This patch adds the kvm-vfio interface for VT-d Posted-Interrrupts.
When guests updates MSI/MSI-x information for an assigned-device,
QEMU will use KVM_DEV_VFIO_DEVICE_POSTING_IRQ attribute to setup
IRTE for VT-d PI. This patch implement this IRQ attribute.
Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
---
virt/kvm/vfio.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 115 insertions(+), 0 deletions(-)
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 6bc7001..435adf4 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -446,6 +446,115 @@ out:
return ret;
}
+static int kvm_update_pi_irte(struct kvm *kvm, int host_irq, int guest_irq)
+{
+ /*
+ * TODO: need to add the real code to update the related IRTE,
+ * Basically, This fucntion will do the following things:
+ * - Get struct kvm_kernel_irq_routing_entry from guest irq
+ * - Get the destination vCPU of the interrupts
+ * - Update the IRTE according the VT-d PI Spec.
+ * 1) guest vector
+ * 2) Posted-Interrupts descritpor addresss
+ */
+
+ return 0;
+}
+
+static int kvm_vfio_pci_get_irq_count(struct pci_dev *pdev, int irq_type)
+{
+ if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
+ u8 pin;
+ pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
+ if (pin)
+ return 1;
+ } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
+ u8 pos;
+ u16 flags;
+
+ pos = pdev->msi_cap;
+ if (pos) {
+ pci_read_config_word(pdev,
+ pos + PCI_MSI_FLAGS, &flags);
+ return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
+ }
+ } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
+ u8 pos;
+ u16 flags;
+
+ pos = pdev->msix_cap;
+ if (pos) {
+ pci_read_config_word(pdev,
+ pos + PCI_MSIX_FLAGS, &flags);
+
+ return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
+ }
+ } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
+ if (pci_is_pcie(pdev))
+ return 1;
+
+ return 0;
+}
+
+static int kvm_vfio_set_pi(struct kvm_device *kdev, int32_t __user *argp)
+{
+ struct kvm_posted_intr pi_info;
+ int *virq;
+ unsigned long minsz;
+ struct vfio_device *vdev;
+ struct msi_desc *entry;
+ struct device *dev;
+ struct pci_dev *pdev;
+ int i, max, ret;
+
+ minsz = offsetofend(struct kvm_posted_intr, count);
+
+ if (copy_from_user(&pi_info, (void __user *)argp, minsz))
+ return -EFAULT;
+
+ if (pi_info.argsz < minsz || pi_info.index >= VFIO_PCI_NUM_IRQS)
+ return -EINVAL;
+
+ vdev = kvm_vfio_get_vfio_device(pi_info.fd);
+ if (IS_ERR(vdev))
+ return PTR_ERR(vdev);
+
+ dev = kvm_vfio_external_base_device(vdev);
+ if (!dev)
+ return -EFAULT;
+
+ pdev = to_pci_dev(dev);
+
+ max = kvm_vfio_pci_get_irq_count(pdev, pi_info.index);
+
+ if (pi_info.argsz - minsz < pi_info.count * sizeof(int) ||
+ pi_info.start >= max || pi_info.start + pi_info.count > max)
+ return -EINVAL;
+
+ virq = memdup_user((void __user *)((unsigned long)argp + minsz),
+ pi_info.count * sizeof(int));
+ if (IS_ERR(virq))
+ return PTR_ERR(virq);
+
+ for (i=0; i<pi_info.count; i++) {
+ list_for_each_entry(entry, &pdev->msi_list, list) {
+ if (entry->msi_attrib.entry_nr != pi_info.start+i)
+ continue;
+
+ ret = kvm_update_pi_irte(kdev->kvm,
+ entry->irq, virq[i]);
+ if (ret) {
+ kfree(virq);
+ return -EFAULT;
+ }
+ }
+ }
+
+ kfree(virq);
+
+ return 0;
+}
+
static int kvm_vfio_set_device(struct kvm_device *kdev, long attr, u64 arg)
{
int32_t __user *argp = (int32_t __user *)(unsigned long)arg;
@@ -456,6 +565,9 @@ static int kvm_vfio_set_device(struct kvm_device *kdev, long attr, u64 arg)
case KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ:
ret = kvm_vfio_control_irq_forward(kdev, attr, argp);
break;
+ case KVM_DEV_VFIO_DEVICE_POSTING_IRQ:
+ ret = kvm_vfio_set_pi(kdev, argp);
+ break;
default:
ret = -ENXIO;
}
@@ -511,6 +623,9 @@ static int kvm_vfio_has_attr(struct kvm_device *dev,
case KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ:
return 0;
#endif
+ case KVM_DEV_VFIO_DEVICE_POSTING_IRQ:
+ return 0;
+
}
break;
}
--
1.7.1
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