[PATCH] block/blkio: fix module_block.py parsing

Stefan Hajnoczi posted 1 patch 10 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20230703103524.162855-1-stefanha@redhat.com
Maintainers: Stefan Hajnoczi <stefanha@redhat.com>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>
There is a newer version of this series
block/blkio.c | 110 ++++++++++++++++++++++++++------------------------
1 file changed, 57 insertions(+), 53 deletions(-)
[PATCH] block/blkio: fix module_block.py parsing
Posted by Stefan Hajnoczi 10 months ago
When QEMU is built with --enable-modules, the module_block.py script
parses block/*.c to find block drivers that are built as modules. The
script generates a table of block drivers called block_driver_modules[].
This table is used for block driver module loading.

The blkio.c driver uses macros to define its BlockDriver structs. This
was done to avoid code duplication but the module_block.py script is
unable to parse the macro. The result is that libblkio-based block
drivers can be built as modules but will not be found at runtime.

One fix is to make the module_block.py script or build system fancier so
it can parse C macros (e.g. by parsing the preprocessed source code). I
chose not to do this because it raises the complexity of the build,
making future issues harder to debug.

Keep things simple: use the macro to avoid duplicating BlockDriver
function pointers but define .format_name and .protocol_name manually
for each BlockDriver. This way the module_block.py is able to parse the
code.

Also get rid of the block driver name macros (e.g. DRIVER_IO_URING)
because module_block.py cannot parse them either.

Fixes: fd66dbd424f5 ("blkio: add libblkio block driver")
Reported-by: Qing Wang <qinwang@redhat.com>
Cc: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/blkio.c | 110 ++++++++++++++++++++++++++------------------------
 1 file changed, 57 insertions(+), 53 deletions(-)

diff --git a/block/blkio.c b/block/blkio.c
index 527323d625..589f829a83 100644
--- a/block/blkio.c
+++ b/block/blkio.c
@@ -22,16 +22,6 @@
 
 #include "block/block-io.h"
 
-/*
- * Keep the QEMU BlockDriver names identical to the libblkio driver names.
- * Using macros instead of typing out the string literals avoids typos.
- */
-#define DRIVER_IO_URING "io_uring"
-#define DRIVER_NVME_IO_URING "nvme-io_uring"
-#define DRIVER_VIRTIO_BLK_VFIO_PCI "virtio-blk-vfio-pci"
-#define DRIVER_VIRTIO_BLK_VHOST_USER "virtio-blk-vhost-user"
-#define DRIVER_VIRTIO_BLK_VHOST_VDPA "virtio-blk-vhost-vdpa"
-
 /*
  * Allocated bounce buffers are kept in a list sorted by buffer address.
  */
@@ -744,15 +734,15 @@ static int blkio_file_open(BlockDriverState *bs, QDict *options, int flags,
         return ret;
     }
 
-    if (strcmp(blkio_driver, DRIVER_IO_URING) == 0) {
+    if (strcmp(blkio_driver, "io_uring") == 0) {
         ret = blkio_io_uring_open(bs, options, flags, errp);
-    } else if (strcmp(blkio_driver, DRIVER_NVME_IO_URING) == 0) {
+    } else if (strcmp(blkio_driver, "nvme-io_uring") == 0) {
         ret = blkio_nvme_io_uring(bs, options, flags, errp);
-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VFIO_PCI) == 0) {
+    } else if (strcmp(blkio_driver, "virtio-blk-vfio-pci") == 0) {
         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_USER) == 0) {
+    } else if (strcmp(blkio_driver, "virtio-blk-vhost-user") == 0) {
         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_VDPA) == 0) {
+    } else if (strcmp(blkio_driver, "virtio-blk-vhost-vdpa") == 0) {
         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
     } else {
         g_assert_not_reached();
@@ -1028,49 +1018,63 @@ static void blkio_refresh_limits(BlockDriverState *bs, Error **errp)
  * - truncate
  */
 
-#define BLKIO_DRIVER(name, ...) \
-    { \
-        .format_name             = name, \
-        .protocol_name           = name, \
-        .instance_size           = sizeof(BDRVBlkioState), \
-        .bdrv_file_open          = blkio_file_open, \
-        .bdrv_close              = blkio_close, \
-        .bdrv_co_getlength       = blkio_co_getlength, \
-        .bdrv_co_truncate        = blkio_truncate, \
-        .bdrv_co_get_info        = blkio_co_get_info, \
-        .bdrv_attach_aio_context = blkio_attach_aio_context, \
-        .bdrv_detach_aio_context = blkio_detach_aio_context, \
-        .bdrv_co_pdiscard        = blkio_co_pdiscard, \
-        .bdrv_co_preadv          = blkio_co_preadv, \
-        .bdrv_co_pwritev         = blkio_co_pwritev, \
-        .bdrv_co_flush_to_disk   = blkio_co_flush, \
-        .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
-        .bdrv_refresh_limits     = blkio_refresh_limits, \
-        .bdrv_register_buf       = blkio_register_buf, \
-        .bdrv_unregister_buf     = blkio_unregister_buf, \
-        __VA_ARGS__ \
-    }
+/*
+ * Do not include .format_name and .protocol_name because module_block.py
+ * does not parse macros in the source code.
+ */
+#define BLKIO_DRIVER_COMMON \
+    .instance_size           = sizeof(BDRVBlkioState), \
+    .bdrv_file_open          = blkio_file_open, \
+    .bdrv_close              = blkio_close, \
+    .bdrv_co_getlength       = blkio_co_getlength, \
+    .bdrv_co_truncate        = blkio_truncate, \
+    .bdrv_co_get_info        = blkio_co_get_info, \
+    .bdrv_attach_aio_context = blkio_attach_aio_context, \
+    .bdrv_detach_aio_context = blkio_detach_aio_context, \
+    .bdrv_co_pdiscard        = blkio_co_pdiscard, \
+    .bdrv_co_preadv          = blkio_co_preadv, \
+    .bdrv_co_pwritev         = blkio_co_pwritev, \
+    .bdrv_co_flush_to_disk   = blkio_co_flush, \
+    .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
+    .bdrv_refresh_limits     = blkio_refresh_limits, \
+    .bdrv_register_buf       = blkio_register_buf, \
+    .bdrv_unregister_buf     = blkio_unregister_buf,
 
-static BlockDriver bdrv_io_uring = BLKIO_DRIVER(
-    DRIVER_IO_URING,
-    .bdrv_needs_filename = true,
-);
+/*
+ * Use the same .format_name and .protocol_name as the libblkio driver name for
+ * consistency.
+ */
 
-static BlockDriver bdrv_nvme_io_uring = BLKIO_DRIVER(
-    DRIVER_NVME_IO_URING,
-);
+static BlockDriver bdrv_io_uring = {
+    .format_name         = "io_uring", \
+    .protocol_name       = "io_uring", \
+    .bdrv_needs_filename = true, \
+    BLKIO_DRIVER_COMMON
+};
 
-static BlockDriver bdrv_virtio_blk_vfio_pci = BLKIO_DRIVER(
-    DRIVER_VIRTIO_BLK_VFIO_PCI
-);
+static BlockDriver bdrv_nvme_io_uring = {
+    .format_name         = "nvme-io_uring", \
+    .protocol_name       = "nvme-io_uring", \
+    BLKIO_DRIVER_COMMON
+};
 
-static BlockDriver bdrv_virtio_blk_vhost_user = BLKIO_DRIVER(
-    DRIVER_VIRTIO_BLK_VHOST_USER
-);
+static BlockDriver bdrv_virtio_blk_vfio_pci = {
+    .format_name         = "virtio-blk-vfio-pci", \
+    .protocol_name       = "virtio-blk-vfio-pci", \
+    BLKIO_DRIVER_COMMON
+};
 
-static BlockDriver bdrv_virtio_blk_vhost_vdpa = BLKIO_DRIVER(
-    DRIVER_VIRTIO_BLK_VHOST_VDPA
-);
+static BlockDriver bdrv_virtio_blk_vhost_user = {
+    .format_name         = "virtio-blk-vhost-user", \
+    .protocol_name       = "virtio-blk-vhost-user", \
+    BLKIO_DRIVER_COMMON
+};
+
+static BlockDriver bdrv_virtio_blk_vhost_vdpa = {
+    .format_name         = "virtio-blk-vhost-vdpa", \
+    .protocol_name       = "virtio-blk-vhost-vdpa", \
+    BLKIO_DRIVER_COMMON
+};
 
 static void bdrv_blkio_init(void)
 {
-- 
2.40.1
Re: [PATCH] block/blkio: fix module_block.py parsing
Posted by Stefano Garzarella 10 months ago
On Mon, Jul 03, 2023 at 12:35:24PM +0200, Stefan Hajnoczi wrote:
>When QEMU is built with --enable-modules, the module_block.py script
>parses block/*.c to find block drivers that are built as modules. The
>script generates a table of block drivers called block_driver_modules[].
>This table is used for block driver module loading.
>
>The blkio.c driver uses macros to define its BlockDriver structs. This
>was done to avoid code duplication but the module_block.py script is
>unable to parse the macro. The result is that libblkio-based block
>drivers can be built as modules but will not be found at runtime.
>
>One fix is to make the module_block.py script or build system fancier so
>it can parse C macros (e.g. by parsing the preprocessed source code). I
>chose not to do this because it raises the complexity of the build,
>making future issues harder to debug.
>
>Keep things simple: use the macro to avoid duplicating BlockDriver
>function pointers but define .format_name and .protocol_name manually
>for each BlockDriver. This way the module_block.py is able to parse the
>code.
>
>Also get rid of the block driver name macros (e.g. DRIVER_IO_URING)
>because module_block.py cannot parse them either.
>
>Fixes: fd66dbd424f5 ("blkio: add libblkio block driver")
>Reported-by: Qing Wang <qinwang@redhat.com>
>Cc: Stefano Garzarella <sgarzare@redhat.com>
>Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
>---
> block/blkio.c | 110 ++++++++++++++++++++++++++------------------------
> 1 file changed, 57 insertions(+), 53 deletions(-)
>
>diff --git a/block/blkio.c b/block/blkio.c
>index 527323d625..589f829a83 100644
>--- a/block/blkio.c
>+++ b/block/blkio.c
>@@ -22,16 +22,6 @@
>
> #include "block/block-io.h"
>
>-/*
>- * Keep the QEMU BlockDriver names identical to the libblkio driver names.
>- * Using macros instead of typing out the string literals avoids typos.
>- */
>-#define DRIVER_IO_URING "io_uring"
>-#define DRIVER_NVME_IO_URING "nvme-io_uring"
>-#define DRIVER_VIRTIO_BLK_VFIO_PCI "virtio-blk-vfio-pci"
>-#define DRIVER_VIRTIO_BLK_VHOST_USER "virtio-blk-vhost-user"
>-#define DRIVER_VIRTIO_BLK_VHOST_VDPA "virtio-blk-vhost-vdpa"
>-
> /*
>  * Allocated bounce buffers are kept in a list sorted by buffer address.
>  */
>@@ -744,15 +734,15 @@ static int blkio_file_open(BlockDriverState *bs, QDict *options, int flags,
>         return ret;
>     }
>
>-    if (strcmp(blkio_driver, DRIVER_IO_URING) == 0) {
>+    if (strcmp(blkio_driver, "io_uring") == 0) {
>         ret = blkio_io_uring_open(bs, options, flags, errp);
>-    } else if (strcmp(blkio_driver, DRIVER_NVME_IO_URING) == 0) {
>+    } else if (strcmp(blkio_driver, "nvme-io_uring") == 0) {
>         ret = blkio_nvme_io_uring(bs, options, flags, errp);
>-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VFIO_PCI) == 0) {
>+    } else if (strcmp(blkio_driver, "virtio-blk-vfio-pci") == 0) {
>         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
>-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_USER) == 0) {
>+    } else if (strcmp(blkio_driver, "virtio-blk-vhost-user") == 0) {
>         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
>-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_VDPA) == 0) {
>+    } else if (strcmp(blkio_driver, "virtio-blk-vhost-vdpa") == 0) {
>         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
>     } else {
>         g_assert_not_reached();
>@@ -1028,49 +1018,63 @@ static void blkio_refresh_limits(BlockDriverState *bs, Error **errp)
>  * - truncate
>  */
>
>-#define BLKIO_DRIVER(name, ...) \
>-    { \
>-        .format_name             = name, \
>-        .protocol_name           = name, \
>-        .instance_size           = sizeof(BDRVBlkioState), \
>-        .bdrv_file_open          = blkio_file_open, \
>-        .bdrv_close              = blkio_close, \
>-        .bdrv_co_getlength       = blkio_co_getlength, \
>-        .bdrv_co_truncate        = blkio_truncate, \
>-        .bdrv_co_get_info        = blkio_co_get_info, \
>-        .bdrv_attach_aio_context = blkio_attach_aio_context, \
>-        .bdrv_detach_aio_context = blkio_detach_aio_context, \
>-        .bdrv_co_pdiscard        = blkio_co_pdiscard, \
>-        .bdrv_co_preadv          = blkio_co_preadv, \
>-        .bdrv_co_pwritev         = blkio_co_pwritev, \
>-        .bdrv_co_flush_to_disk   = blkio_co_flush, \
>-        .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
>-        .bdrv_refresh_limits     = blkio_refresh_limits, \
>-        .bdrv_register_buf       = blkio_register_buf, \
>-        .bdrv_unregister_buf     = blkio_unregister_buf, \
>-        __VA_ARGS__ \
>-    }
>+/*
>+ * Do not include .format_name and .protocol_name because module_block.py
>+ * does not parse macros in the source code.
>+ */
>+#define BLKIO_DRIVER_COMMON \
>+    .instance_size           = sizeof(BDRVBlkioState), \
>+    .bdrv_file_open          = blkio_file_open, \
>+    .bdrv_close              = blkio_close, \
>+    .bdrv_co_getlength       = blkio_co_getlength, \
>+    .bdrv_co_truncate        = blkio_truncate, \
>+    .bdrv_co_get_info        = blkio_co_get_info, \
>+    .bdrv_attach_aio_context = blkio_attach_aio_context, \
>+    .bdrv_detach_aio_context = blkio_detach_aio_context, \
>+    .bdrv_co_pdiscard        = blkio_co_pdiscard, \
>+    .bdrv_co_preadv          = blkio_co_preadv, \
>+    .bdrv_co_pwritev         = blkio_co_pwritev, \
>+    .bdrv_co_flush_to_disk   = blkio_co_flush, \
>+    .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
>+    .bdrv_refresh_limits     = blkio_refresh_limits, \
>+    .bdrv_register_buf       = blkio_register_buf, \
>+    .bdrv_unregister_buf     = blkio_unregister_buf,
>
>-static BlockDriver bdrv_io_uring = BLKIO_DRIVER(
>-    DRIVER_IO_URING,
>-    .bdrv_needs_filename = true,
>-);
>+/*
>+ * Use the same .format_name and .protocol_name as the libblkio driver name for
>+ * consistency.
>+ */
>
>-static BlockDriver bdrv_nvme_io_uring = BLKIO_DRIVER(
>-    DRIVER_NVME_IO_URING,
>-);
>+static BlockDriver bdrv_io_uring = {
>+    .format_name         = "io_uring", \

Thanks for the fast fix :-)

Minor thing: we can remove the backslash here and in the following
`struct BlockDriver`s fields.

With or without this:

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

>+    .protocol_name       = "io_uring", \
>+    .bdrv_needs_filename = true, \
>+    BLKIO_DRIVER_COMMON
>+};
>
>-static BlockDriver bdrv_virtio_blk_vfio_pci = BLKIO_DRIVER(
>-    DRIVER_VIRTIO_BLK_VFIO_PCI
>-);
>+static BlockDriver bdrv_nvme_io_uring = {
>+    .format_name         = "nvme-io_uring", \
>+    .protocol_name       = "nvme-io_uring", \
>+    BLKIO_DRIVER_COMMON
>+};
>
>-static BlockDriver bdrv_virtio_blk_vhost_user = BLKIO_DRIVER(
>-    DRIVER_VIRTIO_BLK_VHOST_USER
>-);
>+static BlockDriver bdrv_virtio_blk_vfio_pci = {
>+    .format_name         = "virtio-blk-vfio-pci", \
>+    .protocol_name       = "virtio-blk-vfio-pci", \
>+    BLKIO_DRIVER_COMMON
>+};
>
>-static BlockDriver bdrv_virtio_blk_vhost_vdpa = BLKIO_DRIVER(
>-    DRIVER_VIRTIO_BLK_VHOST_VDPA
>-);
>+static BlockDriver bdrv_virtio_blk_vhost_user = {
>+    .format_name         = "virtio-blk-vhost-user", \
>+    .protocol_name       = "virtio-blk-vhost-user", \
>+    BLKIO_DRIVER_COMMON
>+};
>+
>+static BlockDriver bdrv_virtio_blk_vhost_vdpa = {
>+    .format_name         = "virtio-blk-vhost-vdpa", \
>+    .protocol_name       = "virtio-blk-vhost-vdpa", \
>+    BLKIO_DRIVER_COMMON
>+};
>
> static void bdrv_blkio_init(void)
> {
>-- 
>2.40.1
>
Re: [PATCH] block/blkio: fix module_block.py parsing
Posted by Stefan Hajnoczi 9 months, 4 weeks ago
On Mon, 3 Jul 2023 at 12:55, Stefano Garzarella <sgarzare@redhat.com> wrote:
>
> On Mon, Jul 03, 2023 at 12:35:24PM +0200, Stefan Hajnoczi wrote:
> >When QEMU is built with --enable-modules, the module_block.py script
> >parses block/*.c to find block drivers that are built as modules. The
> >script generates a table of block drivers called block_driver_modules[].
> >This table is used for block driver module loading.
> >
> >The blkio.c driver uses macros to define its BlockDriver structs. This
> >was done to avoid code duplication but the module_block.py script is
> >unable to parse the macro. The result is that libblkio-based block
> >drivers can be built as modules but will not be found at runtime.
> >
> >One fix is to make the module_block.py script or build system fancier so
> >it can parse C macros (e.g. by parsing the preprocessed source code). I
> >chose not to do this because it raises the complexity of the build,
> >making future issues harder to debug.
> >
> >Keep things simple: use the macro to avoid duplicating BlockDriver
> >function pointers but define .format_name and .protocol_name manually
> >for each BlockDriver. This way the module_block.py is able to parse the
> >code.
> >
> >Also get rid of the block driver name macros (e.g. DRIVER_IO_URING)
> >because module_block.py cannot parse them either.
> >
> >Fixes: fd66dbd424f5 ("blkio: add libblkio block driver")
> >Reported-by: Qing Wang <qinwang@redhat.com>
> >Cc: Stefano Garzarella <sgarzare@redhat.com>
> >Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> >---
> > block/blkio.c | 110 ++++++++++++++++++++++++++------------------------
> > 1 file changed, 57 insertions(+), 53 deletions(-)
> >
> >diff --git a/block/blkio.c b/block/blkio.c
> >index 527323d625..589f829a83 100644
> >--- a/block/blkio.c
> >+++ b/block/blkio.c
> >@@ -22,16 +22,6 @@
> >
> > #include "block/block-io.h"
> >
> >-/*
> >- * Keep the QEMU BlockDriver names identical to the libblkio driver names.
> >- * Using macros instead of typing out the string literals avoids typos.
> >- */
> >-#define DRIVER_IO_URING "io_uring"
> >-#define DRIVER_NVME_IO_URING "nvme-io_uring"
> >-#define DRIVER_VIRTIO_BLK_VFIO_PCI "virtio-blk-vfio-pci"
> >-#define DRIVER_VIRTIO_BLK_VHOST_USER "virtio-blk-vhost-user"
> >-#define DRIVER_VIRTIO_BLK_VHOST_VDPA "virtio-blk-vhost-vdpa"
> >-
> > /*
> >  * Allocated bounce buffers are kept in a list sorted by buffer address.
> >  */
> >@@ -744,15 +734,15 @@ static int blkio_file_open(BlockDriverState *bs, QDict *options, int flags,
> >         return ret;
> >     }
> >
> >-    if (strcmp(blkio_driver, DRIVER_IO_URING) == 0) {
> >+    if (strcmp(blkio_driver, "io_uring") == 0) {
> >         ret = blkio_io_uring_open(bs, options, flags, errp);
> >-    } else if (strcmp(blkio_driver, DRIVER_NVME_IO_URING) == 0) {
> >+    } else if (strcmp(blkio_driver, "nvme-io_uring") == 0) {
> >         ret = blkio_nvme_io_uring(bs, options, flags, errp);
> >-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VFIO_PCI) == 0) {
> >+    } else if (strcmp(blkio_driver, "virtio-blk-vfio-pci") == 0) {
> >         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
> >-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_USER) == 0) {
> >+    } else if (strcmp(blkio_driver, "virtio-blk-vhost-user") == 0) {
> >         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
> >-    } else if (strcmp(blkio_driver, DRIVER_VIRTIO_BLK_VHOST_VDPA) == 0) {
> >+    } else if (strcmp(blkio_driver, "virtio-blk-vhost-vdpa") == 0) {
> >         ret = blkio_virtio_blk_common_open(bs, options, flags, errp);
> >     } else {
> >         g_assert_not_reached();
> >@@ -1028,49 +1018,63 @@ static void blkio_refresh_limits(BlockDriverState *bs, Error **errp)
> >  * - truncate
> >  */
> >
> >-#define BLKIO_DRIVER(name, ...) \
> >-    { \
> >-        .format_name             = name, \
> >-        .protocol_name           = name, \
> >-        .instance_size           = sizeof(BDRVBlkioState), \
> >-        .bdrv_file_open          = blkio_file_open, \
> >-        .bdrv_close              = blkio_close, \
> >-        .bdrv_co_getlength       = blkio_co_getlength, \
> >-        .bdrv_co_truncate        = blkio_truncate, \
> >-        .bdrv_co_get_info        = blkio_co_get_info, \
> >-        .bdrv_attach_aio_context = blkio_attach_aio_context, \
> >-        .bdrv_detach_aio_context = blkio_detach_aio_context, \
> >-        .bdrv_co_pdiscard        = blkio_co_pdiscard, \
> >-        .bdrv_co_preadv          = blkio_co_preadv, \
> >-        .bdrv_co_pwritev         = blkio_co_pwritev, \
> >-        .bdrv_co_flush_to_disk   = blkio_co_flush, \
> >-        .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
> >-        .bdrv_refresh_limits     = blkio_refresh_limits, \
> >-        .bdrv_register_buf       = blkio_register_buf, \
> >-        .bdrv_unregister_buf     = blkio_unregister_buf, \
> >-        __VA_ARGS__ \
> >-    }
> >+/*
> >+ * Do not include .format_name and .protocol_name because module_block.py
> >+ * does not parse macros in the source code.
> >+ */
> >+#define BLKIO_DRIVER_COMMON \
> >+    .instance_size           = sizeof(BDRVBlkioState), \
> >+    .bdrv_file_open          = blkio_file_open, \
> >+    .bdrv_close              = blkio_close, \
> >+    .bdrv_co_getlength       = blkio_co_getlength, \
> >+    .bdrv_co_truncate        = blkio_truncate, \
> >+    .bdrv_co_get_info        = blkio_co_get_info, \
> >+    .bdrv_attach_aio_context = blkio_attach_aio_context, \
> >+    .bdrv_detach_aio_context = blkio_detach_aio_context, \
> >+    .bdrv_co_pdiscard        = blkio_co_pdiscard, \
> >+    .bdrv_co_preadv          = blkio_co_preadv, \
> >+    .bdrv_co_pwritev         = blkio_co_pwritev, \
> >+    .bdrv_co_flush_to_disk   = blkio_co_flush, \
> >+    .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
> >+    .bdrv_refresh_limits     = blkio_refresh_limits, \
> >+    .bdrv_register_buf       = blkio_register_buf, \
> >+    .bdrv_unregister_buf     = blkio_unregister_buf,
> >
> >-static BlockDriver bdrv_io_uring = BLKIO_DRIVER(
> >-    DRIVER_IO_URING,
> >-    .bdrv_needs_filename = true,
> >-);
> >+/*
> >+ * Use the same .format_name and .protocol_name as the libblkio driver name for
> >+ * consistency.
> >+ */
> >
> >-static BlockDriver bdrv_nvme_io_uring = BLKIO_DRIVER(
> >-    DRIVER_NVME_IO_URING,
> >-);
> >+static BlockDriver bdrv_io_uring = {
> >+    .format_name         = "io_uring", \
>
> Thanks for the fast fix :-)
>
> Minor thing: we can remove the backslash here and in the following
> `struct BlockDriver`s fields.
>
> With or without this:
>
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Oops, the slash is not necessary.

Thanks!

Stefan