[xen stable-4.17] x86/p2m-pt: fix off by one in entry check assert

[patchbot@xxxxxxx]

commit 091466ba55d1e2e75738f751818ace2e3ed08ccf
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Fri Feb 2 08:04:33 2024 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Feb 2 08:04:33 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@xxxxxxxxxx>
    Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxx>
    master commit: 610775d0dd61c1bd2f4720c755986098e6a5bafd
    master date: 2024-01-25 16:09:04 +0100
---
 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 eaba2b0fb4..f02ebae372 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -564,7 +564,7 @@ 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#stable-4.17