[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.13] x86/amd: Enumeration for speculative features/hints
commit 4eddf132b5e0246b5e51e6b9edfe9aaa35349ab1 Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> AuthorDate: Fri Oct 15 11:14:46 2021 +0200 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Tue Jul 12 16:33:19 2022 +0100 x86/amd: Enumeration for speculative features/hints There is a step change in speculation protections between the Zen1 and Zen2 microarchitectures. Zen1 and older have no special support. Control bits in non-architectural MSRs are used to make lfence be dispatch-serialising (Spectre v1), and to disable Memory Disambiguation (Speculative Store Bypass). IBPB was retrofitted in a microcode update, and software methods are required for Spectre v2 protections. Because the bit controlling Memory Disambiguation is model specific, hypervisors are expected to expose a MSR_VIRT_SPEC_CTRL interface which abstracts the model specific details. Zen2 and later implement the MSR_SPEC_CTRL interface in hardware, and virtualise the interface for HVM guests to use. A number of hint bits are specified too to help guide OS software to the most efficient mitigation strategy. Zen3 introduced a new feature, Predictive Store Forwarding, along with a control to disable it in sensitive code. Add CPUID and VMCB details for all the new functionality. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> (cherry picked from commit 747424c664bb164a04e7a9f2ffbf02d4a1630d7d) --- tools/libxl/libxl_cpuid.c | 10 ++++++++++ tools/misc/xen-cpuid.c | 9 ++++++++- xen/arch/x86/hvm/svm/svm.c | 1 + xen/include/asm-x86/cpufeature.h | 5 +++++ xen/include/asm-x86/hvm/svm/svm.h | 2 ++ xen/include/asm-x86/hvm/svm/vmcb.h | 4 +++- xen/include/asm-x86/msr-index.h | 2 ++ xen/include/public/arch-x86/cpufeatureset.h | 10 ++++++++++ 8 files changed, 41 insertions(+), 2 deletions(-) diff --git a/tools/libxl/libxl_cpuid.c b/tools/libxl/libxl_cpuid.c index 083869dcf4..977a4377bf 100644 --- a/tools/libxl/libxl_cpuid.c +++ b/tools/libxl/libxl_cpuid.c @@ -264,6 +264,16 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list *cpuid, const char* str) {"rstr-fp-err-ptrs", 0x80000008, NA, CPUID_REG_EBX, 2, 1}, {"wbnoinvd", 0x80000008, NA, CPUID_REG_EBX, 9, 1}, {"ibpb", 0x80000008, NA, CPUID_REG_EBX, 12, 1}, + {"ibrs", 0x80000008, NA, CPUID_REG_EBX, 14, 1}, + {"amd-stibp", 0x80000008, NA, CPUID_REG_EBX, 15, 1}, + {"ibrs-always", 0x80000008, NA, CPUID_REG_EBX, 16, 1}, + {"stibp-always", 0x80000008, NA, CPUID_REG_EBX, 17, 1}, + {"ibrs-fast", 0x80000008, NA, CPUID_REG_EBX, 18, 1}, + {"ibrs-same-mode", 0x80000008, NA, CPUID_REG_EBX, 19, 1}, + {"amd-ssbd", 0x80000008, NA, CPUID_REG_EBX, 24, 1}, + {"virt-ssbd", 0x80000008, NA, CPUID_REG_EBX, 25, 1}, + {"ssb-no", 0x80000008, NA, CPUID_REG_EBX, 26, 1}, + {"psfd", 0x80000008, NA, CPUID_REG_EBX, 28, 1}, {"nc", 0x80000008, NA, CPUID_REG_ECX, 0, 8}, {"apicidsize", 0x80000008, NA, CPUID_REG_ECX, 12, 4}, diff --git a/tools/misc/xen-cpuid.c b/tools/misc/xen-cpuid.c index a09440813b..ff167779df 100644 --- a/tools/misc/xen-cpuid.c +++ b/tools/misc/xen-cpuid.c @@ -147,9 +147,16 @@ static const char *const str_e8b[32] = [ 0] = "clzero", [ 2] = "rstr-fp-err-ptrs", - /* [ 8] */ [ 9] = "wbnoinvd", + /* [ 8] */ [ 9] = "wbnoinvd", [12] = "ibpb", + [14] = "ibrs", [15] = "amd-stibp", + [16] = "ibrs-always", [17] = "stibp-always", + [18] = "ibrs-fast", [19] = "ibrs-same-mode", + + [24] = "amd-ssbd", [25] = "virt-ssbd", + [26] = "ssb-no", + [28] = "psfd", }; static const char *const str_7d0[32] = diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index a6de9ccb8f..c973411019 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -1657,6 +1657,7 @@ const struct hvm_function_table * __init start_svm(void) P(cpu_has_pause_filter, "Pause-Intercept Filter"); P(cpu_has_pause_thresh, "Pause-Intercept Filter Threshold"); P(cpu_has_tsc_ratio, "TSC Rate MSR"); + P(cpu_has_svm_spec_ctrl, "MSR_SPEC_CTRL virtualisation"); #undef P if ( !printed ) diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h index 00d22caac7..6419b4d2c5 100644 --- a/xen/include/asm-x86/cpufeature.h +++ b/xen/include/asm-x86/cpufeature.h @@ -124,6 +124,11 @@ /* CPUID level 0x80000007.edx */ #define cpu_has_itsc boot_cpu_has(X86_FEATURE_ITSC) +/* CPUID level 0x80000008.ebx */ +#define cpu_has_amd_ssbd boot_cpu_has(X86_FEATURE_AMD_SSBD) +#define cpu_has_virt_ssbd boot_cpu_has(X86_FEATURE_VIRT_SSBD) +#define cpu_has_ssb_no boot_cpu_has(X86_FEATURE_SSB_NO) + /* CPUID level 0x00000007:0.edx */ #define cpu_has_avx512_4vnniw boot_cpu_has(X86_FEATURE_AVX512_4VNNIW) #define cpu_has_avx512_4fmaps boot_cpu_has(X86_FEATURE_AVX512_4FMAPS) diff --git a/xen/include/asm-x86/hvm/svm/svm.h b/xen/include/asm-x86/hvm/svm/svm.h index 52752fe5ab..2b522ee79b 100644 --- a/xen/include/asm-x86/hvm/svm/svm.h +++ b/xen/include/asm-x86/hvm/svm/svm.h @@ -74,6 +74,7 @@ extern u32 svm_feature_flags; #define SVM_FEATURE_PAUSETHRESH 12 /* Pause intercept filter support */ #define SVM_FEATURE_VLOADSAVE 15 /* virtual vmload/vmsave */ #define SVM_FEATURE_VGIF 16 /* Virtual GIF */ +#define SVM_FEATURE_SPEC_CTRL 20 /* MSR_SPEC_CTRL virtualisation */ #define cpu_has_svm_feature(f) (svm_feature_flags & (1u << (f))) #define cpu_has_svm_npt cpu_has_svm_feature(SVM_FEATURE_NPT) @@ -87,6 +88,7 @@ extern u32 svm_feature_flags; #define cpu_has_pause_thresh cpu_has_svm_feature(SVM_FEATURE_PAUSETHRESH) #define cpu_has_tsc_ratio cpu_has_svm_feature(SVM_FEATURE_TSCRATEMSR) #define cpu_has_svm_vloadsave cpu_has_svm_feature(SVM_FEATURE_VLOADSAVE) +#define cpu_has_svm_spec_ctrl cpu_has_svm_feature(SVM_FEATURE_SPEC_CTRL) #define SVM_PAUSEFILTER_INIT 4000 #define SVM_PAUSETHRESH_INIT 1000 diff --git a/xen/include/asm-x86/hvm/svm/vmcb.h b/xen/include/asm-x86/hvm/svm/vmcb.h index 10b51c64bb..560dbb2873 100644 --- a/xen/include/asm-x86/hvm/svm/vmcb.h +++ b/xen/include/asm-x86/hvm/svm/vmcb.h @@ -494,7 +494,9 @@ struct vmcb_struct { u64 _lastbranchtoip; /* cleanbit 10 */ u64 _lastintfromip; /* cleanbit 10 */ u64 _lastinttoip; /* cleanbit 10 */ - u64 res17[301]; + u64 res17[9]; + u64 spec_ctrl; + u64 res18[291]; }; struct svm_domain { diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h index 2a80660d84..20653bd660 100644 --- a/xen/include/asm-x86/msr-index.h +++ b/xen/include/asm-x86/msr-index.h @@ -41,6 +41,7 @@ #define SPEC_CTRL_IBRS (_AC(1, ULL) << 0) #define SPEC_CTRL_STIBP (_AC(1, ULL) << 1) #define SPEC_CTRL_SSBD (_AC(1, ULL) << 2) +#define SPEC_CTRL_PSFD (_AC(1, ULL) << 7) #define MSR_PRED_CMD 0x00000049 #define PRED_CMD_IBPB (_AC(1, ULL) << 0) @@ -272,6 +273,7 @@ #define MSR_K8_ENABLE_C1E 0xc0010055 #define MSR_K8_VM_CR 0xc0010114 #define MSR_K8_VM_HSAVE_PA 0xc0010117 +#define MSR_VIRT_SPEC_CTRL 0xc001011f /* Layout matches MSR_SPEC_CTRL */ #define MSR_F15H_CU_POWER 0xc001007a #define MSR_F15H_CU_MAX_POWER 0xc001007b diff --git a/xen/include/public/arch-x86/cpufeatureset.h b/xen/include/public/arch-x86/cpufeatureset.h index a1d1619643..6084e0569d 100644 --- a/xen/include/public/arch-x86/cpufeatureset.h +++ b/xen/include/public/arch-x86/cpufeatureset.h @@ -248,6 +248,16 @@ XEN_CPUFEATURE(CLZERO, 8*32+ 0) /*A CLZERO instruction */ XEN_CPUFEATURE(RSTR_FP_ERR_PTRS, 8*32+ 2) /*A (F)X{SAVE,RSTOR} always saves/restores FPU Error pointers */ XEN_CPUFEATURE(WBNOINVD, 8*32+ 9) /* WBNOINVD instruction */ XEN_CPUFEATURE(IBPB, 8*32+12) /*A IBPB support only (no IBRS, used by AMD) */ +XEN_CPUFEATURE(IBRS, 8*32+14) /* MSR_SPEC_CTRL.IBRS */ +XEN_CPUFEATURE(AMD_STIBP, 8*32+15) /* MSR_SPEC_CTRL.STIBP */ +XEN_CPUFEATURE(IBRS_ALWAYS, 8*32+16) /* IBRS preferred always on */ +XEN_CPUFEATURE(STIBP_ALWAYS, 8*32+17) /* STIBP preferred always on */ +XEN_CPUFEATURE(IBRS_FAST, 8*32+18) /* IBRS preferred over software options */ +XEN_CPUFEATURE(IBRS_SAME_MODE, 8*32+19) /* IBRS provides same-mode protection */ +XEN_CPUFEATURE(AMD_SSBD, 8*32+24) /* MSR_SPEC_CTRL.SSBD available */ +XEN_CPUFEATURE(VIRT_SSBD, 8*32+25) /* MSR_VIRT_SPEC_CTRL.SSBD */ +XEN_CPUFEATURE(SSB_NO, 8*32+26) /* Hardware not vulnerable to SSB */ +XEN_CPUFEATURE(PSFD, 8*32+28) /* MSR_SPEC_CTRL.PSFD */ /* Intel-defined CPU features, CPUID level 0x00000007:0.edx, word 9 */ XEN_CPUFEATURE(AVX512_4VNNIW, 9*32+ 2) /*A AVX512 Neural Network Instructions */ -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.13
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