From 20271d484069f154fb262507e63adc3a37e885d2 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 9 Mar 2017 15:12:10 -0300 Subject: [PATCH 1/3] i386: host_vendor_fms() helper function Helper function for code that needs to check the host CPU vendor/family/model/stepping values. Signed-off-by: Eduardo Habkost Message-Id: <20170309181212.18864-2-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 19 +++++++++++++++++++ target/i386/cpu.h | 1 + 2 files changed, 20 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index fba92125ab..30ba1bd06b 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -688,6 +688,25 @@ void host_cpuid(uint32_t function, uint32_t count, *edx = vec[3]; } +void host_vendor_fms(char *vendor, int *family, int *model, int *stepping) +{ + uint32_t eax, ebx, ecx, edx; + + host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx); + x86_cpu_vendor_words2str(vendor, ebx, edx, ecx); + + host_cpuid(0x1, 0, &eax, &ebx, &ecx, &edx); + if (family) { + *family = ((eax >> 8) & 0x0F) + ((eax >> 20) & 0xFF); + } + if (model) { + *model = ((eax >> 4) & 0x0F) | ((eax & 0xF0000) >> 12); + } + if (stepping) { + *stepping = eax & 0x0F; + } +} + /* CPU class name definitions: */ #define X86_CPU_TYPE_SUFFIX "-" TYPE_X86_CPU diff --git a/target/i386/cpu.h b/target/i386/cpu.h index ac2ad6d443..385dcc8fea 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1436,6 +1436,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, void cpu_clear_apic_feature(CPUX86State *env); void host_cpuid(uint32_t function, uint32_t count, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx); +void host_vendor_fms(char *vendor, int *family, int *model, int *stepping); /* helper.c */ int x86_cpu_handle_mmu_fault(CPUState *cpu, vaddr addr, From 40e80ee4113ad957b633cbdddb7423952bb76974 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 9 Mar 2017 15:12:11 -0300 Subject: [PATCH 2/3] i386/kvm: Blacklist TSX on known broken hosts Some Intel CPUs are known to have a broken TSX implementation. A microcode update from Intel disabled TSX on those CPUs, but GET_SUPPORTED_CPUID might be reporting it as supported if the hosts were not updated yet. Manually fixup the GET_SUPPORTED_CPUID data to ensure we will never enable TSX when running on those hosts. Reference: * glibc commit 2702856bf45c82cf8e69f2064f5aa15c0ceb6359: https://sourceware.org/git/?p=glibc.git;a=commit;h=2702856bf45c82cf8e69f2064f5aa15c0ceb6359 Signed-off-by: Eduardo Habkost Message-Id: <20170309181212.18864-3-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost --- target/i386/kvm.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 887a81268f..472399fb2c 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -266,6 +266,19 @@ static int get_para_features(KVMState *s) return features; } +static bool host_tsx_blacklisted(void) +{ + int family, model, stepping;\ + char vendor[CPUID_VENDOR_SZ + 1]; + + host_vendor_fms(vendor, &family, &model, &stepping); + + /* Check if we are running on a Haswell host known to have broken TSX */ + return !strcmp(vendor, CPUID_VENDOR_INTEL) && + (family == 6) && + ((model == 63 && stepping < 4) || + model == 60 || model == 69 || model == 70); +} /* Returns the value for a specific register on the cpuid entry */ @@ -349,6 +362,10 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, } } else if (function == 6 && reg == R_EAX) { ret |= CPUID_6_EAX_ARAT; /* safe to allow because of emulated APIC */ + } else if (function == 7 && index == 0 && reg == R_EBX) { + if (host_tsx_blacklisted()) { + ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); + } } else if (function == 0x80000001 && reg == R_EDX) { /* On Intel, kvm returns cpuid according to the Intel spec, * so add missing bits according to the AMD spec: From ec56a4a7b07e2943f49da273a31e3195083b1f2e Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 9 Mar 2017 15:12:12 -0300 Subject: [PATCH 3/3] i386: Change stepping of Haswell to non-blacklisted value glibc blacklists TSX on Haswell CPUs with model==60 and stepping < 4. To make the Haswell CPU model more useful, make those guests actually use TSX by changing CPU stepping to 4. References: * glibc commit 2702856bf45c82cf8e69f2064f5aa15c0ceb6359 https://sourceware.org/git/?p=glibc.git;a=commit;h=2702856bf45c82cf8e69f2064f5aa15c0ceb6359 Signed-off-by: Eduardo Habkost Message-Id: <20170309181212.18864-4-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost --- include/hw/i386/pc.h | 5 +++++ target/i386/cpu.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index ab303c7fee..f278b3ae89 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -389,6 +389,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); .driver = TYPE_X86_CPU,\ .property = "vmware-cpuid-freq",\ .value = "off",\ + },\ + {\ + .driver = "Haswell-" TYPE_X86_CPU,\ + .property = "stepping",\ + .value = "1",\ }, #define PC_COMPAT_2_7 \ diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 30ba1bd06b..7aa762245a 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1196,7 +1196,7 @@ static X86CPUDefinition builtin_x86_defs[] = { .vendor = CPUID_VENDOR_INTEL, .family = 6, .model = 60, - .stepping = 1, + .stepping = 4, .features[FEAT_1_EDX] = CPUID_VME | CPUID_SSE2 | CPUID_SSE | CPUID_FXSR | CPUID_MMX | CPUID_CLFLUSH | CPUID_PSE36 | CPUID_PAT | CPUID_CMOV | CPUID_MCA |