@@ -389,6 +389,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
.property = "extended-tseg-mbytes",\
.value = stringify(0),\
},\
+ {\
+ .driver = "hyperv-synic",\
+ .property = "in-kvm-only",\
+ .value = "on",\
+ },\
#define PC_COMPAT_2_8 \
HW_COMPAT_2_8 \
@@ -34,8 +34,10 @@ int kvm_hv_sint_route_set_sint(HvSintRoute *sint_route);
uint32_t hyperv_vp_index(X86CPU *cpu);
X86CPU *hyperv_find_vcpu(uint32_t vp_index);
-void hyperv_synic_add(X86CPU *cpu);
+void hyperv_synic_add(X86CPU *cpu, bool in_kvm_only);
void hyperv_synic_reset(X86CPU *cpu);
void hyperv_synic_update(X86CPU *cpu);
+bool hyperv_synic_usable(void);
+
#endif
@@ -23,6 +23,8 @@ typedef struct SynICState {
X86CPU *cpu;
+ bool in_kvm_only;
+
bool enabled;
hwaddr msg_page_addr;
hwaddr evt_page_addr;
@@ -78,6 +80,10 @@ static void synic_update_evt_page_addr(SynICState *synic)
static void synic_update(SynICState *synic)
{
+ if (synic->in_kvm_only) {
+ return;
+ }
+
synic->enabled = synic->cpu->env.msr_hv_synic_control & HV_SYNIC_ENABLE;
synic_update_msg_page_addr(synic);
synic_update_evt_page_addr(synic);
@@ -154,6 +160,7 @@ HvSintRoute *hyperv_sint_route_new(uint32_t vp_index, uint32_t sint,
}
synic = get_synic(cpu);
+ assert(!synic->in_kvm_only);
sint_route = g_new0(HvSintRoute, 1);
r = event_notifier_init(&sint_route->sint_set_notifier, false);
@@ -240,6 +247,11 @@ int kvm_hv_sint_route_set_sint(HvSintRoute *sint_route)
return event_notifier_set(&sint_route->sint_set_notifier);
}
+static Property synic_props[] = {
+ DEFINE_PROP_BOOL("in-kvm-only", SynICState, in_kvm_only, false),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
static void synic_realize(DeviceState *dev, Error **errp)
{
Object *obj = OBJECT(dev);
@@ -258,18 +270,24 @@ static void synic_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
+ dc->props = synic_props;
dc->realize = synic_realize;
dc->reset = synic_reset;
dc->user_creatable = false;
}
-void hyperv_synic_add(X86CPU *cpu)
+void hyperv_synic_add(X86CPU *cpu, bool in_kvm_only)
{
Object *obj;
+ SynICState *synic;
obj = object_new(TYPE_SYNIC);
object_property_add_child(OBJECT(cpu), "synic", obj, &error_abort);
object_unref(obj);
+
+ synic = SYNIC(obj);
+ synic->in_kvm_only = synic->in_kvm_only || in_kvm_only;
+
object_property_set_bool(obj, true, "realized", &error_abort);
}
@@ -283,6 +301,25 @@ void hyperv_synic_update(X86CPU *cpu)
synic_update(get_synic(cpu));
}
+bool hyperv_synic_usable(void)
+{
+ CPUState *cs;
+
+ CPU_FOREACH(cs) {
+ X86CPU *cpu = X86_CPU(cs);
+
+ if (!cpu->hyperv_synic) {
+ return false;
+ }
+
+ if (get_synic(cpu)->in_kvm_only) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
static const TypeInfo synic_type_info = {
.name = TYPE_SYNIC,
.parent = TYPE_DEVICE,
@@ -700,12 +700,20 @@ static int hyperv_init_vcpu(X86CPU *cpu)
}
if (cpu->hyperv_synic) {
- if (kvm_vcpu_enable_cap(CPU(cpu), KVM_CAP_HYPERV_SYNIC, 0)) {
+ bool in_kvm_only = !cpu->hyperv_vpindex;
+
+ if (!in_kvm_only &&
+ kvm_vcpu_enable_cap(CPU(cpu), KVM_CAP_HYPERV_SYNIC2, 0)) {
+ in_kvm_only = true;
+ }
+
+ if (in_kvm_only &&
+ kvm_vcpu_enable_cap(CPU(cpu), KVM_CAP_HYPERV_SYNIC, 0)) {
fprintf(stderr, "failed to enable Hyper-V SynIC\n");
return -ENOSYS;
}
- hyperv_synic_add(cpu);
+ hyperv_synic_add(cpu, in_kvm_only);
}
return 0;
Certain configurations do not allow SynIC to be used in QEMU. In particular, - when hyperv_vpindex is off, SINT routes can't be used as they refer to the destination vCPU by vp_index - older KVM (which doesn't expose KVM_CAP_HYPERV_SYNIC2) zeroes out SynIC message and event pages on every msr load, breaking migration OTOH in-KVM users of SynIC -- SynIC timers -- do work in those configurations, and we shouldn't stop the guest from using them. Instead, introduce a SynIC property that disallows to use the SynIC within QEMU but not in KVM. The property is set during vCPU init and via compat logic (as older QEMU had no users for SynIC beyond the test device). Also a function is added that allows the devices to query the status of SynIC support across vCPUs. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> --- v1 -> v2: - new patch include/hw/i386/pc.h | 5 +++++ target/i386/hyperv.h | 4 +++- target/i386/hyperv.c | 39 ++++++++++++++++++++++++++++++++++++++- target/i386/kvm.c | 12 ++++++++++-- 4 files changed, 56 insertions(+), 4 deletions(-)