Re: [PATCH v5 09/12] vfio/device: Add a helper to lookup VFIODevice from memory region

[Cédric Le Goater]

On 2/3/26 08:30, Vivek Kasireddy wrote:

Instead of iterating over all QOM devices to find the VFIODevice
associated with a memory region, it is faster to just use the
vfio_device_list to lookup the VFIODevice.

Cc: Alex Williamson <a...@shazbot.org>
Cc: Cédric Le Goater <c...@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasire...@intel.com>
---
  hw/vfio/device.c | 23 +++++++++++++++++++++++
  1 file changed, 23 insertions(+)

diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 973fc35b59..ecb3581fcc 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -644,3 +644,26 @@ static VFIODeviceIOOps vfio_device_io_ops_ioctl = {
      .region_read = vfio_device_io_region_read,
      .region_write = vfio_device_io_region_write,
  };
+
+static bool vfio_device_lookup(struct iovec *iov, VFIODevice **vbasedevp,
+                               Error **errp)
+{
+    VFIODevice *vbasedev;
+    RAMBlock *first_rb;
+    ram_addr_t offset;
+
+    first_rb = qemu_ram_block_from_host(iov[0].iov_base, false, &offset);
+    if (!first_rb) {
+        error_setg(errp, "Could not find first ramblock\n");
+        return false;
+    }
+
+    QLIST_FOREACH(vbasedev, &vfio_device_list, next) {
+        if (vbasedev->dev == first_rb->mr->dev) {
+            *vbasedevp = vbasedev;
+            return true;
+        }
+    }
+    error_setg(errp, "No VFIO device found to create dmabuf from\n");
+    return false;
+}

This won't compile and break bisect. Please merge with the following patch.

Thanks,

C.