Re: [QEMU PATCH v4 09/13] virtio-gpu: Handle resource blob commands

[Huang Rui <ray.huang@xxxxxxx>]

On Thu, Aug 31, 2023 at 06:24:32PM +0800, Akihiko Odaki wrote:
> On 2023/08/31 18:32, Huang Rui wrote:
> > From: Antonio Caggiano <antonio.caggiano@xxxxxxxxxxxxx>
> > 
> > Support BLOB resources creation, mapping and unmapping by calling the
> > new stable virglrenderer 0.10 interface. Only enabled when available and
> > via the blob config. E.g. -device virtio-vga-gl,blob=true
> > 
> > Signed-off-by: Antonio Caggiano <antonio.caggiano@xxxxxxxxxxxxx>
> > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> > Signed-off-by: Xenia Ragiadakou <xenia.ragiadakou@xxxxxxx>
> > Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> > ---
> > 
> > v1->v2:
> >      - Remove unused #include "hw/virtio/virtio-iommu.h"
> > 
> >      - Add a local function, called virgl_resource_destroy(), that is used
> >        to release a vgpu resource on error paths and in resource_unref.
> > 
> >      - Remove virtio_gpu_virgl_resource_unmap from 
> > virtio_gpu_cleanup_mapping(),
> >        since this function won't be called on blob resources and also 
> > because
> >        blob resources are unmapped via virgl_cmd_resource_unmap_blob().
> > 
> >      - In virgl_cmd_resource_create_blob(), do proper cleanup in error paths
> >        and move QTAILQ_INSERT_HEAD(&g->reslist, res, next) after the 
> > resource
> >        has been fully initialized.
> > 
> >      - Memory region has a different life-cycle from virtio gpu resources
> >        i.e. cannot be released synchronously along with the vgpu resource.
> >        So, here the field "region" was changed to a pointer that will be
> >        released automatically once the memory region is unparented and all
> >        of its references have been released.
> >        Also, since the pointer can be used to indicate whether the blob
> >        is mapped, the explicit field "mapped" was removed.
> > 
> >      - In virgl_cmd_resource_map_blob(), add check on the value of
> >        res->region, to prevent beeing called twice on the same resource.
> > 
> >      - Remove direct references to parent_obj.
> > 
> >      - Separate declarations from code.
> > 
> >   hw/display/virtio-gpu-virgl.c  | 213 +++++++++++++++++++++++++++++++++
> >   hw/display/virtio-gpu.c        |   4 +-
> >   include/hw/virtio/virtio-gpu.h |   5 +
> >   meson.build                    |   4 +
> >   4 files changed, 225 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
> > index 312953ec16..17b634d4ee 100644
> > --- a/hw/display/virtio-gpu-virgl.c
> > +++ b/hw/display/virtio-gpu-virgl.c
> > @@ -17,6 +17,7 @@
> >   #include "trace.h"
> >   #include "hw/virtio/virtio.h"
> >   #include "hw/virtio/virtio-gpu.h"
> > +#include "hw/virtio/virtio-gpu-bswap.h"
> >   
> >   #include "ui/egl-helpers.h"
> >   
> > @@ -78,9 +79,24 @@ static void virgl_cmd_create_resource_3d(VirtIOGPU *g,
> >       virgl_renderer_resource_create(&args, NULL, 0);
> >   }
> >   
> > +static void virgl_resource_destroy(VirtIOGPU *g,
> > +                                   struct virtio_gpu_simple_resource *res)
> > +{
> > +    if (!res)
> > +        return;
> > +
> > +    QTAILQ_REMOVE(&g->reslist, res, next);
> > +
> > +    virtio_gpu_cleanup_mapping_iov(g, res->iov, res->iov_cnt);
> > +    g_free(res->addrs);
> > +
> > +    g_free(res);
> > +}
> > +
> >   static void virgl_cmd_resource_unref(VirtIOGPU *g,
> >                                        struct virtio_gpu_ctrl_command *cmd)
> >   {
> > +    struct virtio_gpu_simple_resource *res;
> >       struct virtio_gpu_resource_unref unref;
> >       struct iovec *res_iovs = NULL;
> >       int num_iovs = 0;
> > @@ -88,13 +104,22 @@ static void virgl_cmd_resource_unref(VirtIOGPU *g,
> >       VIRTIO_GPU_FILL_CMD(unref);
> >       trace_virtio_gpu_cmd_res_unref(unref.resource_id);
> >   
> > +    res = virtio_gpu_find_resource(g, unref.resource_id);
> > +
> >       virgl_renderer_resource_detach_iov(unref.resource_id,
> >                                          &res_iovs,
> >                                          &num_iovs);
> >       if (res_iovs != NULL && num_iovs != 0) {
> >           virtio_gpu_cleanup_mapping_iov(g, res_iovs, num_iovs);
> > +        if (res) {
> > +            res->iov = NULL;
> > +            res->iov_cnt = 0;
> > +        }
> >       }
> > +
> >       virgl_renderer_resource_unref(unref.resource_id);
> > +
> > +    virgl_resource_destroy(g, res);
> >   }
> >   
> >   static void virgl_cmd_context_create(VirtIOGPU *g,
> > @@ -426,6 +451,183 @@ static void virgl_cmd_get_capset(VirtIOGPU *g,
> >       g_free(resp);
> >   }
> >   
> > +#ifdef HAVE_VIRGL_RESOURCE_BLOB
> > +
> > +static void virgl_cmd_resource_create_blob(VirtIOGPU *g,
> > +                                           struct virtio_gpu_ctrl_command 
> > *cmd)
> > +{
> > +    struct virtio_gpu_simple_resource *res;
> > +    struct virtio_gpu_resource_create_blob cblob;
> > +    struct virgl_renderer_resource_create_blob_args virgl_args = { 0 };
> > +    int ret;
> > +
> > +    VIRTIO_GPU_FILL_CMD(cblob);
> > +    virtio_gpu_create_blob_bswap(&cblob);
> > +    trace_virtio_gpu_cmd_res_create_blob(cblob.resource_id, cblob.size);
> > +
> > +    if (cblob.resource_id == 0) {
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource id 0 is not 
> > allowed\n",
> > +                      __func__);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +
> > +    res = virtio_gpu_find_resource(g, cblob.resource_id);
> > +    if (res) {
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource already exists %d\n",
> > +                      __func__, cblob.resource_id);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +
> > +    res = g_new0(struct virtio_gpu_simple_resource, 1);
> > +    if (!res) {
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_OUT_OF_MEMORY;
> > +        return;
> > +    }
> > +
> > +    res->resource_id = cblob.resource_id;
> > +    res->blob_size = cblob.size;
> > +
> > +    if (cblob.blob_mem != VIRTIO_GPU_BLOB_MEM_HOST3D) {
> > +        ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, 
> > sizeof(cblob),
> > +                                            cmd, &res->addrs, &res->iov,
> > +                                            &res->iov_cnt);
> > +        if (!ret) {
> > +            g_free(res);
> > +            cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
> > +            return;
> > +        }
> > +    }
> > +
> > +    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
> > +
> > +    virgl_args.res_handle = cblob.resource_id;
> > +    virgl_args.ctx_id = cblob.hdr.ctx_id;
> > +    virgl_args.blob_mem = cblob.blob_mem;
> > +    virgl_args.blob_id = cblob.blob_id;
> > +    virgl_args.blob_flags = cblob.blob_flags;
> > +    virgl_args.size = cblob.size;
> > +    virgl_args.iovecs = res->iov;
> > +    virgl_args.num_iovs = res->iov_cnt;
> > +
> > +    ret = virgl_renderer_resource_create_blob(&virgl_args);
> > +    if (ret) {
> > +        virgl_resource_destroy(g, res);
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: virgl blob create error: %s\n",
> > +                      __func__, strerror(-ret));
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
> > +    }
> > +}
> > +
> > +static void virgl_cmd_resource_map_blob(VirtIOGPU *g,
> > +                                        struct virtio_gpu_ctrl_command 
> > *cmd)
> > +{
> > +    struct virtio_gpu_simple_resource *res;
> > +    struct virtio_gpu_resource_map_blob mblob;
> > +    int ret;
> > +    void *data;
> > +    uint64_t size;
> > +    struct virtio_gpu_resp_map_info resp;
> > +    VirtIOGPUBase *b = VIRTIO_GPU_BASE(g);
> > +
> > +    VIRTIO_GPU_FILL_CMD(mblob);
> > +    virtio_gpu_map_blob_bswap(&mblob);
> > +
> > +    if (mblob.resource_id == 0) {
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource id 0 is not 
> > allowed\n",
> > +                      __func__);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +
> > +    res = virtio_gpu_find_resource(g, mblob.resource_id);
> > +    if (!res) {
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource does not exist %d\n",
> > +                      __func__, mblob.resource_id);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +    if (res->region) {
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource already mapped %d\n",
> > +                 __func__, mblob.resource_id);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +
> > +    ret = virgl_renderer_resource_map(res->resource_id, &data, &size);
> > +    if (ret) {
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource map error: %s\n",
> > +                      __func__, strerror(-ret));
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +
> > +    res->region = g_new0(MemoryRegion, 1);
> > +    if (!res->region) {
> > +        virgl_renderer_resource_unmap(res->resource_id);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_OUT_OF_MEMORY;
> > +        return;
> > +    }
> > +    memory_region_init_ram_device_ptr(res->region, OBJECT(g), NULL, size, 
> > data);
> 
> I think memory_region_init_ram_ptr() should be used instead.

Would you mind to explain the reason?

Thanks,
Ray