
lifetime so you can do:

static u64 hv_features __ro_after_init;

instead, which will do:

static u64 hv_features __attribute__((__section__(".data..ro_after_init")));

and it'll be in the data section and then also marked read-only after
init, after mark_rodata_ro() more specifically.

Thx.

-- 
Regards/Gruss,
    Boris.

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