[PATCH] vp_vdpa: fix the method of calculating vectors
From: gavin.liu <hidden>
Date: 2024-03-18 03:01:17
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
From: Yuxue Liu <redacted> When there is a ctlq and it doesn't require interrupt callbacks,the original method of calculating vectors wastes hardware MSI or MSI-X resources as well as system IRQ resources. Referencing the per_vq_vectors mode in the vp_find_vqs_msix function, calculate the required number of vectors based on whether the callback is set. Signed-off-by: Yuxue Liu <redacted> --- drivers/vdpa/virtio_pci/vp_vdpa.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
index 281287fae89f..5066970b2570 100644
--- a/drivers/vdpa/virtio_pci/vp_vdpa.c
+++ b/drivers/vdpa/virtio_pci/vp_vdpa.c@@ -160,7 +160,13 @@ static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa) struct pci_dev *pdev = mdev->pci_dev; int i, ret, irq; int queues = vp_vdpa->queues; - int vectors = queues + 1; + int vectors = 0; + + for (i = 0; i < queues; i++) { + if (vp_vdpa->vring[i].cb.callback != NULL) + vectors++; + } + vectors = vectors + 1; ret = pci_alloc_irq_vectors(pdev, vectors, vectors, PCI_IRQ_MSIX); if (ret != vectors) {
@@ -172,7 +178,7 @@ static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa) vp_vdpa->vectors = vectors; - for (i = 0; i < queues; i++) { + for (i = 0; i < vectors - 1; i++) { snprintf(vp_vdpa->vring[i].msix_name, VP_VDPA_NAME_SIZE, "vp-vdpa[%s]-%d\n", pci_name(pdev), i); irq = pci_irq_vector(pdev, i);
@@ -191,7 +197,7 @@ static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa) snprintf(vp_vdpa->msix_name, VP_VDPA_NAME_SIZE, "vp-vdpa[%s]-config\n", pci_name(pdev)); - irq = pci_irq_vector(pdev, queues); + irq = pci_irq_vector(pdev, vectors - 1); ret = devm_request_irq(&pdev->dev, irq, vp_vdpa_config_handler, 0, vp_vdpa->msix_name, vp_vdpa); if (ret) {
@@ -199,7 +205,7 @@ static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa) "vp_vdpa: fail to request irq for vq %d\n", i); goto err; } - vp_modern_config_vector(mdev, queues); + vp_modern_config_vector(mdev, vectors - 1); vp_vdpa->config_irq = irq; return 0;
--
2.43.0