vfio/pci: Move the existing hot reset logic to be a helper

This prepares to add another method for hot reset. The major hot reset logic
are moved to vfio_pci_ioctl_pci_hot_reset_groups().

No functional change is intended.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-3-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 4e228e2..3d595ad 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1296,29 +1296,16 @@ reset_info_exit:
        return ret;
 }
 
-static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
-                                       struct vfio_pci_hot_reset __user *arg)
+static int
+vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
+                                   int array_count, bool slot,
+                                   struct vfio_pci_hot_reset __user *arg)
 {
-       unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
-       struct vfio_pci_hot_reset hdr;
        int32_t *group_fds;
        struct file **files;
        struct vfio_pci_group_info info;
-       bool slot = false;
        int file_idx, count = 0, ret = 0;
 
-       if (copy_from_user(&hdr, arg, minsz))
-               return -EFAULT;
-
-       if (hdr.argsz < minsz || hdr.flags)
-               return -EINVAL;
-
-       /* Can we do a slot or bus reset or neither? */
-       if (!pci_probe_reset_slot(vdev->pdev->slot))
-               slot = true;
-       else if (pci_probe_reset_bus(vdev->pdev->bus))
-               return -ENODEV;
-
        /*
         * We can't let userspace give us an arbitrarily large buffer to copy,
         * so verify how many we think there could be.  Note groups can have
@@ -1330,11 +1317,11 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
                return ret;
 
        /* Somewhere between 1 and count is OK */
-       if (!hdr.count || hdr.count > count)
+       if (!array_count || array_count > count)
                return -EINVAL;
 
-       group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
-       files = kcalloc(hdr.count, sizeof(*files), GFP_KERNEL);
+       group_fds = kcalloc(array_count, sizeof(*group_fds), GFP_KERNEL);
+       files = kcalloc(array_count, sizeof(*files), GFP_KERNEL);
        if (!group_fds || !files) {
                kfree(group_fds);
                kfree(files);
@@ -1342,7 +1329,7 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
        }
 
        if (copy_from_user(group_fds, arg->group_fds,
-                          hdr.count * sizeof(*group_fds))) {
+                          array_count * sizeof(*group_fds))) {
                kfree(group_fds);
                kfree(files);
                return -EFAULT;
@@ -1352,7 +1339,7 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
         * Get the group file for each fd to ensure the group is held across
         * the reset
         */
-       for (file_idx = 0; file_idx < hdr.count; file_idx++) {
+       for (file_idx = 0; file_idx < array_count; file_idx++) {
                struct file *file = fget(group_fds[file_idx]);
 
                if (!file) {
@@ -1376,7 +1363,7 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
        if (ret)
                goto hot_reset_release;
 
-       info.count = hdr.count;
+       info.count = array_count;
        info.files = files;
 
        ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info);
@@ -1389,6 +1376,28 @@ hot_reset_release:
        return ret;
 }
 
+static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
+                                       struct vfio_pci_hot_reset __user *arg)
+{
+       unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
+       struct vfio_pci_hot_reset hdr;
+       bool slot = false;
+
+       if (copy_from_user(&hdr, arg, minsz))
+               return -EFAULT;
+
+       if (hdr.argsz < minsz || hdr.flags)
+               return -EINVAL;
+
+       /* Can we do a slot or bus reset or neither? */
+       if (!pci_probe_reset_slot(vdev->pdev->slot))
+               slot = true;
+       else if (pci_probe_reset_bus(vdev->pdev->bus))
+               return -ENODEV;
+
+       return vfio_pci_ioctl_pci_hot_reset_groups(vdev, hdr.count, slot, arg);
+}
+
 static int vfio_pci_ioctl_ioeventfd(struct vfio_pci_core_device *vdev,
                                    struct vfio_device_ioeventfd __user *arg)
 {