* [PATCH v2 6/6] drm/virtio: fix DRM_FORMAT_* handling
From: Gerd Hoffmann @ 2018-09-05 6:04 UTC (permalink / raw)
To: dri-devel
Cc: David Airlie, michel, open list, open list:VIRTIO GPU DRIVER,
imirkin
In-Reply-To: <20180905060445.15008-1-kraxel@redhat.com>
Use DRM_FORMAT_HOST_XRGB8888, so we are using the correct format code
on bigendian machines. Also set the quirk_addfb_prefer_host_byte_order
mode_config bit so drm_mode_addfb() asks for the correct format code.
Both DRM_FORMAT_* and VIRTIO_GPU_FORMAT_* are defined to be little
endian, so using a different mapping on bigendian machines is wrong.
It's there because of broken drm_mode_addfb() behavior. So with
drm_mode_addfb() being fixed we can fix this too.
While wading through the code I've noticed we have a little issue in
virtio: We attach a format to the bo when it is created
(DRM_IOCTL_MODE_CREATE_DUMB), not when we map it as framebuffer
(DRM_IOCTL_MODE_ADDFB). Easy way out: Support a single format only.
Pick DRM_FORMAT_HOST_XRGB8888, it is the only one actually used in
practice. Drop unused mappings in virtio_gpu_translate_format().
With this patch applied both ADDFB and ADDFB2 ioctls work correctly in
the virtio-gpu.ko driver on big endian machines. Without the patch only
ADDFB (which still seems to be used by the majority of userspace) works
correctly.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
drivers/gpu/drm/virtio/virtgpu_display.c | 5 +++
drivers/gpu/drm/virtio/virtgpu_fb.c | 2 +-
drivers/gpu/drm/virtio/virtgpu_gem.c | 7 +++--
drivers/gpu/drm/virtio/virtgpu_plane.c | 54 ++------------------------------
4 files changed, 13 insertions(+), 55 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
index 25503b9335..14a13edc02 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -306,6 +306,10 @@ virtio_gpu_user_framebuffer_create(struct drm_device *dev,
struct virtio_gpu_framebuffer *virtio_gpu_fb;
int ret;
+ if (mode_cmd->pixel_format != DRM_FORMAT_HOST_XRGB8888 &&
+ mode_cmd->pixel_format != DRM_FORMAT_HOST_ARGB8888)
+ return ERR_PTR(-ENOENT);
+
/* lookup object associated with res handle */
obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[0]);
if (!obj)
@@ -354,6 +358,7 @@ int virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev)
int i;
drm_mode_config_init(vgdev->ddev);
+ vgdev->ddev->mode_config.quirk_addfb_prefer_host_byte_order = true;
vgdev->ddev->mode_config.funcs = &virtio_gpu_mode_funcs;
vgdev->ddev->mode_config.helper_private = &virtio_mode_config_helpers;
diff --git a/drivers/gpu/drm/virtio/virtgpu_fb.c b/drivers/gpu/drm/virtio/virtgpu_fb.c
index a121b1c795..9d87ebd645 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fb.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fb.c
@@ -233,7 +233,7 @@ static int virtio_gpufb_create(struct drm_fb_helper *helper,
mode_cmd.width = sizes->surface_width;
mode_cmd.height = sizes->surface_height;
mode_cmd.pitches[0] = mode_cmd.width * 4;
- mode_cmd.pixel_format = drm_mode_legacy_fb_format(32, 24);
+ mode_cmd.pixel_format = DRM_FORMAT_HOST_XRGB8888;
format = virtio_gpu_translate_format(mode_cmd.pixel_format);
if (format == 0)
diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 0f2768eaca..82c817f37c 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -90,7 +90,10 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
uint32_t resid;
uint32_t format;
- pitch = args->width * ((args->bpp + 1) / 8);
+ if (args->bpp != 32)
+ return -EINVAL;
+
+ pitch = args->width * 4;
args->size = pitch * args->height;
args->size = ALIGN(args->size, PAGE_SIZE);
@@ -99,7 +102,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
if (ret)
goto fail;
- format = virtio_gpu_translate_format(DRM_FORMAT_XRGB8888);
+ format = virtio_gpu_translate_format(DRM_FORMAT_HOST_XRGB8888);
virtio_gpu_resource_id_get(vgdev, &resid);
virtio_gpu_cmd_create_resource(vgdev, resid, format,
args->width, args->height);
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index dc5b5b2b7a..3221d50b9a 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -28,22 +28,11 @@
#include <drm/drm_atomic_helper.h>
static const uint32_t virtio_gpu_formats[] = {
- DRM_FORMAT_XRGB8888,
- DRM_FORMAT_ARGB8888,
- DRM_FORMAT_BGRX8888,
- DRM_FORMAT_BGRA8888,
- DRM_FORMAT_RGBX8888,
- DRM_FORMAT_RGBA8888,
- DRM_FORMAT_XBGR8888,
- DRM_FORMAT_ABGR8888,
+ DRM_FORMAT_HOST_XRGB8888,
};
static const uint32_t virtio_gpu_cursor_formats[] = {
-#ifdef __BIG_ENDIAN
- DRM_FORMAT_BGRA8888,
-#else
- DRM_FORMAT_ARGB8888,
-#endif
+ DRM_FORMAT_HOST_ARGB8888,
};
uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
@@ -51,32 +40,6 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
uint32_t format;
switch (drm_fourcc) {
-#ifdef __BIG_ENDIAN
- case DRM_FORMAT_XRGB8888:
- format = VIRTIO_GPU_FORMAT_X8R8G8B8_UNORM;
- break;
- case DRM_FORMAT_ARGB8888:
- format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
- break;
- case DRM_FORMAT_BGRX8888:
- format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
- break;
- case DRM_FORMAT_BGRA8888:
- format = VIRTIO_GPU_FORMAT_B8G8R8A8_UNORM;
- break;
- case DRM_FORMAT_RGBX8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM;
- break;
- case DRM_FORMAT_RGBA8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8A8_UNORM;
- break;
- case DRM_FORMAT_XBGR8888:
- format = VIRTIO_GPU_FORMAT_X8B8G8R8_UNORM;
- break;
- case DRM_FORMAT_ABGR8888:
- format = VIRTIO_GPU_FORMAT_A8B8G8R8_UNORM;
- break;
-#else
case DRM_FORMAT_XRGB8888:
format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
break;
@@ -89,19 +52,6 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
case DRM_FORMAT_BGRA8888:
format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
break;
- case DRM_FORMAT_RGBX8888:
- format = VIRTIO_GPU_FORMAT_X8B8G8R8_UNORM;
- break;
- case DRM_FORMAT_RGBA8888:
- format = VIRTIO_GPU_FORMAT_A8B8G8R8_UNORM;
- break;
- case DRM_FORMAT_XBGR8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM;
- break;
- case DRM_FORMAT_ABGR8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8A8_UNORM;
- break;
-#endif
default:
/*
* This should not happen, we handle everything listed
--
2.9.3
^ permalink raw reply related
* Re: [PATCH] bochs: convert to drm_fb_helper_fbdev_setup/teardown
From: Daniel Vetter @ 2018-09-05 14:46 UTC (permalink / raw)
To: Peter Wu; +Cc: David Airlie, virtualization, dri-devel, linux-kernel
In-Reply-To: <20180905144127.5690-1-peter@lekensteyn.nl>
On Wed, Sep 05, 2018 at 04:41:27PM +0200, Peter Wu wrote:
> Currently unloading bochs_drm (after unbinding the vtconsole) results in
> a warning about a leaked connector:
>
> [drm:drm_mode_config_cleanup] *ERROR* connector Virtual-3 leaked!
>
> While investigating a potential fix I noticed that a lot of open-coded
> functionality is already implemented elsewhere, so start converting it:
> bochs_fbdev_init -> drm_fb_helper_fbdev_setup: trivial (similar impl).
> bochs_fbdev_fini -> drm_fb_helper_fbdev_teardown: requires unembedding
> "struct drm_framebuffer" from "struct bochs_framebuffer".
>
> Unembedding drm_framebuffer is made easy using drm_gem_fbdev_fb_create
> which can replace bochs_fbdev_destroy and custom routines in bochs_mm.c.
> For this to work, the GEM object is moved into "drm_framebuffer". After
> that, "bochs_framebuffer" is no longer needed and therefore removed.
>
> Remove the unused "size" and "initialized" fields from fb, the latter is
> not necessary as drm_fb_helper_fbdev_teardown can be called even if
> bochsfb_create fails. This theory was tested by returning early and
> late (just before drm_gem_fbdev_fb_create). Both scenarios fail
> gracefully although the latter seems to leak the object from
> bochsfb_create_object (not a regression).
>
> Guess on the reason for the encoder leak: drm_framebuffer_cleanup was
> previously used, but did not destroy much. drm_fb_helper_fbdev_teardown
> is now used and calls drm_framebuffer_remove which does a bit more work.
>
> Tested with 'echo 0 > /sys/class/vtconsole/vtcon1/bind; rmmod bochs_drm'
> and also with Xorg + fbdev (startx -> xterm). The latter triggered a
> warning in ttm_bo_vm_open that existed before, see
> https://lkml.kernel.org/r/1464000533-13140-4-git-send-email-mstaudt@suse.de
You can probably get rid of this one if you're refactoring even more. The
generic fb_probe implementation (already merged) plus gem-shmem support
for it (still in flight) from Noralf should be able to pull that off. That
gives you the fb_mmap implementation, but with 100% generic code instead
of a driver specific hack like Max did.
>
> Signed-off-by: Peter Wu <peter@lekensteyn.nl>
lgtm. Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
I'll leave merging to Gerd.
-Daniel
> ---
> drivers/gpu/drm/bochs/bochs.h | 19 ++-----
> drivers/gpu/drm/bochs/bochs_fbdev.c | 79 +++++++----------------------
> drivers/gpu/drm/bochs/bochs_kms.c | 7 +--
> drivers/gpu/drm/bochs/bochs_mm.c | 74 ---------------------------
> 4 files changed, 22 insertions(+), 157 deletions(-)
>
> diff --git a/drivers/gpu/drm/bochs/bochs.h b/drivers/gpu/drm/bochs/bochs.h
> index 375bf92cd04f..8514a84fbdbe 100644
> --- a/drivers/gpu/drm/bochs/bochs.h
> +++ b/drivers/gpu/drm/bochs/bochs.h
> @@ -51,11 +51,6 @@ enum bochs_types {
> BOCHS_UNKNOWN,
> };
>
> -struct bochs_framebuffer {
> - struct drm_framebuffer base;
> - struct drm_gem_object *obj;
> -};
> -
> struct bochs_device {
> /* hw */
> void __iomem *mmio;
> @@ -88,15 +83,11 @@ struct bochs_device {
>
> /* fbdev */
> struct {
> - struct bochs_framebuffer gfb;
> + struct drm_framebuffer *fb;
> struct drm_fb_helper helper;
> - int size;
> - bool initialized;
> } fb;
> };
>
> -#define to_bochs_framebuffer(x) container_of(x, struct bochs_framebuffer, base)
> -
> struct bochs_bo {
> struct ttm_buffer_object bo;
> struct ttm_placement placement;
> @@ -148,15 +139,9 @@ int bochs_dumb_create(struct drm_file *file, struct drm_device *dev,
> int bochs_dumb_mmap_offset(struct drm_file *file, struct drm_device *dev,
> uint32_t handle, uint64_t *offset);
>
> -int bochs_framebuffer_init(struct drm_device *dev,
> - struct bochs_framebuffer *gfb,
> - const struct drm_mode_fb_cmd2 *mode_cmd,
> - struct drm_gem_object *obj);
> int bochs_bo_pin(struct bochs_bo *bo, u32 pl_flag, u64 *gpu_addr);
> int bochs_bo_unpin(struct bochs_bo *bo);
>
> -extern const struct drm_mode_config_funcs bochs_mode_funcs;
> -
> /* bochs_kms.c */
> int bochs_kms_init(struct bochs_device *bochs);
> void bochs_kms_fini(struct bochs_device *bochs);
> @@ -164,3 +149,5 @@ void bochs_kms_fini(struct bochs_device *bochs);
> /* bochs_fbdev.c */
> int bochs_fbdev_init(struct bochs_device *bochs);
> void bochs_fbdev_fini(struct bochs_device *bochs);
> +
> +extern const struct drm_mode_config_funcs bochs_mode_funcs;
> diff --git a/drivers/gpu/drm/bochs/bochs_fbdev.c b/drivers/gpu/drm/bochs/bochs_fbdev.c
> index 14eb8d0d5a00..8f4d6c052f7b 100644
> --- a/drivers/gpu/drm/bochs/bochs_fbdev.c
> +++ b/drivers/gpu/drm/bochs/bochs_fbdev.c
> @@ -6,6 +6,7 @@
> */
>
> #include "bochs.h"
> +#include <drm/drm_gem_framebuffer_helper.h>
>
> /* ---------------------------------------------------------------------- */
>
> @@ -13,9 +14,7 @@ static int bochsfb_mmap(struct fb_info *info,
> struct vm_area_struct *vma)
> {
> struct drm_fb_helper *fb_helper = info->par;
> - struct bochs_device *bochs =
> - container_of(fb_helper, struct bochs_device, fb.helper);
> - struct bochs_bo *bo = gem_to_bochs_bo(bochs->fb.gfb.obj);
> + struct bochs_bo *bo = gem_to_bochs_bo(fb_helper->fb->obj[0]);
>
> return ttm_fbdev_mmap(vma, &bo->bo);
> }
> @@ -101,19 +100,20 @@ static int bochsfb_create(struct drm_fb_helper *helper,
>
> /* init fb device */
> info = drm_fb_helper_alloc_fbi(helper);
> - if (IS_ERR(info))
> + if (IS_ERR(info)) {
> + DRM_ERROR("Failed to allocate fbi: %ld\n", PTR_ERR(info));
> return PTR_ERR(info);
> + }
>
> info->par = &bochs->fb.helper;
>
> - ret = bochs_framebuffer_init(bochs->dev, &bochs->fb.gfb, &mode_cmd, gobj);
> - if (ret)
> - return ret;
> -
> - bochs->fb.size = size;
> + fb = drm_gem_fbdev_fb_create(bochs->dev, sizes, 0, gobj, NULL);
> + if (IS_ERR(fb)) {
> + DRM_ERROR("Failed to create framebuffer: %ld\n", PTR_ERR(fb));
> + return PTR_ERR(fb);
> + }
>
> /* setup helper */
> - fb = &bochs->fb.gfb.base;
> bochs->fb.helper.fb = fb;
>
> strcpy(info->fix.id, "bochsdrmfb");
> @@ -130,27 +130,6 @@ static int bochsfb_create(struct drm_fb_helper *helper,
> drm_vma_offset_remove(&bo->bo.bdev->vma_manager, &bo->bo.vma_node);
> info->fix.smem_start = 0;
> info->fix.smem_len = size;
> -
> - bochs->fb.initialized = true;
> - return 0;
> -}
> -
> -static int bochs_fbdev_destroy(struct bochs_device *bochs)
> -{
> - struct bochs_framebuffer *gfb = &bochs->fb.gfb;
> -
> - DRM_DEBUG_DRIVER("\n");
> -
> - drm_fb_helper_unregister_fbi(&bochs->fb.helper);
> -
> - if (gfb->obj) {
> - drm_gem_object_unreference_unlocked(gfb->obj);
> - gfb->obj = NULL;
> - }
> -
> - drm_framebuffer_unregister_private(&gfb->base);
> - drm_framebuffer_cleanup(&gfb->base);
> -
> return 0;
> }
>
> @@ -158,41 +137,17 @@ static const struct drm_fb_helper_funcs bochs_fb_helper_funcs = {
> .fb_probe = bochsfb_create,
> };
>
> +const struct drm_mode_config_funcs bochs_mode_funcs = {
> + .fb_create = drm_gem_fb_create,
> +};
> +
> int bochs_fbdev_init(struct bochs_device *bochs)
> {
> - int ret;
> -
> - drm_fb_helper_prepare(bochs->dev, &bochs->fb.helper,
> - &bochs_fb_helper_funcs);
> -
> - ret = drm_fb_helper_init(bochs->dev, &bochs->fb.helper, 1);
> - if (ret)
> - return ret;
> -
> - ret = drm_fb_helper_single_add_all_connectors(&bochs->fb.helper);
> - if (ret)
> - goto fini;
> -
> - drm_helper_disable_unused_functions(bochs->dev);
> -
> - ret = drm_fb_helper_initial_config(&bochs->fb.helper, 32);
> - if (ret)
> - goto fini;
> -
> - return 0;
> -
> -fini:
> - drm_fb_helper_fini(&bochs->fb.helper);
> - return ret;
> + return drm_fb_helper_fbdev_setup(bochs->dev, &bochs->fb.helper,
> + &bochs_fb_helper_funcs, 32, 1);
> }
>
> void bochs_fbdev_fini(struct bochs_device *bochs)
> {
> - if (bochs->fb.initialized)
> - bochs_fbdev_destroy(bochs);
> -
> - if (bochs->fb.helper.fbdev)
> - drm_fb_helper_fini(&bochs->fb.helper);
> -
> - bochs->fb.initialized = false;
> + drm_fb_helper_fbdev_teardown(bochs->dev);
> }
> diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c
> index 233980a78591..c7e575511d2f 100644
> --- a/drivers/gpu/drm/bochs/bochs_kms.c
> +++ b/drivers/gpu/drm/bochs/bochs_kms.c
> @@ -35,14 +35,12 @@ static int bochs_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
> {
> struct bochs_device *bochs =
> container_of(crtc, struct bochs_device, crtc);
> - struct bochs_framebuffer *bochs_fb;
> struct bochs_bo *bo;
> u64 gpu_addr = 0;
> int ret;
>
> if (old_fb) {
> - bochs_fb = to_bochs_framebuffer(old_fb);
> - bo = gem_to_bochs_bo(bochs_fb->obj);
> + bo = gem_to_bochs_bo(old_fb->obj[0]);
> ret = ttm_bo_reserve(&bo->bo, true, false, NULL);
> if (ret) {
> DRM_ERROR("failed to reserve old_fb bo\n");
> @@ -55,8 +53,7 @@ static int bochs_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
> if (WARN_ON(crtc->primary->fb == NULL))
> return -EINVAL;
>
> - bochs_fb = to_bochs_framebuffer(crtc->primary->fb);
> - bo = gem_to_bochs_bo(bochs_fb->obj);
> + bo = gem_to_bochs_bo(crtc->primary->fb->obj[0]);
> ret = ttm_bo_reserve(&bo->bo, true, false, NULL);
> if (ret)
> return ret;
> diff --git a/drivers/gpu/drm/bochs/bochs_mm.c b/drivers/gpu/drm/bochs/bochs_mm.c
> index 39cd08416773..cdbc3ca3ec51 100644
> --- a/drivers/gpu/drm/bochs/bochs_mm.c
> +++ b/drivers/gpu/drm/bochs/bochs_mm.c
> @@ -457,77 +457,3 @@ int bochs_dumb_mmap_offset(struct drm_file *file, struct drm_device *dev,
> drm_gem_object_unreference_unlocked(obj);
> return 0;
> }
> -
> -/* ---------------------------------------------------------------------- */
> -
> -static void bochs_user_framebuffer_destroy(struct drm_framebuffer *fb)
> -{
> - struct bochs_framebuffer *bochs_fb = to_bochs_framebuffer(fb);
> -
> - drm_gem_object_unreference_unlocked(bochs_fb->obj);
> - drm_framebuffer_cleanup(fb);
> - kfree(fb);
> -}
> -
> -static const struct drm_framebuffer_funcs bochs_fb_funcs = {
> - .destroy = bochs_user_framebuffer_destroy,
> -};
> -
> -int bochs_framebuffer_init(struct drm_device *dev,
> - struct bochs_framebuffer *gfb,
> - const struct drm_mode_fb_cmd2 *mode_cmd,
> - struct drm_gem_object *obj)
> -{
> - int ret;
> -
> - drm_helper_mode_fill_fb_struct(dev, &gfb->base, mode_cmd);
> - gfb->obj = obj;
> - ret = drm_framebuffer_init(dev, &gfb->base, &bochs_fb_funcs);
> - if (ret) {
> - DRM_ERROR("drm_framebuffer_init failed: %d\n", ret);
> - return ret;
> - }
> - return 0;
> -}
> -
> -static struct drm_framebuffer *
> -bochs_user_framebuffer_create(struct drm_device *dev,
> - struct drm_file *filp,
> - const struct drm_mode_fb_cmd2 *mode_cmd)
> -{
> - struct drm_gem_object *obj;
> - struct bochs_framebuffer *bochs_fb;
> - int ret;
> -
> - DRM_DEBUG_DRIVER("%dx%d, format %c%c%c%c\n",
> - mode_cmd->width, mode_cmd->height,
> - (mode_cmd->pixel_format) & 0xff,
> - (mode_cmd->pixel_format >> 8) & 0xff,
> - (mode_cmd->pixel_format >> 16) & 0xff,
> - (mode_cmd->pixel_format >> 24) & 0xff);
> -
> - if (mode_cmd->pixel_format != DRM_FORMAT_XRGB8888)
> - return ERR_PTR(-ENOENT);
> -
> - obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]);
> - if (obj == NULL)
> - return ERR_PTR(-ENOENT);
> -
> - bochs_fb = kzalloc(sizeof(*bochs_fb), GFP_KERNEL);
> - if (!bochs_fb) {
> - drm_gem_object_unreference_unlocked(obj);
> - return ERR_PTR(-ENOMEM);
> - }
> -
> - ret = bochs_framebuffer_init(dev, bochs_fb, mode_cmd, obj);
> - if (ret) {
> - drm_gem_object_unreference_unlocked(obj);
> - kfree(bochs_fb);
> - return ERR_PTR(ret);
> - }
> - return &bochs_fb->base;
> -}
> -
> -const struct drm_mode_config_funcs bochs_mode_funcs = {
> - .fb_create = bochs_user_framebuffer_create,
> -};
> --
> 2.18.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply
* [RFC] UAPI: Check headers by compiling all together as C++
From: David Howells @ 2018-09-05 15:54 UTC (permalink / raw)
To: linux-api, linux-kbuild
Cc: moderated for non-subscribers, Michael S. Tsirkin, David Airlie,
Mat Martineau, dri-devel, virtualization, dhowells,
Masahiro Yamada, keyrings, Ryusuke Konishi, linux-nilfs,
linux-nvdimm, codalist, coda, coreteam, Kent Overstreet,
linux-arm-msm, Coly Li, linux-bcache, Dan Williams,
Jaroslav Kysela, Jan Harkes, Michal Marek, Takashi Iwai,
linux-kernel, Rob
Here's a set of patches that inserts a step into the build process to make
sure that the UAPI headers can all be built together with C++ (if the
compiler being used supports C++). All but the final patch perform fixups,
including:
(1) Fix member names that conflict with C++ reserved words by providing
alternates that can be used anywhere. An anonymous union is used so
that that the conflicting name is still available outside of C++.
(2) Fix the use of flexible arrays in structs that get embedded (which is
illegal in C++).
(3) Remove the use of internal kernel structs in UAPI structures.
(4) Fix symbol collisions.
(5) Replace usage of u32 and co. with __u32 and co.
(6) Fix use of sparsely initialised arrays (which g++ doesn't implement).
(7) Remove some use of PAGE_SIZE since this isn't valid outside of the
kernel.
And lastly:
(8) Compile all of the UAPI headers (with a few exceptions) together as
C++ to catch new errors occurring as part of the regular build
process.
The patches can also be found here:
http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=uapi-check
Thanks,
David
---
David Howells (11):
UAPI: drm: Fix use of C++ keywords as structural members
UAPI: keys: Fix use of C++ keywords as structural members
UAPI: virtio_net: Fix use of C++ keywords as structural members
UAPI: bcache: Fix use of embedded flexible array
UAPI: coda: Don't use internal kernel structs in UAPI
UAPI: netfilter: Fix symbol collision issues
UAPI: nilfs2: Fix use of undefined byteswapping functions
UAPI: sound: Fix use of u32 and co. in UAPI headers
UAPI: ndctl: Fix g++-unsupported initialisation in headers
UAPI: ndctl: Remove use of PAGE_SIZE
UAPI: Check headers build for C++
Makefile | 1
include/linux/ndctl.h | 22 ++++
include/uapi/drm/i810_drm.h | 7 +
include/uapi/drm/msm_drm.h | 7 +
include/uapi/linux/bcache.h | 2
include/uapi/linux/coda_psdev.h | 4 +
include/uapi/linux/keyctl.h | 7 +
include/uapi/linux/ndctl.h | 20 ++-
include/uapi/linux/netfilter/nfnetlink_cthelper.h | 2
include/uapi/linux/netfilter_ipv4/ipt_ECN.h | 9 --
include/uapi/linux/nilfs2_ondisk.h | 21 ++--
include/uapi/linux/virtio_net.h | 7 +
include/uapi/sound/skl-tplg-interface.h | 106 +++++++++---------
scripts/headers-c++.sh | 124 +++++++++++++++++++++
14 files changed, 255 insertions(+), 84 deletions(-)
create mode 100644 include/linux/ndctl.h
create mode 100755 scripts/headers-c++.sh
^ permalink raw reply
* [PATCH 03/11] UAPI: virtio_net: Fix use of C++ keywords as structural members
From: David Howells @ 2018-09-05 15:54 UTC (permalink / raw)
To: linux-api, linux-kbuild
Cc: dhowells, virtualization, linux-kernel, Michael S. Tsirkin
In-Reply-To: <153616286704.23468.584491117180383924.stgit@warthog.procyon.org.uk>
The virtio_net_ctrl_hdr struct uses a C++ keyword as structural members. Fix
this by inserting an anonymous union that provides an alternative name and
then hide the reserved name in C++.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: "Michael S. Tsirkin" <mst@redhat.com>
cc: Jason Wang <jasowang@redhat.com>
cc: virtualization@lists.linux-foundation.org
---
include/uapi/linux/virtio_net.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index a3715a3224c1..967142bc0e05 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -150,7 +150,12 @@ struct virtio_net_hdr_mrg_rxbuf {
* command goes in between.
*/
struct virtio_net_ctrl_hdr {
- __u8 class;
+ union {
+#ifndef __cplusplus
+ __u8 class;
+#endif
+ __u8 _class;
+ };
__u8 cmd;
} __attribute__((packed));
^ permalink raw reply related
* Re: [PATCH 03/11] UAPI: virtio_net: Fix use of C++ keywords as structural members
From: Greg KH @ 2018-09-05 16:54 UTC (permalink / raw)
To: David Howells
Cc: Michael S. Tsirkin, linux-api, linux-kbuild, linux-kernel,
virtualization
In-Reply-To: <153616289529.23468.7498785670556620808.stgit@warthog.procyon.org.uk>
On Wed, Sep 05, 2018 at 04:54:55PM +0100, David Howells wrote:
> The virtio_net_ctrl_hdr struct uses a C++ keyword as structural members. Fix
> this by inserting an anonymous union that provides an alternative name and
> then hide the reserved name in C++.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: "Michael S. Tsirkin" <mst@redhat.com>
> cc: Jason Wang <jasowang@redhat.com>
> cc: virtualization@lists.linux-foundation.org
> ---
>
> include/uapi/linux/virtio_net.h | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index a3715a3224c1..967142bc0e05 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -150,7 +150,12 @@ struct virtio_net_hdr_mrg_rxbuf {
> * command goes in between.
> */
> struct virtio_net_ctrl_hdr {
> - __u8 class;
> + union {
> +#ifndef __cplusplus
> + __u8 class;
> +#endif
> + __u8 _class;
> + };
Ugh, ick, no!
Come on now, either put the whole C namespace stuff around the file, or
don't care about this at all. Doing this whack-a-mole style is a mess.
"class" is a fine variable name for C code, there's no reason this has
to change here at all.
greg k-h
^ permalink raw reply
* Re: [RFC] UAPI: Check headers by compiling all together as C++
From: Greg KH @ 2018-09-05 16:55 UTC (permalink / raw)
To: David Howells
Cc: moderated for non-subscribers, Michael S. Tsirkin, David Airlie,
Mat Martineau, dri-devel, virtualization, Masahiro Yamada,
keyrings, Ryusuke Konishi, linux-nilfs, linux-nvdimm, codalist,
coda, coreteam, Kent Overstreet, linux-kbuild, linux-arm-msm,
Coly Li, linux-bcache, Dan Williams, Jaroslav Kysela, Jan Harkes,
Michal Marek, linux-api, Takashi Iwai
In-Reply-To: <153616286704.23468.584491117180383924.stgit@warthog.procyon.org.uk>
On Wed, Sep 05, 2018 at 04:54:27PM +0100, David Howells wrote:
>
> Here's a set of patches that inserts a step into the build process to make
> sure that the UAPI headers can all be built together with C++ (if the
> compiler being used supports C++). All but the final patch perform fixups,
> including:
Wait, why do we care? What has recently changed to start to directly
import kernel uapi files into C++ code?
And if userspace wants to do this, can't they do the C namespace trick
themselves when they do the import? That must be how they are doing it
today, right?
thanks,
greg k-h
^ permalink raw reply
* Re: [PATCH 03/11] UAPI: virtio_net: Fix use of C++ keywords as structural members
From: David Howells @ 2018-09-05 17:15 UTC (permalink / raw)
To: Greg KH
Cc: Michael S. Tsirkin, linux-api, linux-kbuild, linux-kernel,
virtualization, dhowells
In-Reply-To: <20180905165436.GA25206@kroah.com>
Greg KH <gregkh@linuxfoundation.org> wrote:
> Come on now, either put the whole C namespace stuff around the file,
You mean wrap it with 'extern "C" { ... }'? That doesn't fix it. That only
affects the symbols generated by the compiler.
> "class" is a fine variable name for C code, there's no reason this has
> to change here at all.
I'm trying to prevent future accidents like the one in linux/keyctl.h. The
easiest way to do this[**] is to pass the entire set of UAPI headers[*]
through the compiler together.
Besides I still have my dark plan to C++-ise the kernel[***] :-D
David
[*] with some obvious exceptions
[**] and it catches other errors too
[***] https://lkml.org/lkml/2018/4/1/116
^ permalink raw reply
* Re: [PATCH 03/11] UAPI: virtio_net: Fix use of C++ keywords as structural members
From: Michael S. Tsirkin @ 2018-09-05 17:35 UTC (permalink / raw)
To: David Howells; +Cc: linux-api, virtualization, linux-kernel, linux-kbuild
In-Reply-To: <153616289529.23468.7498785670556620808.stgit@warthog.procyon.org.uk>
On Wed, Sep 05, 2018 at 04:54:55PM +0100, David Howells wrote:
> The virtio_net_ctrl_hdr struct uses a C++ keyword as structural members. Fix
> this by inserting an anonymous union that provides an alternative name and
> then hide the reserved name in C++.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: "Michael S. Tsirkin" <mst@redhat.com>
> cc: Jason Wang <jasowang@redhat.com>
> cc: virtualization@lists.linux-foundation.org
> ---
>
> include/uapi/linux/virtio_net.h | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index a3715a3224c1..967142bc0e05 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -150,7 +150,12 @@ struct virtio_net_hdr_mrg_rxbuf {
> * command goes in between.
> */
> struct virtio_net_ctrl_hdr {
> - __u8 class;
> + union {
> +#ifndef __cplusplus
> + __u8 class;
> +#endif
> + __u8 _class;
> + };
> __u8 cmd;
> } __attribute__((packed));
As long as you do not intend to use any classes, how about
simply adding
-Dclass=_class
to your command line?
Seems to work fine with gcc 8.1.1 on Fedora.
--
MST
^ permalink raw reply
* Re: [RFC] UAPI: Check headers by compiling all together as C++
From: Michael S. Tsirkin @ 2018-09-05 17:42 UTC (permalink / raw)
To: Yann Droneaud
Cc: moderated for non-subscribers, David Airlie, Greg KH,
Mat Martineau, dri-devel, virtualization, David Howells,
Masahiro Yamada, keyrings, Ryusuke Konishi, linux-nilfs,
linux-nvdimm, codalist, coda, coreteam, Kent Overstreet,
linux-kbuild, linux-arm-msm, Coly Li, linux-bcache, Dan Williams,
Jaroslav Kysela, Jan Harkes, Michal Marek, linux-api, Takashi
In-Reply-To: <a1efae8d26cc5b73b180e9521d6b62590c55aa86.camel@opteya.com>
On Wed, Sep 05, 2018 at 07:33:38PM +0200, Yann Droneaud wrote:
> Hi,
>
> Le mercredi 05 septembre 2018 à 18:55 +0200, Greg KH a écrit :
> > On Wed, Sep 05, 2018 at 04:54:27PM +0100, David Howells wrote:
> > >
> > > Here's a set of patches that inserts a step into the build process to make
> > > sure that the UAPI headers can all be built together with C++ (if the
> > > compiler being used supports C++). All but the final patch perform fixups,
> > > including:
> >
> > Wait, why do we care? What has recently changed to start to directly
> > import kernel uapi files into C++ code?
> >
> > And if userspace wants to do this, can't they do the C namespace trick
> > themselves when they do the import? That must be how they are doing it
> > today, right?
> >
>
> They can't.
>
>
> Adding extern "C" { } doesn't magically make "class" a non keyword.
> Even if it was the case, writing C++ code using whatever->class would
> probably broke because class is a keyword in C++.
I think it's a bug in the language TBH.
> --
> Yann Droneaud
> OPTEYA
>
^ permalink raw reply
* Re: [RFC] UAPI: Check headers by compiling all together as C++
From: David Howells @ 2018-09-05 17:50 UTC (permalink / raw)
To: Greg KH
Cc: alsa-devel, linux-kbuild, linux-api, linux-kernel, dri-devel,
virtualization, dhowells, keyrings, netfilter-devel,
linux-fsdevel, freedreno
In-Reply-To: <20180905165552.GB25206@kroah.com>
Greg KH <greg@kroah.com> wrote:
> > Here's a set of patches that inserts a step into the build process to make
> > sure that the UAPI headers can all be built together with C++ (if the
> > compiler being used supports C++). All but the final patch perform fixups,
> > including:
>
> Wait, why do we care? What has recently changed to start to directly
> import kernel uapi files into C++ code?
There's at least one outstanding bug due to a C++ identifier in the kernel
UAPI headers.
Are you saying you explicitly don't want people to be able to use the kernel
UAPI headers in C++?
> And if userspace wants to do this, can't they do the C namespace trick
> themselves when they do the import? That must be how they are doing it
> today, right?
No, because there's no such trick (except with the preprocessor).
David
^ permalink raw reply
* Re: [RFC] UAPI: Check headers by compiling all together as C++
From: Jan Engelhardt @ 2018-09-05 19:22 UTC (permalink / raw)
To: Greg KH
Cc: moderated for non-subscribers, Michael S. Tsirkin, David Airlie,
Mat Martineau, dri-devel, virtualization, David Howells,
Masahiro Yamada, keyrings, Ryusuke Konishi, linux-nilfs,
linux-nvdimm, codalist, coda, coreteam, Kent Overstreet,
linux-kbuild, linux-arm-msm, Coly Li, linux-bcache, Dan Williams,
Jaroslav Kysela, Jan Harkes, Michal Marek, linux-api
In-Reply-To: <20180905165552.GB25206@kroah.com>
On Wednesday 2018-09-05 18:55, Greg KH wrote:
>On Wed, Sep 05, 2018 at 04:54:27PM +0100, David Howells wrote:
>>
>> Here's a set of patches that inserts a step into the build process to make
>> sure that the UAPI headers can all be built together with C++ (if the
>> compiler being used supports C++). All but the final patch perform fixups,
>> including:
>
>Wait, why do we care? What has recently changed to start to directly
>import kernel uapi files into C++ code?
With C++11, C++ has become a much nicer language to use (for userspace, anyway).
>And if userspace wants to do this, can't they do the C namespace trick
>themselves when they do the import?
The only trick is to use an extra C source file and extensively wrap things.
^ permalink raw reply
* [PATCH net-next 00/11] Vhost_net TX batching
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
Hi all:
This series tries to batch submitting packets to underlayer socket
through msg_control during sendmsg(). This is done by:
1) Doing userspace copy inside vhost_net
2) Build XDP buff
3) Batch at most 64 (VHOST_NET_BATCH) XDP buffs and submit them once
through msg_control during sendmsg().
4) Underlayer sockets can use XDP buffs directly when XDP is enalbed,
or build skb based on XDP buff.
For the packet that can not be built easily with XDP or for the case
that batch submission is hard (e.g sndbuf is limited). We will go for
the previous slow path, passing iov iterator to underlayer socket
through sendmsg() once per packet.
This can help to improve cache utilization and avoid lots of indirect
calls with sendmsg(). It can also co-operate with the batching support
of the underlayer sockets (e.g the case of XDP redirection through
maps).
Testpmd(txonly) in guest shows obvious improvements:
Test /+pps%
XDP_DROP on TAP /+44.8%
XDP_REDIRECT on TAP /+29%
macvtap (skb) /+26%
Netperf TCP_STREAM TX from guest shows obvious improvements on small
packet:
size/session/+thu%/+normalize%
64/ 1/ +2%/ 0%
64/ 2/ +3%/ +1%
64/ 4/ +7%/ +5%
64/ 8/ +8%/ +6%
256/ 1/ +3%/ 0%
256/ 2/ +10%/ +7%
256/ 4/ +26%/ +22%
256/ 8/ +27%/ +23%
512/ 1/ +3%/ +2%
512/ 2/ +19%/ +14%
512/ 4/ +43%/ +40%
512/ 8/ +45%/ +41%
1024/ 1/ +4%/ 0%
1024/ 2/ +27%/ +21%
1024/ 4/ +38%/ +73%
1024/ 8/ +15%/ +24%
2048/ 1/ +10%/ +7%
2048/ 2/ +16%/ +12%
2048/ 4/ 0%/ +2%
2048/ 8/ 0%/ +2%
4096/ 1/ +36%/ +60%
4096/ 2/ -11%/ -26%
4096/ 4/ 0%/ +14%
4096/ 8/ 0%/ +4%
16384/ 1/ -1%/ +5%
16384/ 2/ 0%/ +2%
16384/ 4/ 0%/ -3%
16384/ 8/ 0%/ +4%
65535/ 1/ 0%/ +10%
65535/ 2/ 0%/ +8%
65535/ 4/ 0%/ +1%
65535/ 8/ 0%/ +3%
Please review.
Thanks
Jason Wang (11):
net: sock: introduce SOCK_XDP
tuntap: switch to use XDP_PACKET_HEADROOM
tuntap: enable bh early during processing XDP
tuntap: simplify error handling in tun_build_skb()
tuntap: tweak on the path of non-xdp case in tun_build_skb()
tuntap: split out XDP logic
tuntap: move XDP flushing out of tun_do_xdp()
tun: switch to new type of msg_control
tuntap: accept an array of XDP buffs through sendmsg()
tap: accept an array of XDP buffs through sendmsg()
vhost_net: batch submitting XDP buffers to underlayer sockets
drivers/net/tap.c | 87 +++++++++++++-
drivers/net/tun.c | 251 +++++++++++++++++++++++++++++++----------
drivers/vhost/net.c | 171 +++++++++++++++++++++++++---
include/linux/if_tun.h | 7 ++
include/net/sock.h | 1 +
5 files changed, 437 insertions(+), 80 deletions(-)
--
2.17.1
^ permalink raw reply
* [PATCH net-next 01/11] net: sock: introduce SOCK_XDP
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch introduces a new sock flag - SOCK_XDP. This will be used
for notifying the upper layer that XDP program is attached on the
lower socket, and requires for extra headroom.
TUN will be the first user.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 19 +++++++++++++++++++
include/net/sock.h | 1 +
2 files changed, 20 insertions(+)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ebd07ad82431..2c548bd20393 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -869,6 +869,9 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
tun_napi_init(tun, tfile, napi);
}
+ if (rtnl_dereference(tun->xdp_prog))
+ sock_set_flag(&tfile->sk, SOCK_XDP);
+
tun_set_real_num_queues(tun);
/* device is allowed to go away first, so no need to hold extra
@@ -1241,13 +1244,29 @@ static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
struct netlink_ext_ack *extack)
{
struct tun_struct *tun = netdev_priv(dev);
+ struct tun_file *tfile;
struct bpf_prog *old_prog;
+ int i;
old_prog = rtnl_dereference(tun->xdp_prog);
rcu_assign_pointer(tun->xdp_prog, prog);
if (old_prog)
bpf_prog_put(old_prog);
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ if (prog)
+ sock_set_flag(&tfile->sk, SOCK_XDP);
+ else
+ sock_reset_flag(&tfile->sk, SOCK_XDP);
+ }
+ list_for_each_entry(tfile, &tun->disabled, next) {
+ if (prog)
+ sock_set_flag(&tfile->sk, SOCK_XDP);
+ else
+ sock_reset_flag(&tfile->sk, SOCK_XDP);
+ }
+
return 0;
}
diff --git a/include/net/sock.h b/include/net/sock.h
index 433f45fc2d68..38cae35f6e16 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -800,6 +800,7 @@ enum sock_flags {
SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
SOCK_TXTIME,
+ SOCK_XDP, /* XDP is attached */
};
#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 02/11] tuntap: switch to use XDP_PACKET_HEADROOM
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2c548bd20393..d3677a544b56 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -113,7 +113,6 @@ do { \
} while (0)
#endif
-#define TUN_HEADROOM 256
#define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
/* TUN device flags */
@@ -1654,7 +1653,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
if (xdp_prog)
- pad += TUN_HEADROOM;
+ pad += XDP_PACKET_HEADROOM;
buflen += SKB_DATA_ALIGN(len + pad);
rcu_read_unlock();
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 03/11] tuntap: enable bh early during processing XDP
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch move the bh enabling a little bit earlier, this will be
used for factoring out the core XDP logic of tuntap.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index d3677a544b56..372caf7d67d9 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1726,22 +1726,18 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
goto err_xdp;
}
}
+ rcu_read_unlock();
+ local_bh_enable();
skb = build_skb(buf, buflen);
- if (!skb) {
- rcu_read_unlock();
- local_bh_enable();
+ if (!skb)
return ERR_PTR(-ENOMEM);
- }
skb_reserve(skb, pad - delta);
skb_put(skb, len);
get_page(alloc_frag->page);
alloc_frag->offset += buflen;
- rcu_read_unlock();
- local_bh_enable();
-
return skb;
err_redirect:
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 04/11] tuntap: simplify error handling in tun_build_skb()
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
There's no need to duplicate page get logic in each action. So this
patch tries to get page and calculate the offset before processing XDP
actions, and undo them when meet errors (we don't care the performance
on errors). This will be used for factoring out XDP logic.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 372caf7d67d9..f8cdcfa392c3 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1642,7 +1642,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
int len, int *skb_xdp)
{
struct page_frag *alloc_frag = ¤t->task_frag;
- struct sk_buff *skb;
+ struct sk_buff *skb = NULL;
struct bpf_prog *xdp_prog;
int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
unsigned int delta = 0;
@@ -1668,6 +1668,9 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
if (copied != len)
return ERR_PTR(-EFAULT);
+ get_page(alloc_frag->page);
+ alloc_frag->offset += buflen;
+
/* There's a small window that XDP may be set after the check
* of xdp_prog above, this should be rare and for simplicity
* we do XDP on skb in case the headroom is not enough.
@@ -1695,23 +1698,15 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
switch (act) {
case XDP_REDIRECT:
- get_page(alloc_frag->page);
- alloc_frag->offset += buflen;
err = xdp_do_redirect(tun->dev, &xdp, xdp_prog);
xdp_do_flush_map();
if (err)
- goto err_redirect;
- rcu_read_unlock();
- local_bh_enable();
- return NULL;
+ goto err_xdp;
+ goto out;
case XDP_TX:
- get_page(alloc_frag->page);
- alloc_frag->offset += buflen;
if (tun_xdp_tx(tun->dev, &xdp) < 0)
- goto err_redirect;
- rcu_read_unlock();
- local_bh_enable();
- return NULL;
+ goto err_xdp;
+ goto out;
case XDP_PASS:
delta = orig_data - xdp.data;
len = xdp.data_end - xdp.data;
@@ -1730,23 +1725,23 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
local_bh_enable();
skb = build_skb(buf, buflen);
- if (!skb)
- return ERR_PTR(-ENOMEM);
+ if (!skb) {
+ skb = ERR_PTR(-ENOMEM);
+ goto out;
+ }
skb_reserve(skb, pad - delta);
skb_put(skb, len);
- get_page(alloc_frag->page);
- alloc_frag->offset += buflen;
return skb;
-err_redirect:
- put_page(alloc_frag->page);
err_xdp:
+ alloc_frag->offset -= buflen;
+ put_page(alloc_frag->page);
+out:
rcu_read_unlock();
local_bh_enable();
- this_cpu_inc(tun->pcpu_stats->rx_dropped);
- return NULL;
+ return skb;
}
/* Get packet from user space buffer */
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 05/11] tuntap: tweak on the path of non-xdp case in tun_build_skb()
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
If we're sure not to go native XDP, there's no need for several things
like bh and rcu stuffs.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index f8cdcfa392c3..389aa0727cc6 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1675,10 +1675,12 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
* of xdp_prog above, this should be rare and for simplicity
* we do XDP on skb in case the headroom is not enough.
*/
- if (hdr->gso_type || !xdp_prog)
+ if (hdr->gso_type || !xdp_prog) {
*skb_xdp = 1;
- else
- *skb_xdp = 0;
+ goto build;
+ }
+
+ *skb_xdp = 0;
local_bh_disable();
rcu_read_lock();
@@ -1724,6 +1726,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
rcu_read_unlock();
local_bh_enable();
+build:
skb = build_skb(buf, buflen);
if (!skb) {
skb = ERR_PTR(-ENOMEM);
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 06/11] tuntap: split out XDP logic
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch split out XDP logic into a single function. This make it to
be reused by XDP batching path in the following patch.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 84 ++++++++++++++++++++++++++++-------------------
1 file changed, 51 insertions(+), 33 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 389aa0727cc6..21b125020b3b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1635,6 +1635,44 @@ static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
return true;
}
+static u32 tun_do_xdp(struct tun_struct *tun,
+ struct tun_file *tfile,
+ struct bpf_prog *xdp_prog,
+ struct xdp_buff *xdp,
+ int *err)
+{
+ u32 act = bpf_prog_run_xdp(xdp_prog, xdp);
+
+ switch (act) {
+ case XDP_REDIRECT:
+ *err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
+ xdp_do_flush_map();
+ if (*err)
+ break;
+ goto out;
+ case XDP_TX:
+ *err = tun_xdp_tx(tun->dev, xdp);
+ if (*err < 0)
+ break;
+ *err = 0;
+ goto out;
+ case XDP_PASS:
+ goto out;
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ /* fall through */
+ case XDP_ABORTED:
+ trace_xdp_exception(tun->dev, xdp_prog, act);
+ /* fall through */
+ case XDP_DROP:
+ break;
+ }
+
+ put_page(virt_to_head_page(xdp->data_hard_start));
+out:
+ return act;
+}
+
static struct sk_buff *tun_build_skb(struct tun_struct *tun,
struct tun_file *tfile,
struct iov_iter *from,
@@ -1645,10 +1683,10 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
struct sk_buff *skb = NULL;
struct bpf_prog *xdp_prog;
int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
- unsigned int delta = 0;
char *buf;
size_t copied;
- int err, pad = TUN_RX_PAD;
+ int pad = TUN_RX_PAD;
+ int err = 0;
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
@@ -1685,9 +1723,8 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
local_bh_disable();
rcu_read_lock();
xdp_prog = rcu_dereference(tun->xdp_prog);
- if (xdp_prog && !*skb_xdp) {
+ if (xdp_prog) {
struct xdp_buff xdp;
- void *orig_data;
u32 act;
xdp.data_hard_start = buf;
@@ -1695,33 +1732,14 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + len;
xdp.rxq = &tfile->xdp_rxq;
- orig_data = xdp.data;
- act = bpf_prog_run_xdp(xdp_prog, &xdp);
-
- switch (act) {
- case XDP_REDIRECT:
- err = xdp_do_redirect(tun->dev, &xdp, xdp_prog);
- xdp_do_flush_map();
- if (err)
- goto err_xdp;
- goto out;
- case XDP_TX:
- if (tun_xdp_tx(tun->dev, &xdp) < 0)
- goto err_xdp;
- goto out;
- case XDP_PASS:
- delta = orig_data - xdp.data;
- len = xdp.data_end - xdp.data;
- break;
- default:
- bpf_warn_invalid_xdp_action(act);
- /* fall through */
- case XDP_ABORTED:
- trace_xdp_exception(tun->dev, xdp_prog, act);
- /* fall through */
- case XDP_DROP:
+ act = tun_do_xdp(tun, tfile, xdp_prog, &xdp, &err);
+ if (err)
goto err_xdp;
- }
+ if (act != XDP_PASS)
+ goto out;
+
+ pad = xdp.data - xdp.data_hard_start;
+ len = xdp.data_end - xdp.data;
}
rcu_read_unlock();
local_bh_enable();
@@ -1729,18 +1747,18 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
build:
skb = build_skb(buf, buflen);
if (!skb) {
+ put_page(alloc_frag->page);
skb = ERR_PTR(-ENOMEM);
goto out;
}
- skb_reserve(skb, pad - delta);
+ skb_reserve(skb, pad);
skb_put(skb, len);
return skb;
err_xdp:
- alloc_frag->offset -= buflen;
- put_page(alloc_frag->page);
+ this_cpu_inc(tun->pcpu_stats->rx_dropped);
out:
rcu_read_unlock();
local_bh_enable();
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 07/11] tuntap: move XDP flushing out of tun_do_xdp()
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This will allow adding batch flushing on top.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 21b125020b3b..ff1cbf3ebd50 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1646,7 +1646,6 @@ static u32 tun_do_xdp(struct tun_struct *tun,
switch (act) {
case XDP_REDIRECT:
*err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
- xdp_do_flush_map();
if (*err)
break;
goto out;
@@ -1735,6 +1734,9 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
act = tun_do_xdp(tun, tfile, xdp_prog, &xdp, &err);
if (err)
goto err_xdp;
+
+ if (act == XDP_REDIRECT)
+ xdp_do_flush_map();
if (act != XDP_PASS)
goto out;
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 08/11] tun: switch to new type of msg_control
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch introduces to a new tun/tap specific msg_control:
#define TUN_MSG_UBUF 1
#define TUN_MSG_PTR 2
struct tun_msg_ctl {
int type;
void *ptr;
};
This allows us to pass different kinds of msg_control through
sendmsg(). The first supported type is ubuf (TUN_MSG_UBUF) which will
be used by the existed vhost_net zerocopy code. The second is XDP
buff, which allows vhost_net to pass XDP buff to TUN. This could be
used to implement accepting an array of XDP buffs from vhost_net in
the following patches.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tap.c | 18 ++++++++++++------
drivers/net/tun.c | 6 +++++-
drivers/vhost/net.c | 7 +++++--
include/linux/if_tun.h | 7 +++++++
4 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index f0f7cd977667..7996ed7cbf18 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -619,7 +619,7 @@ static inline struct sk_buff *tap_alloc_skb(struct sock *sk, size_t prepad,
#define TAP_RESERVE HH_DATA_OFF(ETH_HLEN)
/* Get packet from user space buffer */
-static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,
+static ssize_t tap_get_user(struct tap_queue *q, void *msg_control,
struct iov_iter *from, int noblock)
{
int good_linear = SKB_MAX_HEAD(TAP_RESERVE);
@@ -663,7 +663,7 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,
if (unlikely(len < ETH_HLEN))
goto err;
- if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
+ if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
struct iov_iter i;
copylen = vnet_hdr.hdr_len ?
@@ -724,11 +724,11 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,
tap = rcu_dereference(q->tap);
/* copy skb_ubuf_info for callback when skb has no error */
if (zerocopy) {
- skb_shinfo(skb)->destructor_arg = m->msg_control;
+ skb_shinfo(skb)->destructor_arg = msg_control;
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
- } else if (m && m->msg_control) {
- struct ubuf_info *uarg = m->msg_control;
+ } else if (msg_control) {
+ struct ubuf_info *uarg = msg_control;
uarg->callback(uarg, false);
}
@@ -1150,7 +1150,13 @@ static int tap_sendmsg(struct socket *sock, struct msghdr *m,
size_t total_len)
{
struct tap_queue *q = container_of(sock, struct tap_queue, sock);
- return tap_get_user(q, m, &m->msg_iter, m->msg_flags & MSG_DONTWAIT);
+ struct tun_msg_ctl *ctl = m->msg_control;
+
+ if (ctl && ctl->type != TUN_MSG_UBUF)
+ return -EINVAL;
+
+ return tap_get_user(q, ctl ? ctl->ptr : NULL, &m->msg_iter,
+ m->msg_flags & MSG_DONTWAIT);
}
static int tap_recvmsg(struct socket *sock, struct msghdr *m,
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ff1cbf3ebd50..c839a4bdcbd9 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2429,11 +2429,15 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
int ret;
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
struct tun_struct *tun = tun_get(tfile);
+ struct tun_msg_ctl *ctl = m->msg_control;
if (!tun)
return -EBADFD;
- ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
+ if (ctl && ctl->type != TUN_MSG_UBUF)
+ return -EINVAL;
+
+ ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
m->msg_flags & MSG_DONTWAIT,
m->msg_flags & MSG_MORE);
tun_put(tun);
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 4e656f89cb22..fb01ce6d981c 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -620,6 +620,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
.msg_controllen = 0,
.msg_flags = MSG_DONTWAIT,
};
+ struct tun_msg_ctl ctl;
size_t len, total_len = 0;
int err;
struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
@@ -664,8 +665,10 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
ubuf->ctx = nvq->ubufs;
ubuf->desc = nvq->upend_idx;
refcount_set(&ubuf->refcnt, 1);
- msg.msg_control = ubuf;
- msg.msg_controllen = sizeof(ubuf);
+ msg.msg_control = &ctl;
+ ctl.type = TUN_MSG_UBUF;
+ ctl.ptr = ubuf;
+ msg.msg_controllen = sizeof(ctl);
ubufs = nvq->ubufs;
atomic_inc(&ubufs->refcount);
nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 3d2996dc7d85..ba46dced1f38 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -19,6 +19,13 @@
#define TUN_XDP_FLAG 0x1UL
+#define TUN_MSG_UBUF 1
+#define TUN_MSG_PTR 2
+struct tun_msg_ctl {
+ int type;
+ void *ptr;
+};
+
#if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
struct socket *tun_get_socket(struct file *);
struct ptr_ring *tun_get_tx_ring(struct file *file);
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 09/11] tuntap: accept an array of XDP buffs through sendmsg()
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch implement TUN_MSG_PTR msg_control type. This type allows
the caller to pass an array of XDP buffs to tuntap through ptr field
of the tun_msg_control. If an XDP program is attached, tuntap can run
XDP program directly. If not, tuntap will build skb and do a fast
receiving since part of the work has been done by vhost_net.
This will avoid lots of indirect calls thus improves the icache
utilization and allows to do XDP batched flushing when doing XDP
redirection.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 103 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 100 insertions(+), 3 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index c839a4bdcbd9..069db2e5dd08 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2424,22 +2424,119 @@ static void tun_sock_write_space(struct sock *sk)
kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
}
+static int tun_xdp_one(struct tun_struct *tun,
+ struct tun_file *tfile,
+ struct xdp_buff *xdp, int *flush)
+{
+ struct virtio_net_hdr *gso = xdp->data_hard_start + sizeof(int);
+ struct tun_pcpu_stats *stats;
+ struct bpf_prog *xdp_prog;
+ struct sk_buff *skb = NULL;
+ u32 rxhash = 0, act;
+ int buflen = *(int *)xdp->data_hard_start;
+ int err = 0;
+ bool skb_xdp = false;
+
+ xdp_prog = rcu_dereference(tun->xdp_prog);
+ if (xdp_prog) {
+ if (gso->gso_type) {
+ skb_xdp = true;
+ goto build;
+ }
+ xdp_set_data_meta_invalid(xdp);
+ xdp->rxq = &tfile->xdp_rxq;
+ act = tun_do_xdp(tun, tfile, xdp_prog, xdp, &err);
+ if (err)
+ goto out;
+ if (act == XDP_REDIRECT)
+ *flush = true;
+ if (act != XDP_PASS)
+ goto out;
+ }
+
+build:
+ skb = build_skb(xdp->data_hard_start, buflen);
+ if (!skb) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ skb_reserve(skb, xdp->data - xdp->data_hard_start);
+ skb_put(skb, xdp->data_end - xdp->data);
+
+ if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
+ this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
+ kfree_skb(skb);
+ err = -EINVAL;
+ goto out;
+ }
+
+ skb->protocol = eth_type_trans(skb, tun->dev);
+ skb_reset_network_header(skb);
+ skb_probe_transport_header(skb, 0);
+
+ if (skb_xdp) {
+ err = do_xdp_generic(xdp_prog, skb);
+ if (err != XDP_PASS)
+ goto out;
+ }
+
+ if (!rcu_dereference(tun->steering_prog))
+ rxhash = __skb_get_hash_symmetric(skb);
+
+ netif_receive_skb(skb);
+
+ stats = get_cpu_ptr(tun->pcpu_stats);
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_packets++;
+ stats->rx_bytes += skb->len;
+ u64_stats_update_end(&stats->syncp);
+ put_cpu_ptr(stats);
+
+ if (rxhash)
+ tun_flow_update(tun, rxhash, tfile);
+
+out:
+ return err;
+}
+
static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
{
- int ret;
+ int ret, i;
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
struct tun_struct *tun = tun_get(tfile);
struct tun_msg_ctl *ctl = m->msg_control;
+ struct xdp_buff *xdp;
if (!tun)
return -EBADFD;
- if (ctl && ctl->type != TUN_MSG_UBUF)
- return -EINVAL;
+ if (ctl && ((ctl->type & 0xF) == TUN_MSG_PTR)) {
+ int n = ctl->type >> 16;
+ int flush = 0;
+
+ local_bh_disable();
+ rcu_read_lock();
+
+ for (i = 0; i < n; i++) {
+ xdp = &((struct xdp_buff *)ctl->ptr)[i];
+ tun_xdp_one(tun, tfile, xdp, &flush);
+ }
+
+ if (flush)
+ xdp_do_flush_map();
+
+ rcu_read_unlock();
+ local_bh_enable();
+
+ ret = total_len;
+ goto out;
+ }
ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
m->msg_flags & MSG_DONTWAIT,
m->msg_flags & MSG_MORE);
+out:
tun_put(tun);
return ret;
}
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 10/11] tap: accept an array of XDP buffs through sendmsg()
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch implement TUN_MSG_PTR msg_control type. This type allows
the caller to pass an array of XDP buffs to tuntap through ptr field
of the tun_msg_control. Tap will build skb through those XDP buffers.
This will avoid lots of indirect calls thus improves the icache
utilization and allows to do XDP batched flushing when doing XDP
redirection.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tap.c | 73 +++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 71 insertions(+), 2 deletions(-)
diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 7996ed7cbf18..50eb7bf22225 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -1146,14 +1146,83 @@ static const struct file_operations tap_fops = {
#endif
};
+static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp)
+{
+ struct virtio_net_hdr *gso = xdp->data_hard_start + sizeof(int);
+ int buflen = *(int *)xdp->data_hard_start;
+ int vnet_hdr_len = 0;
+ struct tap_dev *tap;
+ struct sk_buff *skb;
+ int err, depth;
+
+ if (q->flags & IFF_VNET_HDR)
+ vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz);
+
+ skb = build_skb(xdp->data_hard_start, buflen);
+ if (!skb) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ skb_reserve(skb, xdp->data - xdp->data_hard_start);
+ skb_put(skb, xdp->data_end - xdp->data);
+
+ skb_set_network_header(skb, ETH_HLEN);
+ skb_reset_mac_header(skb);
+ skb->protocol = eth_hdr(skb)->h_proto;
+
+ if (vnet_hdr_len) {
+ err = virtio_net_hdr_to_skb(skb, gso, tap_is_little_endian(q));
+ if (err)
+ goto err_kfree;
+ }
+
+ skb_probe_transport_header(skb, ETH_HLEN);
+
+ /* Move network header to the right position for VLAN tagged packets */
+ if ((skb->protocol == htons(ETH_P_8021Q) ||
+ skb->protocol == htons(ETH_P_8021AD)) &&
+ __vlan_get_protocol(skb, skb->protocol, &depth) != 0)
+ skb_set_network_header(skb, depth);
+
+ rcu_read_lock();
+ tap = rcu_dereference(q->tap);
+ if (tap) {
+ skb->dev = tap->dev;
+ dev_queue_xmit(skb);
+ } else {
+ kfree_skb(skb);
+ }
+ rcu_read_unlock();
+
+ return 0;
+
+err_kfree:
+ kfree_skb(skb);
+err:
+ rcu_read_lock();
+ tap = rcu_dereference(q->tap);
+ if (tap && tap->count_tx_dropped)
+ tap->count_tx_dropped(tap);
+ rcu_read_unlock();
+ return err;
+}
+
static int tap_sendmsg(struct socket *sock, struct msghdr *m,
size_t total_len)
{
struct tap_queue *q = container_of(sock, struct tap_queue, sock);
struct tun_msg_ctl *ctl = m->msg_control;
+ struct xdp_buff *xdp;
+ int i;
- if (ctl && ctl->type != TUN_MSG_UBUF)
- return -EINVAL;
+ if (ctl && ((ctl->type & 0xF) == TUN_MSG_PTR)) {
+ for (i = 0; i < ctl->type >> 16; i++) {
+ xdp = &((struct xdp_buff *)ctl->ptr)[i];
+ tap_get_user_xdp(q, xdp);
+ }
+ return 0;
+ }
return tap_get_user(q, ctl ? ctl->ptr : NULL, &m->msg_iter,
m->msg_flags & MSG_DONTWAIT);
--
2.17.1
^ permalink raw reply related
* [PATCH net-next 11/11] vhost_net: batch submitting XDP buffers to underlayer sockets
From: Jason Wang @ 2018-09-06 4:05 UTC (permalink / raw)
To: netdev, linux-kernel; +Cc: mst, kvm, virtualization
In-Reply-To: <20180906040526.22518-1-jasowang@redhat.com>
This patch implements XDP batching for vhost_net. The idea is first to
try to do userspace copy and build XDP buff directly in vhost. Instead
of submitting the packet immediately, vhost_net will batch them in an
array and submit every 64 (VHOST_NET_BATCH) packets to the under layer
sockets through msg_control of sendmsg().
When XDP is enabled on the TUN/TAP, TUN/TAP can process XDP inside a
loop without caring GUP thus it can do batch map flushing. When XDP is
not enabled or not supported, the underlayer socket need to build skb
and pass it to network core. The batched packet submission allows us
to do batching like netif_receive_skb_list() in the future.
This saves lots of indirect calls for better cache utilization. For
the case that we can't so batching e.g when sndbuf is limited or
packet size is too large, we will go for usual one packet per
sendmsg() way.
Doing testpmd on various setups gives us:
Test /+pps%
XDP_DROP on TAP /+44.8%
XDP_REDIRECT on TAP /+29%
macvtap (skb) /+26%
Netperf tests shows obvious improvements for small packet transmission:
size/session/+thu%/+normalize%
64/ 1/ +2%/ 0%
64/ 2/ +3%/ +1%
64/ 4/ +7%/ +5%
64/ 8/ +8%/ +6%
256/ 1/ +3%/ 0%
256/ 2/ +10%/ +7%
256/ 4/ +26%/ +22%
256/ 8/ +27%/ +23%
512/ 1/ +3%/ +2%
512/ 2/ +19%/ +14%
512/ 4/ +43%/ +40%
512/ 8/ +45%/ +41%
1024/ 1/ +4%/ 0%
1024/ 2/ +27%/ +21%
1024/ 4/ +38%/ +73%
1024/ 8/ +15%/ +24%
2048/ 1/ +10%/ +7%
2048/ 2/ +16%/ +12%
2048/ 4/ 0%/ +2%
2048/ 8/ 0%/ +2%
4096/ 1/ +36%/ +60%
4096/ 2/ -11%/ -26%
4096/ 4/ 0%/ +14%
4096/ 8/ 0%/ +4%
16384/ 1/ -1%/ +5%
16384/ 2/ 0%/ +2%
16384/ 4/ 0%/ -3%
16384/ 8/ 0%/ +4%
65535/ 1/ 0%/ +10%
65535/ 2/ 0%/ +8%
65535/ 4/ 0%/ +1%
65535/ 8/ 0%/ +3%
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/net.c | 164 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 151 insertions(+), 13 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index fb01ce6d981c..1dd4239cbff8 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -116,6 +116,7 @@ struct vhost_net_virtqueue {
* For RX, number of batched heads
*/
int done_idx;
+ int batched_xdp;
/* an array of userspace buffers info */
struct ubuf_info *ubuf_info;
/* Reference counting for outstanding ubufs.
@@ -123,6 +124,7 @@ struct vhost_net_virtqueue {
struct vhost_net_ubuf_ref *ubufs;
struct ptr_ring *rx_ring;
struct vhost_net_buf rxq;
+ struct xdp_buff xdp[VHOST_NET_BATCH];
};
struct vhost_net {
@@ -338,6 +340,11 @@ static bool vhost_sock_zcopy(struct socket *sock)
sock_flag(sock->sk, SOCK_ZEROCOPY);
}
+static bool vhost_sock_xdp(struct socket *sock)
+{
+ return sock_flag(sock->sk, SOCK_XDP);
+}
+
/* In case of DMA done not in order in lower device driver for some reason.
* upend_idx is used to track end of used idx, done_idx is used to track head
* of used idx. Once lower device DMA done contiguously, we will signal KVM
@@ -444,10 +451,36 @@ static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq)
nvq->done_idx = 0;
}
+static void vhost_tx_batch(struct vhost_net *net,
+ struct vhost_net_virtqueue *nvq,
+ struct socket *sock,
+ struct msghdr *msghdr)
+{
+ struct tun_msg_ctl ctl = {
+ .type = nvq->batched_xdp << 16 | TUN_MSG_PTR,
+ .ptr = nvq->xdp,
+ };
+ int err;
+
+ if (nvq->batched_xdp == 0)
+ goto signal_used;
+
+ msghdr->msg_control = &ctl;
+ err = sock->ops->sendmsg(sock, msghdr, 0);
+ if (unlikely(err < 0)) {
+ vq_err(&nvq->vq, "Fail to batch sending packets\n");
+ return;
+ }
+
+signal_used:
+ vhost_net_signal_used(nvq);
+ nvq->batched_xdp = 0;
+}
+
static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
struct vhost_net_virtqueue *nvq,
unsigned int *out_num, unsigned int *in_num,
- bool *busyloop_intr)
+ struct msghdr *msghdr, bool *busyloop_intr)
{
struct vhost_virtqueue *vq = &nvq->vq;
unsigned long uninitialized_var(endtime);
@@ -455,8 +488,9 @@ static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
out_num, in_num, NULL, NULL);
if (r == vq->num && vq->busyloop_timeout) {
+ /* Flush batched packets first */
if (!vhost_sock_zcopy(vq->private_data))
- vhost_net_signal_used(nvq);
+ vhost_tx_batch(net, nvq, vq->private_data, msghdr);
preempt_disable();
endtime = busy_clock() + vq->busyloop_timeout;
while (vhost_can_busy_poll(endtime)) {
@@ -512,7 +546,7 @@ static int get_tx_bufs(struct vhost_net *net,
struct vhost_virtqueue *vq = &nvq->vq;
int ret;
- ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, busyloop_intr);
+ ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, busyloop_intr);
if (ret < 0 || ret == vq->num)
return ret;
@@ -540,6 +574,83 @@ static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len)
!vhost_vq_avail_empty(vq->dev, vq);
}
+#define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
+
+static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
+ struct iov_iter *from)
+{
+ struct vhost_virtqueue *vq = &nvq->vq;
+ struct socket *sock = vq->private_data;
+ struct page_frag *alloc_frag = ¤t->task_frag;
+ struct virtio_net_hdr *gso;
+ struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp];
+ size_t len = iov_iter_count(from);
+ int headroom = vhost_sock_xdp(sock) ? XDP_PACKET_HEADROOM : 0;
+ int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ int pad = SKB_DATA_ALIGN(VHOST_NET_RX_PAD + headroom + nvq->sock_hlen);
+ int sock_hlen = nvq->sock_hlen;
+ void *buf;
+ int copied;
+
+ if (unlikely(len < nvq->sock_hlen))
+ return -EFAULT;
+
+ if (SKB_DATA_ALIGN(len + pad) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
+ return -ENOSPC;
+
+ buflen += SKB_DATA_ALIGN(len + pad);
+ alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
+ if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
+ return -ENOMEM;
+
+ buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
+
+ /* We store two kinds of metadata in the header which will be
+ * used for XDP_PASS to do build_skb():
+ * offset 0: buflen
+ * offset sizeof(int): vnet header
+ */
+ copied = copy_page_from_iter(alloc_frag->page,
+ alloc_frag->offset + sizeof(int),
+ sock_hlen, from);
+ if (copied != sock_hlen)
+ return -EFAULT;
+
+ gso = (struct virtio_net_hdr *)(buf + sizeof(int));
+
+ if ((gso->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
+ vhost16_to_cpu(vq, gso->csum_start) +
+ vhost16_to_cpu(vq, gso->csum_offset) + 2 >
+ vhost16_to_cpu(vq, gso->hdr_len)) {
+ gso->hdr_len = cpu_to_vhost16(vq,
+ vhost16_to_cpu(vq, gso->csum_start) +
+ vhost16_to_cpu(vq, gso->csum_offset) + 2);
+
+ if (vhost16_to_cpu(vq, gso->hdr_len) > len)
+ return -EINVAL;
+ }
+
+ len -= sock_hlen;
+ copied = copy_page_from_iter(alloc_frag->page,
+ alloc_frag->offset + pad,
+ len, from);
+ if (copied != len)
+ return -EFAULT;
+
+ xdp->data_hard_start = buf;
+ xdp->data = buf + pad;
+ xdp->data_end = xdp->data + len;
+ *(int *)(xdp->data_hard_start) = buflen;
+
+ get_page(alloc_frag->page);
+ alloc_frag->offset += buflen;
+
+ ++nvq->batched_xdp;
+
+ return 0;
+}
+
static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
{
struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
@@ -556,10 +667,14 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
size_t len, total_len = 0;
int err;
int sent_pkts = 0;
+ bool bulking = (sock->sk->sk_sndbuf == INT_MAX);
for (;;) {
bool busyloop_intr = false;
+ if (nvq->done_idx == VHOST_NET_BATCH)
+ vhost_tx_batch(net, nvq, sock, &msg);
+
head = get_tx_bufs(net, nvq, &msg, &out, &in, &len,
&busyloop_intr);
/* On error, stop handling until the next kick. */
@@ -577,14 +692,34 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
break;
}
- vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head);
- vq->heads[nvq->done_idx].len = 0;
-
total_len += len;
- if (tx_can_batch(vq, total_len))
- msg.msg_flags |= MSG_MORE;
- else
- msg.msg_flags &= ~MSG_MORE;
+
+ /* For simplicity, TX batching is only enabled if
+ * sndbuf is unlimited.
+ */
+ if (bulking) {
+ err = vhost_net_build_xdp(nvq, &msg.msg_iter);
+ if (!err) {
+ goto done;
+ } else if (unlikely(err != -ENOSPC)) {
+ vhost_tx_batch(net, nvq, sock, &msg);
+ vhost_discard_vq_desc(vq, 1);
+ vhost_net_enable_vq(net, vq);
+ break;
+ }
+
+ /* We can't build XDP buff, go for single
+ * packet path but let's flush batched
+ * packets.
+ */
+ vhost_tx_batch(net, nvq, sock, &msg);
+ msg.msg_control = NULL;
+ } else {
+ if (tx_can_batch(vq, total_len))
+ msg.msg_flags |= MSG_MORE;
+ else
+ msg.msg_flags &= ~MSG_MORE;
+ }
/* TODO: Check specific error and bomb out unless ENOBUFS? */
err = sock->ops->sendmsg(sock, &msg, len);
@@ -596,15 +731,17 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
if (err != len)
pr_debug("Truncated TX packet: len %d != %zd\n",
err, len);
- if (++nvq->done_idx >= VHOST_NET_BATCH)
- vhost_net_signal_used(nvq);
+done:
+ vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head);
+ vq->heads[nvq->done_idx].len = 0;
+ ++nvq->done_idx;
if (vhost_exceeds_weight(++sent_pkts, total_len)) {
vhost_poll_queue(&vq->poll);
break;
}
}
- vhost_net_signal_used(nvq);
+ vhost_tx_batch(net, nvq, sock, &msg);
}
static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
@@ -1111,6 +1248,7 @@ static int vhost_net_open(struct inode *inode, struct file *f)
n->vqs[i].ubuf_info = NULL;
n->vqs[i].upend_idx = 0;
n->vqs[i].done_idx = 0;
+ n->vqs[i].batched_xdp = 0;
n->vqs[i].vhost_hlen = 0;
n->vqs[i].sock_hlen = 0;
n->vqs[i].rx_ring = NULL;
--
2.17.1
^ permalink raw reply related
* Re: [PATCH 03/11] UAPI: virtio_net: Fix use of C++ keywords as structural members
From: David Howells @ 2018-09-06 7:09 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kbuild, linux-api, linux-kernel, virtualization, dhowells
In-Reply-To: <20180905125636-mutt-send-email-mst@kernel.org>
Michael S. Tsirkin <mst@redhat.com> wrote:
> As long as you do not intend to use any classes, how about
> simply adding
>
> -Dclass=_class
>
> to your command line?
That kind of misses the point;-). It's not reasonable to expect all userspace
C++ users to do this.
David
^ permalink raw reply
* Re: [PATCH] bochs: convert to drm_fb_helper_fbdev_setup/teardown
From: Gerd Hoffmann @ 2018-09-06 7:23 UTC (permalink / raw)
To: Peter Wu; +Cc: David Airlie, linux-kernel, dri-devel, virtualization
In-Reply-To: <20180905150630.GA25979@al>
Hi,
> > You can probably get rid of this one if you're refactoring even more. The
> > generic fb_probe implementation (already merged) plus gem-shmem support
> > for it (still in flight) from Noralf should be able to pull that off. That
> > gives you the fb_mmap implementation, but with 100% generic code instead
> > of a driver specific hack like Max did.
>
> Aside from the warning, I have not observed actual issues. This patch
> was prepared on top of v4.18.1 but the new drm_fb_helper_generic_probe
> helper is in master (future 4.19). I suppose that it can be done as a
> future cleanup. Nice work Noralf on reducing duplication!
FYI: qemu kms driver patches go through drm-misc-next, so you can also
work against that branch.
> > I'll leave merging to Gerd.
>
> Thanks, I somehow missed a patch. This one does not compile due to
> "fb.initialized" still being used in bochs_drv.c. Removal is trivial,
> I'll wait for some more feedback and then send a v2 with another patch
> prepended.
Patch looks good to me (except for the build failure which you've
noticed already).
cheers,
Gerd
^ permalink raw reply
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