On Tue, 11 Jun 2019 15:33:59 -0400
Farhan Ali <address@hidden> wrote:
On 06/07/2019 10:53 AM, Cornelia Huck wrote:
A vfio-ccw device may provide an async command subregion for
issuing halt/clear subchannel requests. If it is present, use
it for sending halt/clear request to the device; if not, fall
back to emulation (as done today).
Signed-off-by: Cornelia Huck <address@hidden>
---
v4->v5:
- It seems we need to take the indirection via the class for the
callbacks after all :(
- Dropped Eric's R-b: for that reason
---
hw/s390x/css.c | 27 +++++++--
hw/s390x/s390-ccw.c | 20 +++++++
hw/vfio/ccw.c | 112 +++++++++++++++++++++++++++++++++++-
include/hw/s390x/css.h | 3 +
include/hw/s390x/s390-ccw.h | 2 +
5 files changed, 158 insertions(+), 6 deletions(-)
@@ -309,11 +400,26 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev,
Error **errp)
vcdev->io_region_offset = info->offset;
vcdev->io_region = g_malloc0(info->size);
+ /* check for the optional async command region */
+ ret = vfio_get_dev_region_info(vdev, VFIO_REGION_TYPE_CCW,
+ VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD, &info);
+ if (!ret) {
+ vcdev->async_cmd_region_size = info->size;
+ if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size) {
+ error_setg(errp, "vfio: Unexpected size of the async cmd region");
+ g_free(info);
+ return;
+ }
+ vcdev->async_cmd_region_offset = info->offset;
+ vcdev->async_cmd_region = g_malloc0(info->size);
+ }
+
g_free(info);
}
static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
{
+ g_free(vcdev->async_cmd_region);
g_free(vcdev->io_region);
}
I think we can have a memory leak given how the code is currently
structured and how we call vfio_ccw_get_region.
vfio_ccw_get_region is called in vfio_ccw_realize. So if we return an
error from vfio_ccw_get_region, we would jump to out_region_err in
vfio_ccw_realize which would call vfio_ccw_put_device.
Now we can also return an error from vfio_ccw_get_region for the async
region, and so we might never end up freeing the io_region for which we
allocated memory successfully.
I think we would also need to change vfio_ccw_realize, no?
Indeed, you're right. I have the following change on top:
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index c9d1c76b4d04..d21ac24f743c 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -407,6 +407,7 @@ static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error
**errp)
vcdev->async_cmd_region_size = info->size;
if (sizeof(*vcdev->async_cmd_region) != vcdev->async_cmd_region_size)
{
error_setg(errp, "vfio: Unexpected size of the async cmd region");
+ g_free(vcdev->io_region);
g_free(info);
return;
}