This patch adds the kvm-vfio interface for VT-d Posted-Interrrupts.
When guests update MSI/MSI-x information for an assigned-device,
QEMU will use KVM_DEV_VFIO_DEVICE_POST_IRQ attribute to setup
IRTE for VT-d PI. Userspace program can also use
KVM_DEV_VFIO_DEVICE_UNPOST_IRQ to change back to irq remapping mode.
This patch implements these IRQ attributes.
Signed-off-by: Feng Wu <feng...@intel.com>
---
include/linux/kvm_host.h | 20 +++++++++
virt/kvm/vfio.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 127 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 5cd4420..ca9a393 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1134,6 +1134,26 @@ static inline int kvm_arch_vfio_set_forward(struct
kvm_fwd_irq *fwd_irq,
}
#endif
+#ifdef __KVM_HAVE_ARCH_KVM_VFIO_POST
+/*
+ * kvm_arch_vfio_update_pi_irte - set IRTE for Posted-Interrupts
+ *
+ * @kvm: kvm
+ * @host_irq: host irq of the interrupt
+ * @guest_irq: gsi of the interrupt
+ * @set: set or unset PI
+ * returns 0 on success, < 0 on failure
+ */
+int kvm_arch_vfio_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
+ uint32_t guest_irq, bool set);
+#else
+static int kvm_arch_vfio_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
+ uint32_t guest_irq, bool set)
+{
+ return 0;
+}
+#endif
+
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 6bc7001..dbc6c3b 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -446,6 +446,99 @@ out:
return ret;
}
+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)
+ return pci_msi_vec_count(pdev);
+ else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX)
+ return pci_msix_vec_count(pdev);
+
+ return 0;
+}
+
+static int kvm_vfio_control_pi(struct kvm_device *kdev,
+ int32_t __user *argp, bool set)
+{
+ struct kvm_vfio_dev_irq pi_info;
+ uint32_t *gsi;
+ 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_vfio_dev_irq, 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 || !dev_is_pci(dev)) {
+ ret = -EFAULT;
+ goto put_vfio_device;
+ }
+
+ pdev = to_pci_dev(dev);
+
+ max = kvm_vfio_pci_get_irq_count(pdev, pi_info.index);
+ if (max <= 0) {
+ ret = -EFAULT;
+ goto put_vfio_device;
+ }
+
+ if (pi_info.argsz - minsz < pi_info.count * sizeof(u32) ||
+ pi_info.start >= max || pi_info.start + pi_info.count > max) {
+ ret = -EINVAL;
+ goto put_vfio_device;
+ }
+
+ gsi = memdup_user((void __user *)((unsigned long)argp + minsz),
+ pi_info.count * sizeof(u32));
+ if (IS_ERR(gsi)) {
+ ret = PTR_ERR(gsi);
+ goto put_vfio_device;
+ }
+
+#ifdef CONFIG_PCI_MSI
+ 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_arch_vfio_update_pi_irte(kdev->kvm,
+ entry->irq,
+ gsi[i],
+ set);
+ if (ret)
+ goto free_gsi;
+ }
+ }
+#endif
+
+ ret = 0;
+
+free_gsi:
+ kfree(gsi);
+
+put_vfio_device:
+ kvm_vfio_put_vfio_device(vdev);
+ return ret;
+}
+
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 +549,14 @@ 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;
+#ifdef __KVM_HAVE_ARCH_KVM_VFIO_POST
+ case KVM_DEV_VFIO_DEVICE_POST_IRQ:
+ ret = kvm_vfio_control_pi(kdev, argp, 1);
+ break;
+ case KVM_DEV_VFIO_DEVICE_UNPOST_IRQ:
+ ret = kvm_vfio_control_pi(kdev, argp, 0);
+ break;
+#endif
default:
ret = -ENXIO;
}
@@ -511,6 +612,12 @@ static int kvm_vfio_has_attr(struct kvm_device *dev,
case KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ:
return 0;
#endif
+#ifdef __KVM_HAVE_ARCH_KVM_VFIO_POST
+ case KVM_DEV_VFIO_DEVICE_POST_IRQ:
+ case KVM_DEV_VFIO_DEVICE_UNPOST_IRQ:
+ return 0;
+#endif
+
}
break;
}
--
1.9.1
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