[PATCH v2 0/2] vfio-ccw: Implement request notifier

[PATCH v2 0/2] vfio-ccw: Implement request notifier

[Eric Farman]

Updated QEMU code for the request notifier, to match version 2
of the kernel code [1]. No changes since the v1/RFC [2],
other than including Conny's r-b on patch 2 (Thank you!).

This registers the QEMU vfio-ccw code's ability to respond to
a request from the kernel to release the device, because of a
(probably fatal) device error that has removed it from the host
configuration, and thus its ability to be used by the guest.

[1] https://lore.kernel.org/kvm/20201120180740.87837-1-farman@linux.ibm.com/
[2] https://lore.kernel.org/qemu-devel/20201117032605.56831-1-farman@linux.ibm.com/

Eric Farman (2):
  Update linux headers
  vfio-ccw: Connect the device request notifier

 hw/vfio/ccw.c              | 40 ++++++++++++++++++++++++++++++++++----
 linux-headers/linux/vfio.h |  1 +
 2 files changed, 37 insertions(+), 4 deletions(-)

-- 
2.17.1

[PATCH v2 1/2] Update linux headers

[Eric Farman]

This is a placeholder for a proper run of scripts/update-linux-headers.sh

Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 linux-headers/linux/vfio.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index b92dcc4daf..609099e455 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -820,6 +820,7 @@ enum {
 enum {
 	VFIO_CCW_IO_IRQ_INDEX,
 	VFIO_CCW_CRW_IRQ_INDEX,
+	VFIO_CCW_REQ_IRQ_INDEX,
 	VFIO_CCW_NUM_IRQS
 };
 
-- 
2.17.1

[PATCH v2 2/2] vfio-ccw: Connect the device request notifier

[Eric Farman]

Now that the vfio-ccw code has a notifier interface to request that
a device be unplugged, let's wire that together.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
 hw/vfio/ccw.c | 40 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 36 insertions(+), 4 deletions(-)

diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index d2755d7fc5..bc78a0ad76 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -49,6 +49,7 @@ struct VFIOCCWDevice {
     struct ccw_crw_region *crw_region;
     EventNotifier io_notifier;
     EventNotifier crw_notifier;
+    EventNotifier req_notifier;
     bool force_orb_pfch;
     bool warned_orb_pfch;
 };
@@ -287,6 +288,21 @@ static void vfio_ccw_crw_read(VFIOCCWDevice *vcdev)
     } while (1);
 }
 
+static void vfio_ccw_req_notifier_handler(void *opaque)
+{
+    VFIOCCWDevice *vcdev = opaque;
+    Error *err = NULL;
+
+    if (!event_notifier_test_and_clear(&vcdev->req_notifier)) {
+        return;
+    }
+
+    qdev_unplug(DEVICE(vcdev), &err);
+    if (err) {
+        warn_reportf_err(err, VFIO_MSG_PREFIX, vcdev->vdev.name);
+    }
+}
+
 static void vfio_ccw_crw_notifier_handler(void *opaque)
 {
     VFIOCCWDevice *vcdev = opaque;
@@ -386,6 +402,10 @@ static void vfio_ccw_register_irq_notifier(VFIOCCWDevice *vcdev,
         notifier = &vcdev->crw_notifier;
         fd_read = vfio_ccw_crw_notifier_handler;
         break;
+    case VFIO_CCW_REQ_IRQ_INDEX:
+        notifier = &vcdev->req_notifier;
+        fd_read = vfio_ccw_req_notifier_handler;
+        break;
     default:
         error_setg(errp, "vfio: Unsupported device irq(%d)", irq);
         return;
@@ -440,6 +460,9 @@ static void vfio_ccw_unregister_irq_notifier(VFIOCCWDevice *vcdev,
     case VFIO_CCW_CRW_IRQ_INDEX:
         notifier = &vcdev->crw_notifier;
         break;
+    case VFIO_CCW_REQ_IRQ_INDEX:
+        notifier = &vcdev->req_notifier;
+        break;
     default:
         error_report("vfio: Unsupported device irq(%d)", irq);
         return;
@@ -661,20 +684,28 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
 
     vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX, &err);
     if (err) {
-        goto out_notifier_err;
+        goto out_io_notifier_err;
     }
 
     if (vcdev->crw_region) {
         vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX, &err);
         if (err) {
-            vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
-            goto out_notifier_err;
+            goto out_crw_notifier_err;
         }
     }
 
+    vfio_ccw_register_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX, &err);
+    if (err) {
+        goto out_req_notifier_err;
+    }
+
     return;
 
-out_notifier_err:
+out_req_notifier_err:
+    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
+out_crw_notifier_err:
+    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
+out_io_notifier_err:
     vfio_ccw_put_region(vcdev);
 out_region_err:
     vfio_ccw_put_device(vcdev);
@@ -696,6 +727,7 @@ static void vfio_ccw_unrealize(DeviceState *dev)
     S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
     VFIOGroup *group = vcdev->vdev.group;
 
+    vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_REQ_IRQ_INDEX);
     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_CRW_IRQ_INDEX);
     vfio_ccw_unregister_irq_notifier(vcdev, VFIO_CCW_IO_IRQ_INDEX);
     vfio_ccw_put_region(vcdev);
-- 
2.17.1