Add handling of SIGNAL_EVENT hypercall. For that, provide an interface
to associate an EventNotifier with an event connection number, so that
it's signaled when the SIGNAL_EVENT hypercall with the matching
parameters is called by the guest.
TODO: we should be able to move this to KVM and avoid expensive user
exit just to look up an eventfd by connection number and signal it.
Signed-off-by: Roman Kagan <rka...@virtuozzo.com>
---
target/i386/hyperv.h | 2 +
target/i386/hyperv.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 111 insertions(+), 4 deletions(-)
diff --git a/target/i386/hyperv.h b/target/i386/hyperv.h
index 3d942e5524..4ce41fe314 100644
--- a/target/i386/hyperv.h
+++ b/target/i386/hyperv.h
@@ -43,4 +43,6 @@ int hyperv_post_msg(HvSintRoute *sint_route, struct
hyperv_message *msg);
int hyperv_set_evt_flag(HvSintRoute *sint_route, unsigned evtno);
+int hyperv_set_evt_notifier(uint32_t conn_id, EventNotifier *notifier);
+
#endif
diff --git a/target/i386/hyperv.c b/target/i386/hyperv.c
index b557cd5d5d..9cf1225385 100644
--- a/target/i386/hyperv.c
+++ b/target/i386/hyperv.c
@@ -19,6 +19,9 @@
#include "exec/address-spaces.h"
#include "sysemu/cpus.h"
#include "qemu/bitops.h"
+#include "qemu/queue.h"
+#include "qemu/rcu.h"
+#include "qemu/rcu_queue.h"
#include "migration/vmstate.h"
#include "hyperv.h"
#include "hyperv-proto.h"
@@ -249,6 +252,106 @@ static void async_synic_update(CPUState *cs,
run_on_cpu_data data)
qemu_mutex_unlock_iothread();
}
+typedef struct EvtHandler {
+ struct rcu_head rcu;
+ QLIST_ENTRY(EvtHandler) le;
+ uint32_t conn_id;
+ EventNotifier *notifier;
+} EvtHandler;
+
+static QLIST_HEAD(, EvtHandler) evt_handlers;
+static QemuMutex handlers_mutex;
+
+static void __attribute__((constructor)) hv_init(void)
+{
+ QLIST_INIT(&evt_handlers);
+ qemu_mutex_init(&handlers_mutex);
+}
+
+int hyperv_set_evt_notifier(uint32_t conn_id, EventNotifier *notifier)
+{
+ int ret;
+ EvtHandler *eh;
+
+ qemu_mutex_lock(&handlers_mutex);
+ QLIST_FOREACH(eh, &evt_handlers, le) {
+ if (eh->conn_id == conn_id) {
+ if (notifier) {
+ ret = -EEXIST;
+ } else {
+ QLIST_REMOVE_RCU(eh, le);
+ g_free_rcu(eh, rcu);
+ ret = 0;
+ }
+ goto unlock;
+ }
+ }
+
+ if (notifier) {
+ eh = g_new(EvtHandler, 1);
+ eh->conn_id = conn_id;
+ eh->notifier = notifier;
+ QLIST_INSERT_HEAD_RCU(&evt_handlers, eh, le);
+ ret = 0;
+ } else {
+ ret = -ENOENT;
+ }
+unlock:
+ qemu_mutex_unlock(&handlers_mutex);
+ return ret;
+}
+
+static uint64_t sigevent_params(hwaddr addr, uint32_t *conn_id)
+{
+ uint64_t ret;
+ hwaddr len;
+ struct hyperv_signal_event_input *msg;
+
+ if (addr & (__alignof__(*msg) - 1)) {
+ return HV_STATUS_INVALID_ALIGNMENT;
+ }
+
+ len = sizeof(*msg);
+ msg = cpu_physical_memory_map(addr, &len, 0);
+ if (len < sizeof(*msg)) {
+ ret = HV_STATUS_INSUFFICIENT_MEMORY;
+ } else {
+ *conn_id = (msg->connection_id & HV_CONNECTION_ID_MASK) +
+ msg->flag_number;
+ ret = 0;
+ }
+ cpu_physical_memory_unmap(msg, len, 0, 0);
+ return ret;
+}
+
+static uint64_t hvcall_signal_event(uint64_t param, bool fast)
+{
+ uint64_t ret;
+ uint32_t conn_id;
+ EvtHandler *eh;
+
+ if (likely(fast)) {
+ conn_id = (param & 0xffffffff) + ((param >> 32) & 0xffff);
+ } else {
+ ret = sigevent_params(param, &conn_id);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ ret = HV_STATUS_INVALID_CONNECTION_ID;
+ rcu_read_lock();
+ QLIST_FOREACH_RCU(eh, &evt_handlers, le) {
+ if (eh->conn_id == conn_id) {
+ event_notifier_set(eh->notifier);
+ ret = 0;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit)
{
CPUX86State *env = &cpu->env;
@@ -281,16 +384,18 @@ int kvm_hv_handle_exit(X86CPU *cpu, struct
kvm_hyperv_exit *exit)
RUN_ON_CPU_HOST_PTR(get_synic(cpu)));
return 0;
case KVM_EXIT_HYPERV_HCALL: {
- uint16_t code;
+ uint16_t code = exit->u.hcall.input & 0xffff;
+ bool fast = exit->u.hcall.input & HV_HYPERCALL_FAST;
+ uint64_t param = exit->u.hcall.params[0];
- code = exit->u.hcall.input & 0xffff;
switch (code) {
- case HV_POST_MESSAGE:
case HV_SIGNAL_EVENT:
+ exit->u.hcall.result = hvcall_signal_event(param, fast);
+ break;
default:
exit->u.hcall.result = HV_STATUS_INVALID_HYPERCALL_CODE;
- return 0;
}
+ return 0;
}
default:
return -1;
--
2.14.3
