From: Borislav Petkov <bp@alien8.de>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, tglx@linutronix.de, jroedel@suse.de,
thomas.lendacky@amd.com, pbonzini@redhat.com, mingo@redhat.com,
dave.hansen@intel.com, rientjes@google.com, seanjc@google.com,
peterz@infradead.org, hpa@zytor.com, tony.luck@intel.com
Subject: Re: [PATCH Part1 RFC v2 09/20] x86/sev: check SEV-SNP features support
Date: Thu, 20 May 2021 18:02:20 +0200 [thread overview]
Message-ID: <YKaIDAHOz4+soLxi@zn.tnic> (raw)
In-Reply-To: <20210430121616.2295-10-brijesh.singh@amd.com>
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
next prev parent reply other threads:[~2021-05-20 16:02 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 12:15 [PATCH Part1 RFC v2 00/20] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-04-30 12:15 ` [PATCH Part1 RFC v2 01/20] x86/sev: Define the GHCB MSR protocol for AP reset hold Brijesh Singh
2021-04-30 12:15 ` [PATCH Part1 RFC v2 02/20] x86/sev: Save the negotiated GHCB version Brijesh Singh
2021-05-11 9:23 ` Borislav Petkov
2021-05-11 18:29 ` Brijesh Singh
2021-05-11 18:41 ` Borislav Petkov
2021-05-12 14:03 ` Brijesh Singh
2021-05-12 14:31 ` Borislav Petkov
2021-05-12 15:03 ` Brijesh Singh
2021-04-30 12:15 ` [PATCH Part1 RFC v2 03/20] x86/sev: Add support for hypervisor feature VMGEXIT Brijesh Singh
2021-05-11 10:01 ` Borislav Petkov
2021-05-11 18:53 ` Brijesh Singh
2021-05-17 14:40 ` Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 04/20] x86/sev: Increase the GHCB protocol version Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 05/20] x86/sev: Define SNP Page State Change VMGEXIT structure Brijesh Singh
2021-05-18 10:41 ` Borislav Petkov
2021-05-18 15:06 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 06/20] x86/sev: Define SNP guest request NAE events Brijesh Singh
2021-05-18 10:45 ` Borislav Petkov
2021-05-18 13:42 ` Brijesh Singh
2021-05-18 13:54 ` Borislav Petkov
2021-05-18 14:13 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 07/20] x86/sev: Define error codes for reason set 1 Brijesh Singh
2021-05-18 11:05 ` Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 08/20] x86/mm: Add sev_snp_active() helper Brijesh Singh
2021-05-18 18:11 ` Borislav Petkov
2021-05-19 17:28 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 09/20] x86/sev: check SEV-SNP features support Brijesh Singh
2021-05-20 16:02 ` Borislav Petkov [this message]
2021-05-20 17:40 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 10/20] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2021-04-30 13:05 ` Brijesh Singh
2021-05-20 17:32 ` Borislav Petkov
2021-05-20 17:44 ` Brijesh Singh
2021-05-20 17:51 ` Borislav Petkov
2021-05-20 17:57 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 11/20] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2021-05-20 17:52 ` Borislav Petkov
2021-05-20 18:05 ` Brijesh Singh
2021-05-25 10:18 ` Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 12/20] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2021-05-25 10:41 ` Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 13/20] x86/sev: " Brijesh Singh
2021-05-25 11:11 ` Borislav Petkov
2021-05-25 14:28 ` Brijesh Singh
2021-05-25 14:35 ` Borislav Petkov
2021-05-25 14:47 ` Brijesh Singh
2021-05-26 9:57 ` Borislav Petkov
2021-05-26 13:23 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 14/20] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2021-05-26 10:39 ` Borislav Petkov
2021-05-26 13:34 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 15/20] x86/kernel: Make the bss.decrypted section shared in RMP table Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 16/20] x86/kernel: Validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-05-27 11:49 ` Borislav Petkov
2021-05-27 12:12 ` Brijesh Singh
2021-05-27 12:23 ` Borislav Petkov
2021-05-27 12:56 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 17/20] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 18/20] x86/boot: Add Confidential Computing address to setup_header Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 19/20] x86/sev: Register SNP guest request platform device Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 20/20] virt: Add SEV-SNP guest driver Brijesh Singh
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