[PATCH] drm/qxl: Add drm_panic support
Jocelyn Falempe
jfalempe at redhat.com
Thu Sep 12 22:33:29 UTC 2024
On 12/09/2024 11:30, Ryosuke Yasuoka wrote:
> QXL supports the drm_panic module, which displays a message to the
> screen when a kernel panic occurs.
Thanks a lot for this work, one more driver that will handle drm_panic.
I have a few comments below, but from drm_panic point of view, it looks
already pretty good.
--
Jocelyn
>
> Signed-off-by: Ryosuke Yasuoka <ryasuoka at redhat.com>
> ---
> Sorry for sending similar mails again and again. Please ignore the
> following my mails. Let me add dri-devel mailing list and Jocelyn who
> developped a drm_panic core and look forward to your comments on this
> mail.
>
> https://lore.kernel.org/all/20240911094644.616280-1-ryasuoka@redhat.com/T/#u
> https://lore.kernel.org/all/20240911101043.618043-1-ryasuoka@redhat.com/T/#u
>
>
> drivers/gpu/drm/qxl/qxl_cmd.c | 29 ++++++++++
> drivers/gpu/drm/qxl/qxl_display.c | 94 +++++++++++++++++++++++++++++++
> drivers/gpu/drm/qxl/qxl_draw.c | 57 ++++++++++++++++++-
> drivers/gpu/drm/qxl/qxl_drv.h | 21 +++++++
> drivers/gpu/drm/qxl/qxl_image.c | 27 +++++++++
> drivers/gpu/drm/qxl/qxl_object.c | 62 ++++++++++++++++++++
> drivers/gpu/drm/qxl/qxl_object.h | 4 ++
> 7 files changed, 293 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/qxl/qxl_cmd.c b/drivers/gpu/drm/qxl/qxl_cmd.c
> index d6ea01f3797b..c70041ce55c0 100644
> --- a/drivers/gpu/drm/qxl/qxl_cmd.c
> +++ b/drivers/gpu/drm/qxl/qxl_cmd.c
> @@ -174,6 +174,35 @@ static bool qxl_ring_pop(struct qxl_ring *ring,
> return true;
> }
>
> +/* For drm panic */
> +int
> +qxl_push_command_ring_without_release(struct qxl_device *qdev,
> + struct qxl_bo *bo, uint32_t type, uint32_t offset)
> +{
> + struct qxl_command cmd;
> + struct qxl_ring *ring = qdev->command_ring;
> + struct qxl_ring_header *header = &(ring->ring->header);
> + uint8_t *elt;
> + int idx;
> +
> + cmd.type = type;
> + cmd.data = qxl_bo_physical_address(qdev, bo, offset);
> +
> + idx = header->prod & (ring->n_elements - 1);
> + elt = ring->ring->elements + idx * ring->element_size;
> +
> + memcpy((void *)elt, &cmd, ring->element_size);
> +
> + header->prod++;
> +
> + mb();
> +
> + if (header->prod == header->notify_on_prod)
> + outb(0, ring->prod_notify);
> +
> + return 0;
> +}
> +
> int
> qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
> uint32_t type, bool interruptible)
> diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c
> index bc24af08dfcd..b5f2ddfe71a9 100644
> --- a/drivers/gpu/drm/qxl/qxl_display.c
> +++ b/drivers/gpu/drm/qxl/qxl_display.c
> @@ -37,6 +37,7 @@
> #include <drm/drm_probe_helper.h>
> #include <drm/drm_simple_kms_helper.h>
> #include <drm/drm_gem_atomic_helper.h>
> +#include <drm/drm_panic.h>
>
> #include "qxl_drv.h"
> #include "qxl_object.h"
> @@ -889,6 +890,97 @@ static void qxl_plane_cleanup_fb(struct drm_plane *plane,
> }
> }
>
> +static int qxl_primary_plane_helper_get_scanout_buffer(struct drm_plane *plane,
> + struct drm_scanout_buffer *sb)
> +{
> + struct qxl_bo *bo;
> +
> + if (!plane->state || !plane->state->fb)
> + return -ENODEV;
> +
> + bo = gem_to_qxl_bo(plane->state->fb->obj[0]);
> +
> + if (!bo->map.vaddr) {
> + int ret;
> +
> + ret = qxl_bo_pin_and_vmap(bo, &sb->map[0]);
> + if (ret)
> + return ret;
> + } else {
> + iosys_map_set_vaddr(&sb->map[0], bo->map.vaddr);
> + }
> +
> + sb->format = plane->state->fb->format;
> + sb->height = plane->state->fb->height;
> + sb->width = plane->state->fb->width;
> + sb->pitch[0] = plane->state->fb->pitches[0];
> + return 0;
> +}
> +
> +static void qxl_panic_flush(struct drm_plane *plane)
> +{
> + struct qxl_device *qdev = to_qxl(plane->dev);
> + struct qxl_bo *_bo = gem_to_qxl_bo(plane->state->fb->obj[0]);
> + uint8_t *surface_base = _bo->map.vaddr;
> + struct drm_clip_rect rect = {
> + .x1 = 0,
> + .y1 = 0,
> + .x2 = plane->state->fb->width,
> + .y2 = plane->state->fb->height
> + };
> + unsigned int num_clips = 1;
> + struct qxl_bo clips_bo = {};
> + struct qxl_bo image_bo = {};
> + struct qxl_bo chunk_bo = {};
> + struct qxl_drm_image dimage;
> + struct qxl_drm_chunk chunk;
> + int width = rect.x2;
> + int height = rect.y2;
> + int stride = plane->state->fb->pitches[0];
> + int depth = plane->state->fb->format->cpp[0] * 8;
> + struct qxl_rect *rects;
> + struct qxl_rect drawable_rect = {
> + .left = 0,
> + .right = width,
> + .top = 0,
> + .bottom = height,
> + };
> + int cur_idx = 0;
> + int size = 256;
> + struct qxl_bo *bo = qxl_bo_ref(qdev->current_release_bo[cur_idx]);
> + uint32_t offset = qdev->current_release_bo_offset[cur_idx] * size;
> + int ret;
> +
> + qxl_panic_bo_create(qdev, sizeof(struct qxl_clip_rects) + sizeof(struct qxl_rect),
> + false, false, QXL_GEM_DOMAIN_VRAM, 0, NULL, &clips_bo);
> +
> + ret = qxl_image_alloc_objects_without_release(qdev, &dimage, &chunk, &image_bo, &chunk_bo,
> + surface_base, width, height, depth, stride);
> + if (ret)
> + return;
> +
> + ret = make_drawable_without_release(qdev, &drawable_rect, bo, &clips_bo,
> + &dimage, offset, height, width);
> + if (ret)
> + return;
> +
> + rects = drawable_set_clipping(qdev, num_clips, &clips_bo);
> + if (!rects)
> + return;
> + rects[0].left = 0;
> + rects[0].right = width;
> + rects[0].top = 0;
> + rects[0].bottom = height;
> +
> + qxl_push_command_ring_without_release(qdev, bo, QXL_CMD_DRAW, offset);
> +
> + qxl_gem_object_free(&chunk_bo.tbo.base);
> + qxl_gem_object_free(&image_bo.tbo.base);
> +
> + qxl_bo_vunmap_locked(&clips_bo);
> + qxl_gem_object_free(&clips_bo.tbo.base);
> +}
> +
> static const uint32_t qxl_cursor_plane_formats[] = {
> DRM_FORMAT_ARGB8888,
> };
> @@ -920,6 +1012,8 @@ static const struct drm_plane_helper_funcs primary_helper_funcs = {
> .atomic_disable = qxl_primary_atomic_disable,
> .prepare_fb = qxl_plane_prepare_fb,
> .cleanup_fb = qxl_plane_cleanup_fb,
> + .get_scanout_buffer = qxl_primary_plane_helper_get_scanout_buffer,
> + .panic_flush = qxl_panic_flush,
> };
>
> static const struct drm_plane_funcs qxl_primary_plane_funcs = {
> diff --git a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c
> index 3a3e127ce297..49fdc0162377 100644
> --- a/drivers/gpu/drm/qxl/qxl_draw.c
> +++ b/drivers/gpu/drm/qxl/qxl_draw.c
> @@ -41,7 +41,8 @@ static int alloc_clips(struct qxl_device *qdev,
> /* returns a pointer to the already allocated qxl_rect array inside
> * the qxl_clip_rects. This is *not* the same as the memory allocated
> * on the device, it is offset to qxl_clip_rects.chunk.data */
> -static struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
> +
> +struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
> unsigned int num_clips,
> struct qxl_bo *clips_bo)
> {
> @@ -74,6 +75,60 @@ free_drawable(struct qxl_device *qdev, struct qxl_release *release)
> qxl_release_free(qdev, release);
> }
>
> +/* For drm panic */
> +int
> +make_drawable_without_release(struct qxl_device *qdev,
> + struct qxl_rect *drawable_rect,
> + struct qxl_bo *bo,
> + struct qxl_bo *clips_bo,
> + struct qxl_drm_image *dimage,
> + uint32_t offset, int height, int width)
> +{
> + struct qxl_drawable *drawable;
> + union qxl_release_info *info;
> + void *ptr;
> + int i;
> +
> + ptr = qxl_bo_kmap_atomic_page(qdev, bo, offset & PAGE_MASK);
> + if (!ptr)
> + return -ENOMEM;
> + drawable = ptr + (offset & ~PAGE_MASK);
> +
> + drawable->type = QXL_DRAW_COPY;
> + drawable->surface_id = 0;
> + drawable->effect = QXL_EFFECT_OPAQUE;
> + drawable->self_bitmap = 0;
> + drawable->self_bitmap_area.top = 0;
> + drawable->self_bitmap_area.left = 0;
> + drawable->self_bitmap_area.bottom = 0;
> + drawable->self_bitmap_area.right = 0;
> +
> + for (i = 0; i < 3; ++i)
> + drawable->surfaces_dest[i] = -1;
> +
> + drawable->bbox = *drawable_rect;
> + drawable->mm_time = qdev->rom->mm_clock;
> + drawable->clip.type = SPICE_CLIP_TYPE_RECTS;
> + drawable->clip.data = qxl_bo_physical_address(qdev, clips_bo, 0);
> + drawable->u.copy.src_area.top = 0;
> + drawable->u.copy.src_area.bottom = height;
> + drawable->u.copy.src_area.left = 0;
> + drawable->u.copy.src_area.right = width;
> + drawable->u.copy.rop_descriptor = SPICE_ROPD_OP_PUT;
> + drawable->u.copy.scale_mode = 0;
> + drawable->u.copy.mask.flags = 0;
> + drawable->u.copy.mask.pos.x = 0;
> + drawable->u.copy.mask.pos.y = 0;
> + drawable->u.copy.mask.bitmap = 0;
> + drawable->u.copy.src_bitmap = qxl_bo_physical_address(qdev, dimage->bo, 0);
> +
> + info = &drawable->release_info;
> + ptr = ((void *)info) - (offset & ~PAGE_MASK);
> + qxl_bo_kunmap_atomic_page(qdev, bo, ptr);
> +
> + return 0;
> +}
> +
> /* release needs to be reserved at this point */
> static int
> make_drawable(struct qxl_device *qdev, int surface, uint8_t type,
> diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
> index 32069acd93f8..93dd0de06c23 100644
> --- a/drivers/gpu/drm/qxl/qxl_drv.h
> +++ b/drivers/gpu/drm/qxl/qxl_drv.h
> @@ -334,6 +334,13 @@ int qxl_image_init(struct qxl_device *qdev,
> const uint8_t *data,
> int x, int y, int width, int height,
> int depth, int stride);
> +
> +int qxl_image_alloc_objects_without_release(struct qxl_device *qdev,
> + struct qxl_drm_image *image, struct qxl_drm_chunk *chunk,
> + struct qxl_bo *image_bo, struct qxl_bo *chunk_bo,
> + uint8_t *surface_base, int width,
> + int height, int depth, int stride);
> +
> int
> qxl_image_alloc_objects(struct qxl_device *qdev,
> struct qxl_release *release,
> @@ -376,6 +383,9 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
> int type, struct qxl_release **release,
> struct qxl_bo **rbo);
>
> +int qxl_push_command_ring_without_release(struct qxl_device *qdev,
> + struct qxl_bo *bo, uint32_t type, uint32_t offset);
> +
> int
> qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
> uint32_t type, bool interruptible);
> @@ -387,6 +397,9 @@ int qxl_alloc_bo_reserved(struct qxl_device *qdev,
> unsigned long size,
> struct qxl_bo **_bo);
> /* qxl drawing commands */
> +struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
> + unsigned int num_clips,
> + struct qxl_bo *clips_bo);
>
> void qxl_draw_dirty_fb(struct qxl_device *qdev,
> struct drm_framebuffer *fb,
> @@ -399,6 +412,14 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
> void qxl_release_free(struct qxl_device *qdev,
> struct qxl_release *release);
>
> +int
> +make_drawable_without_release(struct qxl_device *qdev,
> + struct qxl_rect *drawable_rect,
> + struct qxl_bo *bo,
> + struct qxl_bo *clips_bo,
> + struct qxl_drm_image *dimage,
> + uint32_t offset, int height, int width);
> +
> /* used by qxl_debugfs_release */
> struct qxl_release *qxl_release_from_id_locked(struct qxl_device *qdev,
> uint64_t id);
> diff --git a/drivers/gpu/drm/qxl/qxl_image.c b/drivers/gpu/drm/qxl/qxl_image.c
> index ffff54e5fb31..2efe0cf133a6 100644
> --- a/drivers/gpu/drm/qxl/qxl_image.c
> +++ b/drivers/gpu/drm/qxl/qxl_image.c
> @@ -52,6 +52,33 @@ qxl_allocate_chunk(struct qxl_device *qdev,
> return 0;
> }
>
> +/* For drm panic */
> +int
> +qxl_image_alloc_objects_without_release(struct qxl_device *qdev,
> + struct qxl_drm_image *image, struct qxl_drm_chunk *chunk,
> + struct qxl_bo *image_bo, struct qxl_bo *chunk_bo,
> + uint8_t *surface_base, int width, int height,
> + int depth, int stride)
> +{
> + int ret;
> + unsigned int chunk_size = sizeof(struct qxl_data_chunk) + stride * height;
> +
> + INIT_LIST_HEAD(&image->chunk_list);
> + qxl_panic_bo_create(qdev, sizeof(struct qxl_image), false, false,
> + QXL_GEM_DOMAIN_VRAM, 0, NULL, image_bo);
> + image->bo = image_bo;
> +
> + qxl_panic_bo_create(qdev, chunk_size, false, false,
> + QXL_GEM_DOMAIN_VRAM, 0, NULL, chunk_bo);
> + chunk->bo = chunk_bo;
> + list_add_tail(&chunk->head, &image->chunk_list);
> +
> + ret = qxl_image_init(qdev, NULL, image, surface_base,
> + 0, 0, width, height, depth, stride);
> + return ret;
> +
> +}
> +
> int
> qxl_image_alloc_objects(struct qxl_device *qdev,
> struct qxl_release *release,
> diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
> index 66635c55cf85..9e00700f8f03 100644
> --- a/drivers/gpu/drm/qxl/qxl_object.c
> +++ b/drivers/gpu/drm/qxl/qxl_object.c
> @@ -29,6 +29,23 @@
> #include "qxl_drv.h"
> #include "qxl_object.h"
>
> +/* for drm panic */
> +static void qxl_panic_ttm_bo_destroy(struct ttm_buffer_object *tbo)
> +{
> + struct qxl_bo *bo;
> + struct qxl_device *qdev;
> +
> + bo = to_qxl_bo(tbo);
> + qdev = to_qxl(bo->tbo.base.dev);
> +
> + qxl_surface_evict(qdev, bo, false);
qxl_surface_evict() takes a mutex, so we should avoid to call it.
It may leak things, but it's still better than deadlocking in the panic
handler.
> + WARN_ON_ONCE(bo->map_count > 0);
> + mutex_lock(&qdev->gem.mutex);
> + list_del_init(&bo->list);
> + mutex_unlock(&qdev->gem.mutex);
I think you don't need to remove it from the list. It's added in
qxl_gem_object_create(), which I don't see it being called in the panic
flush function. (But this is something you can check to make sure).
> + drm_gem_object_release(&bo->tbo.base);
> +}
> +
> static void qxl_ttm_bo_destroy(struct ttm_buffer_object *tbo)
> {
> struct qxl_bo *bo;
> @@ -101,6 +118,51 @@ static const struct drm_gem_object_funcs qxl_object_funcs = {
> .print_info = drm_gem_ttm_print_info,
> };
>
> +/* for drm_panic */
> +int qxl_panic_bo_create(struct qxl_device *qdev, unsigned long size,
> + bool kernel, bool pinned, u32 domain, u32 priority,
> + struct qxl_surface *surf, struct qxl_bo *bo)
> +{
All caller to qxl_panic_bo_create() have a priority of 0, and surf set
to NULL, they also have kernel and pinned set to false.
So you can remove them from the argument list, and simplify this
function a bit. There are probably other parameters that can be omitted
like this, in the other "panic" functions.
> + struct ttm_operation_ctx ctx = { !kernel, false };
> + enum ttm_bo_type type;
> + int r;
> +
> + if (kernel)
> + type = ttm_bo_type_kernel;
> + else
> + type = ttm_bo_type_device;
> +
> + size = roundup(size, PAGE_SIZE);
> + r = drm_gem_object_init(&qdev->ddev, &bo->tbo.base, size);
> + if (unlikely(r))
> + return r;
> + bo->tbo.base.funcs = &qxl_object_funcs;
> + bo->type = domain;
> + bo->surface_id = 0;
> + INIT_LIST_HEAD(&bo->list);
> +
> + if (surf)
> + bo->surf = *surf;
> +
> + qxl_ttm_placement_from_domain(bo, domain);
> +
> + bo->tbo.priority = priority;
> + r = ttm_bo_init_reserved(&qdev->mman.bdev, &bo->tbo, type,
> + &bo->placement, 0, &ctx, NULL, NULL,
> + &qxl_panic_ttm_bo_destroy);
> + if (unlikely(r != 0)) {
> + if (r != -ERESTARTSYS)
> + dev_err(qdev->ddev.dev,
> + "object_init failed for (%lu, 0x%08X)\n",
> + size, domain);
> + return r;
> + }
> + if (pinned)
> + ttm_bo_pin(&bo->tbo);
> + ttm_bo_unreserve(&bo->tbo);
> + return 0;
> +}
> +
> int qxl_bo_create(struct qxl_device *qdev, unsigned long size,
> bool kernel, bool pinned, u32 domain, u32 priority,
> struct qxl_surface *surf,
> diff --git a/drivers/gpu/drm/qxl/qxl_object.h b/drivers/gpu/drm/qxl/qxl_object.h
> index 875f63221074..4debb8ce6d08 100644
> --- a/drivers/gpu/drm/qxl/qxl_object.h
> +++ b/drivers/gpu/drm/qxl/qxl_object.h
> @@ -53,6 +53,10 @@ static inline unsigned long qxl_bo_size(struct qxl_bo *bo)
> return bo->tbo.base.size;
> }
>
> +extern int qxl_panic_bo_create(struct qxl_device *qdev, unsigned long size,
> + bool kernel, bool pinned, u32 domain, u32 priority,
> + struct qxl_surface *surf,
> + struct qxl_bo *bo);
> extern int qxl_bo_create(struct qxl_device *qdev,
> unsigned long size,
> bool kernel, bool pinned, u32 domain,
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