summaryrefslogtreecommitdiff
path: root/drivers/vfio/pci
diff options
context:
space:
mode:
authorAlex Williamson <alex.williamson@redhat.com>2016-02-22 16:02:36 -0700
committerAlex Williamson <alex.williamson@redhat.com>2016-02-22 16:10:09 -0700
commit188ad9d6cbbce4a1d322ac208914a1dea34b30b6 (patch)
tree001329c7874b9438e1408bb8d1cf3c4e66da8756 /drivers/vfio/pci
parentff63eb638d63b95e489f976428f1df01391e15e4 (diff)
vfio/pci: Include sparse mmap capability for MSI-X table regions
vfio-pci has never allowed the user to directly mmap the MSI-X vector table, but we've always relied on implicit knowledge of the user that they cannot do this. Now that we have capability chains that we can expose in the region info ioctl and a sparse mmap capability that represents the sub-areas within the region that can be mmap'd, we can make the mmap constraints more explicit. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/pci')
-rw-r--r--drivers/vfio/pci/vfio_pci.c73
1 files changed, 72 insertions, 1 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 2760a7ba3f30..4682207b1ac8 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -421,6 +421,48 @@ static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
return walk.ret;
}
+static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_info_cap_header *header;
+ struct vfio_region_info_cap_sparse_mmap *sparse;
+ size_t end, size;
+ int nr_areas = 2, i = 0;
+
+ end = pci_resource_len(vdev->pdev, vdev->msix_bar);
+
+ /* If MSI-X table is aligned to the start or end, only one area */
+ if (((vdev->msix_offset & PAGE_MASK) == 0) ||
+ (PAGE_ALIGN(vdev->msix_offset + vdev->msix_size) >= end))
+ nr_areas = 1;
+
+ size = sizeof(*sparse) + (nr_areas * sizeof(*sparse->areas));
+
+ header = vfio_info_cap_add(caps, size,
+ VFIO_REGION_INFO_CAP_SPARSE_MMAP, 1);
+ if (IS_ERR(header))
+ return PTR_ERR(header);
+
+ sparse = container_of(header,
+ struct vfio_region_info_cap_sparse_mmap, header);
+ sparse->nr_areas = nr_areas;
+
+ if (vdev->msix_offset & PAGE_MASK) {
+ sparse->areas[i].offset = 0;
+ sparse->areas[i].size = vdev->msix_offset & PAGE_MASK;
+ i++;
+ }
+
+ if (PAGE_ALIGN(vdev->msix_offset + vdev->msix_size) < end) {
+ sparse->areas[i].offset = PAGE_ALIGN(vdev->msix_offset +
+ vdev->msix_size);
+ sparse->areas[i].size = end - sparse->areas[i].offset;
+ i++;
+ }
+
+ return 0;
+}
+
static long vfio_pci_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
@@ -451,6 +493,8 @@ static long vfio_pci_ioctl(void *device_data,
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct pci_dev *pdev = vdev->pdev;
struct vfio_region_info info;
+ struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
+ int ret;
minsz = offsetofend(struct vfio_region_info, offset);
@@ -479,8 +523,15 @@ static long vfio_pci_ioctl(void *device_data,
VFIO_REGION_INFO_FLAG_WRITE;
if (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) &&
pci_resource_flags(pdev, info.index) &
- IORESOURCE_MEM && info.size >= PAGE_SIZE)
+ IORESOURCE_MEM && info.size >= PAGE_SIZE) {
info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
+ if (info.index == vdev->msix_bar) {
+ ret = msix_sparse_mmap_cap(vdev, &caps);
+ if (ret)
+ return ret;
+ }
+ }
+
break;
case VFIO_PCI_ROM_REGION_INDEX:
{
@@ -520,6 +571,26 @@ static long vfio_pci_ioctl(void *device_data,
return -EINVAL;
}
+ if (caps.size) {
+ info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
+ if (info.argsz < sizeof(info) + caps.size) {
+ info.argsz = sizeof(info) + caps.size;
+ info.cap_offset = 0;
+ } else {
+ vfio_info_cap_shift(&caps, sizeof(info));
+ ret = copy_to_user((void __user *)arg +
+ sizeof(info), caps.buf,
+ caps.size);
+ if (ret) {
+ kfree(caps.buf);
+ return ret;
+ }
+ info.cap_offset = sizeof(info);
+ }
+
+ kfree(caps.buf);
+ }
+
return copy_to_user((void __user *)arg, &info, minsz);
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {