kvm-all.c: add qemu_irq/gsi hash table and utility routines

VFIO platform device needs to setup irqfd but it does not know the
gsi corresponding to the device qemu_irq. This patch proposes to
store a hash table in kvm_state using the qemu_irq as key and the gsi
as a value.

kvm_irqchip_set_qemuirq_gsi allows to insert such a pair. The interrupt
controller is supposed to use it.

kvm_irqchip_[add, remove]_irqfd_notifier allows to setup/tear down
irqfd directly from the qemu_irq.
Signed-off-by: NEric Auger <eric.auger@linaro.org>
Tested-by: NVikram Sethi <vikrams@codeaurora.org>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

include/sysemu/kvm.h

@@ -19,6 +19,7 @@
 #include "qemu/queue.h"
 #include "qom/cpu.h"
 #include "exec/memattrs.h"
+#include "hw/irq.h"
 
 #ifdef CONFIG_KVM
 #include <linux/kvm.h>
@@ -420,6 +421,11 @@ int kvm_irqchip_add_irqfd_notifier_gsi(KVMState *s, EventNotifier *n,
                                        EventNotifier *rn, int virq);
 int kvm_irqchip_remove_irqfd_notifier_gsi(KVMState *s, EventNotifier *n,
                                           int virq);
+int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
+                                   EventNotifier *rn, qemu_irq irq);
+int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n,
+                                      qemu_irq irq);
+void kvm_irqchip_set_qemuirq_gsi(KVMState *s, qemu_irq irq, int gsi);
 void kvm_pc_gsi_handler(void *opaque, int n, int level);
 void kvm_pc_setup_irq_routing(bool pci_enabled);
 void kvm_init_irq_routing(KVMState *s);

kvm-all.c

@@ -37,6 +37,7 @@
 #include "exec/address-spaces.h"
 #include "qemu/event_notifier.h"
 #include "trace.h"
+#include "hw/irq.h"
 
 #include "hw/boards.h"
 
@@ -98,6 +99,7 @@ struct KVMState
      * unsigned, and treating them as signed here can break things */
     unsigned irq_set_ioctl;
     unsigned int sigmask_len;
+    GHashTable *gsimap;
 #ifdef KVM_CAP_IRQ_ROUTING
     struct kvm_irq_routing *irq_routes;
     int nr_allocated_irq_routes;
@@ -1342,6 +1344,35 @@ int kvm_irqchip_remove_irqfd_notifier_gsi(KVMState *s, EventNotifier *n,
            false);
 }
 
+int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
+                                   EventNotifier *rn, qemu_irq irq)
+{
+    gpointer key, gsi;
+    gboolean found = g_hash_table_lookup_extended(s->gsimap, irq, &key, &gsi);
+
+    if (!found) {
+        return -ENXIO;
+    }
+    return kvm_irqchip_add_irqfd_notifier_gsi(s, n, rn, GPOINTER_TO_INT(gsi));
+}
+
+int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n,
+                                      qemu_irq irq)
+{
+    gpointer key, gsi;
+    gboolean found = g_hash_table_lookup_extended(s->gsimap, irq, &key, &gsi);
+
+    if (!found) {
+        return -ENXIO;
+    }
+    return kvm_irqchip_remove_irqfd_notifier_gsi(s, n, GPOINTER_TO_INT(gsi));
+}
+
+void kvm_irqchip_set_qemuirq_gsi(KVMState *s, qemu_irq irq, int gsi)
+{
+    g_hash_table_insert(s->gsimap, irq, GINT_TO_POINTER(gsi));
+}
+
 static int kvm_irqchip_create(MachineState *machine, KVMState *s)
 {
     int ret;
@@ -1374,6 +1405,8 @@ static int kvm_irqchip_create(MachineState *machine, KVMState *s)
 
     kvm_init_irq_routing(s);
 
+    s->gsimap = g_hash_table_new(g_direct_hash, g_direct_equal);
+
     return 0;
 }