From 2a1d22e7758fe0ae11050d24f489ce2d76b6e5dc Mon Sep 17 00:00:00 2001 From: John Snow Date: Fri, 25 Jan 2019 22:50:03 +0100 Subject: [PATCH 03/23] exec: extract address_space_translate_iommu, fix page_mask corner case RH-Author: John Snow Message-id: <20190125225007.8197-4-jsnow@redhat.com> Patchwork-id: 84116 O-Subject: [RHEL-7.7 qemu-kvm-rhev PATCH v2 3/7] exec: extract address_space_translate_iommu, fix page_mask corner case Bugzilla: 1597482 RH-Acked-by: Paolo Bonzini RH-Acked-by: Peter Xu RH-Acked-by: Stefano Garzarella From: Paolo Bonzini This will be used to process IOMMUs in a MemoryRegionCache. This includes a small bugfix, in that the returned page_mask is now correctly -1 if the IOMMU memory region maps the entire address space directly. Previously, address_space_get_iotlb_entry would return ~TARGET_PAGE_MASK. Reviewed-by: Peter Xu Signed-off-by: Paolo Bonzini (cherry picked from commit a411c84b561baa94b28165c52f21c33517ee8f59) Signed-off-by: John Snow Signed-off-by: Miroslav Rezanina --- exec.c | 110 ++++++++++++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 75 insertions(+), 35 deletions(-) diff --git a/exec.c b/exec.c index c6aeded..1bd0e6c 100644 --- a/exec.c +++ b/exec.c @@ -445,6 +445,70 @@ address_space_translate_internal(AddressSpaceDispatch *d, hwaddr addr, hwaddr *x } /** + * address_space_translate_iommu - translate an address through an IOMMU + * memory region and then through the target address space. + * + * @iommu_mr: the IOMMU memory region that we start the translation from + * @addr: the address to be translated through the MMU + * @xlat: the translated address offset within the destination memory region. + * It cannot be %NULL. + * @plen_out: valid read/write length of the translated address. It + * cannot be %NULL. + * @page_mask_out: page mask for the translated address. This + * should only be meaningful for IOMMU translated + * addresses, since there may be huge pages that this bit + * would tell. It can be %NULL if we don't care about it. + * @is_write: whether the translation operation is for write + * @is_mmio: whether this can be MMIO, set true if it can + * @target_as: the address space targeted by the IOMMU + * + * This function is called from RCU critical section. It is the common + * part of flatview_do_translate and address_space_translate_cached. + */ +static MemoryRegionSection address_space_translate_iommu(IOMMUMemoryRegion *iommu_mr, + hwaddr *xlat, + hwaddr *plen_out, + hwaddr *page_mask_out, + bool is_write, + bool is_mmio, + AddressSpace **target_as) +{ + MemoryRegionSection *section; + hwaddr page_mask = (hwaddr)-1; + + do { + hwaddr addr = *xlat; + IOMMUMemoryRegionClass *imrc = memory_region_get_iommu_class_nocheck(iommu_mr); + IOMMUTLBEntry iotlb = imrc->translate(iommu_mr, addr, is_write ? + IOMMU_WO : IOMMU_RO); + + if (!(iotlb.perm & (1 << is_write))) { + goto unassigned; + } + + addr = ((iotlb.translated_addr & ~iotlb.addr_mask) + | (addr & iotlb.addr_mask)); + page_mask &= iotlb.addr_mask; + *plen_out = MIN(*plen_out, (addr | iotlb.addr_mask) - addr + 1); + *target_as = iotlb.target_as; + + section = address_space_translate_internal( + address_space_to_dispatch(iotlb.target_as), addr, xlat, + plen_out, is_mmio); + + iommu_mr = memory_region_get_iommu(section->mr); + } while (unlikely(iommu_mr)); + + if (page_mask_out) { + *page_mask_out = page_mask; + } + return *section; + +unassigned: + return (MemoryRegionSection) { .mr = &io_mem_unassigned }; +} + +/** * flatview_do_translate - translate an address in FlatView * * @fv: the flat view that we want to translate on @@ -472,55 +536,31 @@ static MemoryRegionSection flatview_do_translate(FlatView *fv, bool is_mmio, AddressSpace **target_as) { - IOMMUTLBEntry iotlb; MemoryRegionSection *section; IOMMUMemoryRegion *iommu_mr; - IOMMUMemoryRegionClass *imrc; - hwaddr page_mask = (hwaddr)(-1); hwaddr plen = (hwaddr)(-1); if (!plen_out) { plen_out = &plen; } - for (;;) { - section = address_space_translate_internal( - flatview_to_dispatch(fv), addr, xlat, - plen_out, is_mmio); - - iommu_mr = memory_region_get_iommu(section->mr); - if (!iommu_mr) { - break; - } - imrc = memory_region_get_iommu_class_nocheck(iommu_mr); - - addr = *xlat; - iotlb = imrc->translate(iommu_mr, addr, is_write ? - IOMMU_WO : IOMMU_RO); - if (!(iotlb.perm & (1 << is_write))) { - goto translate_fail; - } + section = address_space_translate_internal( + flatview_to_dispatch(fv), addr, xlat, + plen_out, is_mmio); - addr = ((iotlb.translated_addr & ~iotlb.addr_mask) - | (addr & iotlb.addr_mask)); - page_mask &= iotlb.addr_mask; - *plen_out = MIN(*plen_out, (addr | iotlb.addr_mask) - addr + 1); - fv = address_space_to_flatview(iotlb.target_as); - *target_as = iotlb.target_as; + iommu_mr = memory_region_get_iommu(section->mr); + if (unlikely(iommu_mr)) { + return address_space_translate_iommu(iommu_mr, xlat, + plen_out, page_mask_out, + is_write, is_mmio, + target_as); } - if (page_mask_out) { - if (page_mask == (hwaddr)(-1)) { - /* Not behind an IOMMU, use default page size. */ - page_mask = ~TARGET_PAGE_MASK; - } - *page_mask_out = page_mask; + /* Not behind an IOMMU, use default page size. */ + *page_mask_out = ~TARGET_PAGE_MASK; } return *section; - -translate_fail: - return (MemoryRegionSection) { .mr = &io_mem_unassigned }; } /* Called from RCU critical section */ -- 1.8.3.1