From ebfeb40743756dfa7087b43ce4e9afe3e85f9710 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 28 Aug 2019 01:00:55 +0200 Subject: [PATCH 1/4] kvm: i386: halt poll control MSR support RH-Author: Marcelo Tosatti Message-id: <20190828010051.GA30252@amt.cnet> Patchwork-id: 90171 O-Subject: [RHEL-7.8 qemu-kvm PATCH] kvm: i386: halt poll control MSR support Bugzilla: 1734502 RH-Acked-by: Eduardo Habkost RH-Acked-by: Igor Mammedov RH-Acked-by: Miroslav Rezanina This is the qemu part of the haltpoll driver: allows migrating the MSR which the guest uses to disable host side polling. Add support for halt poll control MSR: save/restore, migration and new feature name. The purpose of this MSR is to allow the guest to disable host halt poll. (cherry picked from commit d645e1328726b38b3c79525eb57842ce29c1df7c) Signed-off-by: Marcelo Tosatti Message-Id: <20190603230408.GA7938@amt.cnet> [Do not enable by default, as pointed out by Mark Kanda. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Miroslav Rezanina --- linux-headers/asm-x86/kvm_para.h | 2 ++ target/i386/cpu.c | 4 +++- target/i386/cpu.h | 1 + target/i386/kvm.c | 15 +++++++++++++++ target/i386/machine.c | 20 ++++++++++++++++++++ 5 files changed, 41 insertions(+), 1 deletion(-) diff --git a/linux-headers/asm-x86/kvm_para.h b/linux-headers/asm-x86/kvm_para.h index 4c58184..38ab00d 100644 --- a/linux-headers/asm-x86/kvm_para.h +++ b/linux-headers/asm-x86/kvm_para.h @@ -27,6 +27,7 @@ #define KVM_FEATURE_PV_UNHALT 7 #define KVM_FEATURE_PV_TLB_FLUSH 9 #define KVM_FEATURE_ASYNC_PF_VMEXIT 10 +#define KVM_FEATURE_POLL_CONTROL 12 /* The last 8 bits are used to indicate how to interpret the flags field * in pvclock structure. If no bits are set, all flags are ignored. @@ -43,6 +44,7 @@ #define MSR_KVM_ASYNC_PF_EN 0x4b564d02 #define MSR_KVM_STEAL_TIME 0x4b564d03 #define MSR_KVM_PV_EOI_EN 0x4b564d04 +#define MSR_KVM_POLL_CONTROL 0x4b564d05 struct kvm_steal_time { __u64 steal; diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 1f2f286..928e53c 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -903,7 +903,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { "kvmclock", "kvm-nopiodelay", "kvm-mmu", "kvmclock", "kvm-asyncpf", "kvm-steal-time", "kvm-pv-eoi", "kvm-pv-unhalt", NULL, "kvm-pv-tlb-flush", NULL, NULL, - NULL, NULL, NULL, NULL, + "kvm-poll-control", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "kvmclock-stable-bit", NULL, NULL, NULL, @@ -5342,6 +5342,8 @@ static void x86_cpu_initfn(Object *obj) object_property_add_alias(obj, "kvm_steal_time", obj, "kvm-steal-time", &error_abort); object_property_add_alias(obj, "kvm_pv_eoi", obj, "kvm-pv-eoi", &error_abort); object_property_add_alias(obj, "kvm_pv_unhalt", obj, "kvm-pv-unhalt", &error_abort); + object_property_add_alias(obj, "kvm_poll_control", obj, "kvm-poll-control", + &error_abort); object_property_add_alias(obj, "svm_lock", obj, "svm-lock", &error_abort); object_property_add_alias(obj, "nrip_save", obj, "nrip-save", &error_abort); object_property_add_alias(obj, "tsc_scale", obj, "tsc-scale", &error_abort); diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 8ab313e..095e695 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1233,6 +1233,7 @@ typedef struct CPUX86State { uint64_t steal_time_msr; uint64_t async_pf_en_msr; uint64_t pv_eoi_en_msr; + uint64_t poll_control_msr; /* Partition-wide HV MSRs, will be updated only on the first vcpu */ uint64_t msr_hv_hypercall; diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 7afad93..72901e1 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -1199,6 +1199,9 @@ void kvm_arch_reset_vcpu(X86CPU *cpu) env->msr_hv_synic_sint[i] = HV_SINT_MASKED; } } + + /* enabled by default */ + env->poll_control_msr = 1; } void kvm_arch_do_init_vcpu(X86CPU *cpu) @@ -1869,6 +1872,11 @@ static int kvm_put_msrs(X86CPU *cpu, int level) if (env->features[FEAT_KVM] & (1 << KVM_FEATURE_STEAL_TIME)) { kvm_msr_entry_add(cpu, MSR_KVM_STEAL_TIME, env->steal_time_msr); } + + if (env->features[FEAT_KVM] & (1 << KVM_FEATURE_POLL_CONTROL)) { + kvm_msr_entry_add(cpu, MSR_KVM_POLL_CONTROL, env->poll_control_msr); + } + if (has_architectural_pmu_version > 0) { if (has_architectural_pmu_version > 1) { /* Stop the counter. */ @@ -2241,6 +2249,9 @@ static int kvm_get_msrs(X86CPU *cpu) if (env->features[FEAT_KVM] & (1 << KVM_FEATURE_STEAL_TIME)) { kvm_msr_entry_add(cpu, MSR_KVM_STEAL_TIME, 0); } + if (env->features[FEAT_KVM] & (1 << KVM_FEATURE_POLL_CONTROL)) { + kvm_msr_entry_add(cpu, MSR_KVM_POLL_CONTROL, 1); + } if (has_architectural_pmu_version > 0) { if (has_architectural_pmu_version > 1) { kvm_msr_entry_add(cpu, MSR_CORE_PERF_FIXED_CTR_CTRL, 0); @@ -2470,6 +2481,10 @@ static int kvm_get_msrs(X86CPU *cpu) case MSR_KVM_STEAL_TIME: env->steal_time_msr = msrs[i].data; break; + case MSR_KVM_POLL_CONTROL: { + env->poll_control_msr = msrs[i].data; + break; + } case MSR_CORE_PERF_FIXED_CTR_CTRL: env->msr_fixed_ctr_ctrl = msrs[i].data; break; diff --git a/target/i386/machine.c b/target/i386/machine.c index 9e7256a..52b1eae 100644 --- a/target/i386/machine.c +++ b/target/i386/machine.c @@ -325,6 +325,14 @@ static bool steal_time_msr_needed(void *opaque) return cpu->env.steal_time_msr != 0; } +/* Poll control MSR enabled by default */ +static bool poll_control_msr_needed(void *opaque) +{ + X86CPU *cpu = opaque; + + return cpu->env.poll_control_msr != 1; +} + static const VMStateDescription vmstate_steal_time_msr = { .name = "cpu/steal_time_msr", .version_id = 1, @@ -358,6 +366,17 @@ static const VMStateDescription vmstate_pv_eoi_msr = { } }; +static const VMStateDescription vmstate_poll_control_msr = { + .name = "cpu/poll_control_msr", + .version_id = 1, + .minimum_version_id = 1, + .needed = poll_control_msr_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT64(env.poll_control_msr, X86CPU), + VMSTATE_END_OF_LIST() + } +}; + static bool fpop_ip_dp_needed(void *opaque) { X86CPU *cpu = opaque; @@ -1033,6 +1052,7 @@ VMStateDescription vmstate_x86_cpu = { &vmstate_async_pf_msr, &vmstate_pv_eoi_msr, &vmstate_steal_time_msr, + &vmstate_poll_control_msr, &vmstate_fpop_ip_dp, &vmstate_msr_tsc_adjust, &vmstate_msr_tscdeadline, -- 1.8.3.1