vfio-pci: Add device request interface

Userspace can opt to receive a device request notification,
indicating that the device should be released.  This is setup
the same way as the error IRQ and also supports eventfd signaling.
Future support may forcefully remove the device from the user if
the request is ignored.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 7cc0122a18cecbb7ef45cf8e438112ec2fb4ff00..f8a186381ae8726887657c6c868a8b2ceeef2e54 100644 (file)
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -239,9 +239,12 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
 
                        return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
                }
-       } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
+       } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
                if (pci_is_pcie(vdev->pdev))
                        return 1;
+       } else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
+               return 1;
+       }
 
        return 0;
 }
@@ -464,6 +467,7 @@ static long vfio_pci_ioctl(void *device_data,
 
                switch (info.index) {
                case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
+               case VFIO_PCI_REQ_IRQ_INDEX:
                        break;
                case VFIO_PCI_ERR_IRQ_INDEX:
                        if (pci_is_pcie(vdev->pdev))
@@ -828,6 +832,20 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
                               req_len, vma->vm_page_prot);
 }
 
+static void vfio_pci_request(void *device_data, unsigned int count)
+{
+       struct vfio_pci_device *vdev = device_data;
+
+       mutex_lock(&vdev->igate);
+
+       if (vdev->req_trigger) {
+               dev_dbg(&vdev->pdev->dev, "Requesting device from user\n");
+               eventfd_signal(vdev->req_trigger, 1);
+       }
+
+       mutex_unlock(&vdev->igate);
+}
+
 static const struct vfio_device_ops vfio_pci_ops = {
        .name           = "vfio-pci",
        .open           = vfio_pci_open,
@@ -836,6 +854,7 @@ static const struct vfio_device_ops vfio_pci_ops = {
        .read           = vfio_pci_read,
        .write          = vfio_pci_write,
        .mmap           = vfio_pci_mmap,
+       .request        = vfio_pci_request,
 };
 
 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)

diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index b134befbfd0e450f1b7c177a0686a81970d9f6c8..f88bfdf5b6a036a6bf1aae3b8abe3ec6d944ffe0 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -817,6 +817,16 @@ static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
        return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger, flags, data);
 }
 
+static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
+                                   unsigned index, unsigned start,
+                                   unsigned count, uint32_t flags, void *data)
+{
+       if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count != 1)
+               return -EINVAL;
+
+       return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger, flags, data);
+}
+
 int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
                            unsigned index, unsigned start, unsigned count,
                            void *data)
@@ -858,6 +868,12 @@ int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
                                func = vfio_pci_set_err_trigger;
                        break;
                }
+       case VFIO_PCI_REQ_IRQ_INDEX:
+               switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+               case VFIO_IRQ_SET_ACTION_TRIGGER:
+                       func = vfio_pci_set_req_trigger;
+                       break;
+               }
        }
 
        if (!func)

diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 671c17a6e6d029dfdffe5d7243150ed757e44cf4..c9f9b323f152733685f9dafc67793472921658ec 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -58,6 +58,7 @@ struct vfio_pci_device {
        struct pci_saved_state  *pci_saved_state;
        int                     refcnt;
        struct eventfd_ctx      *err_trigger;
+       struct eventfd_ctx      *req_trigger;
 };
 
 #define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 29715d27548f21b20303861c24f56faeab835cc9..82889c30f4f5a79fb820c1dd20e1e8a0f99b4bf0 100644 (file)
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -333,6 +333,7 @@ enum {
        VFIO_PCI_MSI_IRQ_INDEX,
        VFIO_PCI_MSIX_IRQ_INDEX,
        VFIO_PCI_ERR_IRQ_INDEX,
+       VFIO_PCI_REQ_IRQ_INDEX,
        VFIO_PCI_NUM_IRQS
 };