[Qemu-devel] [PATCH v2 0/2] add qemu_irq/gsi hashtable

[Qemu-devel] [PATCH v2 0/2] add qemu_irq/gsi hashtable

[Eric Auger]

The VFIO platform needs to setup irqfd but it does not know the gsi associated
to the sysbus device qemu_irq.

With PCI there is a PCIINTxRoute bus lookup mechanism that enables to
retrieve the gsi from the PCI host controller/bridge pin. The conversion
is implemented by the PCI host controller. With platform devices, this
conversion function is implemented by the interrupt controller.

This series implements a hash table in kvm-all that stores the mapping
between qemu_irq and gsi. A setter is introduced for the interrupt controller
to insert mappings. Also functions are added to setup/tear down irqfd directly
from a qemu_irq. Those functions now can be used by the VFIO platform device
to setup VFIO signaling.

v1 -> v2:
- series renamed from "irq: add get_gsi callback"
- follow implementation suggested by Paolo (hope I fully understood it)

Eric Auger (2):
  kvm-all.c: add qemu_irq/gsi hash table and utility routines
  intc: arm_gic_kvm: set the qemu_irq/gsi mapping

 hw/intc/arm_gic_kvm.c |  5 +++++
 include/sysemu/kvm.h  |  6 ++++++
 kvm-all.c             | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)

-- 
1.8.3.2

[Qemu-devel] [PATCH v2 1/2] kvm-all.c: add qemu_irq/gsi hash table and utility routines

[Eric Auger]

VFIO platform device needs to setup irqfd but it does not know the
gsi corresponding to the device qemu_irq. This series 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]_qemuirq_irqfd_notifier allows to setup/tear down
irqfd directly from the qemu_irq.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 include/sysemu/kvm.h |  6 ++++++
 kvm-all.c            | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 197e6c0..911aaa8 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -18,6 +18,7 @@
 #include "config-host.h"
 #include "qemu/queue.h"
 #include "qom/cpu.h"
+#include "hw/irq.h"
 
 #ifdef CONFIG_KVM
 #include <linux/kvm.h>
@@ -416,6 +417,11 @@ int kvm_irqchip_add_adapter_route(KVMState *s, AdapterInfo *adapter);
 int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
                                    EventNotifier *rn, int virq);
 int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq);
+int kvm_irqchip_add_qemuirq_irqfd_notifier(KVMState *s, EventNotifier *n,
+                                           EventNotifier *rn, qemu_irq irq);
+int kvm_irqchip_remove_qemuirq_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);
diff --git a/kvm-all.c b/kvm-all.c
index dd44f8c..ec9f4ac 100644
--- a/kvm-all.c
+++ b/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"
 
@@ -99,6 +100,7 @@ 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;
@@ -1381,6 +1383,37 @@ int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq)
            false);
 }
 
+int kvm_irqchip_add_qemuirq_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;
+    } else {
+        return kvm_irqchip_add_irqfd_notifier(s, n, rn, GPOINTER_TO_UINT(gsi));
+    }
+}
+
+int kvm_irqchip_remove_qemuirq_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;
+    } else {
+        return kvm_irqchip_remove_irqfd_notifier(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;
@@ -1413,6 +1446,8 @@ 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;
 }
 
-- 
1.8.3.2

[Qemu-devel] [PATCH v2 2/2] intc: arm_gic_kvm: set the qemu_irq/gsi mapping

[Eric Auger]

The arm_gic_kvm now calls kvm_irqchip_set_qemuirq_gsi to build
the hash table storing qemu_irq/gsi mappings. From that point on
irqfd can be setup directly from the qemu_irq using
kvm_irqchip_add_qemuirq_irqfd_notifier.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 hw/intc/arm_gic_kvm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c
index e1952ad..28506e3 100644
--- a/hw/intc/arm_gic_kvm.c
+++ b/hw/intc/arm_gic_kvm.c
@@ -554,6 +554,11 @@ static void kvm_arm_gic_realize(DeviceState *dev, Error **errp)
      */
     i += (GIC_INTERNAL * s->num_cpu);
     qdev_init_gpio_in(dev, kvm_arm_gic_set_irq, i);
+
+    for (i = 0; i < s->num_irq - GIC_INTERNAL; i++) {
+        qemu_irq irq = qdev_get_gpio_in(dev, i);
+        kvm_irqchip_set_qemuirq_gsi(kvm_state, irq, i);
+    }
     /* We never use our outbound IRQ lines but provide them so that
      * we maintain the same interface as the non-KVM GIC.
      */
-- 
1.8.3.2

Re: [Qemu-devel] [PATCH v2 1/2] kvm-all.c: add qemu_irq/gsi hash table and utility routines

[Eric Auger]

On 04/23/2015 05:22 PM, Paolo Bonzini wrote:
> 
> 
> On 23/04/2015 17:08, Eric Auger wrote:
>>  int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
>>                                     EventNotifier *rn, int virq);
>>  int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq);
>> +int kvm_irqchip_add_qemuirq_irqfd_notifier(KVMState *s, EventNotifier *n,
>> +                                           EventNotifier *rn, qemu_irq irq);
>> +int kvm_irqchip_remove_qemuirq_irqfd_notifier(KVMState *s, EventNotifier *n,
>> +                                              qemu_irq irq);
> 
> 
> Perhaps rename the existing ones to
> 
> kvm_irqchip_add_irqfd_notifier_gsi
> kvm_irqchip_remove_irqfd_notifier_gsi
> 
> and change the new ones to kvm_irqchip_add_irqfd_notifier and
> kvm_irqchip_remove_irqfd_notifier?
OK thanks!

Eric
> 
> Okay with that change; include it in the vfio-platform series and I'll
> ack it.
> 
> Paolo
> 

Re: [Qemu-devel] [PATCH v2 1/2] kvm-all.c: add qemu_irq/gsi hash table and utility routines

[Paolo Bonzini]

On 23/04/2015 17:08, Eric Auger wrote:
>  int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n,
>                                     EventNotifier *rn, int virq);
>  int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq);
> +int kvm_irqchip_add_qemuirq_irqfd_notifier(KVMState *s, EventNotifier *n,
> +                                           EventNotifier *rn, qemu_irq irq);
> +int kvm_irqchip_remove_qemuirq_irqfd_notifier(KVMState *s, EventNotifier *n,
> +                                              qemu_irq irq);


Perhaps rename the existing ones to

kvm_irqchip_add_irqfd_notifier_gsi
kvm_irqchip_remove_irqfd_notifier_gsi

and change the new ones to kvm_irqchip_add_irqfd_notifier and
kvm_irqchip_remove_irqfd_notifier?

Okay with that change; include it in the vfio-platform series and I'll
ack it.

Paolo