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From 194c3226782279235d34de040e318d30665b7b5b Mon Sep 17 00:00:00 2001
From: Sudheesh Mavila <sudheesh.mavila@amd.com>
Date: Mon, 22 Oct 2018 13:28:34 +0530
Subject: [PATCH 59/95] x86/CPU/AMD: Add the Secure Encrypted Virtualization
CPU feature
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Update the CPU features to include identifying and reporting on the
Secure Encrypted Virtualization (SEV) feature. SEV is identified by
CPUID 0x8000001f, but requires BIOS support to enable it (set bit 23 of
MSR_K8_SYSCFG and set bit 0 of MSR_K7_HWCR). Only show the SEV feature
as available if reported by CPUID and enabled by BIOS.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
---
arch/x86/include/asm/cpufeatures.h | 2 +-
arch/x86/include/asm/msr-index.h | 2 +
arch/x86/kernel/cpu/amd.c | 82 +++++++++++++++++++++-----------------
arch/x86/kernel/cpu/scattered.c | 1 +
4 files changed, 50 insertions(+), 37 deletions(-)
mode change 100644 => 100755 arch/x86/include/asm/cpufeatures.h
mode change 100644 => 100755 arch/x86/include/asm/msr-index.h
mode change 100644 => 100755 arch/x86/kernel/cpu/amd.c
mode change 100644 => 100755 arch/x86/kernel/cpu/scattered.c
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
old mode 100644
new mode 100755
index 8418462..76a0ba0
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -210,7 +210,7 @@
#define X86_FEATURE_SSBD ( 7*32+17) /* Speculative Store Bypass Disable */
#define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth Allocation */
#define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* "" Fill RSB on context switches */
-
+#define X86_FEATURE_SEV ( 7*32+20) /* AMD Secure Encrypted Virtualization */
#define X86_FEATURE_USE_IBPB ( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */
#define X86_FEATURE_USE_IBRS_FW ( 7*32+22) /* "" Use IBRS during runtime firmware calls */
#define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE ( 7*32+23) /* "" Disable Speculative Store Bypass. */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
old mode 100644
new mode 100755
index 42b18cc..55d802c
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -413,6 +413,8 @@
#define MSR_K7_PERFCTR3 0xc0010007
#define MSR_K7_CLK_CTL 0xc001001b
#define MSR_K7_HWCR 0xc0010015
+#define MSR_K7_HWCR_SMMLOCK_BIT 0
+#define MSR_K7_HWCR_SMMLOCK BIT_ULL(MSR_K7_HWCR_SMMLOCK_BIT)
#define MSR_K7_FID_VID_CTL 0xc0010041
#define MSR_K7_FID_VID_STATUS 0xc0010042
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
old mode 100644
new mode 100755
index dda741b..c6333e7
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -575,6 +575,51 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)
}
}
+static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
+{
+ u64 msr;
+
+ /*
+ * BIOS support is required for SME and SEV.
+ * For SME: If BIOS has enabled SME then adjust x86_phys_bits by
+ * the SME physical address space reduction value.
+ * If BIOS has not enabled SME then don't advertise the
+ * SME feature (set in scattered.c).
+ * For SEV: If BIOS has not enabled SEV then don't advertise the
+ * SEV feature (set in scattered.c).
+ *
+ * In all cases, since support for SME and SEV requires long mode,
+ * don't advertise the feature under CONFIG_X86_32.
+ */
+ if (cpu_has(c, X86_FEATURE_SME) || cpu_has(c, X86_FEATURE_SEV)) {
+ /* Check if memory encryption is enabled */
+ rdmsrl(MSR_K8_SYSCFG, msr);
+ if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
+ goto clear_all;
+
+ /*
+ * Always adjust physical address bits. Even though this
+ * will be a value above 32-bits this is still done for
+ * CONFIG_X86_32 so that accurate values are reported.
+ */
+ c->x86_phys_bits -= (cpuid_ebx(0x8000001f) >> 6) & 0x3f;
+
+ if (IS_ENABLED(CONFIG_X86_32))
+ goto clear_all;
+
+ rdmsrl(MSR_K7_HWCR, msr);
+ if (!(msr & MSR_K7_HWCR_SMMLOCK))
+ goto clear_sev;
+
+ return;
+
+clear_all:
+ clear_cpu_cap(c, X86_FEATURE_SME);
+clear_sev:
+ clear_cpu_cap(c, X86_FEATURE_SEV);
+ }
+}
+
static void early_init_amd(struct cpuinfo_x86 *c)
{
u64 value;
@@ -647,42 +692,7 @@ static void early_init_amd(struct cpuinfo_x86 *c)
if (cpu_has_amd_erratum(c, amd_erratum_400))
set_cpu_bug(c, X86_BUG_AMD_E400);
- /*
- * BIOS support is required for SME. If BIOS has enabled SME then
- * adjust x86_phys_bits by the SME physical address space reduction
- * value. If BIOS has not enabled SME then don't advertise the
- * feature (set in scattered.c). Also, since the SME support requires
- * long mode, don't advertise the feature under CONFIG_X86_32.
- */
- if (cpu_has(c, X86_FEATURE_SME)) {
- u64 msr;
-
- /* Check if SME is enabled */
- rdmsrl(MSR_K8_SYSCFG, msr);
- if (msr & MSR_K8_SYSCFG_MEM_ENCRYPT) {
- c->x86_phys_bits -= (cpuid_ebx(0x8000001f) >> 6) & 0x3f;
- if (IS_ENABLED(CONFIG_X86_32))
- clear_cpu_cap(c, X86_FEATURE_SME);
- } else {
- clear_cpu_cap(c, X86_FEATURE_SME);
- }
- }
-
- /* Re-enable TopologyExtensions if switched off by BIOS */
- if (c->x86 == 0x15 &&
- (c->x86_model >= 0x10 && c->x86_model <= 0x6f) &&
- !cpu_has(c, X86_FEATURE_TOPOEXT)) {
-
- if (msr_set_bit(0xc0011005, 54) > 0) {
- rdmsrl(0xc0011005, value);
- if (value & BIT_64(54)) {
- set_cpu_cap(c, X86_FEATURE_TOPOEXT);
- pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
- }
- }
- }
-
- amd_get_topology_early(c);
+ early_detect_mem_encrypt(c);
}
static void init_amd_k8(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
old mode 100644
new mode 100755
index df11f5d..3320773
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -29,6 +29,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
{ X86_FEATURE_SME, CPUID_EAX, 0, 0x8000001f, 0 },
+ { X86_FEATURE_SEV, CPUID_EAX, 1, 0x8000001f, 0 },
{ 0, 0, 0, 0, 0 }
};
--
2.7.4
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