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authorOhad Ben-Cohen <ohad@wizery.com>2011-11-10 11:32:26 +0200
committerJoerg Roedel <joerg.roedel@amd.com>2011-11-10 11:40:37 +0100
commit7d3002cc8c160dbda0e6ab9cd66dc6eb401b8b70 (patch)
tree453bad0319d12fc0a3fe6594b8e212615e7e2a70 /virt/kvm/iommu.c
parent5009065d38c95455bd2d27c2838313e3dd0c5bc7 (diff)
downloadlinux-7d3002cc8c160dbda0e6ab9cd66dc6eb401b8b70.tar.gz
iommu/core: split mapping to page sizes as supported by the hardware
When mapping a memory region, split it to page sizes as supported by the iommu hardware. Always prefer bigger pages, when possible, in order to reduce the TLB pressure. The logic to do that is now added to the IOMMU core, so neither the iommu drivers themselves nor users of the IOMMU API have to duplicate it. This allows a more lenient granularity of mappings; traditionally the IOMMU API took 'order' (of a page) as a mapping size, and directly let the low level iommu drivers handle the mapping, but now that the IOMMU core can split arbitrary memory regions into pages, we can remove this limitation, so users don't have to split those regions by themselves. Currently the supported page sizes are advertised once and they then remain static. That works well for OMAP and MSM but it would probably not fly well with intel's hardware, where the page size capabilities seem to have the potential to be different between several DMA remapping devices. register_iommu() currently sets a default pgsize behavior, so we can convert the IOMMU drivers in subsequent patches. After all the drivers are converted, the temporary default settings will be removed. Mainline users of the IOMMU API (kvm and omap-iovmm) are adopted to deal with bytes instead of page order. Many thanks to Joerg Roedel <Joerg.Roedel@amd.com> for significant review! Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Cc: David Brown <davidb@codeaurora.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Joerg Roedel <Joerg.Roedel@amd.com> Cc: Stepan Moskovchenko <stepanm@codeaurora.org> Cc: KyongHo Cho <pullip.cho@samsung.com> Cc: Hiroshi DOYU <hdoyu@nvidia.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: kvm@vger.kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'virt/kvm/iommu.c')
-rw-r--r--virt/kvm/iommu.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index a195c07fa82..304d7e5717e 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -113,7 +113,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
/* Map into IO address space */
r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
- get_order(page_size), flags);
+ page_size, flags);
if (r) {
printk(KERN_ERR "kvm_iommu_map_address:"
"iommu failed to map pfn=%llx\n", pfn);
@@ -292,15 +292,15 @@ static void kvm_iommu_put_pages(struct kvm *kvm,
while (gfn < end_gfn) {
unsigned long unmap_pages;
- int order;
+ size_t size;
/* Get physical address */
phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
pfn = phys >> PAGE_SHIFT;
/* Unmap address from IO address space */
- order = iommu_unmap(domain, gfn_to_gpa(gfn), 0);
- unmap_pages = 1ULL << order;
+ size = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
+ unmap_pages = 1ULL << get_order(size);
/* Unpin all pages we just unmapped to not leak any memory */
kvm_unpin_pages(kvm, pfn, unmap_pages);