BEHAVIOUR CHANGE
Currently if ppc_hash{32,64}_translate() finds a PTE matching the given
virtual address, it will always update the PTE's R & C (Referenced and
Changed) bits. This happens even if the PTE's permissions mean we are
about to deny the translation.
This is clearly a bug, although we get away with it because:
a) It will only incorrectly set, never reset the bits, which should not
cause guest correctness problems.
b) Linux guests never use the R & C bits anyway.
This patch fixes the behaviour, only updating R & C when access is granted
by the PTE.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
ctx->raddr = pte.pte1;
ctx->prot = access;
ret = ppc_hash32_check_prot(ctx->prot, rwx);
- if (ret == 0) {
- /* Access granted */
- LOG_MMU("PTE access granted !\n");
- } else {
+
+ if (ret) {
/* Access right violation */
LOG_MMU("PTE access rejected\n");
+ return ret;
}
- /* Update page flags */
+ LOG_MMU("PTE access granted !\n");
+
+ /* 8. Update PTE referenced and changed bits if necessary */
+
if (ppc_hash32_pte_update_flags(ctx, &pte.pte1, ret, rwx) == 1) {
ppc_hash32_store_hpte1(env, pte_offset, pte.pte1);
}
ctx->raddr = pte.pte1;
ctx->prot = access;
ret = ppc_hash64_check_prot(ctx->prot, rwx);
- if (ret == 0) {
- /* Access granted */
- LOG_MMU("PTE access granted !\n");
- } else {
+
+ if (ret) {
/* Access right violation */
LOG_MMU("PTE access rejected\n");
+ return ret;
}
- /* Update page flags */
+ LOG_MMU("PTE access granted !\n");
+
+ /* 6. Update PTE referenced and changed bits if necessary */
+
if (ppc_hash64_pte_update_flags(ctx, &pte.pte1, ret, rwx) == 1) {
ppc_hash64_store_hpte1(env, pte_offset, pte.pte1);
}