Jason Wang
2022-Feb-08 03:03 UTC
[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
On Tue, Feb 8, 2022 at 10:17 AM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > On Mon, 7 Feb 2022 16:06:15 +0800, Jason Wang <jasowang at redhat.com> wrote: > > On Mon, Feb 7, 2022 at 2:07 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > On Mon, 7 Feb 2022 11:41:06 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > > > > > ? 2022/1/26 ??3:35, Xuan Zhuo ??: > > > > > Add queue_notify_data in struct virtio_pci_common_cfg, which comes from > > > > > here https://github.com/oasis-tcs/virtio-spec/issues/89 > > > > > > > > > > Since I want to add queue_reset after it, I submitted this patch first. > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > > > --- > > > > > include/uapi/linux/virtio_pci.h | 1 + > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h > > > > > index 3a86f36d7e3d..492c89f56c6a 100644 > > > > > --- a/include/uapi/linux/virtio_pci.h > > > > > +++ b/include/uapi/linux/virtio_pci.h > > > > > @@ -164,6 +164,7 @@ struct virtio_pci_common_cfg { > > > > > __le32 queue_avail_hi; /* read-write */ > > > > > __le32 queue_used_lo; /* read-write */ > > > > > __le32 queue_used_hi; /* read-write */ > > > > > + __le16 queue_notify_data; /* read-write */ > > > > > }; > > > > > > > > > > > > So I had the same concern as previous version. > > > > > > > > This breaks uABI where program may try to use sizeof(struct > > > > virtio_pci_common_cfg). > > > > > > > > We probably need a container structure here. > > > > > > I see, I plan to add a struct like this, do you think it's appropriate? > > > > > > struct virtio_pci_common_cfg_v1 { > > > struct virtio_pci_common_cfg cfg; > > > __le16 queue_notify_data; /* read-write */ > > > } > > > > Something like this but we probably need a better name. > > > how about this? > > /* Ext Fields in VIRTIO_PCI_CAP_COMMON_CFG: */ > struct virtio_pci_common_cfg_ext { > struct virtio_pci_common_cfg cfg; > > __le16 queue_notify_data; /* read-write */ > > __le16 reserved0; > __le16 reserved1; > __le16 reserved2; > __le16 reserved3; > __le16 reserved4; > __le16 reserved5; > __le16 reserved6; > __le16 reserved7; > __le16 reserved8; > __le16 reserved9; > __le16 reserved10; > __le16 reserved11; > __le16 reserved12; > __le16 reserved13; > __le16 reserved14; > };I still think the container without padding is better. Otherwise userspace needs to use offset_of() trick instead of sizeof(). Thanks> > Thanks > > > > > Thanks > > > > > > > > Thanks. > > > > > > > > > > > THanks > > > > > > > > > > > > > > > > > > /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */ > > > > > > > > > >
Xuan Zhuo
2022-Feb-08 03:18 UTC
[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
On Tue, 8 Feb 2022 11:03:17 +0800, Jason Wang <jasowang at redhat.com> wrote:> On Tue, Feb 8, 2022 at 10:17 AM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > On Mon, 7 Feb 2022 16:06:15 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > On Mon, Feb 7, 2022 at 2:07 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > > > > > On Mon, 7 Feb 2022 11:41:06 +0800, Jason Wang <jasowang at redhat.com> wrote: > > > > > > > > > > ? 2022/1/26 ??3:35, Xuan Zhuo ??: > > > > > > Add queue_notify_data in struct virtio_pci_common_cfg, which comes from > > > > > > here https://github.com/oasis-tcs/virtio-spec/issues/89 > > > > > > > > > > > > Since I want to add queue_reset after it, I submitted this patch first. > > > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > > > > > --- > > > > > > include/uapi/linux/virtio_pci.h | 1 + > > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > > > diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h > > > > > > index 3a86f36d7e3d..492c89f56c6a 100644 > > > > > > --- a/include/uapi/linux/virtio_pci.h > > > > > > +++ b/include/uapi/linux/virtio_pci.h > > > > > > @@ -164,6 +164,7 @@ struct virtio_pci_common_cfg { > > > > > > __le32 queue_avail_hi; /* read-write */ > > > > > > __le32 queue_used_lo; /* read-write */ > > > > > > __le32 queue_used_hi; /* read-write */ > > > > > > + __le16 queue_notify_data; /* read-write */ > > > > > > }; > > > > > > > > > > > > > > > So I had the same concern as previous version. > > > > > > > > > > This breaks uABI where program may try to use sizeof(struct > > > > > virtio_pci_common_cfg). > > > > > > > > > > We probably need a container structure here. > > > > > > > > I see, I plan to add a struct like this, do you think it's appropriate? > > > > > > > > struct virtio_pci_common_cfg_v1 { > > > > struct virtio_pci_common_cfg cfg; > > > > __le16 queue_notify_data; /* read-write */ > > > > } > > > > > > Something like this but we probably need a better name. > > > > > > how about this? > > > > /* Ext Fields in VIRTIO_PCI_CAP_COMMON_CFG: */ > > struct virtio_pci_common_cfg_ext { > > struct virtio_pci_common_cfg cfg; > > > > __le16 queue_notify_data; /* read-write */ > > > > __le16 reserved0; > > __le16 reserved1; > > __le16 reserved2; > > __le16 reserved3; > > __le16 reserved4; > > __le16 reserved5; > > __le16 reserved6; > > __le16 reserved7; > > __le16 reserved8; > > __le16 reserved9; > > __le16 reserved10; > > __le16 reserved11; > > __le16 reserved12; > > __le16 reserved13; > > __le16 reserved14; > > }; > > I still think the container without padding is better. Otherwise > userspace needs to use offset_of() trick instead of sizeof().In this case, as virtio_pci_common_cfg_ext adds new members in the future, we will add more container structures. In that case, I think virtio_pci_common_cfg_v1 is a good name instead. Thanks.> > Thanks > > > > > Thanks > > > > > > > > Thanks > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > THanks > > > > > > > > > > > > > > > > > > > > > > /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */ > > > > > > > > > > > > > > >