KVM: pci device assignment

Based on a patch from: Amit Shah <amit.shah@qumranet.com>

This patch adds support for handling PCI devices that are assigned to
the guest.

The device to be assigned to the guest is registered in the host kernel
and interrupt delivery is handled.  If a device is already assigned, or
the device driver for it is still loaded on the host, the device
assignment is failed by conveying a -EBUSY reply to the userspace.

Devices that share their interrupt line are not supported at the moment.

By itself, this patch will not make devices work within the guest.
The VT-d extension is required to enable the device to perform DMA.
Another alternative is PVDMA.

Signed-off-by: Amit Shah <amit.shah@qumranet.com>
Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index d29b64881447..ef4bc6f89778 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -383,6 +383,7 @@ struct kvm_trace_rec {
 #define KVM_CAP_MP_STATE 14
 #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
 
 /*
  * ioctls for VM fds
@@ -412,6 +413,10 @@ struct kvm_trace_rec {
                         _IOW(KVMIO,  0x67, struct kvm_coalesced_mmio_zone)
 #define KVM_UNREGISTER_COALESCED_MMIO \
                         _IOW(KVMIO,  0x68, struct kvm_coalesced_mmio_zone)
+#define KVM_ASSIGN_PCI_DEVICE _IOR(KVMIO, 0x69, \
+                                   struct kvm_assigned_pci_dev)
+#define KVM_ASSIGN_IRQ _IOR(KVMIO, 0x70, \
+                            struct kvm_assigned_irq)
 
 /*
  * ioctls for vcpu fds
@@ -476,4 +481,18 @@ struct kvm_trace_rec {
 #define KVM_TRC_STLB_INVAL       (KVM_TRC_HANDLER + 0x18)
 #define KVM_TRC_PPC_INSTR        (KVM_TRC_HANDLER + 0x19)
 
+struct kvm_assigned_pci_dev {
+        __u32 assigned_dev_id;
+        __u32 busnr;
+        __u32 devfn;
+        __u32 flags;
+};
+
+struct kvm_assigned_irq {
+        __u32 assigned_dev_id;
+        __u32 host_irq;
+        __u32 guest_irq;
+        __u32 flags;
+};
+
 #endif