On Fri, Apr 30, 2021 at 07:16:05AM -0500, Brijesh Singh wrote:
> diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
> index 6d9055427f37..7badbeb6cb95 100644
> --- a/arch/x86/boot/compressed/sev.c
> +++ b/arch/x86/boot/compressed/sev.c
> @@ -25,6 +25,8 @@
>
> struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);
> struct ghcb *boot_ghcb;
> +static u64 sev_status_val;
msr_sev_status should be more descriptive.
> +static bool sev_status_checked;
You don't need this one - you can simply do
if (!msr_sev_status)
read the MSR.
> /*
> * Copy a version of this function here - insn-eval.c can't be used in
> @@ -119,11 +121,30 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
> /* Include code for early handlers */
> #include "../../kernel/sev-shared.c"
>
> +static inline bool sev_snp_enabled(void)
> +{
> + unsigned long low, high;
> +
> + if (!sev_status_checked) {
> + asm volatile("rdmsr\n"
> + : "=a" (low), "=d" (high)
> + : "c" (MSR_AMD64_SEV));
> + sev_status_val = (high << 32) | low;
> + sev_status_checked = true;
> + }
> +
> + return sev_status_val & MSR_AMD64_SEV_SNP_ENABLED ? true : false;
return msr_sev_status & MSR_AMD64_SEV_SNP_ENABLED;
is enough.
> +}
> +
> static bool early_setup_sev_es(void)
> {
> if (!sev_es_negotiate_protocol())
> sev_es_terminate(0, GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED);
>
> + /* If SEV-SNP is enabled then check if the hypervisor supports the SEV-SNP features. */
80 cols like the rest of this file pls.
> + if (sev_snp_enabled() && !sev_snp_check_hypervisor_features())
> + sev_es_terminate(0, GHCB_SEV_ES_REASON_SNP_UNSUPPORTED);
> +
> if (set_page_decrypted((unsigned long)&boot_ghcb_page))
> return false;
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
