Discussion:
[PATCH 1/1] virtio-ccw: clean up notify
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Halil Pasic
2018-05-16 13:27:57 UTC
Permalink
Coverity recently started complaining about virtio_ccw_notify(). Turns
out, there is a couple of things that can be cleaned up. Let's clean!

Reported-by: Peter Maydell <***@linaro.org>
Fixes: CID 1390619
Signed-off-by: Halil Pasic <***@linux.ibm.com>
---
hw/s390x/virtio-ccw.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 22df33b509..09fa7eed4c 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -1003,10 +1003,15 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
SubchDev *sch = ccw_dev->sch;
uint64_t indicators;

- /* queue indicators + secondary indicators */
- if (vector >= VIRTIO_QUEUE_MAX + 64) {
+ if (vector == VIRTIO_NO_VECTOR) {
return;
}
+ /*
+ * vector < VIRTIO_QUEUE_MAX: notification for a virtqueue
+ * vector == VIRTIO_QUEUE_MAX: configuration change notification
+ * bits beyond that are unused and should never be notified for
+ */
+ assert(vector <= VIRTIO_QUEUE_MAX);

if (vector < VIRTIO_QUEUE_MAX) {
if (!dev->indicators) {
@@ -1029,6 +1034,7 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
css_adapter_interrupt(CSS_IO_ADAPTER_VIRTIO, dev->thinint_isc);
}
} else {
+ assert(vector < NR_CLASSIC_INDICATOR_BITS);
indicators = address_space_ldq(&address_space_memory,
dev->indicators->addr,
MEMTXATTRS_UNSPECIFIED,
@@ -1042,12 +1048,11 @@ static void virtio_ccw_notify(DeviceState *d, uint16_t vector)
if (!dev->indicators2) {
return;
}
- vector = 0;
indicators = address_space_ldq(&address_space_memory,
dev->indicators2->addr,
MEMTXATTRS_UNSPECIFIED,
NULL);
- indicators |= 1ULL << vector;
+ indicators |= 1ULL;
address_space_stq(&address_space_memory, dev->indicators2->addr,
indicators, MEMTXATTRS_UNSPECIFIED, NULL);
css_conditional_io_interrupt(sch);
--
2.16.3
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