diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index bd83b58..adcc95a 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -34,6 +34,7 @@
#include "pci.h"
#include "trace.h"
#include "qapi/error.h"
+#include "qapi/qapi-events-net.h"
#define MSIX_CAP_LENGTH 12
@@ -42,6 +43,7 @@
static void vfio_disable_interrupts(VFIOPCIDevice *vdev);
static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled);
+static void vfio_failover_notify(VFIOPCIDevice *vdev, bool status);
/*
* Disabling BAR mmaping can be slow, but toggling it around INTx can
@@ -1170,6 +1172,8 @@ void vfio_pci_write_config(PCIDevice *pdev,
{
VFIOPCIDevice *vdev = PCI_VFIO(pdev);
uint32_t val_le = cpu_to_le32(val);
+ bool may_notify = false;
+ bool master_was = false;
trace_vfio_pci_write_config(vdev->vbasedev.name, addr, val, len);
@@ -1180,6 +1184,14 @@ void vfio_pci_write_config(PCIDevice *pdev,
__func__, vdev->vbasedev.name, addr, val, len);
}
+ /* Bus Master Enabling/Disabling */
+ if (pdev->failover_primary && current_cpu &&
+ range_covers_byte(addr, len, PCI_COMMAND)) {
+ master_was = !!(pci_get_word(pdev->config + PCI_COMMAND) &
+ PCI_COMMAND_MASTER);
+ may_notify = true;
+ }
+
/* MSI/MSI-X Enabling/Disabling */
if (pdev->cap_present & QEMU_PCI_CAP_MSI &&
ranges_overlap(addr, len, pdev->msi_cap, vdev->msi_cap_size)) {
@@ -1235,6 +1247,14 @@ void vfio_pci_write_config(PCIDevice *pdev,
/* Write everything to QEMU to keep emulated bits correct */
pci_default_write_config(pdev, addr, val, len);
}
+
+ if (may_notify) {
+ bool master_now = !!(pci_get_word(pdev->config + PCI_COMMAND) &
+ PCI_COMMAND_MASTER);
+ if (master_was != master_now) {
+ vfio_failover_notify(vdev, master_now);
+ }
+ }
}
/*
@@ -2801,6 +2821,17 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice
*vdev)
vdev->req_enabled = false;
}
+static void vfio_failover_notify(VFIOPCIDevice *vdev, bool status)
+{
+ PCIDevice *pdev = &vdev->pdev;
+ const char *n;
+ gchar *path;
+
+ n = pdev->qdev.id ? pdev->qdev.id : vdev->vbasedev.name;
+ path = object_get_canonical_path(OBJECT(vdev));
+ qapi_event_send_failover_primary_changed(!!n, n, path, status);
+}
+
static void vfio_realize(PCIDevice *pdev, Error **errp)
{
VFIOPCIDevice *vdev = PCI_VFIO(pdev);
@@ -3109,10 +3140,36 @@ static void vfio_instance_finalize(Object *obj)
vfio_put_group(group);
}
+static void vfio_exit_failover_notify(VFIOPCIDevice *vdev)
+{
+ PCIDevice *pdev = &vdev->pdev;
+
+ /*
+ * Guest driver may not get the chance to disable bus mastering
+ * before the device object gets to be unrealized. In that event,
+ * send out a "disabled" notification on behalf of guest driver.
+ */
+ if (pdev->failover_primary &&
+ pdev->bus_master_enable_region.enabled) {
+ vfio_failover_notify(vdev, false);
+ }
+}
+
static void vfio_exitfn(PCIDevice *pdev)
{
VFIOPCIDevice *vdev = PCI_VFIO(pdev);
+ /*
+ * During the guest reboot sequence, it is sometimes possible that
+ * the guest may not get sufficient time to complete the entire driver
+ * removal sequence, near the end of which a PCI config space write to
+ * disable bus mastering can be intercepted by device. In such cases,
+ * the FAILOVER_PRIMARY_CHANGED "disable" event will not be emitted. It
+ * is imperative to generate the event on the guest's behalf if the
+ * guest fails to make it.
+ */
+ vfio_exit_failover_notify(vdev);
+
vfio_unregister_req_notifier(vdev);
vfio_unregister_err_notifier(vdev);
pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
diff --git a/qapi/net.json b/qapi/net.json
index 633ac87..a5b8d70 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -757,3 +757,29 @@
##
{ 'command': 'query-standby-status', 'data': { '*device': 'str' },
'returns': ['StandbyStatusInfo'] }
+
+##
+# @FAILOVER_PRIMARY_CHANGED:
+#
+# Emitted whenever the driver of failover primary is loaded or unloaded
+# by the guest.
+#
+# @device: device name
+#
+# @path: device path
+#
+# @enabled: true if driver is loaded thus device is enabled in guest
+#
+# Since: 3.0
+#
+# Example:
+#
+# <- { "event": "FAILOVER_PRIMARY_CHANGED",
+# "data": { "device": "vfio-0",
+# "path": "/machine/peripheral/vfio-0" },
+# "enabled": "true" },
+# "timestamp": { "seconds": 1539935213, "microseconds": 753529 } }
+#
+##
+{ 'event': 'FAILOVER_PRIMARY_CHANGED',
+ 'data': { '*device': 'str', 'path': 'str', 'enabled': 'bool' } }