slackcoder/qemu - QEMU is a generic and open source machine & userspace emulator and virtualizer

Age	Commit message (Collapse)	Author
2022-10-31	block/blkio: Make driver nvme-io_uring take a "path" instead of a "filename"	Alberto Faria
	The nvme-io_uring driver expects a character special file such as /dev/ng0n1. Follow the convention of having a "filename" option when a regular file is expected, and a "path" option otherwise. This makes io_uring the only libblkio-based driver with a "filename" option, as it accepts a regular file (even though it can also take a block special file). Signed-off-by: Alberto Faria <afaria@redhat.com> Message-id: 20221028233854.839933-1-afaria@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-31	block/blkio: Tolerate device size changes	Alberto Faria
	Some libblkio drivers may be able to work with regular files (e.g., io_uring) or otherwise resizable devices. Conservatively set BlockDriver::has_variable_length to true to ensure bdrv_nb_sectors() always gives up-to-date results. Also implement BlockDriver::bdrv_co_truncate for the case where no preallocation is needed and the device already has a size compatible with what was requested. Signed-off-by: Alberto Faria <afaria@redhat.com> Message-id: 20221029122031.975273-1-afaria@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-31	block/blkio: Add virtio-blk-vfio-pci BlockDriver	Alberto Faria
	libblkio 1.1.0 [1] introduces a virtio-blk-vfio-pci driver, which accesses a virtio-blk PCI device using VFIO. Add a corresponding BlockDriver. [1] https://gitlab.com/libblkio/libblkio/-/tree/v1.1.0 Signed-off-by: Alberto Faria <afaria@redhat.com> Message-id: 20221028131635.710267-1-afaria@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-26	blkio: implement BDRV_REQ_REGISTERED_BUF optimization	Stefan Hajnoczi
	Avoid bounce buffers when QEMUIOVector elements are within previously registered bdrv_register_buf() buffers. The idea is that emulated storage controllers will register guest RAM using bdrv_register_buf() and set the BDRV_REQ_REGISTERED_BUF on I/O requests. Therefore no blkio_map_mem_region() calls are necessary in the performance-critical I/O code path. This optimization doesn't apply if the I/O buffer is internally allocated by QEMU (e.g. qcow2 metadata). There we still take the slow path because BDRV_REQ_REGISTERED_BUF is not set. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20221013185908.1297568-13-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-26	blkio: add libblkio block driver	Stefan Hajnoczi
	libblkio (https://gitlab.com/libblkio/libblkio/) is a library for high-performance disk I/O. It currently supports io_uring, virtio-blk-vhost-user, and virtio-blk-vhost-vdpa with additional drivers under development. One of the reasons for developing libblkio is that other applications besides QEMU can use it. This will be particularly useful for virtio-blk-vhost-user which applications may wish to use for connecting to qemu-storage-daemon. libblkio also gives us an opportunity to develop in Rust behind a C API that is easy to consume from QEMU. This commit adds io_uring, nvme-io_uring, virtio-blk-vhost-user, and virtio-blk-vhost-vdpa BlockDrivers to QEMU using libblkio. It will be easy to add other libblkio drivers since they will share the majority of code. For now I/O buffers are copied through bounce buffers if the libblkio driver requires it. Later commits add an optimization for pre-registering guest RAM to avoid bounce buffers. The syntax is: --blockdev io_uring,node-name=drive0,filename=test.img,readonly=on\|off,cache.direct=on\|off --blockdev nvme-io_uring,node-name=drive0,filename=/dev/ng0n1,readonly=on\|off,cache.direct=on --blockdev virtio-blk-vhost-vdpa,node-name=drive0,path=/dev/vdpa...,readonly=on\|off,cache.direct=on --blockdev virtio-blk-vhost-user,node-name=drive0,path=vhost-user-blk.sock,readonly=on\|off,cache.direct=on Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20221013185908.1297568-3-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>