KVM: Device Assignment with VT-d

Based on a patch by: Kay, Allen M <allen.m.kay@intel.com>

This patch enables PCI device assignment based on VT-d support.
When a device is assigned to the guest, the guest memory is pinned and
the mapping is updated in the VT-d IOMMU.

[Amit: Expose KVM_CAP_IOMMU so we can check if an IOMMU is present
and also control enable/disable from userspace]

Signed-off-by: Kay, Allen M <allen.m.kay@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Amit Shah <amit.shah@qumranet.com>

Acked-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 63e661be040a..f42d5c2a396d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -41,6 +41,7 @@
 #include <linux/pagemap.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
+#include <linux/intel-iommu.h>
 
 #include <asm/processor.h>
 #include <asm/io.h>
@@ -76,7 +77,7 @@ static inline int valid_vcpu(int n)
         return likely(n >= 0 && n < KVM_MAX_VCPUS);
 }
 
-static inline int is_mmio_pfn(pfn_t pfn)
+inline int is_mmio_pfn(pfn_t pfn)
 {
         if (pfn_valid(pfn))
                 return PageReserved(pfn_to_page(pfn));
@@ -578,6 +579,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
         }
 
         kvm_free_physmem_slot(&old, &new);
+
+        /* map the pages in iommu page table */
+        r = kvm_iommu_map_pages(kvm, base_gfn, npages);
+        if (r)
+                goto out;
+
         return 0;
 
 out_free: