Re: [Qemu-devel] [PATCH] net: Remove vhostforce option in addition to vhost parameter

[Jason Wang]

On 05/27/2015 02:26 PM, Pankaj Gupta wrote:
> Ping.
>
> Can I get any suggestions on this patch.
>
> Best regards,
> Pankaj
>
>> vhostforce was added to enable vhost when
>>  guest don't have MSI-X support.
>>  Now, we have scenarios like DPDK in Guest which dont use
>>  interrupts and still use vhost. Also, performance of guests
>>  without MSI-X support is getting less popular.
>>
>>  Its OK to remove this extra option and enable vhost
>>  on the basis of vhost=ON/OFF.
>>  Done basic testing with vhost on/off for latest guests
>>  and old guests(non-msix).
>>
>> Signed-off-by: Pankaj Gupta <address@hidden>

Looks good. Two questions:

- Did libvirt use this? if not, we may want to drop vhostfore option
completely.
- If vhostforce=off still attractable (I guess not)? If yes, we may want
to simply make vhostforce default to true?

Thanks
>> ---
>>  hw/net/vhost_net.c        | 2 +-
>>  hw/scsi/vhost-scsi.c      | 2 +-
>>  hw/virtio/vhost.c         | 6 ++----
>>  include/hw/virtio/vhost.h | 3 +--
>>  include/net/vhost_net.h   | 1 -
>>  net/tap.c                 | 4 +---
>>  net/vhost-user.c          | 1 -
>>  7 files changed, 6 insertions(+), 13 deletions(-)
>>
>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>> index 4e3a061..7139b9f 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -159,7 +159,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions
>> *options)
>>      net->dev.vqs = net->vqs;
>>  
>>      r = vhost_dev_init(&net->dev, options->opaque,
>> -                       options->backend_type, options->force);
>> +                       options->backend_type);
>>      if (r < 0) {
>>          goto fail;
>>      }
>> diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
>> index 618b0af..b15390e 100644
>> --- a/hw/scsi/vhost-scsi.c
>> +++ b/hw/scsi/vhost-scsi.c
>> @@ -246,7 +246,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error
>> **errp)
>>      s->dev.backend_features = 0;
>>  
>>      ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
>> -                         VHOST_BACKEND_TYPE_KERNEL, true);
>> +                         VHOST_BACKEND_TYPE_KERNEL);
>>      if (ret < 0) {
>>          error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
>>                     strerror(-ret));
>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>> index 5a12861..ce33e04 100644
>> --- a/hw/virtio/vhost.c
>> +++ b/hw/virtio/vhost.c
>> @@ -811,7 +811,7 @@ static void vhost_virtqueue_cleanup(struct
>> vhost_virtqueue *vq)
>>  }
>>  
>>  int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>> -                   VhostBackendType backend_type, bool force)
>> +                   VhostBackendType backend_type)
>>  {
>>      uint64_t features;
>>      int i, r;
>> @@ -874,7 +874,6 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>>      hdev->started = false;
>>      hdev->memory_changed = false;
>>      memory_listener_register(&hdev->memory_listener, &address_space_memory);
>> -    hdev->force = force;
>>      return 0;
>>  fail_vq:
>>      while (--i >= 0) {
>> @@ -909,8 +908,7 @@ bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice
>> *vdev)
>>      VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>>  
>>      return !k->query_guest_notifiers ||
>> -           k->query_guest_notifiers(qbus->parent) ||
>> -           hdev->force;
>> +           k->query_guest_notifiers(qbus->parent);
>>  }
>>  
>>  /* Stop processing guest IO notifications in qemu.
>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>> index d5593d1..27eae3e 100644
>> --- a/include/hw/virtio/vhost.h
>> +++ b/include/hw/virtio/vhost.h
>> @@ -46,7 +46,6 @@ struct vhost_dev {
>>      vhost_log_chunk_t *log;
>>      unsigned long long log_size;
>>      Error *migration_blocker;
>> -    bool force;
>>      bool memory_changed;
>>      hwaddr mem_changed_start_addr;
>>      hwaddr mem_changed_end_addr;
>> @@ -55,7 +54,7 @@ struct vhost_dev {
>>  };
>>  
>>  int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>> -                   VhostBackendType backend_type, bool force);
>> +                   VhostBackendType backend_type);
>>  void vhost_dev_cleanup(struct vhost_dev *hdev);
>>  bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev);
>>  int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
>> index b1c18a3..966a945 100644
>> --- a/include/net/vhost_net.h
>> +++ b/include/net/vhost_net.h
>> @@ -11,7 +11,6 @@ typedef struct VhostNetOptions {
>>      VhostBackendType backend_type;
>>      NetClientState *net_backend;
>>      void *opaque;
>> -    bool force;
>>  } VhostNetOptions;
>>  
>>  struct vhost_net *vhost_net_init(VhostNetOptions *options);
>> diff --git a/net/tap.c b/net/tap.c
>> index 968df46..b9002f7 100644
>> --- a/net/tap.c
>> +++ b/net/tap.c
>> @@ -635,13 +635,11 @@ static int net_init_tap_one(const NetdevTapOptions
>> *tap, NetClientState *peer,
>>          }
>>      }
>>  
>> -    if (tap->has_vhost ? tap->vhost :
>> -        vhostfdname || (tap->has_vhostforce && tap->vhostforce)) {
>> +    if (tap->has_vhost ? tap->vhost : vhostfdname) {
>>          VhostNetOptions options;
>>  
>>          options.backend_type = VHOST_BACKEND_TYPE_KERNEL;
>>          options.net_backend = &s->nc;
>> -        options.force = tap->has_vhostforce && tap->vhostforce;
>>  
>>          if (tap->has_vhostfd || tap->has_vhostfds) {
>>              vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
>> diff --git a/net/vhost-user.c b/net/vhost-user.c
>> index 24e050c..9966de5 100644
>> --- a/net/vhost-user.c
>> +++ b/net/vhost-user.c
>> @@ -51,7 +51,6 @@ static int vhost_user_start(VhostUserState *s)
>>      options.backend_type = VHOST_BACKEND_TYPE_USER;
>>      options.net_backend = &s->nc;
>>      options.opaque = s->chr;
>> -    options.force = s->vhostforce;
>>  
>>      s->vhost_net = vhost_net_init(&options);
>>  
>> --
>> 1.8.3.1
>>
>>
>>