| Message ID | 20210209153757.1653598-6-eperezma@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vDPA shadow virtqueue - notifications forwarding | expand |
On Tue, Feb 09, 2021 at 04:37:55PM +0100, Eugenio Pérez wrote: > diff --git a/qapi/net.json b/qapi/net.json > index c31748c87f..a1cdffb0f9 100644 > --- a/qapi/net.json > +++ b/qapi/net.json > @@ -77,6 +77,28 @@ > ## > { 'command': 'netdev_del', 'data': {'id': 'str'} } > > +## > +# @x-vhost-enable-shadow-vq: > +# > +# Use vhost shadow virtqueue. Is this command for testing only or do you expect it to be invoked by libvirt in production? I think the shadow virtqueue can be an internal QEMU feature that is hidden from management tools. > +# > +# @name: the device name of the virtual network adapter > +# > +# @enable: true to use he alternate shadow VQ notification path > +# > +# Returns: Error if failure, or 'no error' for success > +# > +# Since: 6.0 Is this a generic feature for any vhost or vDPA device? If yes, please replace "virtual network adapter" in the doc comment. Does this only apply to vhost-net devices? If so, please put "vhost-net" in the name since there are other non-net vhost devices. > +# > +# Example: > +# > +# -> { "execute": "x-vhost-enable-shadow-vq", "arguments": {"enable": true} } Missing "name" field?
On Wed, Feb 17, 2021 at 4:26 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > On Tue, Feb 09, 2021 at 04:37:55PM +0100, Eugenio Pérez wrote: > > diff --git a/qapi/net.json b/qapi/net.json > > index c31748c87f..a1cdffb0f9 100644 > > --- a/qapi/net.json > > +++ b/qapi/net.json > > @@ -77,6 +77,28 @@ > > ## > > { 'command': 'netdev_del', 'data': {'id': 'str'} } > > > > +## > > +# @x-vhost-enable-shadow-vq: > > +# > > +# Use vhost shadow virtqueue. > > Is this command for testing only or do you expect it to be invoked by > libvirt in production? I think the shadow virtqueue can be an internal > QEMU feature that is hidden from management tools. > I think shadow virtqueue should kick in automatically when live migration is triggered and the vhost device does not have _F_LOG too. Maybe something like "prefer shadow vq to vhost logging" could be exposed, but it is not a thing we have to figure now. > > +# > > +# @name: the device name of the virtual network adapter > > +# > > +# @enable: true to use he alternate shadow VQ notification path > > +# > > +# Returns: Error if failure, or 'no error' for success > > +# > > +# Since: 6.0 > > Is this a generic feature for any vhost or vDPA device? If yes, please > replace "virtual network adapter" in the doc comment. > > Does this only apply to vhost-net devices? If so, please put "vhost-net" > in the name since there are other non-net vhost devices. Right, thanks for the catch! > > > +# > > +# Example: > > +# > > +# -> { "execute": "x-vhost-enable-shadow-vq", "arguments": {"enable": true} } > > Missing "name" field? Yes, I will fix the example in future revisions. Thanks!
On Wed, Feb 17, 2021 at 7:47 PM Eugenio Perez Martin <eperezma@redhat.com> wrote: > > On Wed, Feb 17, 2021 at 4:26 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > On Tue, Feb 09, 2021 at 04:37:55PM +0100, Eugenio Pérez wrote: > > > diff --git a/qapi/net.json b/qapi/net.json > > > index c31748c87f..a1cdffb0f9 100644 > > > --- a/qapi/net.json > > > +++ b/qapi/net.json > > > @@ -77,6 +77,28 @@ > > > ## > > > { 'command': 'netdev_del', 'data': {'id': 'str'} } > > > > > > +## > > > +# @x-vhost-enable-shadow-vq: > > > +# > > > +# Use vhost shadow virtqueue. > > > > Is this command for testing only or do you expect it to be invoked by > > libvirt in production? I think the shadow virtqueue can be an internal > > QEMU feature that is hidden from management tools. > > > > I think shadow virtqueue should kick in automatically when live > migration is triggered and the vhost device does not have _F_LOG too. > > Maybe something like "prefer shadow vq to vhost logging" could be > exposed, but it is not a thing we have to figure now. > > > > +# > > > +# @name: the device name of the virtual network adapter > > > +# > > > +# @enable: true to use he alternate shadow VQ notification path > > > +# > > > +# Returns: Error if failure, or 'no error' for success > > > +# > > > +# Since: 6.0 > > > > Is this a generic feature for any vhost or vDPA device? If yes, please > > replace "virtual network adapter" in the doc comment. > > > > Does this only apply to vhost-net devices? If so, please put "vhost-net" > > in the name since there are other non-net vhost devices. > > Right, thanks for the catch! > Moreover, the command should not be in net.json. However, I don't see a generic virtio/vhost file to add the command. > > > > > +# > > > +# Example: > > > +# > > > +# -> { "execute": "x-vhost-enable-shadow-vq", "arguments": {"enable": true} } > > > > Missing "name" field? > > Yes, I will fix the example in future revisions. > > Thanks!
diff --git a/qapi/net.json b/qapi/net.json index c31748c87f..a1cdffb0f9 100644 --- a/qapi/net.json +++ b/qapi/net.json @@ -77,6 +77,28 @@ ## { 'command': 'netdev_del', 'data': {'id': 'str'} } +## +# @x-vhost-enable-shadow-vq: +# +# Use vhost shadow virtqueue. +# +# @name: the device name of the virtual network adapter +# +# @enable: true to use he alternate shadow VQ notification path +# +# Returns: Error if failure, or 'no error' for success +# +# Since: 6.0 +# +# Example: +# +# -> { "execute": "x-vhost-enable-shadow-vq", "arguments": {"enable": true} } +# +## +{ 'command': 'x-vhost-enable-shadow-vq', + 'data': {'name': 'str', 'enable': 'bool'}, + 'if': 'defined(CONFIG_VHOST_KERNEL)' } + ## # @NetLegacyNicOptions: # diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 5d0c817b8f..8fbf14385e 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -15,6 +15,7 @@ #include "qemu/osdep.h" #include "qapi/error.h" +#include "qapi/qapi-commands-net.h" #include "hw/virtio/vhost.h" #include "qemu/atomic.h" #include "qemu/range.h" @@ -1833,3 +1834,8 @@ int vhost_net_set_backend(struct vhost_dev *hdev, return -1; } + +void qmp_x_vhost_enable_shadow_vq(const char *name, bool enable, Error **errp) +{ + error_setg(errp, "Shadow virtqueue still not implemented"); +}
Command to enable shadow virtqueue looks like: { "execute": "x-vhost-enable-shadow-vq", "arguments": { "name": "dev0", "enable": true } } Signed-off-by: Eugenio Pérez <eperezma@redhat.com> --- qapi/net.json | 22 ++++++++++++++++++++++ hw/virtio/vhost.c | 6 ++++++ 2 files changed, 28 insertions(+)