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Message-ID: <434e65bd-49ec-40f1-bd2b-68765ecbb86d@amd.com>
Date: Thu, 15 Feb 2024 17:13:45 +0530
From: "Nikunj A. Dadhania" <nikunj@....com>
To: Borislav Petkov <bp@...en8.de>, Ashish Kalra <ashish.kalra@....com>,
Michael Roth <michael.roth@....com>, Tom Lendacky <thomas.lendacky@....com>
Cc: X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/sev: Dump SEV_STATUS
On 2/13/2024 10:03 PM, Borislav Petkov wrote:
> From: "Borislav Petkov (AMD)" <bp@...en8.de>
>
> It is, and will be even more useful in the future, to dump the SEV
> features enabled according to SEV_STATUS. Do so:
>
> [ 0.542753] Memory Encryption Features active: AMD SEV SEV-ES SEV-SNP
> [ 0.544425] SEV: Status: SEV SEV-ES SEV-SNP DebugSwap
>
> Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Definitely very useful:
Reviewed-by: Nikunj A Dadhania <nikunj@....com>
> ---
> arch/x86/boot/compressed/sev.c | 2 +-
> arch/x86/include/asm/msr-index.h | 59 +++++++++++++++++++-------------
> arch/x86/include/asm/sev.h | 2 ++
> arch/x86/kernel/sev.c | 35 +++++++++++++++++++
> arch/x86/mm/mem_encrypt.c | 5 +++
> 5 files changed, 78 insertions(+), 25 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
> index fffdba4ae806..97561eabfbef 100644
> --- a/arch/x86/boot/compressed/sev.c
> +++ b/arch/x86/boot/compressed/sev.c
> @@ -370,7 +370,7 @@ static void enforce_vmpl0(void)
> MSR_AMD64_SNP_VMPL_SSS | \
> MSR_AMD64_SNP_SECURE_TSC | \
> MSR_AMD64_SNP_VMGEXIT_PARAM | \
> - MSR_AMD64_SNP_VMSA_REG_PROTECTION | \
> + MSR_AMD64_SNP_VMSA_REG_PROT | \
> MSR_AMD64_SNP_RESERVED_BIT13 | \
> MSR_AMD64_SNP_RESERVED_BIT15 | \
> MSR_AMD64_SNP_RESERVED_MASK)
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
> index 237c50cc1c72..24c575cdd6b9 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -605,36 +605,47 @@
> #define MSR_AMD64_SEV_ES_GHCB 0xc0010130
> #define MSR_AMD64_SEV 0xc0010131
> #define MSR_AMD64_SEV_ENABLED_BIT 0
> -#define MSR_AMD64_SEV_ES_ENABLED_BIT 1
> -#define MSR_AMD64_SEV_SNP_ENABLED_BIT 2
> #define MSR_AMD64_SEV_ENABLED BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT)
> +#define MSR_AMD64_SEV_ES_ENABLED_BIT 1
> #define MSR_AMD64_SEV_ES_ENABLED BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT)
> +#define MSR_AMD64_SEV_SNP_ENABLED_BIT 2
> #define MSR_AMD64_SEV_SNP_ENABLED BIT_ULL(MSR_AMD64_SEV_SNP_ENABLED_BIT)
> -#define MSR_AMD64_RMP_BASE 0xc0010132
> -#define MSR_AMD64_RMP_END 0xc0010133
> -
> -/* SNP feature bits enabled by the hypervisor */
> -#define MSR_AMD64_SNP_VTOM BIT_ULL(3)
> -#define MSR_AMD64_SNP_REFLECT_VC BIT_ULL(4)
> -#define MSR_AMD64_SNP_RESTRICTED_INJ BIT_ULL(5)
> -#define MSR_AMD64_SNP_ALT_INJ BIT_ULL(6)
> -#define MSR_AMD64_SNP_DEBUG_SWAP BIT_ULL(7)
> -#define MSR_AMD64_SNP_PREVENT_HOST_IBS BIT_ULL(8)
> -#define MSR_AMD64_SNP_BTB_ISOLATION BIT_ULL(9)
> -#define MSR_AMD64_SNP_VMPL_SSS BIT_ULL(10)
> -#define MSR_AMD64_SNP_SECURE_TSC BIT_ULL(11)
> -#define MSR_AMD64_SNP_VMGEXIT_PARAM BIT_ULL(12)
> -#define MSR_AMD64_SNP_IBS_VIRT BIT_ULL(14)
> -#define MSR_AMD64_SNP_VMSA_REG_PROTECTION BIT_ULL(16)
> -#define MSR_AMD64_SNP_SMT_PROTECTION BIT_ULL(17)
> -
> -/* SNP feature bits reserved for future use. */
> -#define MSR_AMD64_SNP_RESERVED_BIT13 BIT_ULL(13)
> -#define MSR_AMD64_SNP_RESERVED_BIT15 BIT_ULL(15)
> -#define MSR_AMD64_SNP_RESERVED_MASK GENMASK_ULL(63, 18)
> +#define MSR_AMD64_SNP_VTOM_BIT 3
> +#define MSR_AMD64_SNP_VTOM BIT_ULL(MSR_AMD64_SNP_VTOM_BIT)
> +#define MSR_AMD64_SNP_REFLECT_VC_BIT 4
> +#define MSR_AMD64_SNP_REFLECT_VC BIT_ULL(MSR_AMD64_SNP_REFLECT_VC_BIT)
> +#define MSR_AMD64_SNP_RESTRICTED_INJ_BIT 5
> +#define MSR_AMD64_SNP_RESTRICTED_INJ BIT_ULL(MSR_AMD64_SNP_RESTRICTED_INJ_BIT)
> +#define MSR_AMD64_SNP_ALT_INJ_BIT 6
> +#define MSR_AMD64_SNP_ALT_INJ BIT_ULL(MSR_AMD64_SNP_ALT_INJ_BIT)
> +#define MSR_AMD64_SNP_DEBUG_SWAP_BIT 7
> +#define MSR_AMD64_SNP_DEBUG_SWAP BIT_ULL(MSR_AMD64_SNP_DEBUG_SWAP_BIT)
> +#define MSR_AMD64_SNP_PREVENT_HOST_IBS_BIT 8
> +#define MSR_AMD64_SNP_PREVENT_HOST_IBS BIT_ULL(MSR_AMD64_SNP_PREVENT_HOST_IBS_BIT)
> +#define MSR_AMD64_SNP_BTB_ISOLATION_BIT 9
> +#define MSR_AMD64_SNP_BTB_ISOLATION BIT_ULL(MSR_AMD64_SNP_BTB_ISOLATION_BIT)
> +#define MSR_AMD64_SNP_VMPL_SSS_BIT 10
> +#define MSR_AMD64_SNP_VMPL_SSS BIT_ULL(MSR_AMD64_SNP_VMPL_SSS_BIT)
> +#define MSR_AMD64_SNP_SECURE_TSC_BIT 11
> +#define MSR_AMD64_SNP_SECURE_TSC BIT_ULL(MSR_AMD64_SNP_SECURE_TSC_BIT)
> +#define MSR_AMD64_SNP_VMGEXIT_PARAM_BIT 12
> +#define MSR_AMD64_SNP_VMGEXIT_PARAM BIT_ULL(MSR_AMD64_SNP_VMGEXIT_PARAM_BIT)
> +#define MSR_AMD64_SNP_RESERVED_BIT13 BIT_ULL(13)
> +#define MSR_AMD64_SNP_IBS_VIRT_BIT 14
> +#define MSR_AMD64_SNP_IBS_VIRT BIT_ULL(MSR_AMD64_SNP_IBS_VIRT_BIT)
> +#define MSR_AMD64_SNP_RESERVED_BIT15 BIT_ULL(15)
> +#define MSR_AMD64_SNP_VMSA_REG_PROT_BIT 16
> +#define MSR_AMD64_SNP_VMSA_REG_PROT BIT_ULL(MSR_AMD64_SNP_VMSA_REG_PROT_BIT)
> +#define MSR_AMD64_SNP_SMT_PROT_BIT 17
> +#define MSR_AMD64_SNP_SMT_PROT BIT_ULL(MSR_AMD64_SNP_SMT_PROT_BIT)
> +#define MSR_AMD64_SNP_RESV_BIT 18
> +#define MSR_AMD64_SNP_RESERVED_MASK GENMASK_ULL(63, MSR_AMD64_SNP_RESV_BIT)
>
> #define MSR_AMD64_VIRT_SPEC_CTRL 0xc001011f
>
> +#define MSR_AMD64_RMP_BASE 0xc0010132
> +#define MSR_AMD64_RMP_END 0xc0010133
> +
> /* AMD Collaborative Processor Performance Control MSRs */
> #define MSR_AMD_CPPC_CAP1 0xc00102b0
> #define MSR_AMD_CPPC_ENABLE 0xc00102b1
> diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
> index d7b27cb34c2b..10f9f1b259c3 100644
> --- a/arch/x86/include/asm/sev.h
> +++ b/arch/x86/include/asm/sev.h
> @@ -229,6 +229,7 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end);
> u64 snp_get_unsupported_features(u64 status);
> u64 sev_get_status(void);
> void kdump_sev_callback(void);
> +void sev_show_status(void);
> #else
> static inline void sev_es_ist_enter(struct pt_regs *regs) { }
> static inline void sev_es_ist_exit(void) { }
> @@ -258,6 +259,7 @@ static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
> static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
> static inline u64 sev_get_status(void) { return 0; }
> static inline void kdump_sev_callback(void) { }
> +static inline void sev_show_status(void) { }
> #endif
>
> #ifdef CONFIG_KVM_AMD_SEV
> diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
> index 1ef7ae806a01..081d1391bc18 100644
> --- a/arch/x86/kernel/sev.c
> +++ b/arch/x86/kernel/sev.c
> @@ -59,6 +59,25 @@
> #define AP_INIT_CR0_DEFAULT 0x60000010
> #define AP_INIT_MXCSR_DEFAULT 0x1f80
>
> +static const char * const sev_status_feat_names[] = {
> + [MSR_AMD64_SEV_ENABLED_BIT] = "SEV",
> + [MSR_AMD64_SEV_ES_ENABLED_BIT] = "SEV-ES",
> + [MSR_AMD64_SEV_SNP_ENABLED_BIT] = "SEV-SNP",
> + [MSR_AMD64_SNP_VTOM_BIT] = "vTom",
> + [MSR_AMD64_SNP_REFLECT_VC_BIT] = "Reflect VC",
> + [MSR_AMD64_SNP_RESTRICTED_INJ_BIT] = "RI",
> + [MSR_AMD64_SNP_ALT_INJ_BIT] = "AI",
> + [MSR_AMD64_SNP_DEBUG_SWAP_BIT] = "DebugSwap",
> + [MSR_AMD64_SNP_PREVENT_HOST_IBS_BIT] = "No HostIBS",
> + [MSR_AMD64_SNP_BTB_ISOLATION_BIT] = "BTB Isol",
> + [MSR_AMD64_SNP_VMPL_SSS_BIT] = "VmplSSS",
> + [MSR_AMD64_SNP_SECURE_TSC_BIT] = "Secure TSC",
> + [MSR_AMD64_SNP_VMGEXIT_PARAM_BIT] = "VMGExit param",
> + [MSR_AMD64_SNP_IBS_VIRT_BIT] = "IBS Virt",
> + [MSR_AMD64_SNP_VMSA_REG_PROT_BIT] = "VMSA reg prot",
> + [MSR_AMD64_SNP_SMT_PROT_BIT] = "SMT prot",
> +};
> +
> /* For early boot hypervisor communication in SEV-ES enabled guests */
> static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE);
>
> @@ -2275,3 +2294,19 @@ void kdump_sev_callback(void)
> if (cpu_feature_enabled(X86_FEATURE_SEV_SNP))
> wbinvd();
> }
> +
> +void sev_show_status(void)
> +{
> + int i;
> +
> + pr_info("Status: ");
> + for (i = 0; i < MSR_AMD64_SNP_RESV_BIT; i++) {
> + if (sev_status & BIT_ULL(i)) {
> + if (!sev_status_feat_names[i])
> + continue;
> +
> + pr_cont("%s ", sev_status_feat_names[i]);
> + }
> + }
> + pr_cont("\n");
> +}
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index d035bce3a2b0..6f3b3e028718 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -14,6 +14,8 @@
> #include <linux/mem_encrypt.h>
> #include <linux/virtio_anchor.h>
>
> +#include <asm/sev.h>
> +
> /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
> bool force_dma_unencrypted(struct device *dev)
> {
> @@ -74,6 +76,9 @@ static void print_mem_encrypt_feature_info(void)
> pr_cont(" SEV-SNP");
>
> pr_cont("\n");
> +
> + sev_show_status();
> +
> break;
> default:
> pr_cont("Unknown\n");
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