diff mbox series

[for-4.1] vfio/common: Introduce vfio_set_irq_signaling helper

Message ID 20190409155831.18764-1-eric.auger@redhat.com
State New
Headers show
Series [for-4.1] vfio/common: Introduce vfio_set_irq_signaling helper | expand

Commit Message

Eric Auger April 9, 2019, 3:58 p.m. UTC 
The code used to assign an interrupt index/subindex to an
eventfd is duplicated many times. Let's introduce an helper that
allows to set/unset the signaling for an ACTION_TRIGGER or
ACTION_UNMASK action.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

This is a follow-up to
[PATCH v2 0/2] vfio-pci: Introduce vfio_set_event_handler().
It looks to me that introducing vfio_set_irq_signaling() has more
benefits in term of code reduction and the helper abstraction
looks cleaner.
---
 hw/vfio/common.c              |  61 +++++++++
 hw/vfio/pci.c                 | 224 ++++++++--------------------------
 hw/vfio/platform.c            |  55 +++------
 include/hw/vfio/vfio-common.h |   2 +
 4 files changed, 134 insertions(+), 208 deletions(-)

Comments

Cornelia Huck April 12, 2019, 11:31 a.m. UTC | #1 
On Tue,  9 Apr 2019 17:58:31 +0200
Eric Auger <eric.auger@redhat.com> wrote:

> The code used to assign an interrupt index/subindex to an
> eventfd is duplicated many times. Let's introduce an helper that
> allows to set/unset the signaling for an ACTION_TRIGGER or
> ACTION_UNMASK action.

I like that, and it looks like ccw can use the new function as well. (I
can do a patch on top.)

> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> 
> This is a follow-up to
> [PATCH v2 0/2] vfio-pci: Introduce vfio_set_event_handler().
> It looks to me that introducing vfio_set_irq_signaling() has more
> benefits in term of code reduction and the helper abstraction
> looks cleaner.
> ---
>  hw/vfio/common.c              |  61 +++++++++
>  hw/vfio/pci.c                 | 224 ++++++++--------------------------
>  hw/vfio/platform.c            |  55 +++------
>  include/hw/vfio/vfio-common.h |   2 +
>  4 files changed, 134 insertions(+), 208 deletions(-)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Eric Auger April 23, 2019, 3:11 p.m. UTC | #2 
Hi Cornelia

On 4/12/19 1:31 PM, Cornelia Huck wrote:
> On Tue,  9 Apr 2019 17:58:31 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
> 
>> The code used to assign an interrupt index/subindex to an
>> eventfd is duplicated many times. Let's introduce an helper that
>> allows to set/unset the signaling for an ACTION_TRIGGER or
>> ACTION_UNMASK action.
> 
> I like that, and it looks like ccw can use the new function as well. (I
> can do a patch on top.)

Thanks! Yes, feel free to proceed with the ccw patch once this gets
merged.
> 
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> This is a follow-up to
>> [PATCH v2 0/2] vfio-pci: Introduce vfio_set_event_handler().
>> It looks to me that introducing vfio_set_irq_signaling() has more
>> benefits in term of code reduction and the helper abstraction
>> looks cleaner.
>> ---
>>  hw/vfio/common.c              |  61 +++++++++
>>  hw/vfio/pci.c                 | 224 ++++++++--------------------------
>>  hw/vfio/platform.c            |  55 +++------
>>  include/hw/vfio/vfio-common.h |   2 +
>>  4 files changed, 134 insertions(+), 208 deletions(-)
> 
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Thanks

Eric
>
Alex Williamson May 15, 2019, 10:52 p.m. UTC | #3 
On Tue,  9 Apr 2019 17:58:31 +0200
Eric Auger <eric.auger@redhat.com> wrote:

> The code used to assign an interrupt index/subindex to an
> eventfd is duplicated many times. Let's introduce an helper that
> allows to set/unset the signaling for an ACTION_TRIGGER or
> ACTION_UNMASK action.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> 
> This is a follow-up to
> [PATCH v2 0/2] vfio-pci: Introduce vfio_set_event_handler().
> It looks to me that introducing vfio_set_irq_signaling() has more
> benefits in term of code reduction and the helper abstraction
> looks cleaner.
> ---
>  hw/vfio/common.c              |  61 +++++++++
>  hw/vfio/pci.c                 | 224 ++++++++--------------------------
>  hw/vfio/platform.c            |  55 +++------
>  include/hw/vfio/vfio-common.h |   2 +
>  4 files changed, 134 insertions(+), 208 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 4374cc6176..f88fd10ca3 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -95,6 +95,67 @@ void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
>      ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
>  }
>  
> +static inline const char *action_to_str(int action)
> +{
> +    switch (action) {
> +    case VFIO_IRQ_SET_ACTION_MASK:
> +        return "MASK";
> +    case VFIO_IRQ_SET_ACTION_UNMASK:
> +        return "UNMASK";
> +    case VFIO_IRQ_SET_ACTION_TRIGGER:
> +        return "TRIGGER";
> +    default:
> +        return "UNKNOWN ACTION";
> +    }
> +}
> +
> +int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
> +                           int action, int fd, Error **errp)
> +{
> +    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
> +                                      .index = index };
> +    struct vfio_irq_set *irq_set;
> +    int argsz, ret = 0;
> +    int32_t *pfd;
> +
> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
> +    if (ret < 0) {
> +        error_setg_errno(errp, errno, "index %d does not exist", index);
> +        goto error;
> +    }
> +    if (irq_info.count < subindex + 1) {
> +        error_setg_errno(errp, errno, "subindex %d does not exist", subindex);
> +        goto error;
> +    }
> +
> +    argsz = sizeof(*irq_set) + sizeof(*pfd);
> +
> +    irq_set = g_malloc0(argsz);
> +    irq_set->argsz = argsz;
> +    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | action;
> +    irq_set->index = index;
> +    irq_set->start = subindex;
> +    irq_set->count = 1;
> +    pfd = (int32_t *)&irq_set->data;
> +    *pfd = fd;
> +
> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);

Hi Eric,

Sorry for the long delay.  While I like the code reduction and
simplification, is it really acceptable that every SET_IRQS ioctl is
now a GET_IRQ_INFO + SET_IRQS?  Are we trying to protect against
devices dynamically changing their interrupt support?  Do we not trust
the callers?

> +
> +    g_free(irq_set);
> +
> +    if (ret) {
> +        error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
> +        goto error;
> +    }
> +    return 0;
> +error:
> +    error_prepend(errp,
> +                  "Failed to %s %s eventfd signaling for interrupt [%d,%d]: ",
> +                  fd < 0 ? "tear down" : "set up", action_to_str(action),
> +                  index, subindex);


Maybe icing on the cake, but this leaves me wishing it printed "MSIX-3"
rather than "[2,3]" for a PCI device ;)


> +    return ret;
> +}
> +
>  /*
>   * IO Port/MMIO - Beware of the endians, VFIO is always little endian
>   */
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 504019c458..cd93ff6fa3 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
[snip]
> @@ -2718,77 +2630,43 @@ static void vfio_req_notifier_handler(void *opaque)
>  
>  static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
>  {
> -    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
> -                                      .index = VFIO_PCI_REQ_IRQ_INDEX };
> -    int argsz;
> -    struct vfio_irq_set *irq_set;
> -    int32_t *pfd;
> +    Error *err = NULL;
> +    int32_t fd;
>  
>      if (!(vdev->features & VFIO_FEATURE_ENABLE_REQ)) {
>          return;
>      }
>  
> -    if (ioctl(vdev->vbasedev.fd,
> -              VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) {
> -        return;
> -    }

Here we used GET_IRQ_INFO to quietly only enable the request notifier
when it's available, now it looks like this is no longer quiet if that
support is unavailable.  Is that intentional?  Thanks,

Alex

> -
>      if (event_notifier_init(&vdev->req_notifier, 0)) {
>          error_report("vfio: Unable to init event notifier for device request");
>          return;
>      }
>  
> -    argsz = sizeof(*irq_set) + sizeof(*pfd);
> +    fd = event_notifier_get_fd(&vdev->req_notifier);
> +    qemu_set_fd_handler(fd, vfio_req_notifier_handler, NULL, vdev);
>  
> -    irq_set = g_malloc0(argsz);
> -    irq_set->argsz = argsz;
> -    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
> -                     VFIO_IRQ_SET_ACTION_TRIGGER;
> -    irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
> -    irq_set->start = 0;
> -    irq_set->count = 1;
> -    pfd = (int32_t *)&irq_set->data;
> -
> -    *pfd = event_notifier_get_fd(&vdev->req_notifier);
> -    qemu_set_fd_handler(*pfd, vfio_req_notifier_handler, NULL, vdev);
> -
> -    if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
> -        error_report("vfio: Failed to set up device request notification");
> -        qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
> +    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
> +                           VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
> +        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
> +        qemu_set_fd_handler(fd, NULL, NULL, vdev);
>          event_notifier_cleanup(&vdev->req_notifier);
>      } else {
>          vdev->req_enabled = true;
>      }
> -
> -    g_free(irq_set);
>  }
Eric Auger May 20, 2019, 2:17 p.m. UTC | #4 
Hi Alex,

On 5/16/19 12:52 AM, Alex Williamson wrote:
> On Tue,  9 Apr 2019 17:58:31 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
> 
>> The code used to assign an interrupt index/subindex to an
>> eventfd is duplicated many times. Let's introduce an helper that
>> allows to set/unset the signaling for an ACTION_TRIGGER or
>> ACTION_UNMASK action.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> This is a follow-up to
>> [PATCH v2 0/2] vfio-pci: Introduce vfio_set_event_handler().
>> It looks to me that introducing vfio_set_irq_signaling() has more
>> benefits in term of code reduction and the helper abstraction
>> looks cleaner.
>> ---
>>  hw/vfio/common.c              |  61 +++++++++
>>  hw/vfio/pci.c                 | 224 ++++++++--------------------------
>>  hw/vfio/platform.c            |  55 +++------
>>  include/hw/vfio/vfio-common.h |   2 +
>>  4 files changed, 134 insertions(+), 208 deletions(-)
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 4374cc6176..f88fd10ca3 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -95,6 +95,67 @@ void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
>>      ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
>>  }
>>  
>> +static inline const char *action_to_str(int action)
>> +{
>> +    switch (action) {
>> +    case VFIO_IRQ_SET_ACTION_MASK:
>> +        return "MASK";
>> +    case VFIO_IRQ_SET_ACTION_UNMASK:
>> +        return "UNMASK";
>> +    case VFIO_IRQ_SET_ACTION_TRIGGER:
>> +        return "TRIGGER";
>> +    default:
>> +        return "UNKNOWN ACTION";
>> +    }
>> +}
>> +
>> +int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
>> +                           int action, int fd, Error **errp)
>> +{
>> +    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
>> +                                      .index = index };
>> +    struct vfio_irq_set *irq_set;
>> +    int argsz, ret = 0;
>> +    int32_t *pfd;
>> +
>> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
>> +    if (ret < 0) {
>> +        error_setg_errno(errp, errno, "index %d does not exist", index);
>> +        goto error;
>> +    }
>> +    if (irq_info.count < subindex + 1) {
>> +        error_setg_errno(errp, errno, "subindex %d does not exist", subindex);
>> +        goto error;
>> +    }
>> +
>> +    argsz = sizeof(*irq_set) + sizeof(*pfd);
>> +
>> +    irq_set = g_malloc0(argsz);
>> +    irq_set->argsz = argsz;
>> +    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | action;
>> +    irq_set->index = index;
>> +    irq_set->start = subindex;
>> +    irq_set->count = 1;
>> +    pfd = (int32_t *)&irq_set->data;
>> +    *pfd = fd;
>> +
>> +    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
> 
> Hi Eric,
> 
> Sorry for the long delay.  While I like the code reduction and
> simplification, is it really acceptable that every SET_IRQS ioctl is
> now a GET_IRQ_INFO + SET_IRQS?  Are we trying to protect against
> devices dynamically changing their interrupt support?  Do we not trust
> the callers?
I agree this is generally not needed. I will remove the check.
> 
>> +
>> +    g_free(irq_set);
>> +
>> +    if (ret) {
>> +        error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
>> +        goto error;
>> +    }
>> +    return 0;
>> +error:
>> +    error_prepend(errp,
>> +                  "Failed to %s %s eventfd signaling for interrupt [%d,%d]: ",
>> +                  fd < 0 ? "tear down" : "set up", action_to_str(action),
>> +                  index, subindex);
> 
> 
> Maybe icing on the cake, but this leaves me wishing it printed "MSIX-3"
> rather than "[2,3]" for a PCI device ;)
OK
> 
> 
>> +    return ret;
>> +}
>> +
>>  /*
>>   * IO Port/MMIO - Beware of the endians, VFIO is always little endian
>>   */
>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
>> index 504019c458..cd93ff6fa3 100644
>> --- a/hw/vfio/pci.c
>> +++ b/hw/vfio/pci.c
> [snip]
>> @@ -2718,77 +2630,43 @@ static void vfio_req_notifier_handler(void *opaque)
>>  
>>  static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
>>  {
>> -    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
>> -                                      .index = VFIO_PCI_REQ_IRQ_INDEX };
>> -    int argsz;
>> -    struct vfio_irq_set *irq_set;
>> -    int32_t *pfd;
>> +    Error *err = NULL;
>> +    int32_t fd;
>>  
>>      if (!(vdev->features & VFIO_FEATURE_ENABLE_REQ)) {
>>          return;
>>      }
>>  
>> -    if (ioctl(vdev->vbasedev.fd,
>> -              VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) {
>> -        return;
>> -    }
> 
> Here we used GET_IRQ_INFO to quietly only enable the request notifier
> when it's available, now it looks like this is no longer quiet if that
> support is unavailable.  Is that intentional?  Thanks,
not really I acknowledge ;-) I will restore that quiet check here.

Thanks

Eric
> 
> Alex
> 
>> -
>>      if (event_notifier_init(&vdev->req_notifier, 0)) {
>>          error_report("vfio: Unable to init event notifier for device request");
>>          return;
>>      }
>>  
>> -    argsz = sizeof(*irq_set) + sizeof(*pfd);
>> +    fd = event_notifier_get_fd(&vdev->req_notifier);
>> +    qemu_set_fd_handler(fd, vfio_req_notifier_handler, NULL, vdev);
>>  
>> -    irq_set = g_malloc0(argsz);
>> -    irq_set->argsz = argsz;
>> -    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
>> -                     VFIO_IRQ_SET_ACTION_TRIGGER;
>> -    irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
>> -    irq_set->start = 0;
>> -    irq_set->count = 1;
>> -    pfd = (int32_t *)&irq_set->data;
>> -
>> -    *pfd = event_notifier_get_fd(&vdev->req_notifier);
>> -    qemu_set_fd_handler(*pfd, vfio_req_notifier_handler, NULL, vdev);
>> -
>> -    if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
>> -        error_report("vfio: Failed to set up device request notification");
>> -        qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
>> +    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
>> +                           VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
>> +        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
>> +        qemu_set_fd_handler(fd, NULL, NULL, vdev);
>>          event_notifier_cleanup(&vdev->req_notifier);
>>      } else {
>>          vdev->req_enabled = true;
>>      }
>> -
>> -    g_free(irq_set);
>>  }
>
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 4374cc6176..f88fd10ca3 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -95,6 +95,67 @@  void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index)
     ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
 }
 
+static inline const char *action_to_str(int action)
+{
+    switch (action) {
+    case VFIO_IRQ_SET_ACTION_MASK:
+        return "MASK";
+    case VFIO_IRQ_SET_ACTION_UNMASK:
+        return "UNMASK";
+    case VFIO_IRQ_SET_ACTION_TRIGGER:
+        return "TRIGGER";
+    default:
+        return "UNKNOWN ACTION";
+    }
+}
+
+int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
+                           int action, int fd, Error **errp)
+{
+    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
+                                      .index = index };
+    struct vfio_irq_set *irq_set;
+    int argsz, ret = 0;
+    int32_t *pfd;
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
+    if (ret < 0) {
+        error_setg_errno(errp, errno, "index %d does not exist", index);
+        goto error;
+    }
+    if (irq_info.count < subindex + 1) {
+        error_setg_errno(errp, errno, "subindex %d does not exist", subindex);
+        goto error;
+    }
+
+    argsz = sizeof(*irq_set) + sizeof(*pfd);
+
+    irq_set = g_malloc0(argsz);
+    irq_set->argsz = argsz;
+    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | action;
+    irq_set->index = index;
+    irq_set->start = subindex;
+    irq_set->count = 1;
+    pfd = (int32_t *)&irq_set->data;
+    *pfd = fd;
+
+    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+    g_free(irq_set);
+
+    if (ret) {
+        error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
+        goto error;
+    }
+    return 0;
+error:
+    error_prepend(errp,
+                  "Failed to %s %s eventfd signaling for interrupt [%d,%d]: ",
+                  fd < 0 ? "tear down" : "set up", action_to_str(action),
+                  index, subindex);
+    return ret;
+}
+
 /*
  * IO Port/MMIO - Beware of the endians, VFIO is always little endian
  */
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 504019c458..cd93ff6fa3 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -113,9 +113,7 @@  static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
         .gsi = vdev->intx.route.irq,
         .flags = KVM_IRQFD_FLAG_RESAMPLE,
     };
-    struct vfio_irq_set *irq_set;
-    int ret, argsz;
-    int32_t *pfd;
+    Error *err = NULL;
 
     if (vdev->no_kvm_intx || !kvm_irqfds_enabled() ||
         vdev->intx.route.mode != PCI_INTX_ENABLED ||
@@ -143,22 +141,10 @@  static void vfio_intx_enable_kvm(VFIOPCIDevice *vdev, Error **errp)
         goto fail_irqfd;
     }
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
-
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_UNMASK;
-    irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-
-    *pfd = irqfd.resamplefd;
-
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
-    g_free(irq_set);
-    if (ret) {
-        error_setg_errno(errp, -ret, "failed to setup INTx unmask fd");
+    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
+                               VFIO_IRQ_SET_ACTION_UNMASK,
+                               irqfd.resamplefd, &err)) {
+        error_propagate(errp, err);
         goto fail_vfio;
     }
 
@@ -262,10 +248,10 @@  static void vfio_intx_update(PCIDevice *pdev)
 static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
 {
     uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
-    int ret, argsz, retval = 0;
-    struct vfio_irq_set *irq_set;
-    int32_t *pfd;
     Error *err = NULL;
+    int32_t fd;
+    int ret;
+
 
     if (!pin) {
         return 0;
@@ -292,27 +278,15 @@  static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
         error_setg_errno(errp, -ret, "event_notifier_init failed");
         return ret;
     }
+    fd = event_notifier_get_fd(&vdev->intx.interrupt);
+    qemu_set_fd_handler(fd, vfio_intx_interrupt, NULL, vdev);
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
-
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
-    irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-
-    *pfd = event_notifier_get_fd(&vdev->intx.interrupt);
-    qemu_set_fd_handler(*pfd, vfio_intx_interrupt, NULL, vdev);
-
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
-    if (ret) {
-        error_setg_errno(errp, -ret, "failed to setup INTx fd");
-        qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
+    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_INTX_IRQ_INDEX, 0,
+                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+        error_propagate(errp, err);
+        qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->intx.interrupt);
-        retval = -errno;
-        goto cleanup;
+        return -errno;
     }
 
     vfio_intx_enable_kvm(vdev, &err);
@@ -323,11 +297,7 @@  static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
     vdev->interrupt = VFIO_INT_INTx;
 
     trace_vfio_intx_enable(vdev->vbasedev.name);
-
-cleanup:
-    g_free(irq_set);
-
-    return retval;
+    return 0;
 }
 
 static void vfio_intx_disable(VFIOPCIDevice *vdev)
@@ -530,31 +500,19 @@  static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
             error_report("vfio: failed to enable vectors, %d", ret);
         }
     } else {
-        int argsz;
-        struct vfio_irq_set *irq_set;
-        int32_t *pfd;
-
-        argsz = sizeof(*irq_set) + sizeof(*pfd);
-
-        irq_set = g_malloc0(argsz);
-        irq_set->argsz = argsz;
-        irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
-                         VFIO_IRQ_SET_ACTION_TRIGGER;
-        irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX;
-        irq_set->start = nr;
-        irq_set->count = 1;
-        pfd = (int32_t *)&irq_set->data;
+        Error *err = NULL;
+        int32_t fd;
 
         if (vector->virq >= 0) {
-            *pfd = event_notifier_get_fd(&vector->kvm_interrupt);
+            fd = event_notifier_get_fd(&vector->kvm_interrupt);
         } else {
-            *pfd = event_notifier_get_fd(&vector->interrupt);
+            fd = event_notifier_get_fd(&vector->interrupt);
         }
 
-        ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
-        g_free(irq_set);
-        if (ret) {
-            error_report("vfio: failed to modify vector, %d", ret);
+        if (vfio_set_irq_signaling(&vdev->vbasedev,
+                                     VFIO_PCI_MSIX_IRQ_INDEX, nr,
+                                     VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+            error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         }
     }
 
@@ -591,26 +549,10 @@  static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
      * be re-asserted on unmask.  Nothing to do if already using QEMU mode.
      */
     if (vector->virq >= 0) {
-        int argsz;
-        struct vfio_irq_set *irq_set;
-        int32_t *pfd;
+        int32_t fd = event_notifier_get_fd(&vector->interrupt);
 
-        argsz = sizeof(*irq_set) + sizeof(*pfd);
-
-        irq_set = g_malloc0(argsz);
-        irq_set->argsz = argsz;
-        irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
-                         VFIO_IRQ_SET_ACTION_TRIGGER;
-        irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX;
-        irq_set->start = nr;
-        irq_set->count = 1;
-        pfd = (int32_t *)&irq_set->data;
-
-        *pfd = event_notifier_get_fd(&vector->interrupt);
-
-        ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
-
-        g_free(irq_set);
+        vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX, nr,
+                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, NULL);
     }
 }
 
@@ -2629,10 +2571,8 @@  static void vfio_err_notifier_handler(void *opaque)
  */
 static void vfio_register_err_notifier(VFIOPCIDevice *vdev)
 {
-    int ret;
-    int argsz;
-    struct vfio_irq_set *irq_set;
-    int32_t *pfd;
+    Error *err = NULL;
+    int32_t fd;
 
     if (!vdev->pci_aer) {
         return;
@@ -2644,58 +2584,30 @@  static void vfio_register_err_notifier(VFIOPCIDevice *vdev)
         return;
     }
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
+    fd = event_notifier_get_fd(&vdev->err_notifier);
+    qemu_set_fd_handler(fd, vfio_err_notifier_handler, NULL, vdev);
 
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
-                     VFIO_IRQ_SET_ACTION_TRIGGER;
-    irq_set->index = VFIO_PCI_ERR_IRQ_INDEX;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-
-    *pfd = event_notifier_get_fd(&vdev->err_notifier);
-    qemu_set_fd_handler(*pfd, vfio_err_notifier_handler, NULL, vdev);
-
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
-    if (ret) {
-        error_report("vfio: Failed to set up error notification");
-        qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
+    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_ERR_IRQ_INDEX, 0,
+                               VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
+        qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->err_notifier);
         vdev->pci_aer = false;
     }
-    g_free(irq_set);
 }
 
 static void vfio_unregister_err_notifier(VFIOPCIDevice *vdev)
 {
-    int argsz;
-    struct vfio_irq_set *irq_set;
-    int32_t *pfd;
-    int ret;
+    Error *err = NULL;
 
     if (!vdev->pci_aer) {
         return;
     }
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
-
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
-                     VFIO_IRQ_SET_ACTION_TRIGGER;
-    irq_set->index = VFIO_PCI_ERR_IRQ_INDEX;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-    *pfd = -1;
-
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
-    if (ret) {
-        error_report("vfio: Failed to de-assign error fd: %m");
+    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_ERR_IRQ_INDEX, 0,
+                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
-    g_free(irq_set);
     qemu_set_fd_handler(event_notifier_get_fd(&vdev->err_notifier),
                         NULL, NULL, vdev);
     event_notifier_cleanup(&vdev->err_notifier);
@@ -2718,77 +2630,43 @@  static void vfio_req_notifier_handler(void *opaque)
 
 static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
 {
-    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
-                                      .index = VFIO_PCI_REQ_IRQ_INDEX };
-    int argsz;
-    struct vfio_irq_set *irq_set;
-    int32_t *pfd;
+    Error *err = NULL;
+    int32_t fd;
 
     if (!(vdev->features & VFIO_FEATURE_ENABLE_REQ)) {
         return;
     }
 
-    if (ioctl(vdev->vbasedev.fd,
-              VFIO_DEVICE_GET_IRQ_INFO, &irq_info) < 0 || irq_info.count < 1) {
-        return;
-    }
-
     if (event_notifier_init(&vdev->req_notifier, 0)) {
         error_report("vfio: Unable to init event notifier for device request");
         return;
     }
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
+    fd = event_notifier_get_fd(&vdev->req_notifier);
+    qemu_set_fd_handler(fd, vfio_req_notifier_handler, NULL, vdev);
 
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
-                     VFIO_IRQ_SET_ACTION_TRIGGER;
-    irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-
-    *pfd = event_notifier_get_fd(&vdev->req_notifier);
-    qemu_set_fd_handler(*pfd, vfio_req_notifier_handler, NULL, vdev);
-
-    if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
-        error_report("vfio: Failed to set up device request notification");
-        qemu_set_fd_handler(*pfd, NULL, NULL, vdev);
+    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
+                           VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err)) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
+        qemu_set_fd_handler(fd, NULL, NULL, vdev);
         event_notifier_cleanup(&vdev->req_notifier);
     } else {
         vdev->req_enabled = true;
     }
-
-    g_free(irq_set);
 }
 
 static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev)
 {
-    int argsz;
-    struct vfio_irq_set *irq_set;
-    int32_t *pfd;
+    Error *err = NULL;
 
     if (!vdev->req_enabled) {
         return;
     }
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
-
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD |
-                     VFIO_IRQ_SET_ACTION_TRIGGER;
-    irq_set->index = VFIO_PCI_REQ_IRQ_INDEX;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-    *pfd = -1;
-
-    if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set)) {
-        error_report("vfio: Failed to de-assign device request fd: %m");
+    if (vfio_set_irq_signaling(&vdev->vbasedev, VFIO_PCI_REQ_IRQ_INDEX, 0,
+                               VFIO_IRQ_SET_ACTION_TRIGGER, -1, &err)) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
-    g_free(irq_set);
     qemu_set_fd_handler(event_notifier_get_fd(&vdev->req_notifier),
                         NULL, NULL, vdev);
     event_notifier_cleanup(&vdev->req_notifier);
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 398db38f14..d60f391439 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -106,26 +106,19 @@  static int vfio_set_trigger_eventfd(VFIOINTp *intp,
                                     eventfd_user_side_handler_t handler)
 {
     VFIODevice *vbasedev = &intp->vdev->vbasedev;
-    struct vfio_irq_set *irq_set;
-    int argsz, ret;
-    int32_t *pfd;
+    int32_t fd = event_notifier_get_fd(intp->interrupt);
+    Error *err = NULL;
+    int ret;
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
-    irq_set->index = intp->pin;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-    *pfd = event_notifier_get_fd(intp->interrupt);
-    qemu_set_fd_handler(*pfd, (IOHandler *)handler, NULL, intp);
-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
-    if (ret < 0) {
-        error_report("vfio: Failed to set trigger eventfd: %m");
-        qemu_set_fd_handler(*pfd, NULL, NULL, NULL);
+    qemu_set_fd_handler(fd, (IOHandler *)handler, NULL, intp);
+
+    ret = vfio_set_irq_signaling(vbasedev, intp->pin, 0,
+                                 VFIO_IRQ_SET_ACTION_TRIGGER, fd, &err);
+    if (ret) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vbasedev->name);
+        qemu_set_fd_handler(fd, NULL, NULL, NULL);
     }
-    g_free(irq_set);
+
     return ret;
 }
 
@@ -361,26 +354,18 @@  static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
  */
 static int vfio_set_resample_eventfd(VFIOINTp *intp)
 {
+    int32_t fd = event_notifier_get_fd(intp->unmask);
     VFIODevice *vbasedev = &intp->vdev->vbasedev;
-    struct vfio_irq_set *irq_set;
-    int argsz, ret;
-    int32_t *pfd;
+    Error *err = NULL;
+    int ret;
 
-    argsz = sizeof(*irq_set) + sizeof(*pfd);
-    irq_set = g_malloc0(argsz);
-    irq_set->argsz = argsz;
-    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_UNMASK;
-    irq_set->index = intp->pin;
-    irq_set->start = 0;
-    irq_set->count = 1;
-    pfd = (int32_t *)&irq_set->data;
-    *pfd = event_notifier_get_fd(intp->unmask);
-    qemu_set_fd_handler(*pfd, NULL, NULL, NULL);
-    ret = ioctl(vbasedev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
-    g_free(irq_set);
-    if (ret < 0) {
-        error_report("vfio: Failed to set resample eventfd: %m");
+    qemu_set_fd_handler(fd, NULL, NULL, NULL);
+    ret = vfio_set_irq_signaling(vbasedev, intp->pin, 0,
+                                 VFIO_IRQ_SET_ACTION_UNMASK, fd, &err);
+    if (ret) {
+        error_reportf_err(err, VFIO_MSG_PREFIX, vbasedev->name);
     }
+
     return ret;
 }
 
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 1155b79678..686d99ff8c 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -167,6 +167,8 @@  void vfio_put_base_device(VFIODevice *vbasedev);
 void vfio_disable_irqindex(VFIODevice *vbasedev, int index);
 void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index);
 void vfio_mask_single_irqindex(VFIODevice *vbasedev, int index);
+int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
+                           int action, int fd, Error **errp);
 void vfio_region_write(void *opaque, hwaddr addr,
                            uint64_t data, unsigned size);
 uint64_t vfio_region_read(void *opaque,