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[Qemu-devel] [PATCH v3 04/12] memory: fix address_space_get_iotlb_entry(
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH v3 04/12] memory: fix address_space_get_iotlb_entry() |
Date: |
Wed, 10 May 2017 16:01:47 +0800 |
This function has an assumption that we will definitely call translate()
once (or say, the addr will be located inside one IOMMU memory region),
otherwise an empty IOTLB will be returned. Nevertheless, this is not
what we want. When there is no IOMMU memory region, we should build up a
static mapping for the caller, instead of an invalid IOTLB.
We won't trigger this path before VT-d passthrough mode. When
passthrough mode for a vhost device is setup, VT-d is possible to
disable the IOMMU region for that device. Without current patch, we'll
get a vhost boot failure, and it'll be failed over to virtio userspace
mode.
CC: Paolo Bonzini <address@hidden>
CC: Jason Wang <address@hidden>
CC: Michael S. Tsirkin <address@hidden>
Signed-off-by: Peter Xu <address@hidden>
---
exec.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/exec.c b/exec.c
index 072de5d..5cfdacd 100644
--- a/exec.c
+++ b/exec.c
@@ -463,12 +463,13 @@ address_space_translate_internal(AddressSpaceDispatch *d,
hwaddr addr, hwaddr *x
}
/* Called from RCU critical section */
-IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
+IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr iova,
bool is_write)
{
IOMMUTLBEntry iotlb = {0};
MemoryRegionSection *section;
MemoryRegion *mr;
+ hwaddr addr = iova, psize;
for (;;) {
AddressSpaceDispatch *d = atomic_rcu_read(&as->dispatch);
@@ -478,6 +479,23 @@ IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace
*as, hwaddr addr,
mr = section->mr;
if (!mr->iommu_ops) {
+ /*
+ * We didn't translate() but reached here. It possibly
+ * means it's a static mapping. If so (it should be RAM),
+ * we set the IOTLB up.
+ */
+ if (!iotlb.target_as && memory_region_is_ram(mr) &&
+ !memory_region_is_rom(mr)) {
+ psize = mr->ram_block->page_size;
+ iova &= ~(psize - 1);
+ iotlb = (IOMMUTLBEntry) {
+ .target_as = &address_space_memory,
+ .iova = iova,
+ .translated_addr = iova,
+ .addr_mask = psize - 1,
+ .perm = IOMMU_RW,
+ };
+ }
break;
}
--
2.7.4
- [Qemu-devel] [PATCH v3 00/12] VT-d: PT (passthrough) mode support and misc fixes, Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 01/12] pc: add 2.10 machine type, Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 02/12] memory: tune last param of iommu_ops.translate(), Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 03/12] memory: remove the last param in memory_region_iommu_replay(), Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 04/12] memory: fix address_space_get_iotlb_entry(),
Peter Xu <=
- [Qemu-devel] [PATCH v3 05/12] x86-iommu: use DeviceClass properties, Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 07/12] intel_iommu: provide vtd_ce_get_type(), Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 06/12] intel_iommu: renaming context entry helpers, Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 08/12] intel_iommu: use IOMMU_ACCESS_FLAG(), Peter Xu, 2017/05/10
- [Qemu-devel] [PATCH v3 09/12] intel_iommu: allow dev-iotlb context entry conditionally, Peter Xu, 2017/05/10