From: Alessandro Ratti <[email protected]> Improve error reporting when virtqueue ring mapping fails by including a device identifier in the error message.
Introduce a helper qdev_get_printable_name() in qdev-core, which returns either: - the device ID, if explicitly provided (e.g. -device ...,id=foo) - the QOM path from qdev_get_dev_path(dev) otherwise - "<unknown device>" as a fallback when no identifier is present This makes it easier to identify which device triggered the error in multi-device setups or when debugging complex guest configurations. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/230 Buglink: https://bugs.launchpad.net/qemu/+bug/1919021 Suggested-by: Markus Armbruster <[email protected]> Signed-off-by: Alessandro Ratti <[email protected]> Message-Id: <[email protected]> Reviewed-by: Daniel P. Berrangé <[email protected]> Reviewed-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> --- include/hw/qdev-core.h | 1 + hw/core/qdev.c | 29 +++++++++++++++++++++++++++++ hw/virtio/virtio.c | 15 ++++++++++++--- 3 files changed, 42 insertions(+), 3 deletions(-) diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index 530f3da702..a7bfb10dc7 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -1064,6 +1064,7 @@ bool qdev_set_parent_bus(DeviceState *dev, BusState *bus, Error **errp); extern bool qdev_hot_removed; char *qdev_get_dev_path(DeviceState *dev); +const char *qdev_get_printable_name(DeviceState *dev); void qbus_set_hotplug_handler(BusState *bus, Object *handler); void qbus_set_bus_hotplug_handler(BusState *bus); diff --git a/hw/core/qdev.c b/hw/core/qdev.c index f600226176..fab42a7270 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -411,6 +411,35 @@ char *qdev_get_dev_path(DeviceState *dev) return NULL; } +const char *qdev_get_printable_name(DeviceState *vdev) +{ + /* + * Return device ID if explicity set + * (e.g. -device virtio-blk-pci,id=foo) + * This allows users to correlate errors with their custom device + * names. + */ + if (vdev->id) { + return vdev->id; + } + /* + * Fall back to the canonical QOM device path (eg. ID for PCI + * devices). + * This ensures the device is still uniquely and meaningfully + * identified. + */ + const char *path = qdev_get_dev_path(vdev); + if (path) { + return path; + } + + /* + * Final fallback: if all else fails, return a placeholder string. + * This ensures the error message always contains a valid string. + */ + return "<unknown device>"; +} + void qdev_add_unplug_blocker(DeviceState *dev, Error *reason) { dev->unplug_blockers = g_slist_prepend(dev->unplug_blockers, reason); diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index de89e8104a..d38aafe5eb 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -257,7 +257,10 @@ void virtio_init_region_cache(VirtIODevice *vdev, int n) len = address_space_cache_init(&new->desc, vdev->dma_as, addr, size, packed); if (len < size) { - virtio_error(vdev, "Cannot map desc"); + virtio_error(vdev, + "Failed to map descriptor ring for device %s: " + "invalid guest physical address or corrupted queue setup", + qdev_get_printable_name(DEVICE(vdev))); goto err_desc; } @@ -265,7 +268,10 @@ void virtio_init_region_cache(VirtIODevice *vdev, int n) len = address_space_cache_init(&new->used, vdev->dma_as, vq->vring.used, size, true); if (len < size) { - virtio_error(vdev, "Cannot map used"); + virtio_error(vdev, + "Failed to map used ring for device %s: " + "possible guest misconfiguration or insufficient memory", + qdev_get_printable_name(DEVICE(vdev))); goto err_used; } @@ -273,7 +279,10 @@ void virtio_init_region_cache(VirtIODevice *vdev, int n) len = address_space_cache_init(&new->avail, vdev->dma_as, vq->vring.avail, size, false); if (len < size) { - virtio_error(vdev, "Cannot map avail"); + virtio_error(vdev, + "Failed to map avalaible ring for device %s: " + "possible queue misconfiguration or overlapping memory region", + qdev_get_printable_name(DEVICE(vdev))); goto err_avail; } -- MST
