[Qemu-devel] [PATCH v3] vfio/common: Introduce vfio_set_irq_signaling helper

Eric Auger posted 1 patch 13 weeks ago
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git fetch https://github.com/patchew-project/qemu tags/patchew/20190611154725.5343-1-eric.auger@redhat.com
Maintainers: Alex Williamson <alex.williamson@redhat.com>
hw/vfio/common.c              |  83 +++++++++++++
hw/vfio/pci.c                 | 217 ++++++++--------------------------
hw/vfio/platform.c            |  62 ++++------
include/hw/vfio/vfio-common.h |   2 +
4 files changed, 156 insertions(+), 208 deletions(-)

[Qemu-devel] [PATCH v3] vfio/common: Introduce vfio_set_irq_signaling helper

Posted by Eric Auger 13 weeks ago
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,
ACTION_MASK or ACTION_UNMASK action.

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

---

v2 -> v3:
- irq_to_str() simply outputs the IRQ index if the VFIO device is
  not of PCI type
- removed "vfio: failed to start eventfd signaling ../.." in vfio_platform

v1 -> v2:
- don't call GET_IRQ_INFO in vfio_set_irq_signaling()
  and restore quiet check in vfio_register_req_notifier.
  Nicer display of the IRQ name.

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              |  83 +++++++++++++
 hw/vfio/pci.c                 | 217 ++++++++--------------------------
 hw/vfio/platform.c            |  62 ++++------
 include/hw/vfio/vfio-common.h |   2 +
 4 files changed, 156 insertions(+), 208 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 4374cc6176..4b8acd556f 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -95,6 +95,89 @@ 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";
+    }
+}
+
+static char *irq_to_str(VFIODevice *vbasedev, int index, int subindex)
+{
+    char *str;
+
+    if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
+        str = g_strdup_printf("index %d", index);
+        return str;
+    }
+
+    switch (index) {
+    case VFIO_PCI_INTX_IRQ_INDEX:
+        str = g_strdup_printf("INTX-%d", subindex);
+        break;
+    case VFIO_PCI_MSI_IRQ_INDEX:
+        str = g_strdup_printf("MSI-%d", subindex);
+        break;
+    case VFIO_PCI_MSIX_IRQ_INDEX:
+        str = g_strdup_printf("MSIX-%d", subindex);
+        break;
+    case VFIO_PCI_ERR_IRQ_INDEX:
+        str = g_strdup_printf("ERR-%d", subindex);
+        break;
+    case VFIO_PCI_REQ_IRQ_INDEX:
+        str = g_strdup_printf("REQ-%d", subindex);
+        break;
+    default:
+        str = g_strdup_printf("index %d (unknown)", index);
+        break;
+    }
+    return str;
+}
+
+int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
+                           int action, int fd, Error **errp)
+{
+    struct vfio_irq_set *irq_set;
+    int argsz, ret = 0;
+    int32_t *pfd;
+    char *irq_name;
+
+    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) {
+        return 0;
+    }
+
+    error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
+    irq_name = irq_to_str(vbasedev, index, subindex);
+    error_prepend(errp,
+                  "Failed to %s %s eventfd signaling for interrupt %s: ",
+                  fd < 0 ? "tear down" : "set up", action_to_str(action),
+                  irq_name);
+    g_free(irq_name);
+    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 2a4091d216..65c2e17028 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);
     }
 }
 
@@ -2636,10 +2578,8 @@ 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;
@@ -2651,58 +2591,30 @@ 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);
@@ -2727,9 +2639,8 @@ 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;
@@ -2745,57 +2656,31 @@ static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
         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 d52d6552e0..8d6012857e 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;
 }
 
@@ -330,7 +323,6 @@ static void vfio_platform_eoi(VFIODevice *vbasedev)
 
 static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
 {
-    int ret;
     VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
     VFIOINTp *intp;
 
@@ -341,10 +333,7 @@ static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
     }
     assert(intp);
 
-    ret = vfio_set_trigger_eventfd(intp, vfio_intp_interrupt);
-    if (ret) {
-        error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
-                     intp->pin);
+    if (vfio_set_trigger_eventfd(intp, vfio_intp_interrupt)) {
         abort();
     }
 }
@@ -361,25 +350,16 @@ 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;
 }
@@ -435,8 +415,6 @@ static void vfio_start_irqfd_injection(SysBusDevice *sbdev, qemu_irq irq)
     return;
 fail_vfio:
     kvm_irqchip_remove_irqfd_notifier(kvm_state, intp->interrupt, irq);
-    error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
-                 intp->pin);
     abort();
 fail_irqfd:
     vfio_start_eventfd_injection(sbdev, irq);
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,
-- 
2.20.1


Re: [Qemu-devel] [PATCH v3] vfio/common: Introduce vfio_set_irq_signaling helper

Posted by Alex Williamson 13 weeks ago
On Tue, 11 Jun 2019 17:47:25 +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,
> ACTION_MASK or ACTION_UNMASK action.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> 
> v2 -> v3:
> - irq_to_str() simply outputs the IRQ index if the VFIO device is
>   not of PCI type
> - removed "vfio: failed to start eventfd signaling ../.." in vfio_platform
> 
> v1 -> v2:
> - don't call GET_IRQ_INFO in vfio_set_irq_signaling()
>   and restore quiet check in vfio_register_req_notifier.
>   Nicer display of the IRQ name.
> 
> 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              |  83 +++++++++++++
>  hw/vfio/pci.c                 | 217 ++++++++--------------------------
>  hw/vfio/platform.c            |  62 ++++------
>  include/hw/vfio/vfio-common.h |   2 +
>  4 files changed, 156 insertions(+), 208 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 4374cc6176..4b8acd556f 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -95,6 +95,89 @@ 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";
> +    }
> +}
> +
> +static char *irq_to_str(VFIODevice *vbasedev, int index, int subindex)
> +{
> +    char *str;
> +
> +    if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
> +        str = g_strdup_printf("index %d", index);

"index %d-%d", index, subindex?

If this is our generic name, let's not assume subindex doesn't matter.

> +        return str;
> +    }
> +
> +    switch (index) {
> +    case VFIO_PCI_INTX_IRQ_INDEX:
> +        str = g_strdup_printf("INTX-%d", subindex);
> +        break;
> +    case VFIO_PCI_MSI_IRQ_INDEX:
> +        str = g_strdup_printf("MSI-%d", subindex);
> +        break;
> +    case VFIO_PCI_MSIX_IRQ_INDEX:
> +        str = g_strdup_printf("MSIX-%d", subindex);
> +        break;
> +    case VFIO_PCI_ERR_IRQ_INDEX:
> +        str = g_strdup_printf("ERR-%d", subindex);
> +        break;
> +    case VFIO_PCI_REQ_IRQ_INDEX:
> +        str = g_strdup_printf("REQ-%d", subindex);
> +        break;
> +    default:
> +        str = g_strdup_printf("index %d (unknown)", index);

Let's just make this the same as non-PCI, adding "unknown" here implies
we need to extend this for every interrupt type rather than just naming
some of them for convenience.  When we add device specific interrupts
the ROI to generate names might not be worthwhile.

> +        break;
> +    }
> +    return str;
> +}
> +
> +int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
> +                           int action, int fd, Error **errp)
> +{
> +    struct vfio_irq_set *irq_set;
> +    int argsz, ret = 0;
> +    int32_t *pfd;
> +    char *irq_name;
> +
> +    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) {
> +        return 0;
> +    }
> +
> +    error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
> +    irq_name = irq_to_str(vbasedev, index, subindex);
> +    error_prepend(errp,
> +                  "Failed to %s %s eventfd signaling for interrupt %s: ",
> +                  fd < 0 ? "tear down" : "set up", action_to_str(action),
> +                  irq_name);

Can't we repeatedly call error_prepend to avoid needing to allocate
irq_name?  ex:

name = irq_to_str(vbasedev, index); // "INTx", "MSI", "MSIX", ...
error_prepend(errp, "Failed to %s %s eventfd signaling for interrupt "
              fd < 0 ? "tear down" : "set up", action_to_str(action));
if (name) {
    error_prepend(errp, "%s-%d:", name, subindex);
} else {
    error_prepend(errp, "index %d-%d:", index, subindex);
}

Thanks,
Alex


> +    g_free(irq_name);
> +    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 2a4091d216..65c2e17028 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);
>      }
>  }
>  
> @@ -2636,10 +2578,8 @@ 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;
> @@ -2651,58 +2591,30 @@ 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);
> @@ -2727,9 +2639,8 @@ 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;
> @@ -2745,57 +2656,31 @@ static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
>          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 d52d6552e0..8d6012857e 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;
>  }
>  
> @@ -330,7 +323,6 @@ static void vfio_platform_eoi(VFIODevice *vbasedev)
>  
>  static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
>  {
> -    int ret;
>      VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
>      VFIOINTp *intp;
>  
> @@ -341,10 +333,7 @@ static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
>      }
>      assert(intp);
>  
> -    ret = vfio_set_trigger_eventfd(intp, vfio_intp_interrupt);
> -    if (ret) {
> -        error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
> -                     intp->pin);
> +    if (vfio_set_trigger_eventfd(intp, vfio_intp_interrupt)) {
>          abort();
>      }
>  }
> @@ -361,25 +350,16 @@ 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;
>  }
> @@ -435,8 +415,6 @@ static void vfio_start_irqfd_injection(SysBusDevice *sbdev, qemu_irq irq)
>      return;
>  fail_vfio:
>      kvm_irqchip_remove_irqfd_notifier(kvm_state, intp->interrupt, irq);
> -    error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
> -                 intp->pin);
>      abort();
>  fail_irqfd:
>      vfio_start_eventfd_injection(sbdev, irq);
> 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,


Re: [Qemu-devel] [PATCH v3] vfio/common: Introduce vfio_set_irq_signaling helper

Posted by Auger Eric 13 weeks ago
Hi Alex,

On 6/11/19 9:48 PM, Alex Williamson wrote:
> On Tue, 11 Jun 2019 17:47:25 +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,
>> ACTION_MASK or ACTION_UNMASK action.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> v2 -> v3:
>> - irq_to_str() simply outputs the IRQ index if the VFIO device is
>>   not of PCI type
>> - removed "vfio: failed to start eventfd signaling ../.." in vfio_platform
>>
>> v1 -> v2:
>> - don't call GET_IRQ_INFO in vfio_set_irq_signaling()
>>   and restore quiet check in vfio_register_req_notifier.
>>   Nicer display of the IRQ name.
>>
>> 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              |  83 +++++++++++++
>>  hw/vfio/pci.c                 | 217 ++++++++--------------------------
>>  hw/vfio/platform.c            |  62 ++++------
>>  include/hw/vfio/vfio-common.h |   2 +
>>  4 files changed, 156 insertions(+), 208 deletions(-)
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 4374cc6176..4b8acd556f 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -95,6 +95,89 @@ 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";
>> +    }
>> +}
>> +
>> +static char *irq_to_str(VFIODevice *vbasedev, int index, int subindex)
>> +{
>> +    char *str;
>> +
>> +    if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
>> +        str = g_strdup_printf("index %d", index);
> 
> "index %d-%d", index, subindex?
> 
> If this is our generic name, let's not assume subindex doesn't matter.
My bad, I understood from your v2 comment you just wanted to print the
index.
> 
>> +        return str;
>> +    }
>> +
>> +    switch (index) {
>> +    case VFIO_PCI_INTX_IRQ_INDEX:
>> +        str = g_strdup_printf("INTX-%d", subindex);
>> +        break;
>> +    case VFIO_PCI_MSI_IRQ_INDEX:
>> +        str = g_strdup_printf("MSI-%d", subindex);
>> +        break;
>> +    case VFIO_PCI_MSIX_IRQ_INDEX:
>> +        str = g_strdup_printf("MSIX-%d", subindex);
>> +        break;
>> +    case VFIO_PCI_ERR_IRQ_INDEX:
>> +        str = g_strdup_printf("ERR-%d", subindex);
>> +        break;
>> +    case VFIO_PCI_REQ_IRQ_INDEX:
>> +        str = g_strdup_printf("REQ-%d", subindex);
>> +        break;
>> +    default:
>> +        str = g_strdup_printf("index %d (unknown)", index);
> 
> Let's just make this the same as non-PCI, adding "unknown" here implies
> we need to extend this for every interrupt type rather than just naming
> some of them for convenience.  When we add device specific interrupts
> the ROI to generate names might not be worthwhile.
done
> 
>> +        break;
>> +    }
>> +    return str;
>> +}
>> +
>> +int vfio_set_irq_signaling(VFIODevice *vbasedev, int index, int subindex,
>> +                           int action, int fd, Error **errp)
>> +{
>> +    struct vfio_irq_set *irq_set;
>> +    int argsz, ret = 0;
>> +    int32_t *pfd;
>> +    char *irq_name;
>> +
>> +    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) {
>> +        return 0;
>> +    }
>> +
>> +    error_setg_errno(errp, -ret, "VFIO_DEVICE_SET_IRQS failure");
>> +    irq_name = irq_to_str(vbasedev, index, subindex);
>> +    error_prepend(errp,
>> +                  "Failed to %s %s eventfd signaling for interrupt %s: ",
>> +                  fd < 0 ? "tear down" : "set up", action_to_str(action),
>> +                  irq_name);
> 
> Can't we repeatedly call error_prepend to avoid needing to allocate
> irq_name?  ex:
> 
> name = irq_to_str(vbasedev, index); // "INTx", "MSI", "MSIX", ...
> error_prepend(errp, "Failed to %s %s eventfd signaling for interrupt "
>               fd < 0 ? "tear down" : "set up", action_to_str(action));
> if (name) {
>     error_prepend(errp, "%s-%d:", name, subindex);
> } else {
>     error_prepend(errp, "index %d-%d:", index, subindex);
> }
done (in the opposite order).

Thanks

Eric
> 
> Thanks,
> Alex
> 
> 
>> +    g_free(irq_name);
>> +    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 2a4091d216..65c2e17028 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);
>>      }
>>  }
>>  
>> @@ -2636,10 +2578,8 @@ 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;
>> @@ -2651,58 +2591,30 @@ 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);
>> @@ -2727,9 +2639,8 @@ 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;
>> @@ -2745,57 +2656,31 @@ static void vfio_register_req_notifier(VFIOPCIDevice *vdev)
>>          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 d52d6552e0..8d6012857e 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;
>>  }
>>  
>> @@ -330,7 +323,6 @@ static void vfio_platform_eoi(VFIODevice *vbasedev)
>>  
>>  static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
>>  {
>> -    int ret;
>>      VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(sbdev);
>>      VFIOINTp *intp;
>>  
>> @@ -341,10 +333,7 @@ static void vfio_start_eventfd_injection(SysBusDevice *sbdev, qemu_irq irq)
>>      }
>>      assert(intp);
>>  
>> -    ret = vfio_set_trigger_eventfd(intp, vfio_intp_interrupt);
>> -    if (ret) {
>> -        error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
>> -                     intp->pin);
>> +    if (vfio_set_trigger_eventfd(intp, vfio_intp_interrupt)) {
>>          abort();
>>      }
>>  }
>> @@ -361,25 +350,16 @@ 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;
>>  }
>> @@ -435,8 +415,6 @@ static void vfio_start_irqfd_injection(SysBusDevice *sbdev, qemu_irq irq)
>>      return;
>>  fail_vfio:
>>      kvm_irqchip_remove_irqfd_notifier(kvm_state, intp->interrupt, irq);
>> -    error_report("vfio: failed to start eventfd signaling for IRQ %d: %m",
>> -                 intp->pin);
>>      abort();
>>  fail_irqfd:
>>      vfio_start_eventfd_injection(sbdev, irq);
>> 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,
>