Re: [PATCH 10/35] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS
From: Dave Hansen <hidden>
Date: 2022-02-09 16:58:44
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On 1/30/22 13:18, Rick Edgecombe wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c index 99d1781fa5f0..75ce4e823902 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c@@ -1210,7 +1210,7 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu, } /* Clear dirty field. */ - se->val64 &= ~_PAGE_DIRTY; + se->val64 &= ~_PAGE_DIRTY_BITS; ops->clear_pse(se); ops->clear_ips(se);
Are these x86 CPU page table values? I see ->val64 being used like this:
e->val64 &= ~GEN8_PAGE_PRESENT;
and
se.val64 |= GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
where we also have:
#define GEN8_PAGE_PRESENT BIT_ULL(0)
#define GEN8_PAGE_RW BIT_ULL(1)
Which tells me that these are probably *close* to the CPU's page tables.
But, I honestly don't know which format they are. I don't know if
_PAGE_COW is still a software bit in that format or not.
Either way, I don't think we should be messing with i915 device page tables.
Or, are these somehow magically shared with the CPU in some way I don't
know about?
[ If these are device-only page tables, it would probably be nice to
stop using _PAGE_FOO for them. It would avoid confusion like this. ]