From: Tao Xu <tao3.xu@intel.com> To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, mtosatti@redhat.com Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, tao3.xu@intel.com, jingqi.liu@intel.com Subject: [PATCH RESEND v4 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE Date: Wed, 18 Sep 2019 15:23:28 +0800 [thread overview] Message-ID: <20190918072329.1911-2-tao3.xu@intel.com> (raw) In-Reply-To: <20190918072329.1911-1-tao3.xu@intel.com> UMONITOR, UMWAIT and TPAUSE are a set of user wait instructions. This patch adds support for user wait instructions in KVM. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. User wait instructions may be executed at any privilege level, and use IA32_UMWAIT_CONTROL MSR to set the maximum time. The patch enable the umonitor, umwait and tpause features in KVM. Because umwait and tpause can put a (psysical) CPU into a power saving state, by default we dont't expose it to kvm and enable it only when guest CPUID has it. And use QEMU command-line "-overcommit cpu-pm=on" (enable_cpu_pm is enabled), a VM can use UMONITOR, UMWAIT and TPAUSE instructions. If the instruction causes a delay, the amount of time delayed is called here the physical delay. The physical delay is first computed by determining the virtual delay (the time to delay relative to the VM’s timestamp counter). Otherwise, UMONITOR, UMWAIT and TPAUSE cause an invalid-opcode exception(#UD). The release document ref below link: https://software.intel.com/sites/default/files/\ managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf Co-developed-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Tao Xu <tao3.xu@intel.com> --- No changes in v4. --- target/i386/cpu.c | 3 ++- target/i386/cpu.h | 1 + target/i386/kvm.c | 4 ++++ 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 9e0bac31e8..15f888b13f 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1062,7 +1062,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .type = CPUID_FEATURE_WORD, .feat_names = { NULL, "avx512vbmi", "umip", "pku", - NULL /* ospke */, NULL, "avx512vbmi2", NULL, + NULL /* ospke */, "waitpkg", "avx512vbmi2", NULL, "gfni", "vaes", "vpclmulqdq", "avx512vnni", "avx512bitalg", NULL, "avx512-vpopcntdq", NULL, "la57", NULL, NULL, NULL, @@ -5227,6 +5227,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx, &cpu->mwait.ecx, &cpu->mwait.edx); env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR; + env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG; } } diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 5f6e3a029a..33a0b8b365 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -673,6 +673,7 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; #define CPUID_7_0_ECX_UMIP (1U << 2) #define CPUID_7_0_ECX_PKU (1U << 3) #define CPUID_7_0_ECX_OSPKE (1U << 4) +#define CPUID_7_0_ECX_WAITPKG (1U << 5) /* UMONITOR/UMWAIT/TPAUSE Instructions */ #define CPUID_7_0_ECX_VBMI2 (1U << 6) /* Additional VBMI Instrs */ #define CPUID_7_0_ECX_GFNI (1U << 8) #define CPUID_7_0_ECX_VAES (1U << 9) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 92069099ab..dc618e4062 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -400,6 +400,10 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (host_tsx_blacklisted()) { ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); } + } else if (function == 7 && index == 0 && reg == R_ECX) { + if (enable_cpu_pm) { + ret |= CPUID_7_0_ECX_WAITPKG; + } } else if (function == 7 && index == 0 && reg == R_EDX) { /* * Linux v4.17-v4.20 incorrectly return ARCH_CAPABILITIES on SVM hosts. -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Tao Xu <tao3.xu@intel.com> To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, mtosatti@redhat.com Cc: jingqi.liu@intel.com, tao3.xu@intel.com, qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: [Qemu-devel] [PATCH RESEND v4 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE Date: Wed, 18 Sep 2019 15:23:28 +0800 [thread overview] Message-ID: <20190918072329.1911-2-tao3.xu@intel.com> (raw) In-Reply-To: <20190918072329.1911-1-tao3.xu@intel.com> UMONITOR, UMWAIT and TPAUSE are a set of user wait instructions. This patch adds support for user wait instructions in KVM. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. User wait instructions may be executed at any privilege level, and use IA32_UMWAIT_CONTROL MSR to set the maximum time. The patch enable the umonitor, umwait and tpause features in KVM. Because umwait and tpause can put a (psysical) CPU into a power saving state, by default we dont't expose it to kvm and enable it only when guest CPUID has it. And use QEMU command-line "-overcommit cpu-pm=on" (enable_cpu_pm is enabled), a VM can use UMONITOR, UMWAIT and TPAUSE instructions. If the instruction causes a delay, the amount of time delayed is called here the physical delay. The physical delay is first computed by determining the virtual delay (the time to delay relative to the VM’s timestamp counter). Otherwise, UMONITOR, UMWAIT and TPAUSE cause an invalid-opcode exception(#UD). The release document ref below link: https://software.intel.com/sites/default/files/\ managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf Co-developed-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com> Signed-off-by: Tao Xu <tao3.xu@intel.com> --- No changes in v4. --- target/i386/cpu.c | 3 ++- target/i386/cpu.h | 1 + target/i386/kvm.c | 4 ++++ 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 9e0bac31e8..15f888b13f 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1062,7 +1062,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .type = CPUID_FEATURE_WORD, .feat_names = { NULL, "avx512vbmi", "umip", "pku", - NULL /* ospke */, NULL, "avx512vbmi2", NULL, + NULL /* ospke */, "waitpkg", "avx512vbmi2", NULL, "gfni", "vaes", "vpclmulqdq", "avx512vnni", "avx512bitalg", NULL, "avx512-vpopcntdq", NULL, "la57", NULL, NULL, NULL, @@ -5227,6 +5227,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx, &cpu->mwait.ecx, &cpu->mwait.edx); env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR; + env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG; } } diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 5f6e3a029a..33a0b8b365 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -673,6 +673,7 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; #define CPUID_7_0_ECX_UMIP (1U << 2) #define CPUID_7_0_ECX_PKU (1U << 3) #define CPUID_7_0_ECX_OSPKE (1U << 4) +#define CPUID_7_0_ECX_WAITPKG (1U << 5) /* UMONITOR/UMWAIT/TPAUSE Instructions */ #define CPUID_7_0_ECX_VBMI2 (1U << 6) /* Additional VBMI Instrs */ #define CPUID_7_0_ECX_GFNI (1U << 8) #define CPUID_7_0_ECX_VAES (1U << 9) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 92069099ab..dc618e4062 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -400,6 +400,10 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (host_tsx_blacklisted()) { ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); } + } else if (function == 7 && index == 0 && reg == R_ECX) { + if (enable_cpu_pm) { + ret |= CPUID_7_0_ECX_WAITPKG; + } } else if (function == 7 && index == 0 && reg == R_EDX) { /* * Linux v4.17-v4.20 incorrectly return ARCH_CAPABILITIES on SVM hosts. -- 2.20.1
next prev parent reply other threads:[~2019-09-18 7:23 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-09-18 7:23 [PATCH RESEND v4 0/2] x86: Enable user wait instructions Tao Xu 2019-09-18 7:23 ` [Qemu-devel] " Tao Xu 2019-09-18 7:23 ` Tao Xu [this message] 2019-09-18 7:23 ` [Qemu-devel] [PATCH RESEND v4 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE Tao Xu 2019-09-27 20:22 ` Paolo Bonzini 2019-09-27 20:22 ` Paolo Bonzini 2019-09-29 1:30 ` Tao Xu 2019-09-29 1:30 ` Tao Xu 2019-09-18 7:23 ` [PATCH RESEND v4 2/2] target/i386: Add support for save/load IA32_UMWAIT_CONTROL MSR Tao Xu 2019-09-18 7:23 ` [Qemu-devel] " Tao Xu
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