notify(&vdev->pdev, nr);
}
+/*
+ * Get MSI-X enabled, but no vector enabled, by setting vector 0 with an invalid
+ * fd to kernel.
+ */
+static int vfio_enable_msix_no_vec(VFIOPCIDevice *vdev)
+{
+ g_autofree struct vfio_irq_set *irq_set = NULL;
+ int ret = 0, argsz;
+ int32_t *fd;
+
+ argsz = sizeof(*irq_set) + sizeof(*fd);
+
+ 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 = 0;
+ irq_set->count = 1;
+ fd = (int32_t *)&irq_set->data;
+ *fd = -1;
+
+ ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+ return ret;
+}
+
static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix)
{
struct vfio_irq_set *irq_set;
int ret = 0, i, argsz;
int32_t *fds;
+ /*
+ * If dynamic MSI-X allocation is supported, the vectors to be allocated
+ * and enabled can be scattered. Before kernel enabling MSI-X, setting
+ * nr_vectors causes all these vectors to be allocated on host.
+ *
+ * To keep allocation as needed, use vector 0 with an invalid fd to get
+ * MSI-X enabled first, then set vectors with a potentially sparse set of
+ * eventfds to enable interrupts only when enabled in guest.
+ */
+ if (msix && !vdev->msix->noresize) {
+ ret = vfio_enable_msix_no_vec(vdev);
+
+ if (ret) {
+ return ret;
+ }
+ }
+
argsz = sizeof(*irq_set) + (vdev->nr_vectors * sizeof(*fds));
irq_set = g_malloc0(argsz);
VFIOPCIDevice *vdev = VFIO_PCI(pdev);
VFIOMSIVector *vector;
int ret;
+ bool resizing = !!(vdev->nr_vectors < nr + 1);
trace_vfio_msix_vector_do_use(vdev->vbasedev.name, nr);
}
/*
- * We don't want to have the host allocate all possible MSI vectors
- * for a device if they're not in use, so we shutdown and incrementally
- * increase them as needed.
+ * When dynamic allocation is not supported, we don't want to have the
+ * host allocate all possible MSI vectors for a device if they're not
+ * in use, so we shutdown and incrementally increase them as needed.
+ * nr_vectors represents the total number of vectors allocated.
+ *
+ * When dynamic allocation is supported, let the host only allocate
+ * and enable a vector when it is in use in guest. nr_vectors represents
+ * the upper bound of vectors being enabled (but not all of the ranges
+ * is allocated or enabled).
*/
- if (vdev->nr_vectors < nr + 1) {
+ if (resizing) {
vdev->nr_vectors = nr + 1;
- if (!vdev->defer_kvm_irq_routing) {
+ }
+
+ if (!vdev->defer_kvm_irq_routing) {
+ if (vdev->msix->noresize && resizing) {
vfio_disable_irqindex(&vdev->vbasedev, VFIO_PCI_MSIX_IRQ_INDEX);
ret = vfio_enable_vectors(vdev, true);
if (ret) {
error_report("vfio: failed to enable vectors, %d", ret);
}
- }
- } else {
- Error *err = NULL;
- int32_t fd;
-
- if (vector->virq >= 0) {
- fd = event_notifier_get_fd(&vector->kvm_interrupt);
} else {
- fd = event_notifier_get_fd(&vector->interrupt);
- }
+ Error *err = NULL;
+ int32_t fd;
- 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);
+ if (vector->virq >= 0) {
+ fd = event_notifier_get_fd(&vector->kvm_interrupt);
+ } else {
+ fd = event_notifier_get_fd(&vector->interrupt);
+ }
+
+ 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);
+ }
}
}
static void vfio_msix_enable(VFIOPCIDevice *vdev)
{
+ int ret;
+
vfio_disable_interrupts(vdev);
vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->msix->entries);
vfio_commit_kvm_msi_virq_batch(vdev);
if (vdev->nr_vectors) {
- int ret;
-
ret = vfio_enable_vectors(vdev, true);
if (ret) {
error_report("vfio: failed to enable vectors, %d", ret);
* MSI-X capability, but leaves the vector table masked. We therefore
* can't rely on a vector_use callback (from request_irq() in the guest)
* to switch the physical device into MSI-X mode because that may come a
- * long time after pci_enable_msix(). This code enables vector 0 with
- * triggering to userspace, then immediately release the vector, leaving
- * the physical device with no vectors enabled, but MSI-X enabled, just
- * like the guest view.
+ * long time after pci_enable_msix(). This code sets vector 0 with an
+ * invalid fd to make the physical device MSI-X enabled, but with no
+ * vectors enabled, just like the guest view.
*/
- vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL);
- vfio_msix_vector_release(&vdev->pdev, 0);
+ ret = vfio_enable_msix_no_vec(vdev);
+ if (ret) {
+ error_report("vfio: failed to enable MSI-X, %d", ret);
+ }
}
trace_vfio_msix_enable(vdev->vbasedev.name);
uint8_t pos;
uint16_t ctrl;
uint32_t table, pba;
- int fd = vdev->vbasedev.fd;
+ int ret, fd = vdev->vbasedev.fd;
+ struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info),
+ .index = VFIO_PCI_MSIX_IRQ_INDEX };
VFIOMSIXInfo *msix;
pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
msix->pba_offset = pba & ~PCI_MSIX_FLAGS_BIRMASK;
msix->entries = (ctrl & PCI_MSIX_FLAGS_QSIZE) + 1;
+ ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "failed to get MSI-X irq info");
+ g_free(msix);
+ return;
+ }
+
+ msix->noresize = !!(irq_info.flags & VFIO_IRQ_INFO_NORESIZE);
+
/*
* Test the size of the pba_offset variable and catch if it extends outside
* of the specified BAR. If it is the case, we need to apply a hardware
}
trace_vfio_msix_early_setup(vdev->vbasedev.name, pos, msix->table_bar,
- msix->table_offset, msix->entries);
+ msix->table_offset, msix->entries,
+ msix->noresize);
vdev->msix = msix;
vfio_pci_fixup_msix_region(vdev);
}
}
-static void vfio_put_device(VFIOPCIDevice *vdev)
+static void vfio_pci_put_device(VFIOPCIDevice *vdev)
{
g_free(vdev->vbasedev.name);
g_free(vdev->msix);
*
* g_free(vdev->igd_opregion);
*/
- vfio_put_device(vdev);
+ vfio_pci_put_device(vdev);
vfio_put_group(group);
}
projects / mirror_qemu.git / commitdiff