These are the new priviledged interfaces to the VMM backends, and expose
some functionality that wasn't previously available.
It's now possible to allocate a chunk of address-space (even all of it),
without causing page tables to be allocated up-front, and then map into
it at arbitrary locations. This is the basic primitive used to support
features such as sparse mapping, or to allow userspace control over its
own address-space, or HMM (where the GPU driver isn't in control of the
address-space layout).
Rather than being tied to a subtle combination of memory object and VMA
properties, arguments that control map flags (ro, kind, etc) are passed
explicitly at map time.
The compatibility hacks to implement the old frontend on top of the new
driver backends have been replaced with something similar to implement
the old frontend's interfaces on top of the new frontend.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This is the common code to support a rework of the VMM backends.
It adds support for more than 2 levels of page table nesting, which
is required to be able to support GP100's MMU layout.
Sparse mappings (that don't cause MMU faults when accessed) are now
supported, where the backend provides it.
Dual-PT handling had to become more sophisticated to support sparse,
but this also allows us to support an optimisation the MMU provides
on GK104 and newer.
Certain operations can now be combined into a single page tree walk
to avoid some overhead, but also enables optimsations like skipping
PTE unmap writes when the PT will be destroyed anyway.
The old backend has been hacked up to forward requests onto the new
backend, if present, so that it's possible to bisect between issues
in the backend changes vs the upcoming frontend changes.
Until the new frontend has been merged, new backends will leak BAR2
page tables on module unload. This is expected, and it's not worth
the effort of hacking around this as it doesn't effect runtime.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
We previously required each VMM user to allocate their own page directory
and fill in the instance block themselves.
It makes more sense to handle this in a common location.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This is the first chunk of the new VMM code that provides the structures
needed to describe a GPU virtual address-space layout, as well as common
interfaces to handle VMM creation, and connecting instances to a VMM.
The constructor now allocates the PD itself, rather than having the user
handle that manually. This won't/can't be used until after all backends
have been ported to these interfaces, so a little bit of memory will be
wasted on Fermi and newer for a couple of commits in the series.
Compatibility has been hacked into the old code to allow each GPU backend
to be ported individually.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
GP100 "big" (which is a funny name, when it supports "even bigger") page
tables are small enough that we want to be able to suballocate them from
a larger block of memory.
This builds on the previous page table cache interfaces so that the VMM
code doesn't need to know the difference.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Builds up and maintains a small cache of each page table size in order
to reduce the frequency of expensive allocations, particularly in the
pathological case where an address range ping-pongs between allocated
and free.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Removes the need to expose internals outside of MMU, and GP100 is both
different, and a lot harder to deal with.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
We need to be able to prevent memory from being freed while it's still
mapped in a GPU's address-space.
Will be used by upcoming MMU changes.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Different sections of VRAM may have different properties (ie. can't be used
for compression/display, can't be mapped, etc).
We currently already support this, but it's a bit magic. This change makes
it more obvious where we're allocating from.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Even though we've zeroed the PDE, the GPU may have cached the PD, so we
need to flush when deleting them.
Noticed while working on replacement MMU code, but a backport might be a
good idea, so let's fix it in the current code too.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org
We never have any need for a double-linked list here, and as there's
generally a large number of these objects, replace it with a single-
linked list in order to save some memory.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
An upcoming commit requires being able to modify the PRAMIN BAR page
tables while already holding the MMU subdev mutex.
To solve this issue, each VM has been given its own mutex. As a nice
side-effect, this also allows separate VMs to be updated concurrently.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
The namespace of NVKM is being changed to nvkm_ instead of nouveau_,
which will be used for the DRM part of the driver. This is being
done in order to make it very clear as to what part of the driver a
given symbol belongs to, and as a minor step towards splitting the
DRM driver out to be able to stand on its own (for virt).
Because there's already a large amount of churn here anyway, this is
as good a time as any to also switch to NVIDIA's device and chipset
naming to ease collaboration with them.
A comparison of objdump disassemblies proves no code changes.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Switch to NVIDIA's name for the device.
The namespace of NVKM is being changed to nvkm_ instead of nouveau_,
which will be used for the DRM part of the driver. This is being
done in order to make it very clear as to what part of the driver a
given symbol belongs to, and as a minor step towards splitting the
DRM driver out to be able to stand on its own (for virt).
Because there's already a large amount of churn here anyway, this is
as good a time as any to also switch to NVIDIA's device and chipset
naming to ease collaboration with them.
A comparison of objdump disassemblies proves no code changes.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Ben Skeggs