The mdev attribute "name" is required by some middle software, e.g.
KubeVirt, an open source SW that manages VM on Kubernetes cluster uses
the mdev sysfs directory/file structure to discover mediated device in
nodes in the cluster.

v2:

- Fix the missing defination in gvt_type_attrs. (Zhenyu)

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Hui Chun Ong <hui.chun.ong@intel.com>
Cc: Terrence Xu <terrence.xu@intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NZhi Wang <zhi.wang.linux@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220222150532.9090-1-zhi.a.wang@intel.comReviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>

As the excessive #includes from i915_drv.h were axed, kvmgt.c build
started failing. Add the necessary #include where needed.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Fixes: 14da21cc ("drm/i915: axe lots of unnecessary includes from i915_drv.h")
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: intel-gvt-dev@lists.freedesktop.org
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NZhi Wang <zhi.a.wang@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220215122030.2741656-1-jani.nikula@intel.com

Replace direction definition PCI_DMA_BIDIRECTIONAL
with DMA_BIDIRECTIONAL, because it helps to enhance readability
and avoid possible inconsistency.
Signed-off-by: NCai Huoqing <caihuoqing@baidu.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210925124613.144-1-caihuoqing@baidu.com

The user can open multiple device FDs if it likes, however the open
function calls vfio_register_notifier() on device global state. Calling
vfio_register_notifier() twice will trigger a WARN_ON from
notifier_chain_register() and the first close will wrongly delete the
notifier and more.

Since these really want the new open/close_device() semantics just change
the function over.
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/13-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.comSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>

There is no need to keep the dentry around for the debugfs kvmgt cache
file, as we can just look it up when we want to remove it later on.
Simplify the structure by removing the dentry and relying on debugfs
to find the dentry to remove when we want to.

By doing this change, we remove the last in-kernel user that was storing
the result of debugfs_create_long(), so that api can be cleaned up.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gvt-dev@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210518161705.3697143-1-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As kvmgt module contains all handling for VFIO/mdev, leaving mdev attribute
groups in gvt module caused dependency issue. Although it was there for possible
other hypervisor usage, that turns out never to be true. So this moves all mdev
handling into kvmgt module completely to resolve dependency issue.

With this fix, no config workaround is required. So revert previous workaround
commits: adaeb718 ("vfio/gvt: fix DRM_I915_GVT dependency on VFIO_MDEV")
and 07e543f4 ("vfio/gvt: Make DRM_I915_GVT depend on VFIO_MDEV").
Reviewed-by: NColin Xu <colin.xu@intel.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210513083902.2822350-1-zhenyuw@linux.intel.com

The kobj here is a type-erased version of mdev_type, which is already
stored in the struct mdev_device being passed in. It was only ever used to
compute the type_group_id, which is now extracted directly from the mdev.
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Message-Id: <17-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

intel_gvt_init_vgpu_type_groups() makes gvt->types 1:1 with the
supported_type_groups array, so the type_group_id is also the index into
gvt->types. Use it directly and remove the string matching.
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Message-Id: <16-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Adjust the KVMGT page tracking callbacks.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: intel-gvt-dev@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Using struct drm_device.pdev is deprecated. Convert i915 to struct
drm_device.dev. No functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210128133127.2311-4-tzimmermann@suse.de

The current interface of intel_gvt_register_hypervisor() expects a
non-const pointer to struct intel_gvt_mpt, even though the mediator
never modifies (or should modifiy) the content of this struct.

Change the function signature and relevant struct members to const to
properly express the API's intent and allow instances of intel_gvt_mpt
to be allocated as const.

While I was here, I also made KVM's instance of this struct const to
reduce the number of writable function pointers in the kernel.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: intel-gvt-dev@lists.freedesktop.org
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJulian Stecklina <julian.stecklina@cyberus-technology.de>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20201111172811.558443-1-julian.stecklina@cyberus-technology.de

When we fail to take the module reference, we go to the 'undo*' branch and
return. But the returned variable 'ret' has been set as zero by the
above code. Change 'ret' to '-ENODEV' in this situation.

Fixes: 9bdb0734 ("drm/i915/gvt: Change KVMGT as self load module")
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1605187352-51761-1-git-send-email-wangxiongfeng2@huawei.com

Patch series "improve use_mm / unuse_mm", v2.

This series improves the use_mm / unuse_mm interface by better documenting
the assumptions, and my taking the set_fs manipulations spread over the
callers into the core API.

This patch (of 3):

Use the proper API instead.

Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de

These helpers are only for use with kernel threads, and I will tie them
more into the kthread infrastructure going forward.  Also move the
prototypes to kthread.h - mmu_context.h was a little weird to start with
as it otherwise contains very low-level MM bits.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NJens Axboe <axboe@kernel.dk>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: http://lkml.kernel.org/r/20200404094101.672954-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200416053158.586887-1-hch@lst.de
Link: http://lkml.kernel.org/r/20200404094101.672954-5-hch@lst.deSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

substitute vfio_pin_pages() and vfio_unpin_pages() with
vfio_group_pin_pages() and vfio_group_unpin_pages(), so that
it will not go through looking up, checking, referencing,
dereferencing of VFIO group in each call.
Signed-off-by: NYan Zhao <yan.y.zhao@intel.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200313031151.8042-1-yan.y.zhao@intel.com

As a device model, it is better to read/write guest memory using vfio
interface, so that vfio is able to maintain dirty info of device IOVAs.

Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: NYan Zhao <yan.y.zhao@intel.com>
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200313031109.7989-1-yan.y.zhao@intel.com

hold reference count of the VFIO group for each vgpu at vgpu opening and
release the reference at vgpu releasing.
Signed-off-by: NYan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Zhenyu Wang<zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang<zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200313031025.7936-1-yan.y.zhao@intel.com

Teach gvt to use intel_gt directly as it currently assumes direct HW
access.

[Zhenyu: rebase, fix compiling]

Cc: Ding Zhuocheng <zhuocheng.ding@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200304032307.2983-3-zhenyuw@linux.intel.com

Drm specific drm_WARN* calls include device information in the
backtrace, so we know what device the warnings originate from.

Covert all the calls of WARN* with device specific drm_WARN*
variants in functions where drm_device struct pointer is readily
available.

The conversion was done automatically with below coccinelle semantic
patch. checkpatch errors/warnings are fixed manually.

@@
identifier func, T;
@@
func(struct intel_vgpu *T,...) {
+struct drm_i915_private *i915 = T->gvt->dev_priv;
<+...
(
-WARN(
+drm_WARN(&i915->drm,
...)
|
-WARN_ON(
+drm_WARN_ON(&i915->drm,
...)
|
-WARN_ONCE(
+drm_WARN_ONCE(&i915->drm,
...)
|
-WARN_ON_ONCE(
+drm_WARN_ON_ONCE(&i915->drm,
...)
)
...+>

}
Signed-off-by: NPankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200220165507.16823-9-pankaj.laxminarayan.bharadiya@intel.com

Instead of defining KVMGT per-device state in struct intel_vgpu
directly, add an indirection. This makes the GVT code oblivious of
what state KVMGT needs to keep.

The intention here is to eventually make it possible to build
hypervisor backends for the mediator, without having to touch the
mediator itself. This is a first step.

v2:
- rebased onto gvt-staging (no conflicts)
Signed-off-by: NJulian Stecklina <julian.stecklina@cyberus-technology.de>
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200217163858.26496-1-julian.stecklina@cyberus-technology.de

This variable is used nowhere, so remove it.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJulian Stecklina <julian.stecklina@cyberus-technology.de>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200109171357.115936-3-julian.stecklina@cyberus-technology.de

Dma-buf display uses the vgpu dma address saved in the guest part GGTT
table which is updated by vCPU thread. In host side, when the dma
address is used by qemu ui thread, gvt-g must make sure the dma address
is validated before letting it go to the HW. Invalid guest dma address
will easily cause DMA fault and make GPU hang.

v2: Rebase

Fixes: e546e281 ("drm/i915/gvt: Dmabuf support for GVT-g")
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NTina Zhang <tina.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20191212141342.3417-1-tina.zhang@intel.com

Only need to get attribute group instead of attributes and it has
no use, so remove it.
Reviewed-by: NYan Zhao <yan.y.zhao@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20191202070109.73924-1-zhenyuw@linux.intel.com

With the introduction of ctx->engines[] we allow multiple logical
contexts to be used on the same engine (e.g. with virtual engines).
According to bspec, aach logical context requires a unique tag in order
for context-switching to occur correctly between them. [Simple
experiments show that it is not so easy to trick the HW into performing
a lite-restore with matching logical IDs, though my memory from early
Broadwell experiments do suggest that it should be generating
lite-restores.]

We only need to keep a unique tag for the active lifetime of the
context, and for as long as we need to identify that context. The HW
uses the tag to determine if it should use a lite-restore (why not the
LRCA?) and passes the tag back for various status identifies. The only
status we need to track is for OA, so when using perf, we assign the
specific context a unique tag.

v2: Calculate required number of tags to fill ELSP.

Fixes: 976b55f0 ("drm/i915: Allow a context to define its set of engines")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111895Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-14-chris@chris-wilson.co.uk

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Because there is no need to check these functions, a number of local
functions can be made to return void to simplify things as nothing can
fail.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gvt-dev@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace the following form:

sizeof(*sparse) + (nr_areas * sizeof(*sparse->areas)

with:

struct_size(sparse, areas, sparse->nr_areas)

and so on...

Also, notice that variable size is unnecessary, hence it is removed.

This code was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

GPU hang observed during the guest OCL conformance test which is caused
by THP GTT feature used durning the test.

It was observed the same GFN with different size (4K and 2M) requested
from the guest in GVT. So during the guest page dma map stage, it is
required to unmap first with orginal size and then remap again with
requested size.

Fixes: b901b252 ("drm/i915/gvt: Add 2M huge gtt support")
Cc: stable@vger.kernel.org
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NXiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Our eventual goal is to rid request construction of struct_mutex, with
the short term step of lifting the struct_mutex requirements into the
higher levels (i.e. the caller must ensure that the context is already
pinned into the GTT). In this patch, we pin GVT's shadow context upon
allocation and so keep them pinned into the GGTT for as long as the
virtual machine is alive, and so we can use the simpler request
construction path safe in the knowledge that the hard work is already
done.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426163336.15906-1-chris@chris-wilson.co.uk

Fix the sparse warning for blithely using iomem with normal memcpy:

drivers/gpu/drm/i915/gvt/kvmgt.c:916:21: warning: incorrect type in assignment (different address spaces)
drivers/gpu/drm/i915/gvt/kvmgt.c:916:21:    expected void *aperture_va
drivers/gpu/drm/i915/gvt/kvmgt.c:916:21:    got void [noderef] <asn:2> *
drivers/gpu/drm/i915/gvt/kvmgt.c:927:26: warning: incorrect type in argument 1 (different address spaces)
drivers/gpu/drm/i915/gvt/kvmgt.c:927:26:    expected void [noderef] <asn:2> *vaddr
drivers/gpu/drm/i915/gvt/kvmgt.c:927:26:    got void *aperture_va

Fixes: d480b28a ("drm/i915/gvt: Fix aperture read/write emulation when enable x-no-mmap=on")
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Implement VFIO EDID region for vgpu. Support EDID blob update and notify
guest on link state change via hotplug event.

v3: move struct edid_region to kvmgt.c <zhenyu>
v2: add EDID sanity check and size update <zhenyu>
Tested-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NHang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Mixed C99 and kernel types use is getting ugly. Prefer kernel types.

sed -i 's/\buint\(8\|16\|32\|64\)_t\b/u\1/g'
Acked-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

This is to fix missed mmap range check on vGPU bar2 region
and only allow to map vGPU allocated GMADDR range, which means
user space should support sparse mmap to get proper offset for
mmap vGPU aperture. And this takes care of actual pgoff in mmap
request as original code always does from beginning of vGPU
aperture.

Fixes: 659643f7 ("drm/i915/gvt/kvmgt: add vfio/mdev support to KVMGT")
Cc: "Monroy, Rodrigo Axel" <rodrigo.axel.monroy@intel.com>
Cc: "Orrala Contreras, Alfredo" <alfredo.orrala.contreras@intel.com>
Cc: stable@vger.kernel.org # v4.10+
Reviewed-by: NHang Yuan <hang.yuan@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

VFIO region space is allocated when one region is registered for
one vgpu. So free the space when destroy the vgpu.

Also change the parameter of detach_vgpu callback to use vgpu directly.

Fixes: b851adea ("drm/i915/gvt: Add opregion support")
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NHang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

This trys to make 'kvmgt' module as self loadable instead of loading
by i915/gvt device model. So hypervisor specific module could be
stand-alone, e.g only after loading hypervisor specific module, GVT
feature could be enabled via specific hypervisor interface, e.g VFIO/mdev.

So this trys to use hypervisor module register/unregister interface
for that. Hypervisor module needs to take care of module reference
itself when working for hypervisor interface, e.g for VFIO/mdev,
hypervisor module would reference counting mdev when open and release.

This makes 'kvmgt' module really split from GVT device model. User
needs to load 'kvmgt' to enable VFIO/mdev interface.

v6:
- remove unused variable

v5:
- put module reference in register error path

v4:
- fix checkpatch warning

v3:
- Fix module reference handling for device open and release. Unused
  mdev devices would be cleaned up in device unregister when module unload.

v2:
- Fix kvmgt order after i915 for built-in case

Cc: "Yuan, Hang" <hang.yuan@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: "He, Min" <min.he@intel.com>
Reviewed-by: NYuan, Hang <hang.yuan@intel.com>
Acked-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The parameter 'void *gvt' is not used and required for hypervisor's
exit call. Even for non-merged Xen hypervisor support. So just remove it.
Reviewed-by: NYuan, Hang <hang.yuan@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Fix the suspicious RCU usage issue in intel_vgpu_emulate_mmio_write.
Here need to request the srcu read lock of kvm->srcu before doing
gfn_to_memslot(). The detailed log is as below:
[  218.710688] =============================
[  218.710690] WARNING: suspicious RCU usage
[  218.710693] 4.14.15-dd+ #314 Tainted: G     U
[  218.710695] -----------------------------
[  218.710697] ./include/linux/kvm_host.h:575 suspicious rcu_dereference_check() usage!
[  218.710699]
               other info that might help us debug this:

[  218.710702]
               rcu_scheduler_active = 2, debug_locks = 1
[  218.710704] 1 lock held by qemu-system-x86/2144:
[  218.710706]  #0:  (&gvt->lock){+.+.}, at: [<ffffffff816a1eea>] intel_vgpu_emulate_mmio_write+0x5a/0x2d0
[  218.710721]
               stack backtrace:
[  218.710724] CPU: 0 PID: 2144 Comm: qemu-system-x86 Tainted: G     U 4.14.15-dd+ #314
[  218.710727] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.1.1 10/07/2015
[  218.710729] Call Trace:
[  218.710734]  dump_stack+0x7c/0xb3
[  218.710739]  gfn_to_memslot+0x15f/0x170
[  218.710743]  kvm_is_visible_gfn+0xa/0x30
[  218.710746]  intel_vgpu_emulate_gtt_mmio_write+0x267/0x3c0
[  218.710751]  ? __mutex_unlock_slowpath+0x3b/0x260
[  218.710754]  intel_vgpu_emulate_mmio_write+0x182/0x2d0
[  218.710759]  intel_vgpu_rw+0xba/0x170 [kvmgt]
[  218.710763]  intel_vgpu_write+0x14d/0x1a0 [kvmgt]
[  218.710767]  __vfs_write+0x23/0x130
[  218.710770]  vfs_write+0xb0/0x1b0
[  218.710774]  SyS_pwrite64+0x73/0x90
[  218.710777]  entry_SYSCALL_64_fastpath+0x25/0x9c
[  218.710780] RIP: 0033:0x7f33e8a91da3
[  218.710783] RSP: 002b:00007f33dddc8700 EFLAGS: 00000293

v2: add 'Fixes' tag, refine log format.(Zhenyu)
Fixes: cc753fbe ("drm/i915/gvt: validate gfn before set shadow page")
Reviewed-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NWeinan Li <weinan.z.li@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Handle guest mm access life cycle properly with mmget()/mmput().
As noted by Linus, use_mm() depends on valid live page table but
KVM's mmgrab() doesn't guarantee that. As vGPU usage depends on
guest VM life cycle, need to make sure to use mmget()/mmput() to
guarantee VM address access.

v3: fix build

v2: v1 caused a weird dependence issue which failed for vfio
device release, which result invalid mdev vgpu and kvm state
without proper release taken. This trys to put right reference
around VM address space access instead.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: NZhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The 'sparse' variable may leak when return in function
intel_vgpu_ioctl(), and this patch fix this.
Signed-off-by: NYi Wang <wang.yi59@zte.com.cn>
Reviewed-by: NJiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

info.index can be indirectly controlled by user-space, hence leading
to a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/gpu/drm/i915/gvt/kvmgt.c:1232 intel_vgpu_ioctl() warn:
potential spectre issue 'vgpu->vdev.region' [r]

Fix this by sanitizing info.index before indirectly using it to index
vgpu->vdev.region

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Cc: stable@vger.kernel.org
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Currently, the mutex used in GVT dmabuf support is not initialized until
vgpu device is opened. If one vgpu device is opened and then removed, the
mutex will be used in vgpu remove operation without initialization. This
patch initializes the mutex in vgpu create operation to avoid the problem.

Fixes: e546e281("drm/i915/gvt: Dmabuf support for GVT-g")
Signed-off-by: NHang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Some workloads may be prepared in vgpu's queue but not be scheduled
to run yet. If vgpu is released at this time, they will not be freed
in workload complete callback and so need to be freed in vgpu release
operation.

Add new vgpu_release operation in gvt_ops to stop vgpu and release
runtime resources. gvt_ops vgpu_deactivate operation will only stop
vgpu.

v2: add new gvt ops to clean vgpu running status (Xiong Zhang)
Signed-off-by: NHang Yuan <hang.yuan@linux.intel.com>
Reviewed-by: NXiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>