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>

2 files changed, 55 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index ef4bc6f89778..4269be171faf 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -384,6 +384,7 @@ struct kvm_trace_rec {
 #define KVM_CAP_COALESCED_MMIO 15
 #define KVM_CAP_SYNC_MMU 16  /* Changes to host mmap are reflected in guest */
 #define KVM_CAP_DEVICE_ASSIGNMENT 17
+#define KVM_CAP_IOMMU 18
 
 /*
  * ioctls for VM fds
@@ -495,4 +496,6 @@ struct kvm_assigned_irq {
 	__u32 flags;
 };
 
+#define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
+
 #endif
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4b036430ea23..6252802c3cc0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -286,6 +286,53 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v);
 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);
 void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
 
+struct kvm_irq_ack_notifier {
+	struct hlist_node link;
+	unsigned gsi;
+	void (*irq_acked)(struct kvm_irq_ack_notifier *kian);
+};
+
+struct kvm_assigned_dev_kernel {
+	struct kvm_irq_ack_notifier ack_notifier;
+	struct work_struct interrupt_work;
+	struct list_head list;
+	int assigned_dev_id;
+	int host_busnr;
+	int host_devfn;
+	int host_irq;
+	int guest_irq;
+	int irq_requested;
+	struct pci_dev *dev;
+	struct kvm *kvm;
+};
+
+#ifdef CONFIG_DMAR
+int kvm_iommu_map_pages(struct kvm *kvm, gfn_t base_gfn,
+			unsigned long npages);
+int kvm_iommu_map_guest(struct kvm *kvm,
+			struct kvm_assigned_dev_kernel *assigned_dev);
+int kvm_iommu_unmap_guest(struct kvm *kvm);
+#else /* CONFIG_DMAR */
+static inline int kvm_iommu_map_pages(struct kvm *kvm,
+				      gfn_t base_gfn,
+				      unsigned long npages)
+{
+	return 0;
+}
+
+static inline int kvm_iommu_map_guest(struct kvm *kvm,
+				      struct kvm_assigned_dev_kernel
+				      *assigned_dev)
+{
+	return -ENODEV;
+}
+
+static inline int kvm_iommu_unmap_guest(struct kvm *kvm)
+{
+	return 0;
+}
+#endif /* CONFIG_DMAR */
+
 static inline void kvm_guest_enter(void)
 {
 	account_system_vtime(current);
@@ -308,6 +355,11 @@ static inline gpa_t gfn_to_gpa(gfn_t gfn)
 	return (gpa_t)gfn << PAGE_SHIFT;
 }
 
+static inline hpa_t pfn_to_hpa(pfn_t pfn)
+{
+	return (hpa_t)pfn << PAGE_SHIFT;
+}
+
 static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
 {
 	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);