| Message ID | 1342022894-1034-1-git-send-email-asias.hejun@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/11/2012 07:08 PM, Asias He wrote: > VHOST_SET_MEM_TABLE failed: Operation not supported > > In vhost_set_memory(), We have > > if (mem.padding) > return -EOPNOTSUPP; > > So, we need to zero struct vhost_memory. > Is this due to a change in vhost?
On Thu, Jul 12, 2012 at 12:09 AM, Avi Kivity <avi@redhat.com> wrote: > On 07/11/2012 07:08 PM, Asias He wrote: >> VHOST_SET_MEM_TABLE failed: Operation not supported >> >> In vhost_set_memory(), We have >> >> if (mem.padding) >> return -EOPNOTSUPP; >> >> So, we need to zero struct vhost_memory. >> > > Is this due to a change in vhost? Seems we have this bit in the very beginning (commit 3a4d5c94).
On 07/12/2012 05:46 AM, Asias He wrote: > On Thu, Jul 12, 2012 at 12:09 AM, Avi Kivity <avi@redhat.com> wrote: >> On 07/11/2012 07:08 PM, Asias He wrote: >>> VHOST_SET_MEM_TABLE failed: Operation not supported >>> >>> In vhost_set_memory(), We have >>> >>> if (mem.padding) >>> return -EOPNOTSUPP; >>> >>> So, we need to zero struct vhost_memory. >>> >> >> Is this due to a change in vhost? > > Seems we have this bit in the very beginning (commit 3a4d5c94). Okay, so it's a documentation problem. Michael, where is the documentation for vhost-net? Note we have to initialize it with memset(); presumably when we repurpose it the name will change, and anonymous unions are not very portable.
On Thu, Jul 12, 2012 at 11:19:47AM +0300, Avi Kivity wrote: > On 07/12/2012 05:46 AM, Asias He wrote: > > On Thu, Jul 12, 2012 at 12:09 AM, Avi Kivity <avi@redhat.com> wrote: > >> On 07/11/2012 07:08 PM, Asias He wrote: > >>> VHOST_SET_MEM_TABLE failed: Operation not supported > >>> > >>> In vhost_set_memory(), We have > >>> > >>> if (mem.padding) > >>> return -EOPNOTSUPP; > >>> > >>> So, we need to zero struct vhost_memory. > >>> > >> > >> Is this due to a change in vhost? > > > > Seems we have this bit in the very beginning (commit 3a4d5c94). > > Okay, so it's a documentation problem. Michael, where is the > documentation for vhost-net? Most fields are documented in include/linux/vhost.h Yes the approach vhost consistently takes is to require all unused fields to be zeroed out. > Note we have to initialize it with memset(); We can also use = {} if we want to avoid naming it. > presumably when we > repurpose it the name will change, and anonymous unions are not very > portable. Looks like in the new C standard they are :) I'm not sure what we'll do, exactly, if we need to reuse this padding for something else, but not breaking build for old userspace will be a priority. > -- > error compiling committee.c: too many arguments to function > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/tools/kvm/virtio/net.c b/tools/kvm/virtio/net.c index ae17eb5..aa769d9 100644 --- a/tools/kvm/virtio/net.c +++ b/tools/kvm/virtio/net.c @@ -471,7 +471,7 @@ static void virtio_net__vhost_init(struct kvm *kvm, struct net_dev *ndev) if (ndev->vhost_fd < 0) die_perror("Failed openning vhost-net device"); - mem = malloc(sizeof(*mem) + sizeof(struct vhost_memory_region)); + mem = calloc(1, sizeof(*mem) + sizeof(struct vhost_memory_region)); if (mem == NULL) die("Failed allocating memory for vhost memory map");
VHOST_SET_MEM_TABLE failed: Operation not supported In vhost_set_memory(), We have if (mem.padding) return -EOPNOTSUPP; So, we need to zero struct vhost_memory. Signed-off-by: Asias He <asias.hejun@gmail.com> --- tools/kvm/virtio/net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)