----- Original Message -----
> On Sat, Sep 19, 2015 at 12:12:02PM +0200, marcandre.lur...@redhat.com wrote:
> > From: Marc-André Lureau <marcandre.lur...@redhat.com>
> >
> > Send the shm for the dirty pages logging if the backend supports
> > VHOST_USER_PROTOCOL_F_LOG_SHMFD.
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > ---
> > hw/virtio/vhost-backend.c | 3 ++-
> > hw/virtio/vhost-user.c | 17 ++++++++++++++---
> > hw/virtio/vhost.c | 5 +++--
> > include/hw/virtio/vhost-backend.h | 4 +++-
> > 4 files changed, 22 insertions(+), 7 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> > index bf2d1d4..3f2d6ea 100644
> > --- a/hw/virtio/vhost-backend.c
> > +++ b/hw/virtio/vhost-backend.c
> > @@ -66,7 +66,8 @@ static int vhost_scsi_get_abi_version(struct vhost_dev
> > *dev, int *version)
> > return vhost_kernel_call(dev, VHOST_SCSI_GET_ABI_VERSION, version);
> > }
> >
> > -static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base)
> > +static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base,
> > + struct vhost_log *log)
> > {
> > return vhost_kernel_call(dev, VHOST_SET_LOG_BASE, &base);
> > }
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index d3334f5..3cb5559 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -26,7 +26,9 @@
> > #define VHOST_MEMORY_MAX_NREGIONS 8
> >
> > #define VHOST_USER_F_PROTOCOL_FEATURES 30
> > -#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x0ULL
> > +
> > +#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x1ULL
> > +#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 0
> >
> > typedef enum VhostUserRequest {
> > VHOST_USER_NONE = 0,
> > @@ -182,8 +184,11 @@ static int vhost_scsi_get_abi_version(struct vhost_dev
> > *dev, int *version)
> > return -1;
> > }
> >
> > -static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base)
> > +static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base,
> > + struct vhost_log *log)
> > {
> > + int fds[VHOST_MEMORY_MAX_NREGIONS];
> > + size_t fd_num = 0;
> > VhostUserMsg msg = {
> > .request = VHOST_USER_SET_LOG_BASE,
> > .flags = VHOST_USER_VERSION,
> > @@ -191,7 +196,13 @@ static int vhost_set_log_base(struct vhost_dev *dev,
> > uint64_t base)
> > .size = sizeof(m.u64),
> > };
> >
> > - vhost_user_write(dev, &msg, NULL, 0);
> > + if (virtio_has_feature(dev->protocol_features,
> > + VHOST_USER_PROTOCOL_F_LOG_SHMFD) &&
> > + log->fd != -1) {
> > + fds[fd_num++] = log->fd;
> > + }
> > +
> > + vhost_user_write(dev, &msg, fds, fd_num);
> >
> > return 0;
> > }
>
> Doesn't this one have to get a response?
> Otherwise the other side might still be using the old
> buffer after we've updated this one.
That make sense, though I wonder about all other SET commands in the protocol
then. Isn't there other commands that may change the fd or memory region over
time?
> Probably need a protocol feature, but I guess we can reuse
> VHOST_USER_PROTOCOL_F_LOG_SHMFD - IIUC logging doesn't
> work without this anyway ...
ok
>
>
> > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> > index 83ef164..0fa7b69 100644
> > --- a/hw/virtio/vhost.c
> > +++ b/hw/virtio/vhost.c
> > @@ -359,7 +359,7 @@ static inline void vhost_dev_log_resize(struct
> > vhost_dev* dev, uint64_t size)
> >
> > /* inform backend of log switching, this must be done before
> > releasing the current log, to ensure no logging is lost */
> > - r = dev->vhost_ops->vhost_set_log_base(dev, log_base);
> > + r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log);
> > assert(r >= 0);
> > vhost_log_put(dev, true);
> > dev->log = log;
> > @@ -1167,7 +1167,8 @@ int vhost_dev_start(struct vhost_dev *hdev,
> > VirtIODevice *vdev)
> > hdev->log = vhost_log_get(hdev->log_size, share);
> > log_base = (uintptr_t)hdev->log->log;
> > r = hdev->vhost_ops->vhost_set_log_base(hdev,
> > - hdev->log_size ? log_base
> > : 0);
> > + hdev->log_size ? log_base
> > : 0,
> > + hdev->log);
> > if (r < 0) {
> > r = -errno;
> > goto fail_log;
> > diff --git a/include/hw/virtio/vhost-backend.h
> > b/include/hw/virtio/vhost-backend.h
> > index 42cfb87..a87f0b3 100644
> > --- a/include/hw/virtio/vhost-backend.h
> > +++ b/include/hw/virtio/vhost-backend.h
> > @@ -20,6 +20,7 @@ typedef enum VhostBackendType {
> >
> > struct vhost_dev;
> > struct vhost_memory;
> > +struct vhost_log;
> > struct vhost_vring_file;
> > struct vhost_vring_state;
> > struct vhost_vring_addr;
> > @@ -36,7 +37,8 @@ typedef int (*vhost_scsi_clear_endpoint_op)(struct
> > vhost_dev *dev,
> > struct vhost_scsi_target
> > *target);
> > typedef int (*vhost_scsi_get_abi_version_op)(struct vhost_dev *dev,
> > int *version);
> > -typedef int (*vhost_set_log_base_op)(struct vhost_dev *dev, uint64_t
> > base);
> > +typedef int (*vhost_set_log_base_op)(struct vhost_dev *dev, uint64_t base,
> > + struct vhost_log *log);
> > typedef int (*vhost_set_mem_table_op)(struct vhost_dev *dev,
> > struct vhost_memory *mem);
> > typedef int (*vhost_set_vring_addr_op)(struct vhost_dev *dev,
> > --
> > 2.4.3
>
