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[xen master] x86/p2m-pt: fix off by one in entry check assert
commit 610775d0dd61c1bd2f4720c755986098e6a5bafd
Author: Roger Pau Monné <roger.pau@citrix.com>
AuthorDate: Thu Jan 25 16:09:04 2024 +0100
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Thu Jan 25 16:09:04 2024 +0100

x86/p2m-pt: fix off by one in entry check assert

The MMIO RO rangeset overlap check is bogus: the rangeset is inclusive so the
passed end mfn should be the last mfn to be mapped (not last + 1).

Fixes: 6fa1755644d0 ('amd/npt/shadow: replace assert that prevents creating 2M/1G MMIO entries')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@cloud.com>
---
xen/arch/x86/mm/p2m-pt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index 640a11f564..348130d0dd 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -552,7 +552,7 @@ static void check_entry(mfn_t mfn, p2m_type_t new, p2m_type_t old,
if ( new == p2m_mmio_direct )
ASSERT(!mfn_eq(mfn, INVALID_MFN) &&
!rangeset_overlaps_range(mmio_ro_ranges, mfn_x(mfn),
- mfn_x(mfn) + (1UL << order)));
+ mfn_x(mfn) + (1UL << order) - 1));
else if ( p2m_allows_invalid_mfn(new) || new == p2m_invalid ||
new == p2m_mmio_dm )
ASSERT(mfn_valid(mfn) || mfn_eq(mfn, INVALID_MFN));
--
generated by git-patchbot for /home/xen/git/xen.git#master