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target/ppc: Check page dir/table base alignment

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According to PowerISA 3.1B, Book III 6.7.6 programming note, the
page directory base addresses are expected to be aligned to their
size. Real hardware seems to rely on that and will access the
wrong address if they are misaligned. This results in a
translation failure even if the page tables seem to be properly
populated.

Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220628133959.15131-4-leandro.lupori@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This commit is contained in:
Leandro Lupori 2022-06-28 10:39:59 -03:00 committed by Daniel Henrique Barboza
parent 47e83d9107
commit d2066bc50d
1 changed files with 24 additions and 4 deletions
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28
target/ppc/mmu-radix64.c
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@ -265,7 +265,7 @@ static int ppc_radix64_next_level(AddressSpace *as, vaddr eaddr,
uint64_t *pte_addr, uint64_t *nls,
int *psize, uint64_t *pte, int *fault_cause)
{
uint64_t index, pde;
uint64_t index, mask, nlb, pde;
/* Read page <directory/table> entry from guest address space */
pde = ldq_phys(as, *pte_addr);
@ -280,7 +280,17 @@ static int ppc_radix64_next_level(AddressSpace *as, vaddr eaddr,
*nls = pde & R_PDE_NLS;
index = eaddr >> (*psize - *nls); /* Shift */
index &= ((1UL << *nls) - 1); /* Mask */
*pte_addr = (pde & R_PDE_NLB) + (index * sizeof(pde));
nlb = pde & R_PDE_NLB;
mask = MAKE_64BIT_MASK(0, *nls + 3);
if (nlb & mask) {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: misaligned page dir/table base: 0x"TARGET_FMT_lx
" page dir size: 0x"TARGET_FMT_lx"\n",
__func__, nlb, mask + 1);
nlb &= ~mask;
}
*pte_addr = nlb + index * sizeof(pde);
}
return 0;
}
@ -294,8 +304,18 @@ static int ppc_radix64_walk_tree(AddressSpace *as, vaddr eaddr,
int level = 0;
index = eaddr >> (*psize - nls); /* Shift */
index &= ((1UL << nls) - 1); /* Mask */
*pte_addr = base_addr + (index * sizeof(pde));
index &= ((1UL << nls) - 1); /* Mask */
mask = MAKE_64BIT_MASK(0, nls + 3);
if (base_addr & mask) {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: misaligned page dir base: 0x"TARGET_FMT_lx
" page dir size: 0x"TARGET_FMT_lx"\n",
__func__, base_addr, mask + 1);
base_addr &= ~mask;
}
*pte_addr = base_addr + index * sizeof(pde);
do {
int ret;