0010-x86-p2m-pt-fix-off-by-one-in-entry-check-assert.patch


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From 091466ba55d1e2e75738f751818ace2e3ed08ccf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau@citrix.com>
Date: Fri, 2 Feb 2024 08:04:33 +0100
Subject: [PATCH 10/10] x86/p2m-pt: fix off by one in entry check assert
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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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>
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));
-- 
2.43.0