From: Liran Alon <liran.a...@oracle.com>
Kernel commit 8fcc4b5923af ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE")
introduced new IOCTLs to extract and restore KVM internal state used to
run a VM that is in VMX operation.
Utilize these IOCTLs to add support of migration of VMs which are
running nested hypervisors.
Reviewed-by: Nikita Leshenko <nikita.leshche...@oracle.com>
Signed-off-by: Liran Alon <liran.a...@oracle.com>
[Simplified subsection needed functions and computation of
kvm_min_nested_state_len(); adjusted for upstream kernel field
names; fixed !CONFIG_KVM compilation. - Paolo]
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
accel/kvm/kvm-all.c | 8 ++
include/sysemu/kvm.h | 1 +
target/i386/cpu.h | 3 +
target/i386/kvm.c | 52 ++++++++++++
target/i386/machine.c | 182 ++++++++++++++++++++++++++++++++++++++++++
5 files changed, 246 insertions(+)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index e4ac3386cb..e1c6c067e8 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -88,6 +88,7 @@ struct KVMState
#ifdef KVM_CAP_SET_GUEST_DEBUG
QTAILQ_HEAD(, kvm_sw_breakpoint) kvm_sw_breakpoints;
#endif
+ uint32_t max_nested_state_len;
int many_ioeventfds;
int intx_set_mask;
bool sync_mmu;
@@ -1677,6 +1678,8 @@ 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
@@ -2244,6 +2247,11 @@ int kvm_has_debugregs(void)
return kvm_state->debugregs;
}
+uint32_t 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 a6d1cd190f..5eb79b594c 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -210,6 +210,7 @@ bool kvm_has_sync_mmu(void);
int kvm_has_vcpu_events(void);
int kvm_has_robust_singlestep(void);
int kvm_has_debugregs(void);
+uint32_t 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 bbeb7a9521..550d397807 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1355,6 +1355,9 @@ typedef struct CPUX86State {
#if defined(CONFIG_KVM) || defined(CONFIG_HVF)
void *xsave_buf;
#endif
+#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 dca76830ec..d48fafa22b 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -968,6 +968,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
struct kvm_cpuid_entry2 *c;
uint32_t signature[3];
int kvm_base = KVM_CPUID_SIGNATURE;
+ uint32_t nested_state_len;
int r;
Error *local_err = NULL;
@@ -1368,6 +1369,13 @@ int kvm_arch_init_vcpu(CPUState *cs)
if (has_xsave) {
env->xsave_buf = qemu_memalign(4096, sizeof(struct kvm_xsave));
}
+
+ nested_state_len = kvm_max_nested_state_length();
+ if (nested_state_len > 0) {
+ assert(nested_state_len >= offsetof(struct kvm_nested_state, data));
+ env->nested_state = g_malloc0(nested_state_len);
+ }
+
cpu->kvm_msr_buf = g_malloc0(MSR_BUF_SIZE);
if (!(env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_RDTSCP)) {
@@ -3125,6 +3133,41 @@ static int kvm_get_debugregs(X86CPU *cpu)
return 0;
}
+static int kvm_put_nested_state(X86CPU *cpu)
+{
+ CPUX86State *env = &cpu->env;
+ uint32_t nested_state_len = kvm_max_nested_state_length();
+
+ if (nested_state_len == 0) {
+ return 0;
+ }
+
+ assert(env->nested_state->size <= 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;
+ uint32_t nested_state_len = kvm_max_nested_state_length();
+
+ if (nested_state_len == 0) {
+ return 0;
+ }
+
+ /*
+ * It is possible that migration restored a smaller size into
+ * nested_state->size than what our kernel supports.
+ * We preserve migration origin nested_state->size for
+ * the call to KVM_SET_NESTED_STATE but wish that our next call
+ * to KVM_GET_NESTED_STATE will use the maximum size supported by
+ * the kernel we're running on.
+ */
+ env->nested_state->size = nested_state_len;
+
+ return kvm_vcpu_ioctl(CPU(cpu), KVM_GET_NESTED_STATE, env->nested_state);
+}
+
int kvm_arch_put_registers(CPUState *cpu, int level)
{
X86CPU *x86_cpu = X86_CPU(cpu);
@@ -3132,6 +3175,11 @@ 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) {
@@ -3247,6 +3295,10 @@ 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 41460be54b..45dbae6054 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -246,6 +246,15 @@ 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 (is_nested_virt_enabled(env) && !env->nested_state) {
+ error_report("Guest enabled nested virtualization but kernel "
+ "do not support saving nested state");
+ return -EINVAL;
+ }
+#endif
+
return 0;
}
@@ -909,6 +918,176 @@ 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,
+ vmx.data[0].vmcs12));
+}
+
+static const VMStateDescription vmstate_vmx_vmcs12_state = {
+ .name = "cpu/kvm_nested_state/vmx/vmcs12",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = vmx_vmcs12_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT8_ARRAY(vmx.data[0].vmcs12,
+ struct kvm_nested_state, 0x1000),
+ 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,
+ vmx.data[0].shadow_vmcs12));
+}
+
+static const VMStateDescription vmstate_vmx_shadow_vmcs12_state = {
+ .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(vmx.data[0].shadow_vmcs12,
+ struct kvm_nested_state, 0x1000),
+ 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->vmx.vmxon_pa != -1ull));
+}
+
+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(vmx.vmxon_pa, struct kvm_nested_state),
+ VMSTATE_U64(vmx.vmcs_pa, struct kvm_nested_state),
+ VMSTATE_U16(vmx.smm.flags, struct kvm_nested_state),
+ VMSTATE_END_OF_LIST()
+ },
+ .subsections = (const VMStateDescription*[]) {
+ &vmstate_vmx_vmcs12_state,
+ &vmstate_vmx_shadow_vmcs12_state,
+ 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 (is_vmx_enabled(env) && vmx_nested_state_needed(env->nested_state))
||
+ (is_svm_enabled(env) && 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;
+ uint32_t min_nested_state_len = offsetof(struct kvm_nested_state, data);
+ uint32_t 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;
@@ -1148,6 +1327,9 @@ VMStateDescription vmstate_x86_cpu = {
&vmstate_msr_intel_pt,
&vmstate_msr_virt_ssbd,
&vmstate_svm_npt,
+#ifdef CONFIG_KVM
+ &vmstate_nested_state,
+#endif
NULL
}
};
--
2.21.0
