Today there is a global limit of pages mapped via /dev/xen/gntdev set
to 1 million pages per default. There is no reason why that limit is
existing, as total number of grant mappings is limited by the
hypervisor anyway and preferring kernel mappings over userspace ones
doesn't make sense. It should be noted that the gntdev device is
usable by root only.
Additionally checking of that limit is fragile, as the number of pages
to map via one call is specified in a 32-bit unsigned variable which
isn't tested to stay within reasonable limits (the only test is the
value to be <= zero, which basically excludes only calls without any
mapping requested). So trying to map e.g. 0xffff0000 pages while
already nearly 1000000 pages are mapped will effectively lower the
global number of mapped pages such that a parallel call mapping a
reasonable amount of pages can succeed in spite of the global limit
being violated.
So drop the global limit and introduce per call limit instead. This
per call limit (default: 65536 grant mappings) protects against
allocating insane large arrays in the kernel for doing a hypercall
which will fail anyway in case a user is e.g. trying to map billions
of pages.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Check if there are any imported dma-bufs left not released by
user-space when grant device's release callback is called and
free those if this is the case. This can happen if user-space
leaks the buffers because of a bug or application has been
terminated for any reason.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
If there are exported DMA buffers which are still in use and
grant device is closed by either normal user-space close or by
a signal this leads to the grant device context to be destroyed,
thus making it not possible to correctly destroy those exported
buffers when they are returned back to gntdev and makes the module
crash:
[ 339.617540] [<ffff00000854c0d8>] dmabuf_exp_ops_release+0x40/0xa8
[ 339.617560] [<ffff00000867a6e8>] dma_buf_release+0x60/0x190
[ 339.617577] [<ffff0000082211f0>] __fput+0x88/0x1d0
[ 339.617589] [<ffff000008221394>] ____fput+0xc/0x18
[ 339.617607] [<ffff0000080ed4e4>] task_work_run+0x9c/0xc0
[ 339.617622] [<ffff000008089714>] do_notify_resume+0xfc/0x108
Fix this by referencing gntdev on each DMA buffer export and
unreferencing on buffer release.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
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Merge tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie:
"This is the main drm pull request for 4.19.
Rob has some new hardware support for new qualcomm hw that I'll send
along separately. This has the display part of it, the remaining pull
is for the acceleration engine.
This also contains a wound-wait/wait-die mutex rework, Peter has acked
it for merging via my tree.
Otherwise mostly the usual level of activity. Summary:
core:
- Wound-wait/wait-die mutex rework
- Add writeback connector type
- Add "content type" property for HDMI
- Move GEM bo to drm_framebuffer
- Initial gpu scheduler documentation
- GPU scheduler fixes for dying processes
- Console deferred fbcon takeover support
- Displayport support for CEC tunneling over AUX
panel:
- otm8009a panel driver fixes
- Innolux TV123WAM and G070Y2-L01 panel driver
- Ilitek ILI9881c panel driver
- Rocktech RK070ER9427 LCD
- EDT ETM0700G0EDH6 and EDT ETM0700G0BDH6
- DLC DLC0700YZG-1
- BOE HV070WSA-100
- newhaven, nhd-4.3-480272ef-atxl LCD
- DataImage SCF0700C48GGU18
- Sharp LQ035Q7DB03
- p079zca: Refactor to support multiple panels
tinydrm:
- ILI9341 display panel
New driver:
- vkms - virtual kms driver to testing.
i915:
- Icelake:
Display enablement
DSI support
IRQ support
Powerwell support
- GPU reset fixes and improvements
- Full ppgtt support refactoring
- PSR fixes and improvements
- Execlist improvments
- GuC related fixes
amdgpu:
- Initial amdgpu documentation
- JPEG engine support on VCN
- CIK uses powerplay by default
- Move to using core PCIE functionality for gens/lanes
- DC/Powerplay interface rework
- Stutter mode support for RV
- Vega12 Powerplay updates
- GFXOFF fixes
- GPUVM fault debugging
- Vega12 GFXOFF
- DC improvements
- DC i2c/aux changes
- UVD 7.2 fixes
- Powerplay fixes for Polaris12, CZ/ST
- command submission bo_list fixes
amdkfd:
- Raven support
- Power management fixes
udl:
- Cleanups and fixes
nouveau:
- misc fixes and cleanups.
msm:
- DPU1 support display controller in sdm845
- GPU coredump support.
vmwgfx:
- Atomic modesetting validation fixes
- Support for multisample surfaces
armada:
- Atomic modesetting support completed.
exynos:
- IPPv2 fixes
- Move g2d to component framework
- Suspend/resume support cleanups
- Driver cleanups
imx:
- CSI configuration improvements
- Driver cleanups
- Use atomic suspend/resume helpers
- ipu-v3 V4L2 XRGB32/XBGR32 support
pl111:
- Add Nomadik LCDC variant
v3d:
- GPU scheduler jobs management
sun4i:
- R40 display engine support
- TCON TOP driver
mediatek:
- MT2712 SoC support
rockchip:
- vop fixes
omapdrm:
- Workaround for DRA7 errata i932
- Fix mm_list locking
mali-dp:
- Writeback implementation
PM improvements
- Internal error reporting debugfs
tilcdc:
- Single fix for deferred probing
hdlcd:
- Teardown fixes
tda998x:
- Converted to a bridge driver.
etnaviv:
- Misc fixes"
* tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drm: (1506 commits)
drm/amdgpu/sriov: give 8s for recover vram under RUNTIME
drm/scheduler: fix param documentation
drm/i2c: tda998x: correct PLL divider calculation
drm/i2c: tda998x: get rid of private fill_modes function
drm/i2c: tda998x: move mode_valid() to bridge
drm/i2c: tda998x: register bridge outside of component helper
drm/i2c: tda998x: cleanup from previous changes
drm/i2c: tda998x: allocate tda998x_priv inside tda998x_create()
drm/i2c: tda998x: convert to bridge driver
drm/scheduler: fix timeout worker setup for out of order job completions
drm/amd/display: display connected to dp-1 does not light up
drm/amd/display: update clk for various HDMI color depths
drm/amd/display: program display clock on cache match
drm/amd/display: Add NULL check for enabling dp ss
drm/amd/display: add vbios table check for enabling dp ss
drm/amd/display: Don't share clk source between DP and HDMI
drm/amd/display: Fix DP HBR2 Eye Diagram Pattern on Carrizo
drm/amd/display: Use calculated disp_clk_khz value for dce110
drm/amd/display: Implement custom degamma lut on dcn
drm/amd/display: Destroy aux_engines only once
...
Currently when the allocation of gntdev_dmabuf fails, the error exit
path will call dmabuf_imp_free_storage and causes a null pointer
dereference on gntdev_dmabuf. Fix this by adding an error exit path
that won't free gntdev_dmabuf.
Detected by CoverityScan, CID#1472124 ("Dereference after null check")
Fixes: bf8dc55b13 ("xen/gntdev: Implement dma-buf import functionality")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
1. Import a dma-buf with the file descriptor provided and export
granted references to the pages of that dma-buf into the array
of grant references.
2. Add API to close all references to an imported buffer, so it can be
released by the owner. This is only valid for buffers created with
IOCTL_GNTDEV_DMABUF_IMP_TO_REFS.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
1. Create a dma-buf from grant references provided by the foreign
domain. By default dma-buf is backed by system memory pages, but
by providing GNTDEV_DMA_FLAG_XXX flags it can also be created
as a DMA write-combine/coherent buffer, e.g. allocated with
corresponding dma_alloc_xxx API.
Export the resulting buffer as a new dma-buf.
2. Implement waiting for the dma-buf to be released: block until the
dma-buf with the file descriptor provided is released.
If within the time-out provided the buffer is not released then
-ETIMEDOUT error is returned. If the buffer with the file descriptor
does not exist or has already been released, then -ENOENT is
returned. For valid file descriptors this must not be treated as
error.
3. Make gntdev's common code and structures available to dma-buf.
[boris: added 'args.fd = -1' to dmabuf_exp_from_refs() to avoid an
unnecessary warning about it not being initialized on i386 with gcc 8.1.1]
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Add UAPI and IOCTLs for dma-buf grant device driver extension:
the extension allows userspace processes and kernel modules to
use Xen backed dma-buf implementation. With this extension grant
references to the pages of an imported dma-buf can be exported
for other domain use and grant references coming from a foreign
domain can be converted into a local dma-buf for local export.
Implement basic initialization and stubs for Xen DMA buffers'
support.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Juergen Gross