[Qemu-devel] [PATCH v4 2/3] VFIO-AER: Vfio-pci driver changes for supporting AER

[Vijay Mohan Pandarathil]

- New VFIO_SET_IRQ ioctl option to pass the eventfd that is signaled 
when
  an error occurs in the vfio_pci_device

- Register pci_error_handler for the vfio_pci driver

- When the device encounters an error, the error handler registered by
  the vfio_pci driver gets invoked by the AER infrastructure

- In the error handler, signal the eventfd registered for the device.

- This results in the qemu eventfd handler getting invoked and
  appropriate action taken for the guest.

Signed-off-by: Vijay Mohan Pandarathil vijaymohan.pandarat...@hp.com
---
 drivers/vfio/pci/vfio_pci.c | 44 +-
 drivers/vfio/pci/vfio_pci_intrs.c   | 47 +
 drivers/vfio/pci/vfio_pci_private.h |  1 +
 include/uapi/linux/vfio.h   |  1 +
 4 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index b28e66c..d70bd58 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -196,7 +196,9 @@ 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)
+   if (pci_is_pcie(vdev-pdev))
+   return 1;
 
return 0;
 }
@@ -302,6 +304,17 @@ static long vfio_pci_ioctl(void *device_data,
if (info.argsz  minsz || info.index = VFIO_PCI_NUM_IRQS)
return -EINVAL;
 
+   switch (info.index) {
+   case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
+   break;
+   case VFIO_PCI_ERR_IRQ_INDEX:
+   if (pci_is_pcie(vdev-pdev))
+   break;
+   /* pass thru to return error */
+   default:
+   return -EINVAL;
+   }
+
info.flags = VFIO_IRQ_INFO_EVENTFD;
 
info.count = vfio_pci_get_irq_count(vdev, info.index);
@@ -538,11 +551,40 @@ static void vfio_pci_remove(struct pci_dev *pdev)
kfree(vdev);
 }
 
+static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
+ pci_channel_state_t state)
+{
+   struct vfio_pci_device *vpdev;
+   struct vfio_device *vdev;
+
+   vdev = vfio_device_get_from_dev(pdev-dev);
+   if (vdev == NULL)
+   return PCI_ERS_RESULT_DISCONNECT;
+
+   vpdev = vfio_device_data(vdev);
+   if (vpdev == NULL) {
+   vfio_device_put(vdev);
+   return PCI_ERS_RESULT_DISCONNECT;
+   }
+
+   if (vpdev-err_trigger)
+   eventfd_signal(vpdev-err_trigger, 1);
+
+   vfio_device_put(vdev);
+
+   return PCI_ERS_RESULT_CAN_RECOVER;
+}
+
+static struct pci_error_handlers vfio_err_handlers = {
+   .error_detected = vfio_pci_aer_err_detected,
+};
+
 static struct pci_driver vfio_pci_driver = {
.name   = vfio-pci,
.id_table   = NULL, /* only dynamic ids */
.probe  = vfio_pci_probe,
.remove = vfio_pci_remove,
+   .err_handler= vfio_err_handlers,
 };
 
 static void __exit vfio_pci_cleanup(void)
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c 
b/drivers/vfio/pci/vfio_pci_intrs.c
index 3639371..8036f3a 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -745,6 +745,46 @@ static int vfio_pci_set_msi_trigger(struct vfio_pci_device 
*vdev,
return 0;
 }
 
+static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
+   unsigned index, unsigned start,
+   unsigned count, uint32_t flags, void *data)
+{
+   int32_t fd = *(int32_t *)data;
+
+   if ((index != VFIO_PCI_ERR_IRQ_INDEX) ||
+   !(flags  VFIO_IRQ_SET_DATA_TYPE_MASK))
+   return -EINVAL;
+
+   /* DATA_NONE/DATA_BOOL enables loopback testing */
+
+   if (flags  VFIO_IRQ_SET_DATA_NONE) {
+   if (vdev-err_trigger)
+   eventfd_signal(vdev-err_trigger, 1);
+   return 0;
+   } else if (flags  VFIO_IRQ_SET_DATA_BOOL) {
+   uint8_t trigger = *(uint8_t *)data;
+   if (trigger  vdev-err_trigger)
+   eventfd_signal(vdev-err_trigger, 1);
+   return 0;
+   }
+
+   /* Handle SET_DATA_EVENTFD */
+
+   if (fd == -1) {
+   if (vdev-err_trigger)
+   eventfd_ctx_put(vdev-err_trigger);
+   vdev-err_trigger = NULL;
+   return 0;
+   } else if (fd = 0) {
+   struct eventfd_ctx *efdctx;
+   efdctx = eventfd_ctx_fdget(fd);
+   if (IS_ERR(efdctx))
+   return PTR_ERR(efdctx);
+ 

Re: [Qemu-devel] [PATCH v4 2/3] VFIO-AER: Vfio-pci driver changes for supporting AER

[Alex Williamson]

On Thu, 2013-02-14 at 04:41 -0600, Vijay Mohan Pandarathil wrote:
   - New VFIO_SET_IRQ ioctl option to pass the eventfd that is signaled 
 when
   an error occurs in the vfio_pci_device
 
   - Register pci_error_handler for the vfio_pci driver
 
   - When the device encounters an error, the error handler registered by
   the vfio_pci driver gets invoked by the AER infrastructure
 
   - In the error handler, signal the eventfd registered for the device.
 
   - This results in the qemu eventfd handler getting invoked and
   appropriate action taken for the guest.
 
 Signed-off-by: Vijay Mohan Pandarathil vijaymohan.pandarat...@hp.com
 ---
  drivers/vfio/pci/vfio_pci.c | 44 +-
  drivers/vfio/pci/vfio_pci_intrs.c   | 47 
 +
  drivers/vfio/pci/vfio_pci_private.h |  1 +
  include/uapi/linux/vfio.h   |  1 +
  4 files changed, 92 insertions(+), 1 deletion(-)
 
 diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
 index b28e66c..d70bd58 100644
 --- a/drivers/vfio/pci/vfio_pci.c
 +++ b/drivers/vfio/pci/vfio_pci.c
 @@ -196,7 +196,9 @@ 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)
 + if (pci_is_pcie(vdev-pdev))
 + return 1;
  
   return 0;
  }
 @@ -302,6 +304,17 @@ static long vfio_pci_ioctl(void *device_data,
   if (info.argsz  minsz || info.index = VFIO_PCI_NUM_IRQS)
   return -EINVAL;
  
 + switch (info.index) {
 + case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
 + break;
 + case VFIO_PCI_ERR_IRQ_INDEX:
 + if (pci_is_pcie(vdev-pdev))
 + break;
 + /* pass thru to return error */
 + default:
 + return -EINVAL;
 + }
 +
   info.flags = VFIO_IRQ_INFO_EVENTFD;
  
   info.count = vfio_pci_get_irq_count(vdev, info.index);
 @@ -538,11 +551,40 @@ static void vfio_pci_remove(struct pci_dev *pdev)
   kfree(vdev);
  }
  
 +static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
 +   pci_channel_state_t state)
 +{
 + struct vfio_pci_device *vpdev;
 + struct vfio_device *vdev;

These are very confusing given that everywhere else in this file vdev is
a struct vfio_pci_device.  I'd suggest vdev and device.

 +
 + vdev = vfio_device_get_from_dev(pdev-dev);
 + if (vdev == NULL)
 + return PCI_ERS_RESULT_DISCONNECT;
 +
 + vpdev = vfio_device_data(vdev);
 + if (vpdev == NULL) {
 + vfio_device_put(vdev);
 + return PCI_ERS_RESULT_DISCONNECT;
 + }
 +
 + if (vpdev-err_trigger)
 + eventfd_signal(vpdev-err_trigger, 1);
 +
 + vfio_device_put(vdev);
 +
 + return PCI_ERS_RESULT_CAN_RECOVER;
 +}
 +
 +static struct pci_error_handlers vfio_err_handlers = {
 + .error_detected = vfio_pci_aer_err_detected,
 +};
 +
  static struct pci_driver vfio_pci_driver = {
   .name   = vfio-pci,
   .id_table   = NULL, /* only dynamic ids */
   .probe  = vfio_pci_probe,
   .remove = vfio_pci_remove,
 + .err_handler= vfio_err_handlers,
  };
  
  static void __exit vfio_pci_cleanup(void)
 diff --git a/drivers/vfio/pci/vfio_pci_intrs.c 
 b/drivers/vfio/pci/vfio_pci_intrs.c
 index 3639371..8036f3a 100644
 --- a/drivers/vfio/pci/vfio_pci_intrs.c
 +++ b/drivers/vfio/pci/vfio_pci_intrs.c
 @@ -745,6 +745,46 @@ static int vfio_pci_set_msi_trigger(struct 
 vfio_pci_device *vdev,
   return 0;
  }
  
 +static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
 + unsigned index, unsigned start,
 + unsigned count, uint32_t flags, void *data)
 +{
 + int32_t fd = *(int32_t *)data;
 +
 + if ((index != VFIO_PCI_ERR_IRQ_INDEX) ||
 + !(flags  VFIO_IRQ_SET_DATA_TYPE_MASK))
 + return -EINVAL;
 +
 + /* DATA_NONE/DATA_BOOL enables loopback testing */
 +
 + if (flags  VFIO_IRQ_SET_DATA_NONE) {
 + if (vdev-err_trigger)
 + eventfd_signal(vdev-err_trigger, 1);
 + return 0;
 + } else if (flags  VFIO_IRQ_SET_DATA_BOOL) {
 + uint8_t trigger = *(uint8_t *)data;
 + if (trigger  vdev-err_trigger)
 + eventfd_signal(vdev-err_trigger, 1);
 + return 0;
 + }
 +
 + /* Handle SET_DATA_EVENTFD */
 +
 + if (fd == -1) {
 + if (vdev-err_trigger)
 + eventfd_ctx_put(vdev-err_trigger);
 + vdev-err_trigger = NULL;
 + return 0;
 + } else if (fd =