From da3e04b26fd8d15b344944504d5ffa9c5f20b54b Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Tue, 21 Nov 2023 16:44:10 +0800 Subject: vfio/pci: Make vfio cdev pre-openable by passing a file handle MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This gives management tools like libvirt a chance to open the vfio cdev with privilege and pass FD to qemu. This way qemu never needs to have privilege to open a VFIO or iommu cdev node. Together with the earlier support of pre-opening /dev/iommu device, now we have full support of passing a vfio device to unprivileged qemu by management tool. This mode is no more considered for the legacy backend. So let's remove the "TODO" comment. Add helper functions vfio_device_set_fd() and vfio_device_get_name() to set fd and get device name, they will also be used by other vfio devices. There is no easy way to check if a device is mdev with FD passing, so fail the x-balloon-allowed check unconditionally in this case. There is also no easy way to get BDF as name with FD passing, so we fake a name by VFIO_FD[fd]. Signed-off-by: Zhenzhong Duan Reviewed-by: Cédric Le Goater Tested-by: Eric Auger Tested-by: Nicolin Chen Signed-off-by: Cédric Le Goater --- include/hw/vfio/vfio-common.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index 3dac5c1..697bf24 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -251,4 +251,8 @@ int vfio_devices_query_dirty_bitmap(VFIOContainerBase *bcontainer, hwaddr size); int vfio_get_dirty_bitmap(VFIOContainerBase *bcontainer, uint64_t iova, uint64_t size, ram_addr_t ram_addr); + +/* Returns 0 on success, or a negative errno. */ +int vfio_device_get_name(VFIODevice *vbasedev, Error **errp); +void vfio_device_set_fd(VFIODevice *vbasedev, const char *str, Error **errp); #endif /* HW_VFIO_VFIO_COMMON_H */ -- cgit v1.1