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authorSheng Yang <sheng@linux.intel.com>2009-04-27 08:35:43 -0400
committerAvi Kivity <avi@redhat.com>2009-06-10 04:48:50 -0400
commit522c68c4416de3cd3e11a9ff10d58e776a69ae1e (patch)
tree62940e35988f5e2a52df10276882ec64518ee369 /virt/kvm/iommu.c
parent4b12f0de33a64dfc624b2480f55b674f7fa23ef2 (diff)
KVM: Enable snooping control for supported hardware
Memory aliases with different memory type is a problem for guest. For the guest without assigned device, the memory type of guest memory would always been the same as host(WB); but for the assigned device, some part of memory may be used as DMA and then set to uncacheable memory type(UC/WC), which would be a conflict of host memory type then be a potential issue. Snooping control can guarantee the cache correctness of memory go through the DMA engine of VT-d. [avi: fix build on ia64] Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm/iommu.c')
-rw-r--r--virt/kvm/iommu.c27
1 files changed, 24 insertions, 3 deletions
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 4c4037503600..15147583abd1 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -39,11 +39,16 @@ int kvm_iommu_map_pages(struct kvm *kvm,
39 pfn_t pfn; 39 pfn_t pfn;
40 int i, r = 0; 40 int i, r = 0;
41 struct iommu_domain *domain = kvm->arch.iommu_domain; 41 struct iommu_domain *domain = kvm->arch.iommu_domain;
42 int flags;
42 43
43 /* check if iommu exists and in use */ 44 /* check if iommu exists and in use */
44 if (!domain) 45 if (!domain)
45 return 0; 46 return 0;
46 47
48 flags = IOMMU_READ | IOMMU_WRITE;
49 if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
50 flags |= IOMMU_CACHE;
51
47 for (i = 0; i < npages; i++) { 52 for (i = 0; i < npages; i++) {
48 /* check if already mapped */ 53 /* check if already mapped */
49 if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) 54 if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn)))
@@ -53,8 +58,7 @@ int kvm_iommu_map_pages(struct kvm *kvm,
53 r = iommu_map_range(domain, 58 r = iommu_map_range(domain,
54 gfn_to_gpa(gfn), 59 gfn_to_gpa(gfn),
55 pfn_to_hpa(pfn), 60 pfn_to_hpa(pfn),
56 PAGE_SIZE, 61 PAGE_SIZE, flags);
57 IOMMU_READ | IOMMU_WRITE);
58 if (r) { 62 if (r) {
59 printk(KERN_ERR "kvm_iommu_map_address:" 63 printk(KERN_ERR "kvm_iommu_map_address:"
60 "iommu failed to map pfn=%lx\n", pfn); 64 "iommu failed to map pfn=%lx\n", pfn);
@@ -88,7 +92,7 @@ int kvm_assign_device(struct kvm *kvm,
88{ 92{
89 struct pci_dev *pdev = NULL; 93 struct pci_dev *pdev = NULL;
90 struct iommu_domain *domain = kvm->arch.iommu_domain; 94 struct iommu_domain *domain = kvm->arch.iommu_domain;
91 int r; 95 int r, last_flags;
92 96
93 /* check if iommu exists and in use */ 97 /* check if iommu exists and in use */
94 if (!domain) 98 if (!domain)
@@ -107,12 +111,29 @@ int kvm_assign_device(struct kvm *kvm,
107 return r; 111 return r;
108 } 112 }
109 113
114 last_flags = kvm->arch.iommu_flags;
115 if (iommu_domain_has_cap(kvm->arch.iommu_domain,
116 IOMMU_CAP_CACHE_COHERENCY))
117 kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
118
119 /* Check if need to update IOMMU page table for guest memory */
120 if ((last_flags ^ kvm->arch.iommu_flags) ==
121 KVM_IOMMU_CACHE_COHERENCY) {
122 kvm_iommu_unmap_memslots(kvm);
123 r = kvm_iommu_map_memslots(kvm);
124 if (r)
125 goto out_unmap;
126 }
127
110 printk(KERN_DEBUG "assign device: host bdf = %x:%x:%x\n", 128 printk(KERN_DEBUG "assign device: host bdf = %x:%x:%x\n",
111 assigned_dev->host_busnr, 129 assigned_dev->host_busnr,
112 PCI_SLOT(assigned_dev->host_devfn), 130 PCI_SLOT(assigned_dev->host_devfn),
113 PCI_FUNC(assigned_dev->host_devfn)); 131 PCI_FUNC(assigned_dev->host_devfn));
114 132
115 return 0; 133 return 0;
134out_unmap:
135 kvm_iommu_unmap_memslots(kvm);
136 return r;
116} 137}
117 138
118int kvm_deassign_device(struct kvm *kvm, 139int kvm_deassign_device(struct kvm *kvm,