diff options
| author | Shenming Lu <lushenming@huawei.com> | 2021-03-10 11:02:33 +0800 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2021-03-16 10:06:44 -0600 |
| commit | ecebe53fe99379243695e817450124d69e061e39 (patch) | |
| tree | 69bd3b2883ba79b52d115b2def362c31eeef7955 /hw/vfio | |
| parent | 8ce1ff990eff6affbdd0492fe4fc95e113235e35 (diff) | |
vfio: Avoid disabling and enabling vectors repeatedly in VFIO migration
In VFIO migration resume phase and some guest startups, there are
already unmasked vectors in the vector table when calling
vfio_msix_enable(). So in order to avoid inefficiently disabling
and enabling vectors repeatedly, let's allocate all needed vectors
first and then enable these unmasked vectors one by one without
disabling.
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Message-Id: <20210310030233.1133-4-lushenming@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'hw/vfio')
| -rw-r--r-- | hw/vfio/pci.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 759a3b1abf..5c65aa0a98 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -569,6 +569,9 @@ static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr) static void vfio_msix_enable(VFIOPCIDevice *vdev) { + PCIDevice *pdev = &vdev->pdev; + unsigned int nr, max_vec = 0; + vfio_disable_interrupts(vdev); vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->msix->entries); @@ -587,11 +590,22 @@ static void vfio_msix_enable(VFIOPCIDevice *vdev) * 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. + * If there are already unmasked vectors (in migration resume phase and + * some guest startups) which will be enabled soon, we can allocate all + * of them here to avoid inefficiently disabling and enabling vectors + * repeatedly later. */ - vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL); - vfio_msix_vector_release(&vdev->pdev, 0); + if (!pdev->msix_function_masked) { + for (nr = 0; nr < msix_nr_vectors_allocated(pdev); nr++) { + if (!msix_is_masked(pdev, nr)) { + max_vec = nr; + } + } + } + vfio_msix_vector_do_use(pdev, max_vec, NULL, NULL); + vfio_msix_vector_release(pdev, max_vec); - if (msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use, + if (msix_set_vector_notifiers(pdev, vfio_msix_vector_use, vfio_msix_vector_release, NULL)) { error_report("vfio: msix_set_vector_notifiers failed"); } |