[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v7 03/17] vfio: allow to notify unmap for very large
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH v7 03/17] vfio: allow to notify unmap for very large region |
Date: |
Tue, 7 Feb 2017 16:28:05 +0800 |
Linux vfio driver supports to do VFIO_IOMMU_UNMAP_DMA for a very big
region. This can be leveraged by QEMU IOMMU implementation to cleanup
existing page mappings for an entire iova address space (by notifying
with an IOTLB with extremely huge addr_mask). However current
vfio_iommu_map_notify() does not allow that. It make sure that all the
translated address in IOTLB is falling into RAM range.
The check makes sense, but it should only be a sensible checker for
mapping operations, and mean little for unmap operations.
This patch moves this check into map logic only, so that we'll get
faster unmap handling (no need to translate again), and also we can then
better support unmapping a very big region when it covers non-ram ranges
or even not-existing ranges.
Acked-by: Alex Williamson <address@hidden>
Signed-off-by: Peter Xu <address@hidden>
---
hw/vfio/common.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 42c4790..f3ba9b9 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -352,11 +352,10 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n,
IOMMUTLBEntry *iotlb)
rcu_read_lock();
- if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) {
- goto out;
- }
-
if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
+ if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) {
+ goto out;
+ }
/*
* vaddr is only valid until rcu_read_unlock(). But after
* vfio_dma_map has set up the mapping the pages will be
--
2.7.4
- [Qemu-devel] [PATCH v7 00/17] VT-d: vfio enablement and misc enhances, Peter Xu, 2017/02/07
- [Qemu-devel] [PATCH v7 01/17] vfio: trace map/unmap for notify as well, Peter Xu, 2017/02/07
- [Qemu-devel] [PATCH v7 02/17] vfio: introduce vfio_get_vaddr(), Peter Xu, 2017/02/07
- [Qemu-devel] [PATCH v7 03/17] vfio: allow to notify unmap for very large region,
Peter Xu <=
- [Qemu-devel] [PATCH v7 05/17] intel_iommu: simplify irq region translation, Peter Xu, 2017/02/07
- [Qemu-devel] [PATCH v7 04/17] intel_iommu: add "caching-mode" option, Peter Xu, 2017/02/07
- [Qemu-devel] [PATCH v7 06/17] intel_iommu: renaming gpa to iova where proper, Peter Xu, 2017/02/07
- [Qemu-devel] [PATCH v7 07/17] intel_iommu: convert dbg macros to traces for inv, Peter Xu, 2017/02/07