On 13.05.19 14:20, Cornelia Huck wrote:
On Fri, 26 Apr 2019 20:32:45 +0200
Halil Pasic <pasic@xxxxxxxxxxxxx> wrote:
Hypervisor needs to interact with the summary indicators, so these
need to be DMA memory as well (at least for protected virtualization
guests).
Signed-off-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
---
drivers/s390/virtio/virtio_ccw.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
(...)
@@ -237,7 +243,8 @@ static void virtio_airq_handler(struct airq_struct *airq)
read_unlock(&info->lock);
}
-static struct airq_info *new_airq_info(void)
+/* call with drivers/s390/virtio/virtio_ccw.cheld */
Hm, where is airq_areas_lock defined? If it was introduced in one of
the previous patches, I have missed it.
There is no airq_areas_lock defined currently. My assumption is that
this will be used in context with the likely race condition this
part of the patch is talking about.
@@ -273,8 +281,9 @@ static unsigned long get_airq_indicator(struct
virtqueue *vqs[], int nvqs,
unsigned long bit, flags;
for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
+ /* TODO: this seems to be racy */
if (!airq_areas[i])
- airq_areas[i] = new_airq_info();
+ airq_areas[i] = new_airq_info(i);
As this shall be handled by a separate patch I will drop the comment
in regard to airq_areas_lock from this patch as well for v2.
Michael
+static struct airq_info *new_airq_info(int index)
{
struct airq_info *info;
int rc;
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