From 0a1fd178d9b7c054d229b60540b7d12d87eb8070 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 22 Jul 2019 18:22:15 +0100 Subject: [PATCH 34/39] target/i386: kvm: Add support for save and restore nested state RH-Author: Paolo Bonzini Message-id: <20190722182220.19374-14-pbonzini@redhat.com> Patchwork-id: 89629 O-Subject: [RHEL-8.1.0 PATCH qemu-kvm v3 13/18] target/i386: kvm: Add support for save and restore nested state Bugzilla: 1689269 RH-Acked-by: Peter Xu RH-Acked-by: Laurent Vivier RH-Acked-by: Dr. David Alan Gilbert From: Liran Alon Kernel commit 8fcc4b5923af ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE") introduced new IOCTLs to extract and restore vCPU state related to Intel VMX & AMD SVM. Utilize these IOCTLs to add support for migration of VMs which are running nested hypervisors. Reviewed-by: Nikita Leshenko Reviewed-by: Maran Wilson Tested-by: Maran Wilson Signed-off-by: Liran Alon Message-Id: <20190619162140.133674-9-liran.alon@oracle.com> Signed-off-by: Paolo Bonzini (cherry picked from commit ebbfef2f34cfc749c045a4569dedb4f748ec024a) Signed-off-by: Danilo C. L. de Paula --- accel/kvm/kvm-all.c | 8 ++ include/sysemu/kvm.h | 1 + target/i386/cpu.h | 3 + target/i386/kvm.c | 80 ++++++++++++++++++++ target/i386/machine.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 290 insertions(+) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index a939b26..2130fcb 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -87,6 +87,7 @@ struct KVMState #ifdef KVM_CAP_SET_GUEST_DEBUG struct kvm_sw_breakpoint_head kvm_sw_breakpoints; #endif + int max_nested_state_len; int many_ioeventfds; int intx_set_mask; bool sync_mmu; @@ -1646,6 +1647,8 @@ static int kvm_init(MachineState *ms) s->debugregs = kvm_check_extension(s, KVM_CAP_DEBUGREGS); #endif + s->max_nested_state_len = kvm_check_extension(s, KVM_CAP_NESTED_STATE); + #ifdef KVM_CAP_IRQ_ROUTING kvm_direct_msi_allowed = (kvm_check_extension(s, KVM_CAP_SIGNAL_MSI) > 0); #endif @@ -2207,6 +2210,11 @@ int kvm_has_debugregs(void) return kvm_state->debugregs; } +int kvm_max_nested_state_length(void) +{ + return kvm_state->max_nested_state_len; +} + int kvm_has_many_ioeventfds(void) { if (!kvm_enabled()) { diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index a5a6dff..3cf04cf 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -211,6 +211,7 @@ bool kvm_has_sync_mmu(void); int kvm_has_vcpu_events(void); int kvm_has_robust_singlestep(void); int kvm_has_debugregs(void); +int kvm_max_nested_state_length(void); int kvm_has_pit_state2(void); int kvm_has_many_ioeventfds(void); int kvm_has_gsi_routing(void); diff --git a/target/i386/cpu.h b/target/i386/cpu.h index f595fc3..86f3d98 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1335,6 +1335,9 @@ typedef struct CPUX86State { int64_t tsc_khz; int64_t user_tsc_khz; /* for sanity check only */ void *kvm_xsave_buf; +#if defined(CONFIG_KVM) + struct kvm_nested_state *nested_state; +#endif #if defined(CONFIG_HVF) HVFX86EmulatorState *hvf_emul; #endif diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 8a6da90..ddceb7d 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -789,6 +789,7 @@ int kvm_arch_init_vcpu(CPUState *cs) struct kvm_cpuid_entry2 *c; uint32_t signature[3]; int kvm_base = KVM_CPUID_SIGNATURE; + int max_nested_state_len; int r; Error *local_err = NULL; @@ -1180,6 +1181,24 @@ int kvm_arch_init_vcpu(CPUState *cs) if (has_xsave) { env->kvm_xsave_buf = qemu_memalign(4096, sizeof(struct kvm_xsave)); } + + max_nested_state_len = kvm_max_nested_state_length(); + if (max_nested_state_len > 0) { + assert(max_nested_state_len >= offsetof(struct kvm_nested_state, data)); + env->nested_state = g_malloc0(max_nested_state_len); + + env->nested_state->size = max_nested_state_len; + + if (IS_INTEL_CPU(env)) { + struct kvm_vmx_nested_state_hdr *vmx_hdr = + &env->nested_state->hdr.vmx; + + env->nested_state->format = KVM_STATE_NESTED_FORMAT_VMX; + vmx_hdr->vmxon_pa = -1ull; + vmx_hdr->vmcs12_pa = -1ull; + } + } + cpu->kvm_msr_buf = g_malloc0(MSR_BUF_SIZE); if (!(env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_RDTSCP)) { @@ -1199,12 +1218,18 @@ int kvm_arch_init_vcpu(CPUState *cs) int kvm_arch_destroy_vcpu(CPUState *cs) { X86CPU *cpu = X86_CPU(cs); + CPUX86State *env = &cpu->env; if (cpu->kvm_msr_buf) { g_free(cpu->kvm_msr_buf); cpu->kvm_msr_buf = NULL; } + if (env->nested_state) { + g_free(env->nested_state); + env->nested_state = NULL; + } + return 0; } @@ -2875,6 +2900,52 @@ static int kvm_get_debugregs(X86CPU *cpu) return 0; } +static int kvm_put_nested_state(X86CPU *cpu) +{ + CPUX86State *env = &cpu->env; + int max_nested_state_len = kvm_max_nested_state_length(); + + if (max_nested_state_len <= 0) { + return 0; + } + + assert(env->nested_state->size <= max_nested_state_len); + return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_NESTED_STATE, env->nested_state); +} + +static int kvm_get_nested_state(X86CPU *cpu) +{ + CPUX86State *env = &cpu->env; + int max_nested_state_len = kvm_max_nested_state_length(); + int ret; + + if (max_nested_state_len <= 0) { + return 0; + } + + /* + * It is possible that migration restored a smaller size into + * nested_state->hdr.size than what our kernel support. + * We preserve migration origin nested_state->hdr.size for + * call to KVM_SET_NESTED_STATE but wish that our next call + * to KVM_GET_NESTED_STATE will use max size our kernel support. + */ + env->nested_state->size = max_nested_state_len; + + ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_NESTED_STATE, env->nested_state); + if (ret < 0) { + return ret; + } + + if (env->nested_state->flags & KVM_STATE_NESTED_GUEST_MODE) { + env->hflags |= HF_GUEST_MASK; + } else { + env->hflags &= ~HF_GUEST_MASK; + } + + return ret; +} + int kvm_arch_put_registers(CPUState *cpu, int level) { X86CPU *x86_cpu = X86_CPU(cpu); @@ -2882,6 +2953,11 @@ int kvm_arch_put_registers(CPUState *cpu, int level) assert(cpu_is_stopped(cpu) || qemu_cpu_is_self(cpu)); + ret = kvm_put_nested_state(x86_cpu); + if (ret < 0) { + return ret; + } + if (level >= KVM_PUT_RESET_STATE) { ret = kvm_put_msr_feature_control(x86_cpu); if (ret < 0) { @@ -2997,6 +3073,10 @@ int kvm_arch_get_registers(CPUState *cs) if (ret < 0) { goto out; } + ret = kvm_get_nested_state(cpu); + if (ret < 0) { + goto out; + } ret = 0; out: cpu_sync_bndcs_hflags(&cpu->env); diff --git a/target/i386/machine.c b/target/i386/machine.c index 561d4a5..a2ddbba 100644 --- a/target/i386/machine.c +++ b/target/i386/machine.c @@ -230,6 +230,15 @@ static int cpu_pre_save(void *opaque) env->segs[R_SS].flags &= ~(env->segs[R_SS].flags & DESC_DPL_MASK); } +#ifdef CONFIG_KVM + /* Verify we have nested virtualization state from kernel if required */ + if (kvm_enabled() && cpu_has_vmx(env) && !env->nested_state) { + error_report("Guest enabled nested virtualization but kernel " + "does not support saving of nested state"); + return -EINVAL; + } +#endif + return 0; } @@ -277,6 +286,16 @@ static int cpu_post_load(void *opaque, int version_id) env->hflags &= ~HF_CPL_MASK; env->hflags |= (env->segs[R_SS].flags >> DESC_DPL_SHIFT) & HF_CPL_MASK; +#ifdef CONFIG_KVM + if ((env->hflags & HF_GUEST_MASK) && + (!env->nested_state || + !(env->nested_state->flags & KVM_STATE_NESTED_GUEST_MODE))) { + error_report("vCPU set in guest-mode inconsistent with " + "migrated kernel nested state"); + return -EINVAL; + } +#endif + env->fpstt = (env->fpus_vmstate >> 11) & 7; env->fpus = env->fpus_vmstate & ~0x3800; env->fptag_vmstate ^= 0xff; @@ -819,6 +838,182 @@ static const VMStateDescription vmstate_tsc_khz = { } }; +#ifdef CONFIG_KVM + +static bool vmx_vmcs12_needed(void *opaque) +{ + struct kvm_nested_state *nested_state = opaque; + return (nested_state->size > + offsetof(struct kvm_nested_state, data.vmx[0].vmcs12)); +} + +static const VMStateDescription vmstate_vmx_vmcs12 = { + .name = "cpu/kvm_nested_state/vmx/vmcs12", + .version_id = 1, + .minimum_version_id = 1, + .needed = vmx_vmcs12_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT8_ARRAY(data.vmx[0].vmcs12, + struct kvm_nested_state, + KVM_STATE_NESTED_VMX_VMCS_SIZE), + VMSTATE_END_OF_LIST() + } +}; + +static bool vmx_shadow_vmcs12_needed(void *opaque) +{ + struct kvm_nested_state *nested_state = opaque; + return (nested_state->size > + offsetof(struct kvm_nested_state, data.vmx[0].shadow_vmcs12)); +} + +static const VMStateDescription vmstate_vmx_shadow_vmcs12 = { + .name = "cpu/kvm_nested_state/vmx/shadow_vmcs12", + .version_id = 1, + .minimum_version_id = 1, + .needed = vmx_shadow_vmcs12_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT8_ARRAY(data.vmx[0].shadow_vmcs12, + struct kvm_nested_state, + KVM_STATE_NESTED_VMX_VMCS_SIZE), + VMSTATE_END_OF_LIST() + } +}; + +static bool vmx_nested_state_needed(void *opaque) +{ + struct kvm_nested_state *nested_state = opaque; + + return ((nested_state->format == KVM_STATE_NESTED_FORMAT_VMX) && + ((nested_state->hdr.vmx.vmxon_pa != -1ull) || + (nested_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON))); +} + +static const VMStateDescription vmstate_vmx_nested_state = { + .name = "cpu/kvm_nested_state/vmx", + .version_id = 1, + .minimum_version_id = 1, + .needed = vmx_nested_state_needed, + .fields = (VMStateField[]) { + VMSTATE_U64(hdr.vmx.vmxon_pa, struct kvm_nested_state), + VMSTATE_U64(hdr.vmx.vmcs12_pa, struct kvm_nested_state), + VMSTATE_U16(hdr.vmx.smm.flags, struct kvm_nested_state), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription*[]) { + &vmstate_vmx_vmcs12, + &vmstate_vmx_shadow_vmcs12, + NULL, + } +}; + +static bool svm_nested_state_needed(void *opaque) +{ + struct kvm_nested_state *nested_state = opaque; + + return (nested_state->format == KVM_STATE_NESTED_FORMAT_SVM); +} + +static const VMStateDescription vmstate_svm_nested_state = { + .name = "cpu/kvm_nested_state/svm", + .version_id = 1, + .minimum_version_id = 1, + .needed = svm_nested_state_needed, + .fields = (VMStateField[]) { + VMSTATE_END_OF_LIST() + } +}; + +static bool nested_state_needed(void *opaque) +{ + X86CPU *cpu = opaque; + CPUX86State *env = &cpu->env; + + return (env->nested_state && + (vmx_nested_state_needed(env->nested_state) || + svm_nested_state_needed(env->nested_state))); +} + +static int nested_state_post_load(void *opaque, int version_id) +{ + X86CPU *cpu = opaque; + CPUX86State *env = &cpu->env; + struct kvm_nested_state *nested_state = env->nested_state; + int min_nested_state_len = offsetof(struct kvm_nested_state, data); + int max_nested_state_len = kvm_max_nested_state_length(); + + /* + * If our kernel don't support setting nested state + * and we have received nested state from migration stream, + * we need to fail migration + */ + if (max_nested_state_len <= 0) { + error_report("Received nested state when kernel cannot restore it"); + return -EINVAL; + } + + /* + * Verify that the size of received nested_state struct + * at least cover required header and is not larger + * than the max size that our kernel support + */ + if (nested_state->size < min_nested_state_len) { + error_report("Received nested state size less than min: " + "len=%d, min=%d", + nested_state->size, min_nested_state_len); + return -EINVAL; + } + if (nested_state->size > max_nested_state_len) { + error_report("Recieved unsupported nested state size: " + "nested_state->size=%d, max=%d", + nested_state->size, max_nested_state_len); + return -EINVAL; + } + + /* Verify format is valid */ + if ((nested_state->format != KVM_STATE_NESTED_FORMAT_VMX) && + (nested_state->format != KVM_STATE_NESTED_FORMAT_SVM)) { + error_report("Received invalid nested state format: %d", + nested_state->format); + return -EINVAL; + } + + return 0; +} + +static const VMStateDescription vmstate_kvm_nested_state = { + .name = "cpu/kvm_nested_state", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_U16(flags, struct kvm_nested_state), + VMSTATE_U16(format, struct kvm_nested_state), + VMSTATE_U32(size, struct kvm_nested_state), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription*[]) { + &vmstate_vmx_nested_state, + &vmstate_svm_nested_state, + NULL + } +}; + +static const VMStateDescription vmstate_nested_state = { + .name = "cpu/nested_state", + .version_id = 1, + .minimum_version_id = 1, + .needed = nested_state_needed, + .post_load = nested_state_post_load, + .fields = (VMStateField[]) { + VMSTATE_STRUCT_POINTER(env.nested_state, X86CPU, + vmstate_kvm_nested_state, + struct kvm_nested_state), + VMSTATE_END_OF_LIST() + } +}; + +#endif + static bool mcg_ext_ctl_needed(void *opaque) { X86CPU *cpu = opaque; @@ -1080,6 +1275,9 @@ VMStateDescription vmstate_x86_cpu = { #ifndef TARGET_X86_64 &vmstate_efer32, #endif +#ifdef CONFIG_KVM + &vmstate_nested_state, +#endif NULL } }; -- 1.8.3.1