On Tue, Aug 15, 2023 at 8:07 AM Akihiko Odaki <akihiko.odaki@gmail.com
<mailto:akihiko.odaki@gmail.com>> wrote:
On 2023/08/15 9:35, Gurchetan Singh wrote:
> 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>>
> ---
> 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
> - Report error when default socket doesn't fit in Wayland
socket path
>
> hw/display/virtio-gpu-pci-rutabaga.c | 48 ++
> hw/display/virtio-gpu-rutabaga.c | 1114
++++++++++++++++++++++++++
> hw/display/virtio-vga-rutabaga.c | 51 ++
> 3 files changed, 1213 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..c71173d8ca
> --- /dev/null
> +++ b/hw/display/virtio-gpu-pci-rutabaga.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#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..3f9f106abc
> --- /dev/null
> +++ b/hw/display/virtio-gpu-rutabaga.c
> @@ -0,0 +1,1114 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#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.
> + */
> +#ifndef UNIX_PATH_MAX
You shouldn't need this ifndef.
> +#define UNIX_PATH_MAX sizeof((struct sockaddr_un) {} .sun_path)
> +#endif
> +
> +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) {
You should disable scanout as virtio-gpu-virgl does.
> + 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;
> + uint32_t current_id;
> +
> + VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
> +
> + VIRTIO_GPU_FILL_CMD(gc);
> + for (uint32_t i = 0; i < vr->num_capsets; i++) {
> + CHECK(i < vr->num_capsets, cmd);
This CHECK will not work since you have i < vr->num_capsets as the loop
condition.
> + result = rutabaga_get_capset_info(vr->rutabaga, i,
> + ¤t_id, &capset_size,
> + &capset_size);
> + CHECK(!result, cmd);
> +
> + if (current_id == gc.capset_id) {
> + break;
> + }
> + }
> +
> + 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_full(qemu_get_aio_context(),
> + virtio_gpu_rutabaga_aio_cb,
> + data, "aio");
> +}
> +
> +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 int 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 -EINVAL;
> + }
> +
> + 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 -EINVAL;
> + }
> + }
> +
> + result = rutabaga_calculate_capset_mask(vr->capset_names,
&capset_mask);
> + if (result) {
> + error_setg(errp, "invalid capset names: %s",
vr->capset_names);
> + return result;
> + }
> +
> + builder.fence_cb = virtio_gpu_rutabaga_fence_cb;
> + builder.debug_cb = virtio_gpu_rutabaga_debug_cb;
> + builder.capset_mask = capset_mask;
> + builder.user_data = (uint64_t)g;
> +
> + /*
> + * If the user doesn't specify the wayland socket path, we
try to infer
> + * the socket via a process similar to the one used by
libwayland.
> + * libwayland does the following:
> + *
> + * 1) If $WAYLAND_DISPLAY is set, attempt to connect to
> + * $XDG_RUNTIME_DIR/$WAYLAND_DISPLAY
> + * 2) Otherwise, attempt to connect to
$XDG_RUNTIME_DIR/wayland-0
> + * 3) Otherwise, don't pass a wayland socket to rutabaga. If
a guest
> + * wayland proxy is launched, it will fail to work.
> + */
> + channel.channel_type = RUTABAGA_CHANNEL_TYPE_WAYLAND;
> + if (!vr->wayland_socket_path) {
> + const char *runtime_dir = getenv("XDG_RUNTIME_DIR");
> + const char *display = getenv("WAYLAND_DISPLAY");
> + if (!display) {
> + display = "wayland-0";
> + }
> +
> + if (runtime_dir) {
> + result = snprintf(wayland_socket_path, UNIX_PATH_MAX,
> + "%s/%s", runtime_dir, display);
> + if (result > 0 && result < UNIX_PATH_MAX) {
> + channel.channel_name = wayland_socket_path;
> + }
As I said in the last email, I think it's better to make a hard
error if
the user requested RUTABAGA_CAPSET_CROSS_DOMAIN but the default socket
path does not fit in wayland_socket_path.
I mentioned this in the cover-letter to v5, but messed up the commit
message of patch 6. But we do want to be possible to use cross_domain
without wayland for following reason:
"It is possible to use cross-domain without enabling Wayland, for guest
swapchain allocation [a] which often needs special handling. We might
We want to use this capability on MacOS/Windows in the future without
Wayland, hence we shouldn't have hard errors if the default wayland socket
isn't found.
[a]
https://android.googlesource.com/platform/external/minigbm/+/refs/heads/main/virtgpu_cross_domain.c <https://android.googlesource.com/platform/external/minigbm/+/refs/heads/main/virtgpu_cross_domain.c>"
I'll incorporate your other suggestions in v6 though.