On Wed, Apr 05, 2023 at 09:55:59AM +0200, Juergen Gross wrote:
On 03.04.23 18:03, Borislav Petkov wrote:
On Sat, Apr 01, 2023 at 08:36:40AM +0200, Juergen Gross wrote:
@@ -643,10 +646,12 @@ static bool set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr)
unsigned int lo, hi;
bool changed = false;
+#define BASE_MASK (MTRR_BASE_TYPE_MASK | (size_and_mask << PAGE_SHIFT))
+#define MASK_MASK (MTRR_MASK_VALID | (size_and_mask << PAGE_SHIFT))
No, "MASK_MASK" is too much. :-)
Any better suggestion for the name? :-)
Looking at this again, what this is actually doing is masking out the
reserved bits. But in an unnecessarily complicated way.
What it should do, instead, is do that explicitly:
/* Zap the reserved bits and compare only the valid fields: */
if (((vr->base_lo & ~RESV_LOW) != (lo & ~RESV_LOW)) ||
((vr->base_hi & ~RESV_HI) != (hi & ~RESV_HI)))
where
#define RESV_LOW GENMASK_ULL(8, 11)
#define RESV_HI GENMASK(phys_addr - 1, 63)
and then we can get rid of that size_or_mask and size_and_mask
stupidity.
I think that would simplify this variable ranges handling code a lot
more and make it pretty straightforward...
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