On 2026/02/10 16:33, Akihiko Odaki wrote:
On 2026/02/10 15:59, Vivek Kasireddy wrote:
Make the error handling more robust in virtio_gpu_init_udmabuf()
by passing in 'Error **' parameter to capture errors from
virtio_gpu_create_udmabuf() and virtio_gpu_remap_dmabuf().
And, since they now take in 'Error **' parameter, have them
return a bool to adhere to best practices.
Cc: Marc-André Lureau <[email protected]>
Cc: Alex Bennée <[email protected]>
Cc: Akihiko Odaki <[email protected]>
Cc: Dmitry Osipenko <[email protected]>
Cc: Alex Williamson <[email protected]>
Cc: Cédric Le Goater <[email protected]>
Signed-off-by: Vivek Kasireddy <[email protected]>
---
hw/display/virtio-gpu-dmabuf.c | 45 ++++++++++++++++++++++------------
1 file changed, 30 insertions(+), 15 deletions(-)
diff --git a/hw/display/virtio-gpu-dmabuf.c b/hw/display/virtio-gpu-
dmabuf.c
index 8d67ef7c2a..d9b2ecaf31 100644
--- a/hw/display/virtio-gpu-dmabuf.c
+++ b/hw/display/virtio-gpu-dmabuf.c
@@ -27,7 +27,8 @@
#include "standard-headers/linux/udmabuf.h"
#include "standard-headers/drm/drm_fourcc.h"
-static void virtio_gpu_create_udmabuf(struct
virtio_gpu_simple_resource *res)
+static bool virtio_gpu_create_udmabuf(struct
virtio_gpu_simple_resource *res,
+ Error **errp)
{
g_autofree struct udmabuf_create_list *list = NULL;
RAMBlock *rb;
@@ -36,7 +37,8 @@ static void virtio_gpu_create_udmabuf(struct
virtio_gpu_simple_resource *res)
udmabuf = udmabuf_fd();
if (udmabuf < 0) {
- return;
+ error_setg(errp, "udmabuf device not available");
+ return false;
}
list = g_malloc0(sizeof(struct udmabuf_create_list) +
@@ -45,7 +47,10 @@ static void virtio_gpu_create_udmabuf(struct
virtio_gpu_simple_resource *res)
for (i = 0; i < res->iov_cnt; i++) {
rb = qemu_ram_block_from_host(res->iov[i].iov_base, false,
&offset);
if (!rb || rb->fd < 0) {
- return;
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "%s: Could not find valid ramblock\n",
+ __func__);
+ return false;
include/qapi/error.h suggests the following error handling pattern:
> Call a function, receive an error from it, and pass it to the caller
> - when the function returns a value that indicates failure, say
> false:
> if (!foo(arg, errp)) {
> handle the error...
> }
Returning false without passing an error to the caller breaks it so
please don't do that.
}
list->list[i].memfd = rb->fd;
@@ -58,20 +63,26 @@ static void virtio_gpu_create_udmabuf(struct
virtio_gpu_simple_resource *res)
res->dmabuf_fd = ioctl(udmabuf, UDMABUF_CREATE_LIST, list);
if (res->dmabuf_fd < 0) {
- warn_report("%s: UDMABUF_CREATE_LIST: %s", __func__,
- strerror(errno));
+ error_setg_errno(errp, -res->dmabuf_fd,
+ "Could not create dmabuf fd via udmabuf
driver");
This is a guest error since it indicates that the guest specified wrong
addresses.
Regards,
Akihiko Odaki
+ return false;
}
+ return true;
}
-static void virtio_gpu_remap_dmabuf(struct virtio_gpu_simple_resource
*res)
+static bool virtio_gpu_remap_dmabuf(struct virtio_gpu_simple_resource
*res,
+ Error **errp)
{
- res->remapped = mmap(NULL, res->blob_size, PROT_READ,
- MAP_SHARED, res->dmabuf_fd, 0);
- if (res->remapped == MAP_FAILED) {
- warn_report("%s: dmabuf mmap failed: %s", __func__,
- strerror(errno));
+ void *map;
+
+ map = mmap(NULL, res->blob_size, PROT_READ, MAP_SHARED, res-
>dmabuf_fd, 0);
+ if (map == MAP_FAILED) {
+ error_setg_errno(errp, errno, "dmabuf mmap failed");
res->remapped = NULL;
+ return false;
}
+ res->remapped = map;
+ return true;
}
static void virtio_gpu_destroy_dmabuf(struct
virtio_gpu_simple_resource *res)
@@ -125,6 +136,7 @@ bool virtio_gpu_have_udmabuf(void)
void virtio_gpu_init_dmabuf(struct virtio_gpu_simple_resource *res)
{
+ Error *local_err = NULL;
void *pdata = NULL;
res->dmabuf_fd = -1;
@@ -132,12 +144,15 @@ void virtio_gpu_init_dmabuf(struct
virtio_gpu_simple_resource *res)
res->iov[0].iov_len < 4096) {
pdata = res->iov[0].iov_base;
} else {
- virtio_gpu_create_udmabuf(res);
- if (res->dmabuf_fd < 0) {
+ if (!virtio_gpu_create_udmabuf(res, &local_err)) {
+ if (local_err) {
+ error_report_err(local_err);
+ }
return;
}
- virtio_gpu_remap_dmabuf(res);
- if (!res->remapped) {
+
+ if (!virtio_gpu_remap_dmabuf(res, &local_err)) {
+ error_report_err(local_err);
return;
}
pdata = res->remapped;
