From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
If kvmclock is used, which implies the kernel supports it, register a
kvmclock device with the sysbus. Its main purpose is to save and restore
the kernel state on migration, but this will also allow to visualize it
one day.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
CC: Glauber Costa <glommer@xxxxxxxxxx>
---
target-i386/kvm.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 91 insertions(+), 1 deletions(-)
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 69b8234..47cb22b 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -29,6 +29,7 @@
#include "hw/apic.h"
#include "ioport.h"
#include "kvm_x86.h"
+#include "hw/sysbus.h"
#ifdef CONFIG_KVM_PARA
#include <linux/kvm_para.h>
@@ -309,6 +310,85 @@ void kvm_inject_x86_mce(CPUState *cenv, int bank, uint64_t status,
#endif
}
+#if defined(CONFIG_KVM_PARA) && defined(KVM_CAP_ADJUST_CLOCK)
+typedef struct KVMClockState {
+ SysBusDevice busdev;
+ uint64_t clock;
+ bool clock_valid;
+} KVMClockState;
+
+static void kvmclock_pre_save(void *opaque)
+{
+ KVMClockState *s = opaque;
+ struct kvm_clock_data data;
+ int ret;
+
+ if (s->clock_valid) {
+ return;
+ }
+ ret = kvm_vm_ioctl(KVM_GET_CLOCK, &data);
+ if (ret < 0) {
+ fprintf(stderr, "KVM_GET_CLOCK failed: %s\n", strerror(ret));
+ data.clock = 0;
+ }
+ s->clock = data.clock;
+ /*
+ * If the VM is stopped, declare the clock state valid to avoid re-reading
+ * it on next vmsave (which would return a different value). Will be reset
+ * when the VM is continued.
+ */
+ s->clock_valid = !vm_running;
+}
+
+static int kvmclock_post_load(void *opaque, int version_id)
+{
+ KVMClockState *s = opaque;
+ struct kvm_clock_data data;
+
+ data.clock = s->clock;
+ data.flags = 0;
+ return kvm_vm_ioctl(KVM_SET_CLOCK, &data);
+}
+
+static void kvmclock_vm_state_change(void *opaque, int running, int reason)
+{
+ KVMClockState *s = opaque;
+
+ if (running) {
+ s->clock_valid = false;
+ }
+}
+
+static int kvmclock_init(SysBusDevice *dev)
+{
+ KVMClockState *s = FROM_SYSBUS(KVMClockState, dev);
+
+ qemu_add_vm_change_state_handler(kvmclock_vm_state_change, s);
+ return 0;
+}
+
+static const VMStateDescription kvmclock_vmsd= {
+ .name = "kvmclock",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .pre_save = kvmclock_pre_save,
+ .post_load = kvmclock_post_load,
+ .fields = (VMStateField []) {
+ VMSTATE_UINT64(clock, KVMClockState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static SysBusDeviceInfo kvmclock_info = {
+ .qdev.name = "kvmclock",
+ .qdev.size = sizeof(KVMClockState),
+ .qdev.vmsd = &kvmclock_vmsd,
+ .qdev.no_user = 1,
+ .init = kvmclock_init,
+};
+#endif /* CONFIG_KVM_PARA && KVM_CAP_ADJUST_CLOCK */
+
int kvm_arch_init_vcpu(CPUState *env)
{
struct {
@@ -335,7 +415,6 @@ int kvm_arch_init_vcpu(CPUState *env)
env->cpuid_svm_features &= kvm_x86_get_supported_cpuid(0x8000000A,
0, R_EDX);
-
cpuid_i = 0;
#ifdef CONFIG_KVM_PARA
@@ -442,6 +521,13 @@ int kvm_arch_init_vcpu(CPUState *env)
}
#endif
+#if defined(CONFIG_KVM_PARA) && defined(KVM_CAP_ADJUST_CLOCK)
+ if (cpu_is_bsp(env) &&
+ (env->cpuid_kvm_features & (1ULL << KVM_FEATURE_CLOCKSOURCE))) {
+ sysbus_create_simple("kvmclock", -1, NULL);
+ }
+#endif
+
return kvm_vcpu_ioctl(env, KVM_SET_CPUID2, &cpuid_data);
}
@@ -531,6 +617,10 @@ int kvm_arch_init(int smp_cpus)
int ret;
struct utsname utsname;
+#if defined(CONFIG_KVM_PARA) && defined(KVM_CAP_ADJUST_CLOCK)
+ sysbus_register_withprop(&kvmclock_info);
+#endif
+
ret = kvm_get_supported_msrs();
if (ret < 0) {
return ret;
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
