From bfef624895673866b4beb1757725a565c7048c1f Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Wed, 12 Jul 2017 13:20:56 -0300 Subject: [PATCH 1/3] target/i386: Use host_vendor_fms() in max_x86_cpu_initfn() The existing code duplicated the logic in host_vendor_fms(), so reuse the helper function instead. Signed-off-by: Eduardo Habkost Message-Id: <20170712162058.10538-3-ehabkost@redhat.com> Reviewed-by: Igor Mammedov Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 89f5fb7a3f..156dc955d2 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1636,13 +1636,8 @@ static void max_x86_cpu_initfn(Object *obj) X86CPUDefinition host_cpudef = { }; uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0; - host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx); - x86_cpu_vendor_words2str(host_cpudef.vendor, ebx, edx, ecx); - - host_cpuid(0x1, 0, &eax, &ebx, &ecx, &edx); - host_cpudef.family = ((eax >> 8) & 0x0F) + ((eax >> 20) & 0xFF); - host_cpudef.model = ((eax >> 4) & 0x0F) | ((eax & 0xF0000) >> 12); - host_cpudef.stepping = eax & 0x0F; + host_vendor_fms(host_cpudef.vendor, &host_cpudef.family, + &host_cpudef.model, &host_cpudef.stepping); cpu_x86_fill_model_id(host_cpudef.model_id); From 7d8050b5142c5b9132be25835a3d7f261f1411a6 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Wed, 12 Jul 2017 13:20:57 -0300 Subject: [PATCH 2/3] target/i386: Define CPUID_MODEL_ID_SZ macro Document cpu_x86_fill_model_id() and define CPUID_MODEL_ID_SZ to help callers use the right buffer size. Signed-off-by: Eduardo Habkost Message-Id: <20170712162058.10538-4-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 156dc955d2..8558c600bf 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1585,6 +1585,17 @@ static bool lmce_supported(void) return !!(mce_cap & MCG_LMCE_P); } +#define CPUID_MODEL_ID_SZ 48 + +/** + * cpu_x86_fill_model_id: + * Get CPUID model ID string from host CPU. + * + * @str should have at least CPUID_MODEL_ID_SZ bytes + * + * The function does NOT add a null terminator to the string + * automatically. + */ static int cpu_x86_fill_model_id(char *str) { uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0; From bd1820227ecc0c77cc2aeba7c7c25b2d0a72ff3c Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Wed, 12 Jul 2017 13:20:58 -0300 Subject: [PATCH 3/3] target/i386: Don't use x86_cpu_load_def() on "max" CPU model When commit 0bacd8b3046f ('i386: Don't set CPUClass::cpu_def on "max" model') removed the CPUClass::cpu_def field, we kept using the x86_cpu_load_def() helper directly in max_x86_cpu_initfn(), emulating the previous behavior when CPUClass::cpu_def was set. However, x86_cpu_load_def() is intended to help initialization of CPU models from the builtin_x86_defs table, and does lots of other steps that are not necessary for "max". One of the things x86_cpu_load_def() do is to set the properties listed at tcg_default_props/kvm_default_props. We must not do that on the "max" CPU model, otherwise under KVM we will incorrectly report all KVM features as always available, and the "svm" feature as always unavailable. The latter caused the bug reported at: https://bugzilla.redhat.com/show_bug.cgi?id=1467599 ("Unable to start domain: the CPU is incompatible with host CPU: Host CPU does not provide required features: svm") Replace x86_cpu_load_def() with simple object_property_set*() calls. In addition to fixing the above bug, this makes the KVM branch in max_x86_cpu_initfn() very similar to the existing TCG branch. For reference, the full list of steps performed by x86_cpu_load_def() is: * Setting min-level and min-xlevel. Already done by max_x86_cpu_initfn(). * Setting family/model/stepping/model-id. Done by the code added to max_x86_cpu_initfn() in this patch. * Copying def->features. Wrong because "-cpu max" features need to be calculated at realize time. This was not a problem in the current code because host_cpudef.features was all zeroes. * x86_cpu_apply_props() calls. This causes the bug above, and shouldn't be done. * Setting CPUID_EXT_HYPERVISOR. Not needed because it is already reported by x86_cpu_get_supported_feature_word(), and because "-cpu max" features need to be calculated at realize time. * Setting CPU vendor to host CPU vendor if on KVM mode. Redundant, because max_x86_cpu_initfn() already sets it to the host CPU vendor. Signed-off-by: Eduardo Habkost Message-Id: <20170712162058.10538-5-ehabkost@redhat.com> Reviewed-by: Igor Mammedov Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 8558c600bf..ddc45abd70 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1644,15 +1644,21 @@ static void max_x86_cpu_initfn(Object *obj) cpu->max_features = true; if (kvm_enabled()) { - X86CPUDefinition host_cpudef = { }; - uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0; + char vendor[CPUID_VENDOR_SZ + 1] = { 0 }; + char model_id[CPUID_MODEL_ID_SZ + 1] = { 0 }; + int family, model, stepping; - host_vendor_fms(host_cpudef.vendor, &host_cpudef.family, - &host_cpudef.model, &host_cpudef.stepping); + host_vendor_fms(vendor, &family, &model, &stepping); - cpu_x86_fill_model_id(host_cpudef.model_id); + cpu_x86_fill_model_id(model_id); - x86_cpu_load_def(cpu, &host_cpudef, &error_abort); + object_property_set_str(OBJECT(cpu), vendor, "vendor", &error_abort); + object_property_set_int(OBJECT(cpu), family, "family", &error_abort); + object_property_set_int(OBJECT(cpu), model, "model", &error_abort); + object_property_set_int(OBJECT(cpu), stepping, "stepping", + &error_abort); + object_property_set_str(OBJECT(cpu), model_id, "model-id", + &error_abort); env->cpuid_min_level = kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);