From: Alejandro Jimenez <[email protected]> Simplify amdvi_page_walk() by making it call the fetch_pte() helper that is already in use by the shadow page synchronization code. Ensures all code uses the same page table walking algorithm.
Signed-off-by: Alejandro Jimenez <[email protected]> Reviewed-by: Michael S. Tsirkin <[email protected]> Message-ID: <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> --- hw/i386/amd_iommu.c | 77 ++++++++++++++++----------------------------- 1 file changed, 27 insertions(+), 50 deletions(-) diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c index 1bda2a8ac3..b6851784fb 100644 --- a/hw/i386/amd_iommu.c +++ b/hw/i386/amd_iommu.c @@ -513,24 +513,6 @@ static inline uint8_t get_pte_translation_mode(uint64_t pte) return (pte >> AMDVI_DEV_MODE_RSHIFT) & AMDVI_DEV_MODE_MASK; } -static inline uint64_t pte_override_page_mask(uint64_t pte) -{ - uint8_t page_mask = 13; - uint64_t addr = (pte & AMDVI_DEV_PT_ROOT_MASK) >> 12; - /* find the first zero bit */ - while (addr & 1) { - page_mask++; - addr = addr >> 1; - } - - return ~((1ULL << page_mask) - 1); -} - -static inline uint64_t pte_get_page_mask(uint64_t oldlevel) -{ - return ~((1UL << ((oldlevel * 9) + 3)) - 1); -} - static inline uint64_t amdvi_get_pte_entry(AMDVIState *s, uint64_t pte_addr, uint16_t devid) { @@ -1718,11 +1700,13 @@ static void amdvi_page_walk(AMDVIAddressSpace *as, uint64_t *dte, IOMMUTLBEntry *ret, unsigned perms, hwaddr addr) { - unsigned level, present, pte_perms, oldlevel; - uint64_t pte = dte[0], pte_addr, page_mask; + hwaddr page_mask, pagesize = 0; + uint8_t mode; + uint64_t pte; + int fetch_ret; /* make sure the DTE has TV = 1 */ - if (!(pte & AMDVI_DEV_TRANSLATION_VALID)) { + if (!(dte[0] & AMDVI_DEV_TRANSLATION_VALID)) { /* * A DTE with V=1, TV=0 does not have a valid Page Table Root Pointer. * An IOMMU processing a request that requires a table walk terminates @@ -1733,42 +1717,35 @@ static void amdvi_page_walk(AMDVIAddressSpace *as, uint64_t *dte, return; } - level = get_pte_translation_mode(pte); - if (level >= 7) { - trace_amdvi_mode_invalid(level, addr); + mode = get_pte_translation_mode(dte[0]); + if (mode >= 7) { + trace_amdvi_mode_invalid(mode, addr); return; } - if (level == 0) { + if (mode == 0) { goto no_remap; } - /* we are at the leaf page table or page table encodes a huge page */ - do { - pte_perms = amdvi_get_perms(pte); - present = pte & 1; - if (!present || perms != (perms & pte_perms)) { - amdvi_page_fault(as->iommu_state, as->devfn, addr, perms); - trace_amdvi_page_fault(addr); - return; - } - /* go to the next lower level */ - pte_addr = pte & AMDVI_DEV_PT_ROOT_MASK; - /* add offset and load pte */ - pte_addr += ((addr >> (3 + 9 * level)) & 0x1FF) << 3; - pte = amdvi_get_pte_entry(as->iommu_state, pte_addr, as->devfn); - if (!pte) { - return; - } - oldlevel = level; - level = get_pte_translation_mode(pte); - } while (level > 0 && level < 7); + /* Attempt to fetch the PTE to determine if a valid mapping exists */ + fetch_ret = fetch_pte(as, addr, dte[0], &pte, &pagesize); - if (level == 0x7) { - page_mask = pte_override_page_mask(pte); - } else { - page_mask = pte_get_page_mask(oldlevel); + /* + * If walking the page table results in an error of any type, returns an + * empty PTE i.e. no mapping, or the permissions do not match, return since + * there is no translation available. + */ + if (fetch_ret < 0 || !IOMMU_PTE_PRESENT(pte) || + perms != (perms & amdvi_get_perms(pte))) { + + amdvi_page_fault(as->iommu_state, as->devfn, addr, perms); + trace_amdvi_page_fault(addr); + return; } + /* A valid PTE and page size has been retrieved */ + assert(pagesize); + page_mask = ~(pagesize - 1); + /* get access permissions from pte */ ret->iova = addr & page_mask; ret->translated_addr = (pte & AMDVI_DEV_PT_ROOT_MASK) & page_mask; @@ -1780,7 +1757,7 @@ no_remap: ret->iova = addr & AMDVI_PAGE_MASK_4K; ret->translated_addr = addr & AMDVI_PAGE_MASK_4K; ret->addr_mask = ~AMDVI_PAGE_MASK_4K; - ret->perm = amdvi_get_perms(pte); + ret->perm = amdvi_get_perms(dte[0]); } static void amdvi_do_translate(AMDVIAddressSpace *as, hwaddr addr, -- MST
