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[Stable-7.2.10 41/47] target/i386: mask high bits of CR3 in 32-bit mode


From: Michael Tokarev
Subject: [Stable-7.2.10 41/47] target/i386: mask high bits of CR3 in 32-bit mode
Date: Wed, 28 Feb 2024 23:35:09 +0300

From: Paolo Bonzini <pbonzini@redhat.com>

CR3 bits 63:32 are ignored in 32-bit mode (either legacy 2-level
paging or PAE paging).  Do this in mmu_translate() to remove
the last where get_physical_address() meaningfully drops the high
bits of the address.

Cc: qemu-stable@nongnu.org
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Fixes: 4a1e9d4d11c ("target/i386: Use atomic operations for pte updates", 
2022-10-18)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 68fb78d7d5723066ec2cacee7d25d67a4143b42f)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/target/i386/tcg/sysemu/excp_helper.c 
b/target/i386/tcg/sysemu/excp_helper.c
index 55bd1194d3..c253226b3c 100644
--- a/target/i386/tcg/sysemu/excp_helper.c
+++ b/target/i386/tcg/sysemu/excp_helper.c
@@ -236,7 +236,7 @@ static bool mmu_translate(CPUX86State *env, const 
TranslateParams *in,
             /*
              * Page table level 3
              */
-            pte_addr = ((in->cr3 & ~0x1f) + ((addr >> 27) & 0x18)) & a20_mask;
+            pte_addr = ((in->cr3 & 0xffffffe0ULL) + ((addr >> 27) & 0x18)) & 
a20_mask;
             if (!ptw_translate(&pte_trans, pte_addr)) {
                 return false;
             }
@@ -304,7 +304,7 @@ static bool mmu_translate(CPUX86State *env, const 
TranslateParams *in,
         /*
          * Page table level 2
          */
-        pte_addr = ((in->cr3 & ~0xfff) + ((addr >> 20) & 0xffc)) & a20_mask;
+        pte_addr = ((in->cr3 & 0xfffff000ULL) + ((addr >> 20) & 0xffc)) & 
a20_mask;
         if (!ptw_translate(&pte_trans, pte_addr)) {
             return false;
         }
-- 
2.39.2




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