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 <marcandre.lureau@redhat.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Cc: Alex Williamson <alex@shazbot.org>
Cc: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
hw/display/virtio-gpu-dmabuf.c | 44 ++++++++++++++++++++++------------
1 file changed, 29 insertions(+), 15 deletions(-)
diff --git a/hw/display/virtio-gpu-dmabuf.c b/hw/display/virtio-gpu-dmabuf.c
index 8d67ef7c2a..22e66fbb12 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 +47,11 @@ 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__);
+ error_setg(errp, "Could not find ramblock for dmabuf segment");
+ return false;
}
list->list[i].memfd = rb->fd;
@@ -58,20 +64,26 @@ 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");
+ 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 **err1)
{
- 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(err1, 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 +137,7 @@ bool virtio_gpu_have_udmabuf(void)
void virtio_gpu_init_dmabuf(struct virtio_gpu_simple_resource *res)
{
+ Error *err1 = NULL;
void *pdata = NULL;
res->dmabuf_fd = -1;
@@ -132,12 +145,13 @@ 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, &err1)) {
+ error_report_err(err1);
return;
}
- virtio_gpu_remap_dmabuf(res);
- if (!res->remapped) {
+
+ if (!virtio_gpu_remap_dmabuf(res, &err1)) {
+ error_report_err(err1);
return;
}
pdata = res->remapped;
--
2.50.1
On 2026/02/03 16:30, 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 <marcandre.lureau@redhat.com>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Cc: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
> Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> Cc: Alex Williamson <alex@shazbot.org>
> Cc: Cédric Le Goater <clg@redhat.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
> ---
> hw/display/virtio-gpu-dmabuf.c | 44 ++++++++++++++++++++++------------
> 1 file changed, 29 insertions(+), 15 deletions(-)
>
> diff --git a/hw/display/virtio-gpu-dmabuf.c b/hw/display/virtio-gpu-dmabuf.c
> index 8d67ef7c2a..22e66fbb12 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 +47,11 @@ 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__);
> + error_setg(errp, "Could not find ramblock for dmabuf segment");
This should stay LOG_GUEST_ERROR as this may be triggered by the guest.
Regards,
Akihiko Odaki
> + return false;
> }
>
> list->list[i].memfd = rb->fd;
> @@ -58,20 +64,26 @@ 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");
> + 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 **err1)
> {
> - 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(err1, 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 +137,7 @@ bool virtio_gpu_have_udmabuf(void)
>
> void virtio_gpu_init_dmabuf(struct virtio_gpu_simple_resource *res)
> {
> + Error *err1 = NULL;
> void *pdata = NULL;
>
> res->dmabuf_fd = -1;
> @@ -132,12 +145,13 @@ 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, &err1)) {
> + error_report_err(err1);
> return;
> }
> - virtio_gpu_remap_dmabuf(res);
> - if (!res->remapped) {
> +
> + if (!virtio_gpu_remap_dmabuf(res, &err1)) {
> + error_report_err(err1);
> return;
> }
> pdata = res->remapped;
Hi Akihiko,
> Subject: Re: [PATCH v5 06/12] virtio-gpu-dmabuf: Improve error
> handling by introducing 'Error **'
>
> On 2026/02/03 16:30, 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 <marcandre.lureau@redhat.com>
> > Cc: Alex Bennée <alex.bennee@linaro.org>
> > Cc: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
> > Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> > Cc: Alex Williamson <alex@shazbot.org>
> > Cc: Cédric Le Goater <clg@redhat.com>
> > Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
> > ---
> > hw/display/virtio-gpu-dmabuf.c | 44 ++++++++++++++++++++++--------
> ----
> > 1 file changed, 29 insertions(+), 15 deletions(-)
> >
> > diff --git a/hw/display/virtio-gpu-dmabuf.c b/hw/display/virtio-gpu-
> dmabuf.c
> > index 8d67ef7c2a..22e66fbb12 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 +47,11 @@ 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__);
> > + error_setg(errp, "Could not find ramblock for dmabuf
> segment");
>
> This should stay LOG_GUEST_ERROR as this may be triggered by the
> guest.
Ok, I'll drop the error_setg() above.
Thanks,
Vivek
>
> Regards,
> Akihiko Odaki
>
> > + return false;
> > }
> >
> > list->list[i].memfd = rb->fd;
> > @@ -58,20 +64,26 @@ 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");
> > + 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 **err1)
> > {
> > - 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(err1, 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 +137,7 @@ bool virtio_gpu_have_udmabuf(void)
> >
> > void virtio_gpu_init_dmabuf(struct virtio_gpu_simple_resource *res)
> > {
> > + Error *err1 = NULL;
> > void *pdata = NULL;
> >
> > res->dmabuf_fd = -1;
> > @@ -132,12 +145,13 @@ 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, &err1)) {
> > + error_report_err(err1);
> > return;
> > }
> > - virtio_gpu_remap_dmabuf(res);
> > - if (!res->remapped) {
> > +
> > + if (!virtio_gpu_remap_dmabuf(res, &err1)) {
> > + error_report_err(err1);
> > return;
> > }
> > pdata = res->remapped;
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