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>

3 files changed, 58 insertions, 20 deletions

diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 68a3ac13afce..805629c0f15f 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -331,26 +331,6 @@ struct kvm_mem_alias {
         gfn_t target_gfn;
 };
 
-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;
-};
-
 struct kvm_arch{
         int naliases;
         struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS];
@@ -364,6 +344,7 @@ struct kvm_arch{
          */
         struct list_head active_mmu_pages;
         struct list_head assigned_dev_head;
+        struct dmar_domain *intel_iommu_domain;
         struct kvm_pic *vpic;
         struct kvm_ioapic *vioapic;
         struct kvm_pit *vpit;
@@ -514,6 +495,8 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
                   gpa_t addr, unsigned long *ret);
 
+int is_mmio_pfn(pfn_t pfn);
+
 extern bool tdp_enabled;
 
 enum emulation_result {
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);