From 2a1d22e7758fe0ae11050d24f489ce2d76b6e5dc Mon Sep 17 00:00:00 2001
From: John Snow <jsnow@redhat.com>
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 <jsnow@redhat.com>
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 <pbonzini@redhat.com>
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
From: Paolo Bonzini <pbonzini@redhat.com>
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 <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit a411c84b561baa94b28165c52f21c33517ee8f59)
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
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