- Create eventfd per vfio device assigned to a guest and register an
event handler
- This fd is passed to the vfio_pci driver through a new ioctl
- When the device encounters an error, the eventfd is signaled
and the qemu eventfd handler gets invoked.
- In the handler decide what action to take. Current action taken
is to terminate the guest.
Signed-off-by: Vijay Mohan Pandarathil <vijaymohan.pandarathil@xxxxxx>
---
hw/vfio_pci.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++
linux-headers/linux/vfio.h | 9 ++++++++
2 files changed, 65 insertions(+)
diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
index 28c8303..9c3c28b 100644
--- a/hw/vfio_pci.c
+++ b/hw/vfio_pci.c
@@ -38,6 +38,7 @@
#include "qemu/error-report.h"
#include "qemu/queue.h"
#include "qemu/range.h"
+#include "sysemu/sysemu.h"
/* #define DEBUG_VFIO */
#ifdef DEBUG_VFIO
@@ -130,6 +131,8 @@ typedef struct VFIODevice {
QLIST_ENTRY(VFIODevice) next;
struct VFIOGroup *group;
bool reset_works;
+ EventNotifier errfd;
+ __u32 dev_info_flags;
} VFIODevice;
typedef struct VFIOGroup {
@@ -1805,6 +1808,8 @@ static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev)
DPRINTF("Device %s flags: %u, regions: %u, irgs: %u\n", name,
dev_info.flags, dev_info.num_regions, dev_info.num_irqs);
+ vdev->dev_info_flags = dev_info.flags;
+
if (!(dev_info.flags & VFIO_DEVICE_FLAGS_PCI)) {
error_report("vfio: Um, this isn't a PCI device\n");
goto error;
@@ -1900,6 +1905,55 @@ static void vfio_put_device(VFIODevice *vdev)
}
}
+static void vfio_errfd_handler(void *opaque)
+{
+ VFIODevice *vdev = opaque;
+
+ if (!event_notifier_test_and_clear(&vdev->errfd)) {
+ return;
+ }
+
+ /*
+ * TBD. Retrieve the error details and decide what action
+ * needs to be taken. One of the actions could be to pass
+ * the error to the guest and have the guest driver recover
+ * the error. This requires that PCIe capabilities be
+ * exposed to the guest. At present, we just terminate the
+ * guest to contain the error.
+ */
+ error_report("%s(%04x:%02x:%02x.%x) "
+ "Unrecoverable error detected... Terminating guest\n",
+ __func__, vdev->host.domain, vdev->host.bus, vdev->host.slot,
+ vdev->host.function);
+
+ qemu_system_shutdown_request();
+ return;
+}
+
+static void vfio_register_errfd(VFIODevice *vdev)
+{
+ int32_t pfd;
+ int ret;
+
+ if (!(vdev->dev_info_flags & VFIO_DEVICE_FLAGS_AER_NOTIFY)) {
+ error_report("vfio: Warning: Error notification not supported for the device\n");
+ return;
+ }
+ if (event_notifier_init(&vdev->errfd, 0)) {
+ error_report("vfio: Warning: Unable to init event notifier for error detection\n");
+ return;
+ }
+ pfd = event_notifier_get_fd(&vdev->errfd);
+ qemu_set_fd_handler(pfd, vfio_errfd_handler, NULL, vdev);
+
+ ret = ioctl(vdev->fd, VFIO_DEVICE_SET_ERRFD, pfd);
+ if (ret) {
+ error_report("vfio: Warning: Failed to setup error fd: %d\n", ret);
+ qemu_set_fd_handler(pfd, NULL, NULL, vdev);
+ event_notifier_cleanup(&vdev->errfd);
+ }
+ return;
+}
static int vfio_initfn(PCIDevice *pdev)
{
VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
@@ -2010,6 +2064,8 @@ static int vfio_initfn(PCIDevice *pdev)
}
}
+ vfio_register_errfd(vdev);
+
return 0;
out_teardown:
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index 4758d1b..0ca4eeb 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -147,6 +147,7 @@ struct vfio_device_info {
__u32 flags;
#define VFIO_DEVICE_FLAGS_RESET (1 << 0) /* Device supports reset */
#define VFIO_DEVICE_FLAGS_PCI (1 << 1) /* vfio-pci device */
+#define VFIO_DEVICE_FLAGS_AER_NOTIFY (1 << 2) /* Supports aer notification */
__u32 num_regions; /* Max region index + 1 */
__u32 num_irqs; /* Max IRQ index + 1 */
};
@@ -288,6 +289,14 @@ struct vfio_irq_set {
*/
#define VFIO_DEVICE_RESET _IO(VFIO_TYPE, VFIO_BASE + 11)
+/**
+ * VFIO_DEVICE_SET_ERRFD - _IO(VFIO_TYPE, VFIO_BASE + 12)
+ *
+ * Pass the eventfd to the vfio-pci driver for signalling any device
+ * error notifications
+ */
+#define VFIO_DEVICE_SET_ERRFD _IO(VFIO_TYPE, VFIO_BASE + 12)
+
/*
* The VFIO-PCI bus driver makes use of the following fixed region and
* IRQ index mapping. Unimplemented regions return a size of zero.
--
1.7.11.3
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