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>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2134f3e..c8a2793 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -35,6 +35,7 @@
#include <linux/module.h>
#include <linux/mman.h>
#include <linux/highmem.h>
+#include <linux/intel-iommu.h>
#include <asm/uaccess.h>
#include <asm/msr.h>
@@ -277,9 +278,18 @@
list_add(&match->list, &kvm->arch.assigned_dev_head);
+ if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
+ r = kvm_iommu_map_guest(kvm, match);
+ if (r)
+ goto out_list_del;
+ }
+
out:
mutex_unlock(&kvm->lock);
return r;
+out_list_del:
+ list_del(&match->list);
+ pci_release_regions(dev);
out_disable:
pci_disable_device(dev);
out_put:
@@ -1147,6 +1157,9 @@
case KVM_CAP_PV_MMU:
r = !tdp_enabled;
break;
+ case KVM_CAP_IOMMU:
+ r = intel_iommu_found();
+ break;
default:
r = 0;
break;
@@ -4282,6 +4295,7 @@
void kvm_arch_destroy_vm(struct kvm *kvm)
{
+ kvm_iommu_unmap_guest(kvm);
kvm_free_assigned_devices(kvm);
kvm_free_pit(kvm);
kfree(kvm->arch.vpic);