kvm: Change kvm_iommu_map_pages to map large pages

This patch changes the implementation of of
kvm_iommu_map_pages to map the pages with the host page size
into the io virtual address space.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-By: Avi Kivity <avi@redhat.com>

diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 80fd3ad..11692b9 100644 (file)
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -32,12 +32,30 @@ static int kvm_iommu_unmap_memslots(struct kvm *kvm);
 static void kvm_iommu_put_pages(struct kvm *kvm,
                                gfn_t base_gfn, unsigned long npages);
 
+static pfn_t kvm_pin_pages(struct kvm *kvm, struct kvm_memory_slot *slot,
+                          gfn_t gfn, unsigned long size)
+{
+       gfn_t end_gfn;
+       pfn_t pfn;
+
+       pfn     = gfn_to_pfn_memslot(kvm, slot, gfn);
+       end_gfn = gfn + (size >> PAGE_SHIFT);
+       gfn    += 1;
+
+       if (is_error_pfn(pfn))
+               return pfn;
+
+       while (gfn < end_gfn)
+               gfn_to_pfn_memslot(kvm, slot, gfn++);
+
+       return pfn;
+}
+
 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
-       gfn_t gfn = slot->base_gfn;
-       unsigned long npages = slot->npages;
+       gfn_t gfn, end_gfn;
        pfn_t pfn;
-       int i, r = 0;
+       int r = 0;
        struct iommu_domain *domain = kvm->arch.iommu_domain;
        int flags;
 
@@ -45,31 +63,62 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
        if (!domain)
                return 0;
 
+       gfn     = slot->base_gfn;
+       end_gfn = gfn + slot->npages;
+
        flags = IOMMU_READ | IOMMU_WRITE;
        if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
                flags |= IOMMU_CACHE;
 
-       for (i = 0; i < npages; i++) {
-               /* check if already mapped */
-               if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn)))
+
+       while (gfn < end_gfn) {
+               unsigned long page_size;
+
+               /* Check if already mapped */
+               if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) {
+                       gfn += 1;
+                       continue;
+               }
+
+               /* Get the page size we could use to map */
+               page_size = kvm_host_page_size(kvm, gfn);
+
+               /* Make sure the page_size does not exceed the memslot */
+               while ((gfn + (page_size >> PAGE_SHIFT)) > end_gfn)
+                       page_size >>= 1;
+
+               /* Make sure gfn is aligned to the page size we want to map */
+               while ((gfn << PAGE_SHIFT) & (page_size - 1))
+                       page_size >>= 1;
+
+               /*
+                * Pin all pages we are about to map in memory. This is
+                * important because we unmap and unpin in 4kb steps later.
+                */
+               pfn = kvm_pin_pages(kvm, slot, gfn, page_size);
+               if (is_error_pfn(pfn)) {
+                       gfn += 1;
                        continue;
+               }
 
-               pfn = gfn_to_pfn_memslot(kvm, slot, gfn);
-               r = iommu_map_range(domain,
-                                   gfn_to_gpa(gfn),
-                                   pfn_to_hpa(pfn),
-                                   PAGE_SIZE, flags);
+               /* Map into IO address space */
+               r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
+                             get_order(page_size), flags);
                if (r) {
                        printk(KERN_ERR "kvm_iommu_map_address:"
                               "iommu failed to map pfn=%lx\n", pfn);
                        goto unmap_pages;
                }
-               gfn++;
+
+               gfn += page_size >> PAGE_SHIFT;
+
+
        }
+
        return 0;
 
 unmap_pages:
-       kvm_iommu_put_pages(kvm, slot->base_gfn, i);
+       kvm_iommu_put_pages(kvm, slot->base_gfn, gfn);
        return r;
 }
 
@@ -189,27 +238,47 @@ out_unmap:
        return r;
 }
 
+static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
+{
+       unsigned long i;
+
+       for (i = 0; i < npages; ++i)
+               kvm_release_pfn_clean(pfn + i);
+}
+
 static void kvm_iommu_put_pages(struct kvm *kvm,
                                gfn_t base_gfn, unsigned long npages)
 {
-       gfn_t gfn = base_gfn;
+       struct iommu_domain *domain;
+       gfn_t end_gfn, gfn;
        pfn_t pfn;
-       struct iommu_domain *domain = kvm->arch.iommu_domain;
-       unsigned long i;
        u64 phys;
 
+       domain  = kvm->arch.iommu_domain;
+       end_gfn = base_gfn + npages;
+       gfn     = base_gfn;
+
        /* check if iommu exists and in use */
        if (!domain)
                return;
 
-       for (i = 0; i < npages; i++) {
+       while (gfn < end_gfn) {
+               unsigned long unmap_pages;
+               int order;
+
+               /* Get physical address */
                phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
-               pfn = phys >> PAGE_SHIFT;
-               kvm_release_pfn_clean(pfn);
-               gfn++;
-       }
+               pfn  = phys >> PAGE_SHIFT;
+
+               /* Unmap address from IO address space */
+               order       = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
+               unmap_pages = 1ULL << order;
 
-       iommu_unmap_range(domain, gfn_to_gpa(base_gfn), PAGE_SIZE * npages);
+               /* Unpin all pages we just unmapped to not leak any memory */
+               kvm_unpin_pages(kvm, pfn, unmap_pages);
+
+               gfn += unmap_pages;
+       }
 }
 
 static int kvm_iommu_unmap_memslots(struct kvm *kvm)