qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v11 6/9] gfxstream + rutabaga: add initial support for gfxstr


From: Akihiko Odaki
Subject: Re: [PATCH v11 6/9] gfxstream + rutabaga: add initial support for gfxstream
Date: Fri, 22 Sep 2023 11:41:37 +0900
User-agent: Mozilla Thunderbird

On 2023/09/22 8:44, Gurchetan Singh wrote:


On Tue, Sep 19, 2023 at 3:07 PM Akihiko Odaki <akihiko.odaki@gmail.com <mailto:akihiko.odaki@gmail.com>> wrote:

    On 2023/09/20 3:36, Bernhard Beschow wrote:
     >
     >
     > Am 15. September 2023 02:38:02 UTC schrieb Gurchetan Singh
    <gurchetansingh@chromium.org <mailto:gurchetansingh@chromium.org>>:
     >> On Thu, Sep 14, 2023 at 12:23 AM Bernhard Beschow
    <shentey@gmail.com <mailto:shentey@gmail.com>> wrote:
     >>
     >>>
     >>>
     >>> Am 14. September 2023 04:38:51 UTC schrieb Gurchetan Singh <
     >>> gurchetansingh@chromium.org <mailto:gurchetansingh@chromium.org>>:
     >>>> On Wed, Sep 13, 2023 at 4:58 AM Bernhard Beschow
    <shentey@gmail.com <mailto:shentey@gmail.com>>
     >>> wrote:
     >>>>
     >>>>>
     >>>>>
     >>>>> Am 23. August 2023 01:25:38 UTC schrieb Gurchetan Singh <
     >>>>> gurchetansingh@chromium.org
    <mailto:gurchetansingh@chromium.org>>:
     >>>>>> This adds initial support for gfxstream and cross-domain.  Both
     >>>>>> features rely on virtio-gpu blob resources and context
    types, which
     >>>>>> are also implemented in this patch.
     >>>>>>
     >>>>>> gfxstream has a long and illustrious history in Android graphics
     >>>>>> paravirtualization.  It has been powering graphics in the
    Android
     >>>>>> Studio Emulator for more than a decade, which is the main
    developer
     >>>>>> platform.
     >>>>>>
     >>>>>> Originally conceived by Jesse Hall, it was first known as
    "EmuGL" [a].
     >>>>>> The key design characteristic was a 1:1 threading model and
>>>>>> auto-generation, which fit nicely with the OpenGLES spec. It also
     >>>>>> allowed easy layering with ANGLE on the host, which provides
    the GLES
     >>>>>> implementations on Windows or MacOS enviroments.
     >>>>>>
     >>>>>> gfxstream has traditionally been maintained by a single
    engineer, and
     >>>>>> between 2015 to 2021, the goldfish throne passed to Frank Yang.
     >>>>>> Historians often remark this glorious reign ("pax
    gfxstreama" is the
     >>>>>> academic term) was comparable to that of Augustus and both Queen
     >>>>>> Elizabeths.  Just to name a few accomplishments in a resplendent
     >>>>>> panoply: higher versions of GLES, address space graphics,
    snapshot
     >>>>>> support and CTS compliant Vulkan [b].
     >>>>>>
     >>>>>> One major drawback was the use of out-of-tree goldfish drivers.
     >>>>>> Android engineers didn't know much about DRM/KMS and
    especially TTM so
     >>>>>> a simple guest to host pipe was conceived.
     >>>>>>
     >>>>>> Luckily, virtio-gpu 3D started to emerge in 2016 due to the
    work of
     >>>>>> the Mesa/virglrenderer communities.  In 2018, the initial
    virtio-gpu
     >>>>>> port of gfxstream was done by Cuttlefish enthusiast Alistair
    Delva.
     >>>>>> It was a symbol compatible replacement of virglrenderer [c]
    and named
     >>>>>> "AVDVirglrenderer".  This implementation forms the basis of the
     >>>>>> current gfxstream host implementation still in use today.
     >>>>>>
     >>>>>> cross-domain support follows a similar arc.  Originally
    conceived by
     >>>>>> Wayland aficionado David Reveman and crosvm enjoyer Zach
    Reizner in
     >>>>>> 2018, it initially relied on the downstream "virtio-wl" device.
     >>>>>>
     >>>>>> In 2020 and 2021, virtio-gpu was extended to include blob
    resources
     >>>>>> and multiple timelines by yours truly, features
    gfxstream/cross-domain
     >>>>>> both require to function correctly.
     >>>>>>
     >>>>>> Right now, we stand at the precipice of a truly fantastic
    possibility:
     >>>>>> the Android Emulator powered by upstream QEMU and upstream Linux
     >>>>>> kernel.  gfxstream will then be packaged properfully, and app
     >>>>>> developers can even fix gfxstream bugs on their own if they
    encounter
     >>>>>> them.
     >>>>>>
     >>>>>> It's been quite the ride, my friends.  Where will gfxstream
    head next,
     >>>>>> nobody really knows.  I wouldn't be surprised if it's around for
     >>>>>> another decade, maintained by a new generation of Android
    graphics
     >>>>>> enthusiasts.
     >>>>>>
     >>>>>> Technical details:
     >>>>>>   - Very simple initial display integration: just used Pixman
     >>>>>>   - Largely, 1:1 mapping of virtio-gpu hypercalls to
    rutabaga function
     >>>>>>     calls
     >>>>>>
     >>>>>> Next steps for Android VMs:
     >>>>>>   - The next step would be improving display integration and UI
     >>> interfaces
     >>>>>>     with the goal of the QEMU upstream graphics being in an
    emulator
     >>>>>>     release [d].
     >>>>>>
     >>>>>> Next steps for Linux VMs for display virtualization:
     >>>>>>   - For widespread distribution, someone needs to package
    Sommelier or
     >>> the
     >>>>>>     wayland-proxy-virtwl [e] ideally into Debian main. In
    addition,
     >>> newer
     >>>>>>     versions of the Linux kernel come with
    DRM_VIRTIO_GPU_KMS option,
     >>>>>>     which allows disabling KMS hypercalls.  If anyone cares
    enough,
     >>> it'll
     >>>>>>     probably be possible to build a custom VM variant that
    uses this
     >>>>> display
     >>>>>>     virtualization strategy.
     >>>>>>
     >>>>>> [a]
     >>>>>
    https://android-review.googlesource.com/c/platform/development/+/34470 
<https://android-review.googlesource.com/c/platform/development/+/34470>
     >>>>>> [b]
     >>>>>
     >>>
    https://android-review.googlesource.com/q/topic:%22vulkan-hostconnection-start%22 
<https://android-review.googlesource.com/q/topic:%22vulkan-hostconnection-start%22>
     >>>>>> [c]
     >>>>>
     >>>
    https://android-review.googlesource.com/c/device/generic/goldfish-opengl/+/761927 
<https://android-review.googlesource.com/c/device/generic/goldfish-opengl/+/761927>
     >>>>>> [d] https://developer.android.com/studio/releases/emulator
    <https://developer.android.com/studio/releases/emulator>
     >>>>>> [e] https://github.com/talex5/wayland-proxy-virtwl
    <https://github.com/talex5/wayland-proxy-virtwl>
     >>>>>>
     >>>>>> Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org
    <mailto:gurchetansingh@chromium.org>>
     >>>>>> Tested-by: Alyssa Ross <hi@alyssa.is <mailto:hi@alyssa.is>>
     >>>>>> Tested-by: Emmanouil Pitsidianakis
    <manos.pitsidianakis@linaro.org <mailto:manos.pitsidianakis@linaro.org>>
     >>>>>> Reviewed-by: Emmanouil Pitsidianakis
    <manos.pitsidianakis@linaro.org <mailto:manos.pitsidianakis@linaro.org>>
     >>>>>> ---
     >>>>>> v1: Incorported various suggestions by Akihiko Odaki and Bernard
     >>> Berschow
     >>>>>>     - Removed GET_VIRTIO_GPU_GL / GET_RUTABAGA macros
     >>>>>>     - Used error_report(..)
     >>>>>>     - Used g_autofree to fix leaks on error paths
     >>>>>>     - Removed unnecessary casts
     >>>>>>     - added virtio-gpu-pci-rutabaga.c +
    virtio-vga-rutabaga.c files
     >>>>>>
     >>>>>> v2: Incorported various suggestions by Akihiko Odaki,
    Marc-André Lureau
     >>>>> and
     >>>>>>     Bernard Berschow:
     >>>>>>     - Parenthesis in CHECK macro
     >>>>>>     - CHECK_RESULT(result, ..) --> CHECK(!result, ..)
     >>>>>>     - delay until g->parent_obj.enable = 1
     >>>>>>     - Additional cast fixes
     >>>>>>     - initialize directly in virtio_gpu_rutabaga_realize(..)
     >>>>>>     - add debug callback to hook into QEMU error's APIs
     >>>>>>
     >>>>>> v3: Incorporated feedback from Akihiko Odaki and Alyssa Ross:
     >>>>>>     - Autodetect Wayland socket when not explicitly specified
     >>>>>>     - Fix map_blob error paths
     >>>>>>     - Add comment why we need both `res` and `resource` in
    create blob
     >>>>>>     - Cast and whitespace fixes
     >>>>>>     - Big endian check comes before virtio_gpu_rutabaga_init().
     >>>>>>     - VirtIOVGARUTABAGA --> VirtIOVGARutabaga
     >>>>>>
     >>>>>> v4: Incorporated feedback from Akihiko Odaki and Alyssa Ross:
     >>>>>>     - Double checked all casts
     >>>>>>     - Remove unnecessary parenthesis
     >>>>>>     - Removed `resource` in create_blob
     >>>>>>     - Added comment about failure case
     >>>>>>     - Pass user-provided socket as-is
     >>>>>>     - Use stack variable rather than heap allocation
     >>>>>>     - Future-proofed map info API to give access flags as well
     >>>>>>
     >>>>>> v5: Incorporated feedback from Akihiko Odaki:
     >>>>>>     - Check (ss.scanout_id < VIRTIO_GPU_MAX_SCANOUTS)
     >>>>>>     - Simplify num_capsets check
     >>>>>>     - Call cleanup mapping on error paths
     >>>>>>     - uint64_t --> void* for rutabaga_map(..)
     >>>>>>     - Removed unnecessary parenthesis
     >>>>>>     - Removed unnecessary cast
     >>>>>>     - #define UNIX_PATH_MAX sizeof((struct sockaddr_un)
    {}.sun_path)
     >>>>>>     - Reuse result variable
     >>>>>>
     >>>>>> v6: Incorporated feedback from Akihiko Odaki:
     >>>>>>     - Remove unnecessary #ifndef
     >>>>>>     - Disable scanout when appropriate
     >>>>>>     - CHECK capset index within range outside loop
     >>>>>>     - Add capset_version
     >>>>>>
     >>>>>> v7: Incorporated feedback from Akihiko Odaki:
     >>>>>>     - aio_bh_schedule_oneshot_full --> aio_bh_schedule_oneshot
     >>>>>>
     >>>>>> v9: Incorportated feedback from Akihiko Odaki:
     >>>>>>     - Remove extra error_setg(..) after
    virtio_gpu_rutabaga_init(..)
     >>>>>>     - Add error_setg(..) after rutabaga_init(..)
     >>>>>>
     >>>>>> v10: Incorportated feedback from Akihiko Odaki:
     >>>>>>     - error_setg(..) --> error_setg_errno(..) when appropriate
     >>>>>>     - virtio_gpu_rutabaga_init returns a bool instead of an int
     >>>>>>
     >>>>>> v11: Incorportated feedback from Philippe Mathieu-Daudé:
     >>>>>>     - C-style /* */ comments and avoid // comments.
     >>>>>>     - GPL-2.0 --> GPL-2.0-or-later
     >>>>>>
     >>>>>> hw/display/virtio-gpu-pci-rutabaga.c |   50 ++
     >>>>>> hw/display/virtio-gpu-rutabaga.c     | 1121
    ++++++++++++++++++++++++++
     >>>>>> hw/display/virtio-vga-rutabaga.c     |   53 ++
     >>>>>> 3 files changed, 1224 insertions(+)
     >>>>>> create mode 100644 hw/display/virtio-gpu-pci-rutabaga.c
     >>>>>> create mode 100644 hw/display/virtio-gpu-rutabaga.c
     >>>>>> create mode 100644 hw/display/virtio-vga-rutabaga.c
     >>>>>>
     >>>>>> diff --git a/hw/display/virtio-gpu-pci-rutabaga.c
     >>>>> b/hw/display/virtio-gpu-pci-rutabaga.c
     >>>>>> new file mode 100644
     >>>>>> index 0000000000..311eff308a
     >>>>>> --- /dev/null
     >>>>>> +++ b/hw/display/virtio-gpu-pci-rutabaga.c
     >>>>>> @@ -0,0 +1,50 @@
     >>>>>> +/*
     >>>>>> + * SPDX-License-Identifier: GPL-2.0-or-later
     >>>>>> + */
     >>>>>> +
     >>>>>> +#include "qemu/osdep.h"
     >>>>>> +#include "qapi/error.h"
     >>>>>> +#include "qemu/module.h"
     >>>>>> +#include "hw/pci/pci.h"
     >>>>>> +#include "hw/qdev-properties.h"
     >>>>>> +#include "hw/virtio/virtio.h"
     >>>>>> +#include "hw/virtio/virtio-bus.h"
     >>>>>> +#include "hw/virtio/virtio-gpu-pci.h"
     >>>>>> +#include "qom/object.h"
     >>>>>> +
     >>>>>> +#define TYPE_VIRTIO_GPU_RUTABAGA_PCI "virtio-gpu-rutabaga-pci"
     >>>>>> +typedef struct VirtIOGPURutabagaPCI VirtIOGPURutabagaPCI;
     >>>>>> +DECLARE_INSTANCE_CHECKER(VirtIOGPURutabagaPCI,
     >>> VIRTIO_GPU_RUTABAGA_PCI,
     >>>>>> +                         TYPE_VIRTIO_GPU_RUTABAGA_PCI)
     >>>>>> +
     >>>>>> +struct VirtIOGPURutabagaPCI {
     >>>>>> +    VirtIOGPUPCIBase parent_obj;
     >>>>>> +    VirtIOGPURutabaga vdev;
     >>>>>> +};
     >>>>>> +
     >>>>>> +static void virtio_gpu_rutabaga_initfn(Object *obj)
     >>>>>> +{
     >>>>>> +    VirtIOGPURutabagaPCI *dev = VIRTIO_GPU_RUTABAGA_PCI(obj);
     >>>>>> +
     >>>>>> +    virtio_instance_init_common(obj, &dev->vdev,
    sizeof(dev->vdev),
     >>>>>> +                                TYPE_VIRTIO_GPU_RUTABAGA);
     >>>>>> +    VIRTIO_GPU_PCI_BASE(obj)->vgpu =
    VIRTIO_GPU_BASE(&dev->vdev);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static const VirtioPCIDeviceTypeInfo
    virtio_gpu_rutabaga_pci_info = {
     >>>>>> +    .generic_name = TYPE_VIRTIO_GPU_RUTABAGA_PCI,
     >>>>>> +    .parent = TYPE_VIRTIO_GPU_PCI_BASE,
     >>>>>> +    .instance_size = sizeof(VirtIOGPURutabagaPCI),
     >>>>>> +    .instance_init = virtio_gpu_rutabaga_initfn,
     >>>>>> +};
     >>>>>> +module_obj(TYPE_VIRTIO_GPU_RUTABAGA_PCI);
     >>>>>> +module_kconfig(VIRTIO_PCI);
     >>>>>> +
     >>>>>> +static void virtio_gpu_rutabaga_pci_register_types(void)
     >>>>>> +{
     >>>>>> +    virtio_pci_types_register(&virtio_gpu_rutabaga_pci_info);
     >>>>>> +}
     >>>>>> +
     >>>>>> +type_init(virtio_gpu_rutabaga_pci_register_types)
     >>>>>> +
     >>>>>> +module_dep("hw-display-virtio-gpu-pci");
     >>>>>> diff --git a/hw/display/virtio-gpu-rutabaga.c
     >>>>> b/hw/display/virtio-gpu-rutabaga.c
     >>>>>> new file mode 100644
     >>>>>> index 0000000000..9018e5a702
     >>>>>> --- /dev/null
     >>>>>> +++ b/hw/display/virtio-gpu-rutabaga.c
     >>>>>> @@ -0,0 +1,1121 @@
     >>>>>> +/*
     >>>>>> + * SPDX-License-Identifier: GPL-2.0-or-later
     >>>>>> + */
     >>>>>> +
     >>>>>> +#include "qemu/osdep.h"
     >>>>>> +#include "qapi/error.h"
     >>>>>> +#include "qemu/error-report.h"
     >>>>>> +#include "qemu/iov.h"
     >>>>>> +#include "trace.h"
     >>>>>> +#include "hw/virtio/virtio.h"
     >>>>>> +#include "hw/virtio/virtio-gpu.h"
     >>>>>> +#include "hw/virtio/virtio-gpu-pixman.h"
     >>>>>> +#include "hw/virtio/virtio-iommu.h"
     >>>>>> +
     >>>>>> +#include <glib/gmem.h>
     >>>>>> +#include <rutabaga_gfx/rutabaga_gfx_ffi.h>
     >>>>>> +
     >>>>>> +#define CHECK(condition, cmd)
     >>>>>       \
     >>>>>> +    do {
     >>>>>        \
     >>>>>> +        if (!(condition)) {
     >>>>>       \
     >>>>>> +            error_report("CHECK failed in %s() %s:" "%d",
    __func__,
     >>>>>       \
     >>>>>> +                         __FILE__, __LINE__);
     >>>>>       \
     >>>>>> +            (cmd)->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
     >>>>>        \
     >>>>>> +            return;
     >>>>>       \
     >>>>>> +       }
     >>>>>        \
     >>>>>> +    } while (0)
     >>>>>> +
     >>>>>> +/*
     >>>>>> + * This is the size of the char array in struct
    sock_addr_un. No
     >>> Wayland
     >>>>> socket
     >>>>>> + * can be created with a path longer than this, including
    the null
     >>>>> terminator.
     >>>>>> + */
     >>>>>> +#define UNIX_PATH_MAX sizeof((struct sockaddr_un) {} .sun_path)
     >>>>>> +
     >>>>>> +struct rutabaga_aio_data {
     >>>>>> +    struct VirtIOGPURutabaga *vr;
     >>>>>> +    struct rutabaga_fence fence;
     >>>>>> +};
     >>>>>> +
     >>>>>> +static void
     >>>>>> +virtio_gpu_rutabaga_update_cursor(VirtIOGPU *g, struct
     >>>>> virtio_gpu_scanout *s,
     >>>>>> +                                  uint32_t resource_id)
     >>>>>> +{
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct rutabaga_transfer transfer = { 0 };
     >>>>>> +    struct iovec transfer_iovec;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, resource_id);
     >>>>>> +    if (!res) {
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    if (res->width != s->current_cursor->width ||
     >>>>>> +        res->height != s->current_cursor->height) {
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    transfer.x = 0;
     >>>>>> +    transfer.y = 0;
     >>>>>> +    transfer.z = 0;
     >>>>>> +    transfer.w = res->width;
     >>>>>> +    transfer.h = res->height;
     >>>>>> +    transfer.d = 1;
     >>>>>> +
     >>>>>> +    transfer_iovec.iov_base = s->current_cursor->data;
     >>>>>> +    transfer_iovec.iov_len = res->width * res->height * 4;
     >>>>>> +
     >>>>>> +    rutabaga_resource_transfer_read(vr->rutabaga, 0,
     >>>>>> +                                    resource_id, &transfer,
     >>>>>> +                                    &transfer_iovec);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +virtio_gpu_rutabaga_gl_flushed(VirtIOGPUBase *b)
     >>>>>> +{
     >>>>>> +    VirtIOGPU *g = VIRTIO_GPU(b);
     >>>>>> +    virtio_gpu_process_cmdq(g);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_create_resource_2d(VirtIOGPU *g,
     >>>>>> +                                struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct rutabaga_create_3d rc_3d = { 0 };
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_resource_create_2d c2d;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(c2d);
     >>>>>> +    trace_virtio_gpu_cmd_res_create_2d(c2d.resource_id,
    c2d.format,
     >>>>>> +                                       c2d.width, c2d.height);
     >>>>>> +
     >>>>>> +    rc_3d.target = 2;
     >>>>>> +    rc_3d.format = c2d.format;
     >>>>>> +    rc_3d.bind = (1 << 1);
     >>>>>> +    rc_3d.width = c2d.width;
     >>>>>> +    rc_3d.height = c2d.height;
     >>>>>> +    rc_3d.depth = 1;
     >>>>>> +    rc_3d.array_size = 1;
     >>>>>> +    rc_3d.last_level = 0;
     >>>>>> +    rc_3d.nr_samples = 0;
     >>>>>> +    rc_3d.flags = VIRTIO_GPU_RESOURCE_FLAG_Y_0_TOP;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_create_3d(vr->rutabaga,
     >>> c2d.resource_id,
     >>>>> &rc_3d);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    res = g_new0(struct virtio_gpu_simple_resource, 1);
     >>>>>> +    res->width = c2d.width;
     >>>>>> +    res->height = c2d.height;
     >>>>>> +    res->format = c2d.format;
     >>>>>> +    res->resource_id = c2d.resource_id;
     >>>>>> +
     >>>>>> +    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_create_resource_3d(VirtIOGPU *g,
     >>>>>> +                                struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct rutabaga_create_3d rc_3d = { 0 };
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_resource_create_3d c3d;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(c3d);
     >>>>>> +
     >>>>>> +    trace_virtio_gpu_cmd_res_create_3d(c3d.resource_id,
    c3d.format,
     >>>>>> +                                       c3d.width, c3d.height,
     >>> c3d.depth);
     >>>>>> +
     >>>>>> +    rc_3d.target = c3d.target;
     >>>>>> +    rc_3d.format = c3d.format;
     >>>>>> +    rc_3d.bind = c3d.bind;
     >>>>>> +    rc_3d.width = c3d.width;
     >>>>>> +    rc_3d.height = c3d.height;
     >>>>>> +    rc_3d.depth = c3d.depth;
     >>>>>> +    rc_3d.array_size = c3d.array_size;
     >>>>>> +    rc_3d.last_level = c3d.last_level;
     >>>>>> +    rc_3d.nr_samples = c3d.nr_samples;
     >>>>>> +    rc_3d.flags = c3d.flags;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_create_3d(vr->rutabaga,
     >>> c3d.resource_id,
     >>>>> &rc_3d);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    res = g_new0(struct virtio_gpu_simple_resource, 1);
     >>>>>> +    res->width = c3d.width;
     >>>>>> +    res->height = c3d.height;
     >>>>>> +    res->format = c3d.format;
     >>>>>> +    res->resource_id = c3d.resource_id;
     >>>>>> +
     >>>>>> +    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_resource_unref(VirtIOGPU *g,
     >>>>>> +                            struct virtio_gpu_ctrl_command
    *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_resource_unref unref;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(unref);
     >>>>>> +
     >>>>>> +    trace_virtio_gpu_cmd_res_unref(unref.resource_id);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, unref.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_unref(vr->rutabaga,
    unref.resource_id);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    if (res->image) {
     >>>>>> +        pixman_image_unref(res->image);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    QTAILQ_REMOVE(&g->reslist, res, next);
     >>>>>> +    g_free(res);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_context_create(VirtIOGPU *g,
     >>>>>> +                            struct virtio_gpu_ctrl_command
    *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_ctx_create cc;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(cc);
     >>>>>> +    trace_virtio_gpu_cmd_ctx_create(cc.hdr.ctx_id,
     >>>>>> +                                    cc.debug_name);
     >>>>>> +
     >>>>>> +    result = rutabaga_context_create(vr->rutabaga,
    cc.hdr.ctx_id,
     >>>>>> +                                     cc.context_init,
    cc.debug_name,
     >>>>> cc.nlen);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_context_destroy(VirtIOGPU *g,
     >>>>>> +                             struct virtio_gpu_ctrl_command
    *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_ctx_destroy cd;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(cd);
     >>>>>> +    trace_virtio_gpu_cmd_ctx_destroy(cd.hdr.ctx_id);
     >>>>>> +
     >>>>>> +    result = rutabaga_context_destroy(vr->rutabaga,
    cd.hdr.ctx_id);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_resource_flush(VirtIOGPU *g, struct
     >>> virtio_gpu_ctrl_command
     >>>>> *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result, i;
     >>>>>> +    struct virtio_gpu_scanout *scanout = NULL;
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct rutabaga_transfer transfer = { 0 };
     >>>>>> +    struct iovec transfer_iovec;
     >>>>>> +    struct virtio_gpu_resource_flush rf;
     >>>>>> +    bool found = false;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +    if (vr->headless) {
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(rf);
     >>>>>> +    trace_virtio_gpu_cmd_res_flush(rf.resource_id,
     >>>>>> +                                   rf.r.width, rf.r.height,
    rf.r.x,
     >>>>> rf.r.y);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, rf.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +
     >>>>>> +    for (i = 0; i < g->parent_obj.conf.max_outputs; i++) {
     >>>>>> +        scanout = &g->parent_obj.scanout[i];
     >>>>>> +        if (i == res->scanout_bitmask) {
     >>>>>> +            found = true;
     >>>>>> +            break;
     >>>>>> +        }
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    if (!found) {
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    transfer.x = 0;
     >>>>>> +    transfer.y = 0;
     >>>>>> +    transfer.z = 0;
     >>>>>> +    transfer.w = res->width;
     >>>>>> +    transfer.h = res->height;
     >>>>>> +    transfer.d = 1;
     >>>>>> +
     >>>>>> +    transfer_iovec.iov_base =
    pixman_image_get_data(res->image);
     >>>>>> +    transfer_iovec.iov_len = res->width * res->height * 4;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_transfer_read(vr->rutabaga, 0,
     >>>>>> +                                             rf.resource_id,
     >>> &transfer,
     >>>>>> +                                             &transfer_iovec);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +    dpy_gfx_update_full(scanout->con);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_set_scanout(VirtIOGPU *g, struct
    virtio_gpu_ctrl_command
     >>>>> *cmd)
     >>>>>> +{
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_scanout *scanout = NULL;
     >>>>>> +    struct virtio_gpu_set_scanout ss;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +    if (vr->headless) {
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(ss);
     >>>>>> +    trace_virtio_gpu_cmd_set_scanout(ss.scanout_id,
    ss.resource_id,
     >>>>>> +                                     ss.r.width,
    ss.r.height, ss.r.x,
     >>>>> ss.r.y);
     >>>>>> +
     >>>>>> +    CHECK(ss.scanout_id < VIRTIO_GPU_MAX_SCANOUTS, cmd);
     >>>>>> +    scanout = &g->parent_obj.scanout[ss.scanout_id];
     >>>>>> +
     >>>>>> +    if (ss.resource_id == 0) {
     >>>>>> +        dpy_gfx_replace_surface(scanout->con, NULL);
     >>>>>> +        dpy_gl_scanout_disable(scanout->con);
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, ss.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +
     >>>>>> +    if (!res->image) {
     >>>>>> +        pixman_format_code_t pformat;
     >>>>>> +        pformat = virtio_gpu_get_pixman_format(res->format);
     >>>>>> +        CHECK(pformat, cmd);
     >>>>>> +
     >>>>>> +        res->image = pixman_image_create_bits(pformat,
     >>>>>> +                                              res->width,
     >>>>>> +                                              res->height,
     >>>>>> +                                              NULL, 0);
     >>>>>> +        CHECK(res->image, cmd);
     >>>>>> +        pixman_image_ref(res->image);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    g->parent_obj.enable = 1;
     >>>>>> +
     >>>>>> +    /* realloc the surface ptr */
     >>>>>> +    scanout->ds =
    qemu_create_displaysurface_pixman(res->image);
     >>>>>> +    dpy_gfx_replace_surface(scanout->con, NULL);
     >>>>>> +    dpy_gfx_replace_surface(scanout->con, scanout->ds);
     >>>>>> +    res->scanout_bitmask = ss.scanout_id;
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_submit_3d(VirtIOGPU *g,
     >>>>>> +                       struct virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_cmd_submit cs;
     >>>>>> +    struct rutabaga_command rutabaga_cmd = { 0 };
     >>>>>> +    g_autofree uint8_t *buf = NULL;
     >>>>>> +    size_t s;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(cs);
     >>>>>> +    trace_virtio_gpu_cmd_ctx_submit(cs.hdr.ctx_id, cs.size);
     >>>>>> +
     >>>>>> +    buf = g_new0(uint8_t, cs.size);
     >>>>>> +    s = iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num,
     >>>>>> +                   sizeof(cs), buf, cs.size);
     >>>>>> +    CHECK(s == cs.size, cmd);
     >>>>>> +
     >>>>>> +    rutabaga_cmd.ctx_id = cs.hdr.ctx_id;
     >>>>>> +    rutabaga_cmd.cmd = buf;
     >>>>>> +    rutabaga_cmd.cmd_size = cs.size;
     >>>>>> +
     >>>>>> +    result = rutabaga_submit_command(vr->rutabaga,
    &rutabaga_cmd);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_transfer_to_host_2d(VirtIOGPU *g,
     >>>>>> +                                 struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct rutabaga_transfer transfer = { 0 };
     >>>>>> +    struct virtio_gpu_transfer_to_host_2d t2d;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(t2d);
     >>>>>> +    trace_virtio_gpu_cmd_res_xfer_toh_2d(t2d.resource_id);
     >>>>>> +
     >>>>>> +    transfer.x = t2d.r.x;
     >>>>>> +    transfer.y = t2d.r.y;
     >>>>>> +    transfer.z = 0;
     >>>>>> +    transfer.w = t2d.r.width;
     >>>>>> +    transfer.h = t2d.r.height;
     >>>>>> +    transfer.d = 1;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_transfer_write(vr->rutabaga, 0,
     >>>>> t2d.resource_id,
     >>>>>> +                                              &transfer);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_transfer_to_host_3d(VirtIOGPU *g,
     >>>>>> +                                 struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct rutabaga_transfer transfer = { 0 };
     >>>>>> +    struct virtio_gpu_transfer_host_3d t3d;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(t3d);
     >>>>>> +    trace_virtio_gpu_cmd_res_xfer_toh_3d(t3d.resource_id);
     >>>>>> +
     >>>>>> +    transfer.x = t3d.box.x;
     >>>>>> +    transfer.y = t3d.box.y;
     >>>>>> +    transfer.z = t3d.box.z;
     >>>>>> +    transfer.w = t3d.box.w;
     >>>>>> +    transfer.h = t3d.box.h;
     >>>>>> +    transfer.d = t3d.box.d;
     >>>>>> +    transfer.level = t3d.level;
     >>>>>> +    transfer.stride = t3d.stride;
     >>>>>> +    transfer.layer_stride = t3d.layer_stride;
     >>>>>> +    transfer.offset = t3d.offset;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_transfer_write(vr->rutabaga,
     >>>>> t3d.hdr.ctx_id,
     >>>>>> +                                              t3d.resource_id,
     >>>>> &transfer);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_transfer_from_host_3d(VirtIOGPU *g,
     >>>>>> +                                   struct
    virtio_gpu_ctrl_command
     >>> *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct rutabaga_transfer transfer = { 0 };
     >>>>>> +    struct virtio_gpu_transfer_host_3d t3d;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(t3d);
     >>>>>> +    trace_virtio_gpu_cmd_res_xfer_fromh_3d(t3d.resource_id);
     >>>>>> +
     >>>>>> +    transfer.x = t3d.box.x;
     >>>>>> +    transfer.y = t3d.box.y;
     >>>>>> +    transfer.z = t3d.box.z;
     >>>>>> +    transfer.w = t3d.box.w;
     >>>>>> +    transfer.h = t3d.box.h;
     >>>>>> +    transfer.d = t3d.box.d;
     >>>>>> +    transfer.level = t3d.level;
     >>>>>> +    transfer.stride = t3d.stride;
     >>>>>> +    transfer.layer_stride = t3d.layer_stride;
     >>>>>> +    transfer.offset = t3d.offset;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_transfer_read(vr->rutabaga,
     >>>>> t3d.hdr.ctx_id,
     >>>>>> +                                             t3d.resource_id,
     >>> &transfer,
     >>>>> NULL);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_attach_backing(VirtIOGPU *g, struct
     >>> virtio_gpu_ctrl_command
     >>>>> *cmd)
     >>>>>> +{
     >>>>>> +    struct rutabaga_iovecs vecs = { 0 };
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_resource_attach_backing att_rb;
     >>>>>> +    int ret;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(att_rb);
     >>>>>> +    trace_virtio_gpu_cmd_res_back_attach(att_rb.resource_id);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, att_rb.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +    CHECK(!res->iov, cmd);
     >>>>>> +
     >>>>>> +    ret = virtio_gpu_create_mapping_iov(g, att_rb.nr_entries,
     >>>>> sizeof(att_rb),
     >>>>>> +                                        cmd, NULL, &res->iov,
     >>>>> &res->iov_cnt);
     >>>>>> +    CHECK(!ret, cmd);
     >>>>>> +
     >>>>>> +    vecs.iovecs = res->iov;
     >>>>>> +    vecs.num_iovecs = res->iov_cnt;
     >>>>>> +
     >>>>>> +    ret = rutabaga_resource_attach_backing(vr->rutabaga,
     >>>>> att_rb.resource_id,
     >>>>>> +                                           &vecs);
     >>>>>> +    if (ret != 0) {
     >>>>>> +        virtio_gpu_cleanup_mapping(g, res);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    CHECK(!ret, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_detach_backing(VirtIOGPU *g, struct
     >>> virtio_gpu_ctrl_command
     >>>>> *cmd)
     >>>>>> +{
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_resource_detach_backing detach_rb;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(detach_rb);
>>>>>> + trace_virtio_gpu_cmd_res_back_detach(detach_rb.resource_id);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, detach_rb.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +
     >>>>>> +    rutabaga_resource_detach_backing(vr->rutabaga,
     >>>>>> +                                     detach_rb.resource_id);
     >>>>>> +
     >>>>>> +    virtio_gpu_cleanup_mapping(g, res);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_ctx_attach_resource(VirtIOGPU *g,
     >>>>>> +                                 struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_ctx_resource att_res;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(att_res);
     >>>>>> +    trace_virtio_gpu_cmd_ctx_res_attach(att_res.hdr.ctx_id,
     >>>>>> +                                        att_res.resource_id);
     >>>>>> +
     >>>>>> +    result = rutabaga_context_attach_resource(vr->rutabaga,
     >>>>> att_res.hdr.ctx_id,
>>>>>> + att_res.resource_id);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_ctx_detach_resource(VirtIOGPU *g,
     >>>>>> +                                 struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_ctx_resource det_res;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(det_res);
     >>>>>> +    trace_virtio_gpu_cmd_ctx_res_detach(det_res.hdr.ctx_id,
     >>>>>> +                                        det_res.resource_id);
     >>>>>> +
     >>>>>> +    result = rutabaga_context_detach_resource(vr->rutabaga,
     >>>>> det_res.hdr.ctx_id,
>>>>>> + det_res.resource_id);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_get_capset_info(VirtIOGPU *g, struct
     >>>>> virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_get_capset_info info;
     >>>>>> +    struct virtio_gpu_resp_capset_info resp;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(info);
     >>>>>> +
     >>>>>> +    result = rutabaga_get_capset_info(vr->rutabaga,
    info.capset_index,
     >>>>>> +                                      &resp.capset_id,
     >>>>> &resp.capset_max_version,
     >>>>>> +                                      &resp.capset_max_size);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    resp.hdr.type = VIRTIO_GPU_RESP_OK_CAPSET_INFO;
     >>>>>> +    virtio_gpu_ctrl_response(g, cmd, &resp.hdr, sizeof(resp));
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_get_capset(VirtIOGPU *g, struct
    virtio_gpu_ctrl_command
     >>>>> *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    struct virtio_gpu_get_capset gc;
     >>>>>> +    struct virtio_gpu_resp_capset *resp;
     >>>>>> +    uint32_t capset_size, capset_version;
     >>>>>> +    uint32_t current_id, i;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(gc);
     >>>>>> +    for (i = 0; i < vr->num_capsets; i++) {
     >>>>>> +        result = rutabaga_get_capset_info(vr->rutabaga, i,
     >>>>>> +                                          &current_id,
     >>> &capset_version,
     >>>>>> +                                          &capset_size);
     >>>>>> +        CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +        if (current_id == gc.capset_id) {
     >>>>>> +            break;
     >>>>>> +        }
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    CHECK(i < vr->num_capsets, cmd);
     >>>>>> +
     >>>>>> +    resp = g_malloc0(sizeof(*resp) + capset_size);
     >>>>>> +    resp->hdr.type = VIRTIO_GPU_RESP_OK_CAPSET;
     >>>>>> +    rutabaga_get_capset(vr->rutabaga, gc.capset_id,
    gc.capset_version,
     >>>>>> +                        resp->capset_data, capset_size);
     >>>>>> +
     >>>>>> +    virtio_gpu_ctrl_response(g, cmd, &resp->hdr,
    sizeof(*resp) +
     >>>>> capset_size);
     >>>>>> +    g_free(resp);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_resource_create_blob(VirtIOGPU *g,
     >>>>>> +                                  struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int result;
     >>>>>> +    struct rutabaga_iovecs vecs = { 0 };
     >>>>>> +    g_autofree struct virtio_gpu_simple_resource *res = NULL;
     >>>>>> +    struct virtio_gpu_resource_create_blob cblob;
     >>>>>> +    struct rutabaga_create_blob rc_blob = { 0 };
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(cblob);
     >>>>>> +    trace_virtio_gpu_cmd_res_create_blob(cblob.resource_id,
     >>> cblob.size);
     >>>>>> +
     >>>>>> +    CHECK(cblob.resource_id != 0, cmd);
     >>>>>> +
     >>>>>> +    res = g_new0(struct virtio_gpu_simple_resource, 1);
     >>>>>> +
     >>>>>> +    res->resource_id = cblob.resource_id;
     >>>>>> +    res->blob_size = cblob.size;
     >>>>>> +
     >>>>>> +    if (cblob.blob_mem != VIRTIO_GPU_BLOB_MEM_HOST3D) {
     >>>>>> +        result = virtio_gpu_create_mapping_iov(g,
    cblob.nr_entries,
>>>>>> +  sizeof(cblob), cmd,
     >>>>> &res->addrs,
     >>>>>> +                                               &res->iov,
     >>> &res->iov_cnt);
     >>>>>> +        CHECK(!result, cmd);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    rc_blob.blob_id = cblob.blob_id;
     >>>>>> +    rc_blob.blob_mem = cblob.blob_mem;
     >>>>>> +    rc_blob.blob_flags = cblob.blob_flags;
     >>>>>> +    rc_blob.size = cblob.size;
     >>>>>> +
     >>>>>> +    vecs.iovecs = res->iov;
     >>>>>> +    vecs.num_iovecs = res->iov_cnt;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_create_blob(vr->rutabaga,
     >>>>> cblob.hdr.ctx_id,
     >>>>>> +                                           cblob.resource_id,
     >>> &rc_blob,
     >>>>> &vecs,
     >>>>>> +                                           NULL);
     >>>>>> +
     >>>>>> +    if (result && cblob.blob_mem !=
    VIRTIO_GPU_BLOB_MEM_HOST3D) {
     >>>>>> +        virtio_gpu_cleanup_mapping(g, res);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
     >>>>>> +    res = NULL;
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_resource_map_blob(VirtIOGPU *g,
     >>>>>> +                               struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    uint32_t map_info = 0;
     >>>>>> +    uint32_t slot = 0;
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct rutabaga_mapping mapping = { 0 };
     >>>>>> +    struct virtio_gpu_resource_map_blob mblob;
     >>>>>> +    struct virtio_gpu_resp_map_info resp = { 0 };
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(mblob);
     >>>>>> +
     >>>>>> +    CHECK(mblob.resource_id != 0, cmd);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, mblob.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_map_info(vr->rutabaga,
     >>> mblob.resource_id,
     >>>>>> +                                        &map_info);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    /*
     >>>>>> +     * RUTABAGA_MAP_ACCESS_* flags are not part of the
    virtio-gpu
     >>> spec,
     >>>>> but do
     >>>>>> +     * exist to potentially allow the hypervisor to
    restrict write
     >>>>> access to
     >>>>>> +     * memory. QEMU does not need to use this functionality
    at the
     >>>>> moment.
     >>>>>> +     */
     >>>>>> +    resp.map_info = map_info & RUTABAGA_MAP_CACHE_MASK;
     >>>>>> +
     >>>>>> +    result = rutabaga_resource_map(vr->rutabaga,
    mblob.resource_id,
     >>>>> &mapping);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +
     >>>>>> +    for (slot = 0; slot < MAX_SLOTS; slot++) {
     >>>>>> +        if (vr->memory_regions[slot].used) {
     >>>>>> +            continue;
     >>>>>> +        }
     >>>>>> +
     >>>>>> +        MemoryRegion *mr = &(vr->memory_regions[slot].mr);
     >>>>>> +        memory_region_init_ram_ptr(mr, NULL, "blob",
    mapping.size,
     >>>>>> +                                   mapping.ptr);
     >>>>>> +        memory_region_add_subregion(&g->parent_obj.hostmem,
     >>>>>> +                                    mblob.offset, mr);
     >>>>>> +        vr->memory_regions[slot].resource_id =
    mblob.resource_id;
     >>>>>> +        vr->memory_regions[slot].used = 1;
     >>>>>> +        break;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    if (slot >= MAX_SLOTS) {
     >>>>>> +        result = rutabaga_resource_unmap(vr->rutabaga,
     >>>>> mblob.resource_id);
     >>>>>> +        CHECK(!result, cmd);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    CHECK(slot < MAX_SLOTS, cmd);
     >>>>>> +
     >>>>>> +    resp.hdr.type = VIRTIO_GPU_RESP_OK_MAP_INFO;
     >>>>>> +    virtio_gpu_ctrl_response(g, cmd, &resp.hdr, sizeof(resp));
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +rutabaga_cmd_resource_unmap_blob(VirtIOGPU *g,
     >>>>>> +                                 struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    int32_t result;
     >>>>>> +    uint32_t slot = 0;
     >>>>>> +    struct virtio_gpu_simple_resource *res;
     >>>>>> +    struct virtio_gpu_resource_unmap_blob ublob;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(ublob);
     >>>>>> +
     >>>>>> +    CHECK(ublob.resource_id != 0, cmd);
     >>>>>> +
     >>>>>> +    res = virtio_gpu_find_resource(g, ublob.resource_id);
     >>>>>> +    CHECK(res, cmd);
     >>>>>> +
     >>>>>> +    for (slot = 0; slot < MAX_SLOTS; slot++) {
     >>>>>> +        if (vr->memory_regions[slot].resource_id !=
     >>> ublob.resource_id) {
     >>>>>> +            continue;
     >>>>>> +        }
     >>>>>> +
     >>>>>> +        MemoryRegion *mr = &(vr->memory_regions[slot].mr);
     >>>>>> +        memory_region_del_subregion(&g->parent_obj.hostmem,
    mr);
     >>>>>> +
     >>>>>> +        vr->memory_regions[slot].resource_id = 0;
     >>>>>> +        vr->memory_regions[slot].used = 0;
     >>>>>> +        break;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    CHECK(slot < MAX_SLOTS, cmd);
     >>>>>> +    result = rutabaga_resource_unmap(vr->rutabaga,
    res->resource_id);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +virtio_gpu_rutabaga_process_cmd(VirtIOGPU *g,
     >>>>>> +                                struct
    virtio_gpu_ctrl_command *cmd)
     >>>>>> +{
     >>>>>> +    struct rutabaga_fence fence = { 0 };
     >>>>>> +    int32_t result;
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    VIRTIO_GPU_FILL_CMD(cmd->cmd_hdr);
     >>>>>> +
     >>>>>> +    switch (cmd->cmd_hdr.type) {
     >>>>>> +    case VIRTIO_GPU_CMD_CTX_CREATE:
     >>>>>> +        rutabaga_cmd_context_create(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_CTX_DESTROY:
     >>>>>> +        rutabaga_cmd_context_destroy(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_CREATE_2D:
     >>>>>> +        rutabaga_cmd_create_resource_2d(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_CREATE_3D:
     >>>>>> +        rutabaga_cmd_create_resource_3d(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_SUBMIT_3D:
     >>>>>> +        rutabaga_cmd_submit_3d(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D:
     >>>>>> +        rutabaga_cmd_transfer_to_host_2d(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_TRANSFER_TO_HOST_3D:
     >>>>>> +        rutabaga_cmd_transfer_to_host_3d(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_TRANSFER_FROM_HOST_3D:
     >>>>>> +        rutabaga_cmd_transfer_from_host_3d(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING:
     >>>>>> +        rutabaga_cmd_attach_backing(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING:
     >>>>>> +        rutabaga_cmd_detach_backing(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_SET_SCANOUT:
     >>>>>> +        rutabaga_cmd_set_scanout(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_FLUSH:
     >>>>>> +        rutabaga_cmd_resource_flush(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_UNREF:
     >>>>>> +        rutabaga_cmd_resource_unref(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_CTX_ATTACH_RESOURCE:
     >>>>>> +        rutabaga_cmd_ctx_attach_resource(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_CTX_DETACH_RESOURCE:
     >>>>>> +        rutabaga_cmd_ctx_detach_resource(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_GET_CAPSET_INFO:
     >>>>>> +        rutabaga_cmd_get_capset_info(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_GET_CAPSET:
     >>>>>> +        rutabaga_cmd_get_capset(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_GET_DISPLAY_INFO:
     >>>>>> +        virtio_gpu_get_display_info(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_GET_EDID:
     >>>>>> +        virtio_gpu_get_edid(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_CREATE_BLOB:
     >>>>>> +        rutabaga_cmd_resource_create_blob(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_MAP_BLOB:
     >>>>>> +        rutabaga_cmd_resource_map_blob(g, cmd);
     >>>>>> +        break;
     >>>>>> +    case VIRTIO_GPU_CMD_RESOURCE_UNMAP_BLOB:
     >>>>>> +        rutabaga_cmd_resource_unmap_blob(g, cmd);
     >>>>>> +        break;
     >>>>>> +    default:
     >>>>>> +        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
     >>>>>> +        break;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    if (cmd->finished) {
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +    if (cmd->error) {
     >>>>>> +        error_report("%s: ctrl 0x%x, error 0x%x", __func__,
     >>>>>> +                     cmd->cmd_hdr.type, cmd->error);
     >>>>>> +        virtio_gpu_ctrl_response_nodata(g, cmd, cmd->error);
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +    if (!(cmd->cmd_hdr.flags & VIRTIO_GPU_FLAG_FENCE)) {
     >>>>>> +        virtio_gpu_ctrl_response_nodata(g, cmd,
     >>>>> VIRTIO_GPU_RESP_OK_NODATA);
     >>>>>> +        return;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    fence.flags = cmd->cmd_hdr.flags;
     >>>>>> +    fence.ctx_id = cmd->cmd_hdr.ctx_id;
     >>>>>> +    fence.fence_id = cmd->cmd_hdr.fence_id;
     >>>>>> +    fence.ring_idx = cmd->cmd_hdr.ring_idx;
     >>>>>> +
     >>>>>> +    trace_virtio_gpu_fence_ctrl(cmd->cmd_hdr.fence_id,
     >>>>> cmd->cmd_hdr.type);
     >>>>>> +
     >>>>>> +    result = rutabaga_create_fence(vr->rutabaga, &fence);
     >>>>>> +    CHECK(!result, cmd);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +virtio_gpu_rutabaga_aio_cb(void *opaque)
     >>>>>> +{
     >>>>>> +    struct rutabaga_aio_data *data = opaque;
     >>>>>> +    VirtIOGPU *g = VIRTIO_GPU(data->vr);
     >>>>>> +    struct rutabaga_fence fence_data = data->fence;
     >>>>>> +    struct virtio_gpu_ctrl_command *cmd, *tmp;
     >>>>>> +
     >>>>>> +    uint32_t signaled_ctx_specific = fence_data.flags &
>>>>>> +  RUTABAGA_FLAG_INFO_RING_IDX;
     >>>>>> +
     >>>>>> +    QTAILQ_FOREACH_SAFE(cmd, &g->fenceq, next, tmp) {
     >>>>>> +        /*
     >>>>>> +         * Due to context specific timelines.
     >>>>>> +         */
     >>>>>> +        uint32_t target_ctx_specific = cmd->cmd_hdr.flags &
>>>>>> +  RUTABAGA_FLAG_INFO_RING_IDX;
     >>>>>> +
     >>>>>> +        if (signaled_ctx_specific != target_ctx_specific) {
     >>>>>> +            continue;
     >>>>>> +        }
     >>>>>> +
     >>>>>> +        if (signaled_ctx_specific &&
     >>>>>> +           (cmd->cmd_hdr.ring_idx != fence_data.ring_idx)) {
     >>>>>> +            continue;
     >>>>>> +        }
     >>>>>> +
     >>>>>> +        if (cmd->cmd_hdr.fence_id > fence_data.fence_id) {
     >>>>>> +            continue;
     >>>>>> +        }
     >>>>>> +
     >>>>>> +        trace_virtio_gpu_fence_resp(cmd->cmd_hdr.fence_id);
     >>>>>> +        virtio_gpu_ctrl_response_nodata(g, cmd,
     >>>>> VIRTIO_GPU_RESP_OK_NODATA);
     >>>>>> +        QTAILQ_REMOVE(&g->fenceq, cmd, next);
     >>>>>> +        g_free(cmd);
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    g_free(data);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +virtio_gpu_rutabaga_fence_cb(uint64_t user_data,
     >>>>>> +                             const struct rutabaga_fence
    *fence) {
     >>>>>> +    struct rutabaga_aio_data *data;
     >>>>>> +    VirtIOGPU *g = (VirtIOGPU *)user_data;
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +
     >>>>>> +    /*
     >>>>>> +     * gfxstream and both cross-domain (and even newer versions
     >>>>> virglrenderer:
     >>>>>> +     * see VIRGL_RENDERER_ASYNC_FENCE_CB) like to signal fence
     >>>>> completion on
     >>>>>> +     * threads ("callback threads") that are different from
    the thread
     >>>>> that
     >>>>>> +     * processes the command queue ("main thread").
     >>>>>> +     *
     >>>>>> +     * crosvm and other virtio-gpu 1.1 implementations
    enable callback
     >>>>> threads
     >>>>>> +     * via locking.  However, on QEMU a deadlock is observed if
     >>>>>> +     * virtio_gpu_ctrl_response_nodata(..) [used in the fence
     >>> callback]
     >>>>> is used
     >>>>>> +     * from a thread that is not the main thread.
     >>>>>> +     *
     >>>>>> +     * The reason is QEMU's internal locking is designed to
    work with
     >>>>> QEMU
     >>>>>> +     * threads (see rcu_register_thread()) and not generic
    C/C++/Rust
     >>>>> threads.
     >>>>>> +     * For now, we can workaround this by scheduling the
    return of the
     >>>>>> +     * fence descriptors on the main thread.
     >>>>>> +     */
     >>>>>> +
     >>>>>> +    data = g_new0(struct rutabaga_aio_data, 1);
     >>>>>> +    data->vr = vr;
     >>>>>> +    data->fence = *fence;
     >>>>>> +    aio_bh_schedule_oneshot(qemu_get_aio_context(),
     >>>>>> +                            virtio_gpu_rutabaga_aio_cb,
     >>>>>> +                            data);
     >>>>>> +}
     >>>>>> +
     >>>>>> +static void
     >>>>>> +virtio_gpu_rutabaga_debug_cb(uint64_t user_data,
     >>>>>> +                             const struct rutabaga_debug
    *debug) {
     >>>>>> +
     >>>>>> +    if (debug->debug_type == RUTABAGA_DEBUG_ERROR) {
     >>>>>> +        error_report("%s", debug->message);
     >>>>>> +    } else if (debug->debug_type == RUTABAGA_DEBUG_WARN) {
     >>>>>> +        warn_report("%s", debug->message);
     >>>>>> +    } else if (debug->debug_type == RUTABAGA_DEBUG_INFO) {
     >>>>>> +        info_report("%s", debug->message);
     >>>>>> +    }
     >>>>>> +}
     >>>>>> +
     >>>>>> +static bool virtio_gpu_rutabaga_init(VirtIOGPU *g, Error
    **errp)
     >>>>>> +{
     >>>>>> +    int result;
     >>>>>> +    uint64_t capset_mask;
     >>>>>> +    struct rutabaga_builder builder = { 0 };
     >>>>>> +    char wayland_socket_path[UNIX_PATH_MAX];
     >>>>>> +    struct rutabaga_channel channel = { 0 };
     >>>>>> +    struct rutabaga_channels channels = { 0 };
     >>>>>> +
     >>>>>> +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
     >>>>>> +    vr->rutabaga = NULL;
     >>>>>> +
     >>>>>> +    if (!vr->capset_names) {
     >>>>>> +        error_setg(errp, "a capset name from the virtio-gpu
    spec is
     >>>>> required");
     >>>>>> +        return false;
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    builder.wsi = RUTABAGA_WSI_SURFACELESS;
     >>>>>> +    /*
     >>>>>> +     * Currently, if WSI is specified, the only valid
    strings are
     >>>>> "surfaceless"
     >>>>>> +     * or "headless".  Surfaceless doesn't create a native
    window
     >>>>> surface, but
     >>>>>> +     * does copy from the render target to the Pixman
    buffer if a
     >>>>> virtio-gpu
     >>>>>> +     * 2D hypercall is issued.  Surfacless is the default.
     >>>>>> +     *
     >>>>>> +     * Headless is like surfaceless, but doesn't copy to
    the Pixman
     >>>>> buffer. The
     >>>>>> +     * use case is automated testing environments where
    there is no
     >>> need
     >>>>> to view
     >>>>>> +     * results.
     >>>>>> +     *
     >>>>>> +     * In the future, more performant virtio-gpu 2D UI
    integration may
     >>>>> be added.
     >>>>>> +     */
     >>>>>> +    if (vr->wsi) {
     >>>>>> +        if (g_str_equal(vr->wsi, "surfaceless")) {
     >>>>>> +            vr->headless = false;
     >>>>>> +        } else if (g_str_equal(vr->wsi, "headless")) {
     >>>>>> +            vr->headless = true;
     >>>>>> +        } else {
     >>>>>> +            error_setg(errp, "invalid wsi option selected");
     >>>>>> +            return false;
     >>>>>> +        }
     >>>>>> +    }
     >>>>>> +
     >>>>>> +    result = rutabaga_calculate_capset_mask(vr->capset_names,
     >>>>> &capset_mask);
     >>>>>
     >>>>> First, sorry for responding after such a long time. I've been
    busy with
     >>>>> work and I'm doing QEMU in my free time.
     >>>>>
     >>>>> In iteration 1 I've raised the topic on capset_names [1] and
    I haven't
     >>>>> seen it answered properly. Perhaps I need to rephrase a bit
    so here we
     >>> go:
     >>>>> capset_names seems to be colon-separated list of bit options
    managed by
     >>>>> rutabaga. This introduces yet another way of options
    handling. There
     >>> have
     >>>>> been talks about harmonizing options handling in QEMU since
    apparently
     >>> it
     >>>>> is considered too complex [2,3].
     >>>>
     >>>>
     >>>>> Why not pass the "capset" as a bitfield like capset_mask and
    have QEMU
     >>>>> create "capset" from QOM properties?
     >>>>
     >>>> IIUC these flags could come from virtio_gpu.h which is already
    present in
     >>>>> the QEMU tree. This would not inly shortcut the dependency on
    rutabaga
     >>> here
     >>>>> but would also be more idiomatic QEMU (since it makes the
    options more
     >>>>> introspectable by internal machinery).
     >>>>
     >>>>
     >>>>> Of course the bitfield approach would require modifications
    in QEMU
     >>>>> whenever rutabaga gains new features. However, I figure that
    in the long
     >>>>> term rutabaga will be quite feature complete such that the
    benefits of
     >>>>> idiomatic QEMU handling will outweigh the decoupling of the
    projects.
     >>>>>
     >>>>> What do you think?
     >>>>>
     >>>>
     >>>> I think what you're suggesting is something like -device
     >>>> virtio-gpu-rutabaga,capset_mask=0x10100 [40, which would be
     >>>> gfxstream_vulkan + cross_domain]?
     >>>
     >>> I was thinking more along the lines of
     >>> `virtio-gpu-rutabaga,gfxstream_vulkan=on,cross_domain=on` where
     >>> gfxstream_vulkan and cross_domain are boolean QOM properties.
    This would
     >>> make for a human-readable format which follows QEMU style.
     >>>
     >>>>
     >>>> We actually did consider something like that when adding the
     >>>> --context-types flag [with crosvm], but there was a desire for a
     >>>> human-readable format rather than numbers [even if they are in the
     >>>> virtio-gpu spec].
     >>>>
     >>>> Additionally, there are quite a few context types that people
    are playing
     >>>> around with [gfxstream-gles, gfxstream-composer] that are
    launchable and
     >>>> aren't in the spec just yet.
     >>>
     >>> Right, QEMU had to be modified for this kind of experimentation. I
     >>> considered this in my last paragraph and figured that in the
    long run QEMU
     >>> *may* prefer more idiomatic option handling since it tries hard
    to not
     >>> break its command line interface. I'm just pointing this out -- the
     >>> decision is ultimately up to the community.
     >>>
     >>> Why not have dedicated QEMU development branches for
    experimentation?
     >>> Wouldn't upstreaming new features into QEMU be a good
    motivation to get the
     >>> missing pieces into the spec, once they are mature?
     >>
     >>
     >>>>
     >>>> Also, a key feature we want to explicitly **not** turn on all
    available
     >>>> context-types and let the user decide.
     >>>
     >>> How would you prevent that with the current colon-separated
    approach?
     >>> Splitting capset_mask in multiple parameters is just a different
     >>> syntactical representation of the same thing.
     >>>
     >>>> That'll allow guest Mesa in
     >>>> particular to do its magic in its loader.  So one may run Zink
    + ANV with
     >>>> ioctl forwarding, or Iris + ioctl forwarding and compare
    performance with
     >>>> the same guest image.
     >>>>
     >>>> And another thing is one needs some knowledge of the host
    system to choose
     >>>> the right context type.  You wouldn't do Zink + ANV ioctl
    forwarding on
     >>>> MacOS.  So I think the task of choosing the right context type
    will fall
     >>> to
     >>>> projects that depend on QEMU (such as Android Emulator) which
    have some
     >>>> knowledge of the host environment.
     >>>>
     >>>> We actually have a graphics detector somewhere that calls
    VK/OpenGL before
     >>>> launching the VM and sets the right options.  Plan is to port into
     >>>> gfxstream, maybe we could use that.
     >>>
     >>> You could bail out in QEMU if rutabaga_calculate_capset_mask()
    detects
     >>> conflicting combinations, no?
     >>>
     >>>>
     >>>> So given the desire for human readable formats, being portable
    across VMMs
     >>>> (crosvm, qemu, rust-vmm??) and experimentation, the string ->
    capset mask
     >>>> conversion was put in the rutabaga API.  So I wouldn't change
    it for those
     >>>> reasons.
     >>>
     >>> What do you mean by being portable across VMMs?
     >>
     >>
     >> Having the API inside rutabaga is (mildly) useful when multiple
    VMMs have
     >> the need to translate from a human-readable format to flags
    digestible by
     >> rutabaga.
     >>
     >>
    
https://android.googlesource.com/device/google/cuttlefish/+/refs/heads/main/host/libs/vm_manager/qemu_manager.cpp#452
 
<https://android.googlesource.com/device/google/cuttlefish/+/refs/heads/main/host/libs/vm_manager/qemu_manager.cpp#452>
     >>
     >>
    
https://android.googlesource.com/device/google/cuttlefish/+/refs/heads/main/host/libs/vm_manager/crosvm_manager.cpp#353
 
<https://android.googlesource.com/device/google/cuttlefish/+/refs/heads/main/host/libs/vm_manager/crosvm_manager.cpp#353>
     >>
     >>
    
https://chromium.googlesource.com/chromiumos/platform2/+/refs/heads/main/vm_tools/concierge/vm_builder.cc#505
 
<https://chromium.googlesource.com/chromiumos/platform2/+/refs/heads/main/vm_tools/concierge/vm_builder.cc#505>
     >>
     >> For these crosvm/qemu launchers, I imagine capset names will be
    plumbed all
     >> the way through eventually (launch_cvd
     >> --gpu_context=gfxstream-vulkan:cross-domain if you've played
    around with
     >> Cuttlefish, or vmc start --gpu_contexts=gfxstream-vulkan if you
    played
     >> around with Termina VMs).
     >>
     >> I think rust-vmm could also use the same API ("--capset_names") too.
     >>
     >>
     >>> Sure, QEMU had to be taught new flags before being able to use new
     >>> rutabaga features. I agree that this comes with a certain
    inconvenience.
     >>> But it may also be inconvenient for QEMU to deal with
    additional ad-hoc
     >>> options parsing when there are efforts for harmonization.
     >>>
     >>> Did my comments shed new light into the discussion?
     >>
     >>
     >> Yes, they do.  I agree with you that both crosvm/qemu have too
    many flags,
     >> and having a stable command line interface is important.  We are
    aiming for
     >> stability with the `--capset_names={colon string}` command line,
    and at
     >> least for crosvm looking to deprecate older options [since we've
    never had
     >> an official release of crosvm yet].
     >>
     >> I do think:
     >>
     >> 1) "capset_names=gfxstream-vulkan:cross-domain"
     >> 2) "cross-domain=on,gfxstream-vulkan=on"
     >>
     >> are similar enough.  I would choose (1) for since I think not
    duplicating
     >> the [name] -> flag logic and having a similar interface across
    VMMs + VMM
     >> launchers is ever-so slightly useful.
     >
     > I think we've now reached a good understanding of the issue. It's
    now up to the QEMU community to make a choice. So I'm cc'ing Markus
    and Thomas as the experts of the topic.

    As a virtio-gpu user, I'm slightly inclined to (2) since it would be
    easier to implement the same option for virtio-gpu-virgl when a need
    arises.


The rutabaga/virgl implementations will likely be done via DEFINE_PROP_BIT, no?  For virgl, it'll set the virgl flags, and for rutabaga, it'll set the capset mask.  So it would be different.

Currently virtio-gpu-gl does not have properties for capsets so it exposes all capsets it implements (VIRTIO_GPU_CAPSET_VIRGL and VIRTIO_GPU_CAPSET_VIRGL2. VIRTIO_GPU_CAPSET_VENUS follows soon.), but it is possible to add them.

Regards,
Akihiko Odaki



reply via email to

[Prev in Thread] Current Thread [Next in Thread]