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Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by SN1PEPF0002BA52.mail.protection.outlook.com (10.167.242.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7159.9 via Frontend Transport; Sat, 30 Dec 2023 16:30:10 +0000 Received: from localhost (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.34; Sat, 30 Dec 2023 10:30:05 -0600 From: Michael Roth To: CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Brijesh Singh Subject: [PATCH v1 04/26] x86/sev: Add the host SEV-SNP initialization support Date: Sat, 30 Dec 2023 10:19:32 -0600 Message-ID: <20231230161954.569267-5-michael.roth@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231230161954.569267-1-michael.roth@amd.com> References: <20231230161954.569267-1-michael.roth@amd.com> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN1PEPF0002BA52:EE_|MW3PR12MB4585:EE_ X-MS-Office365-Filtering-Correlation-Id: 0b50c9fd-2ac2-49e4-42d3-08dc09549791 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Dec 2023 16:30:10.3925 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 0b50c9fd-2ac2-49e4-42d3-08dc09549791 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SN1PEPF0002BA52.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR12MB4585 From: Brijesh Singh The memory integrity guarantees of SEV-SNP are enforced through a new structure called the Reverse Map Table (RMP). The RMP is a single data structure shared across the system that contains one entry for every 4K page of DRAM that may be used by SEV-SNP VMs. APM2 section 15.36 details a number of steps needed to detect/enable SEV-SNP and RMP table support on the host: - Detect SEV-SNP support based on CPUID bit - Initialize the RMP table memory reported by the RMP base/end MSR registers and configure IOMMU to be compatible with RMP access restrictions - Set the MtrrFixDramModEn bit in SYSCFG MSR - Set the SecureNestedPagingEn and VMPLEn bits in the SYSCFG MSR - Configure IOMMU RMP table entry format is non-architectural and it can vary by processor. It is defined by the PPR. Restrict SNP support to CPU models/families which are compatible with the current RMP table entry format to guard against any undefined behavior when running on other system types. Future models/support will handle this through an architectural mechanism to allow for broader compatibility. SNP host code depends on CONFIG_KVM_AMD_SEV config flag, which may be enabled even when CONFIG_AMD_MEM_ENCRYPT isn't set, so update the SNP-specific IOMMU helpers used here to rely on CONFIG_KVM_AMD_SEV instead of CONFIG_AMD_MEM_ENCRYPT. Signed-off-by: Brijesh Singh Co-developed-by: Ashish Kalra Signed-off-by: Ashish Kalra Co-developed-by: Tom Lendacky Signed-off-by: Tom Lendacky Co-developed-by: Michael Roth Signed-off-by: Michael Roth Signed-off-by: Borislav Petkov (AMD) --- arch/x86/Kbuild | 2 + arch/x86/include/asm/msr-index.h | 11 +- arch/x86/include/asm/sev.h | 6 + arch/x86/kernel/cpu/amd.c | 15 +++ arch/x86/virt/svm/Makefile | 3 + arch/x86/virt/svm/sev.c | 219 +++++++++++++++++++++++++++++++ 6 files changed, 255 insertions(+), 1 deletion(-) create mode 100644 arch/x86/virt/svm/Makefile create mode 100644 arch/x86/virt/svm/sev.c diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild index 5a83da703e87..6a1f36df6a18 100644 --- a/arch/x86/Kbuild +++ b/arch/x86/Kbuild @@ -28,5 +28,7 @@ obj-y += net/ obj-$(CONFIG_KEXEC_FILE) += purgatory/ +obj-y += virt/svm/ + # for cleaning subdir- += boot tools diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index f1bd7b91b3c6..15ce1269f270 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -599,6 +599,8 @@ #define MSR_AMD64_SEV_ENABLED BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT) #define MSR_AMD64_SEV_ES_ENABLED BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT) #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) @@ -709,7 +711,14 @@ #define MSR_K8_TOP_MEM2 0xc001001d #define MSR_AMD64_SYSCFG 0xc0010010 #define MSR_AMD64_SYSCFG_MEM_ENCRYPT_BIT 23 -#define MSR_AMD64_SYSCFG_MEM_ENCRYPT BIT_ULL(MSR_AMD64_SYSCFG_MEM_ENCRYPT_BIT) +#define MSR_AMD64_SYSCFG_MEM_ENCRYPT BIT_ULL(MSR_AMD64_SYSCFG_MEM_ENCRYPT_BIT) +#define MSR_AMD64_SYSCFG_SNP_EN_BIT 24 +#define MSR_AMD64_SYSCFG_SNP_EN BIT_ULL(MSR_AMD64_SYSCFG_SNP_EN_BIT) +#define MSR_AMD64_SYSCFG_SNP_VMPL_EN_BIT 25 +#define MSR_AMD64_SYSCFG_SNP_VMPL_EN BIT_ULL(MSR_AMD64_SYSCFG_SNP_VMPL_EN_BIT) +#define MSR_AMD64_SYSCFG_MFDM_BIT 19 +#define MSR_AMD64_SYSCFG_MFDM BIT_ULL(MSR_AMD64_SYSCFG_MFDM_BIT) + #define MSR_K8_INT_PENDING_MSG 0xc0010055 /* C1E active bits in int pending message */ #define K8_INTP_C1E_ACTIVE_MASK 0x18000000 diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 5b4a1ce3d368..1f59d8ba9776 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -243,4 +243,10 @@ static inline u64 snp_get_unsupported_features(u64 status) { return 0; } static inline u64 sev_get_status(void) { return 0; } #endif +#ifdef CONFIG_KVM_AMD_SEV +bool snp_probe_rmptable_info(void); +#else +static inline bool snp_probe_rmptable_info(void) { return false; } +#endif + #endif diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 9a17165dfe84..0f0d425f0440 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -20,6 +20,7 @@ #include #include #include +#include #ifdef CONFIG_X86_64 # include @@ -574,6 +575,20 @@ static void bsp_init_amd(struct cpuinfo_x86 *c) break; } + if (cpu_has(c, X86_FEATURE_SEV_SNP)) { + /* + * RMP table entry format is not architectural and it can vary by processor + * and is defined by the per-processor PPR. Restrict SNP support on the + * known CPU model and family for which the RMP table entry format is + * currently defined for. + */ + if (!(c->x86 == 0x19 && c->x86_model <= 0xaf) && + !(c->x86 == 0x1a && c->x86_model <= 0xf)) + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); + else if (!snp_probe_rmptable_info()) + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); + } + return; warn: diff --git a/arch/x86/virt/svm/Makefile b/arch/x86/virt/svm/Makefile new file mode 100644 index 000000000000..ef2a31bdcc70 --- /dev/null +++ b/arch/x86/virt/svm/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_KVM_AMD_SEV) += sev.o diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c new file mode 100644 index 000000000000..ce7ede9065ed --- /dev/null +++ b/arch/x86/virt/svm/sev.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD SVM-SEV Host Support. + * + * Copyright (C) 2023 Advanced Micro Devices, Inc. + * + * Author: Ashish Kalra + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * The RMP entry format is not architectural. The format is defined in PPR + * Family 19h Model 01h, Rev B1 processor. + */ +struct rmpentry { + u64 assigned : 1, + pagesize : 1, + immutable : 1, + rsvd1 : 9, + gpa : 39, + asid : 10, + vmsa : 1, + validated : 1, + rsvd2 : 1; + u64 rsvd3; +} __packed; + +/* + * The first 16KB from the RMP_BASE is used by the processor for the + * bookkeeping, the range needs to be added during the RMP entry lookup. + */ +#define RMPTABLE_CPU_BOOKKEEPING_SZ 0x4000 + +static u64 probed_rmp_base, probed_rmp_size; +static struct rmpentry *rmptable __ro_after_init; +static u64 rmptable_max_pfn __ro_after_init; + +#undef pr_fmt +#define pr_fmt(fmt) "SEV-SNP: " fmt + +static int __mfd_enable(unsigned int cpu) +{ + u64 val; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return 0; + + rdmsrl(MSR_AMD64_SYSCFG, val); + + val |= MSR_AMD64_SYSCFG_MFDM; + + wrmsrl(MSR_AMD64_SYSCFG, val); + + return 0; +} + +static __init void mfd_enable(void *arg) +{ + __mfd_enable(smp_processor_id()); +} + +static int __snp_enable(unsigned int cpu) +{ + u64 val; + + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return 0; + + rdmsrl(MSR_AMD64_SYSCFG, val); + + val |= MSR_AMD64_SYSCFG_SNP_EN; + val |= MSR_AMD64_SYSCFG_SNP_VMPL_EN; + + wrmsrl(MSR_AMD64_SYSCFG, val); + + return 0; +} + +static __init void snp_enable(void *arg) +{ + __snp_enable(smp_processor_id()); +} + +#define RMP_ADDR_MASK GENMASK_ULL(51, 13) + +bool snp_probe_rmptable_info(void) +{ + u64 max_rmp_pfn, calc_rmp_sz, rmp_sz, rmp_base, rmp_end; + + rdmsrl(MSR_AMD64_RMP_BASE, rmp_base); + rdmsrl(MSR_AMD64_RMP_END, rmp_end); + + if (!(rmp_base & RMP_ADDR_MASK) || !(rmp_end & RMP_ADDR_MASK)) { + pr_err("Memory for the RMP table has not been reserved by BIOS\n"); + return false; + } + + if (rmp_base > rmp_end) { + pr_err("RMP configuration not valid: base=%#llx, end=%#llx\n", rmp_base, rmp_end); + return false; + } + + rmp_sz = rmp_end - rmp_base + 1; + + /* + * Calculate the amount the memory that must be reserved by the BIOS to + * address the whole RAM, including the bookkeeping area. The RMP itself + * must also be covered. + */ + max_rmp_pfn = max_pfn; + if (PHYS_PFN(rmp_end) > max_pfn) + max_rmp_pfn = PHYS_PFN(rmp_end); + + calc_rmp_sz = (max_rmp_pfn << 4) + RMPTABLE_CPU_BOOKKEEPING_SZ; + + if (calc_rmp_sz > rmp_sz) { + pr_err("Memory reserved for the RMP table does not cover full system RAM (expected 0x%llx got 0x%llx)\n", + calc_rmp_sz, rmp_sz); + return false; + } + + probed_rmp_base = rmp_base; + probed_rmp_size = rmp_sz; + + pr_info("RMP table physical range [0x%016llx - 0x%016llx]\n", + probed_rmp_base, probed_rmp_base + probed_rmp_size - 1); + + return true; +} + +static int __init __snp_rmptable_init(void) +{ + u64 rmptable_size; + void *rmptable_start; + u64 val; + + if (!probed_rmp_size) + return 1; + + rmptable_start = memremap(probed_rmp_base, probed_rmp_size, MEMREMAP_WB); + if (!rmptable_start) { + pr_err("Failed to map RMP table\n"); + return 1; + } + + /* + * Check if SEV-SNP is already enabled, this can happen in case of + * kexec boot. + */ + rdmsrl(MSR_AMD64_SYSCFG, val); + if (val & MSR_AMD64_SYSCFG_SNP_EN) + goto skip_enable; + + memset(rmptable_start, 0, probed_rmp_size); + + /* Flush the caches to ensure that data is written before SNP is enabled. */ + wbinvd_on_all_cpus(); + + /* MtrrFixDramModEn must be enabled on all the CPUs prior to enabling SNP. */ + on_each_cpu(mfd_enable, NULL, 1); + + on_each_cpu(snp_enable, NULL, 1); + +skip_enable: + rmptable_start += RMPTABLE_CPU_BOOKKEEPING_SZ; + rmptable_size = probed_rmp_size - RMPTABLE_CPU_BOOKKEEPING_SZ; + + rmptable = (struct rmpentry *)rmptable_start; + rmptable_max_pfn = rmptable_size / sizeof(struct rmpentry) - 1; + + return 0; +} + +static int __init snp_rmptable_init(void) +{ + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return 0; + + if (!amd_iommu_snp_en) + return 0; + + if (__snp_rmptable_init()) + goto nosnp; + + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/rmptable_init:online", __snp_enable, NULL); + + return 0; + +nosnp: + setup_clear_cpu_cap(X86_FEATURE_SEV_SNP); + return -ENOSYS; +} + +/* + * This must be called after the IOMMU has been initialized. + */ +device_initcall(snp_rmptable_init);