Re: [Xen-devel] [Intel-gfx] [PATCH] drm/i915: fix i915 running as dom0 under Xen
On Thu, Feb 02, 2017 at 11:48:21AM +0100, Daniel Vetter wrote:
> On Thu, Feb 02, 2017 at 10:47:11AM +0100, Juergen Gross wrote:
> > Commit 920cf4194954ec ("drm/i915: Introduce an internal allocator for
> > disposable private objects") introduced a regression for the kernel
> > running as Xen dom0: when switching to graphics mode a GPU HANG
> > occurred.
> >
> > Reason seems to be a missing adaption similar to that done in
> > commit 7453c549f5f648 ("swiotlb: Export swiotlb_max_segment to users")
> > to i915_gem_object_get_pages_internal().
> >
> > So limit the maximum page order to be used according to the maximum
> > swiotlb segment size instead to the complete swiotlb size.
> >
> > Signed-off-by: Juergen Gross
> Fixes: 920cf4194954 ("drm/i915: Introduce an internal allocator for
> disposable private objects")
> Cc: Chris Wilson
> Cc: Tvrtko Ursulin
> Cc: Daniel Vetter
> Cc: Jani Nikula
> Cc: intel-...@lists.freedesktop.org
> Cc: # v4.10-rc1+
>
> We have a nice script for these :-)
Pffifle. 7453c549f5f648 allowed Xen to change it and silently conflicted
with those that already used the previous limits, which didn't land in
our tree until v4.10-rc3.
-Chris
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Re: [Xen-devel] [Intel-gfx] [PATCH] drm/i915: fix i915 running as dom0 under Xen
On Thu, Feb 02, 2017 at 12:11:29PM +, Tvrtko Ursulin wrote:
>
> On 02/02/2017 09:47, Juergen Gross wrote:
> >Commit 920cf4194954ec ("drm/i915: Introduce an internal allocator for
> >disposable private objects") introduced a regression for the kernel
> >running as Xen dom0: when switching to graphics mode a GPU HANG
> >occurred.
> >
> >Reason seems to be a missing adaption similar to that done in
> >commit 7453c549f5f648 ("swiotlb: Export swiotlb_max_segment to users")
> >to i915_gem_object_get_pages_internal().
> >
> >So limit the maximum page order to be used according to the maximum
> >swiotlb segment size instead to the complete swiotlb size.
> >
> >Signed-off-by: Juergen Gross
> >---
> >Please consider for 4.10 as otherwise 4.10 will be unusable as Xen dom0
> >with i915 graphics.
> >---
> > drivers/gpu/drm/i915/i915_gem_internal.c | 12 ++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> >diff --git a/drivers/gpu/drm/i915/i915_gem_internal.c
> >b/drivers/gpu/drm/i915/i915_gem_internal.c
> >index 4b3ff3e..d09c749 100644
> >--- a/drivers/gpu/drm/i915/i915_gem_internal.c
> >+++ b/drivers/gpu/drm/i915/i915_gem_internal.c
> >@@ -66,8 +66,16 @@ i915_gem_object_get_pages_internal(struct
> >drm_i915_gem_object *obj)
> >
> > max_order = MAX_ORDER;
> > #ifdef CONFIG_SWIOTLB
> >-if (swiotlb_nr_tbl()) /* minimum max swiotlb size is IO_TLB_SEGSIZE */
> >-max_order = min(max_order, ilog2(IO_TLB_SEGPAGES));
> >+if (swiotlb_nr_tbl()) {
> >+unsigned int max_segment;
> >+
> >+max_segment = swiotlb_max_segment();
> >+if (max_segment) {
> >+max_segment = max_t(unsigned int, max_segment,
> >+PAGE_SIZE) >> PAGE_SHIFT;
> >+max_order = min(max_order, ilog2(max_segment));
> >+}
> >+}
> > #endif
> >
> > gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_RECLAIMABLE;
> >
>
> Looks OK to me. We could bikeshed it to only use
> swiotlb_max_segment() which I think was the intention when that API
> was added but can leave that for the future.
>
> Reviewed-by: Tvrtko Ursulin
Pushed, I imagine this has been added to the list of sg cleanups you
have :)
-Chris
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Re: [Xen-devel] [Intel-gfx] [Announcement] 2015-Q3 release of XenGT - a Mediated Graphics Passthrough Solution from Intel
On Tue, Nov 24, 2015 at 12:19:18PM +0100, Daniel Vetter wrote: > Downside: Tracking mapping changes on the guest side won't be any easier. > This is mostly a problem for integrated gpus, since discrete ones usually > require contiguous vram for scanout. I think saying "don't do that" is a > valid option though, i.e. we're assuming that page mappings for a in-use > scanout range never changes on the guest side. That is true for at least > all the current linux drivers. Apart from we already suffer limitations of fixed mappings and have patches that want to change the page mapping of active scanouts. -Chris -- Chris Wilson, Intel Open Source Technology Centre ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
