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authorPaolo Bonzini <pbonzini@redhat.com>2023-12-22 09:48:35 +0100
committerMichael Tokarev <mjt@tls.msk.ru>2024-02-28 21:19:03 +0300
commitdecafac46bec616add565fcfa71ce0184850f79b (patch)
tree64c68e06732bebabfb0e79dad297094444f3a6ee /target/i386
parent6801a20ebd0e541f45855665a75571d4d24188a0 (diff)
target/i386: leave the A20 bit set in the final NPT walk
The A20 mask is only applied to the final memory access. Nested page tables are always walked with the raw guest-physical address. Unlike the previous patch, in this one the masking must be kept, but it was done too early. Cc: qemu-stable@nongnu.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 b5a9de3259f4c791bde2faff086dd5737625e41e) Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Diffstat (limited to 'target/i386')
-rw-r--r--target/i386/tcg/sysemu/excp_helper.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/target/i386/tcg/sysemu/excp_helper.c b/target/i386/tcg/sysemu/excp_helper.c
index 89df61eec6..e16d3a69d1 100644
--- a/target/i386/tcg/sysemu/excp_helper.c
+++ b/target/i386/tcg/sysemu/excp_helper.c
@@ -134,7 +134,6 @@ static inline bool ptw_setl(const PTETranslate *in, uint32_t old, uint32_t set)
static bool mmu_translate(CPUX86State *env, const TranslateParams *in,
TranslateResult *out, TranslateFault *err)
{
- const int32_t a20_mask = x86_get_a20_mask(env);
const target_ulong addr = in->addr;
const int pg_mode = in->pg_mode;
const bool is_user = (in->mmu_idx == MMU_USER_IDX);
@@ -417,10 +416,13 @@ do_check_protect_pse36:
}
}
- /* align to page_size */
- paddr = (pte & a20_mask & PG_ADDRESS_MASK & ~(page_size - 1))
- | (addr & (page_size - 1));
+ /* merge offset within page */
+ paddr = (pte & PG_ADDRESS_MASK & ~(page_size - 1)) | (addr & (page_size - 1));
+ /*
+ * Note that NPT is walked (for both paging structures and final guest
+ * addresses) using the address with the A20 bit set.
+ */
if (in->ptw_idx == MMU_NESTED_IDX) {
CPUTLBEntryFull *full;
int flags, nested_page_size;
@@ -459,7 +461,7 @@ do_check_protect_pse36:
}
}
- out->paddr = paddr;
+ out->paddr = paddr & x86_get_a20_mask(env);
out->prot = prot;
out->page_size = page_size;
return true;