search for: vhost_zerocopy_callback

vhost_zerocopy_callback accesses VQ right after it drops a ubuf reference. In theory, this could race with device removal which waits on the ubuf kref, and crash on use after free. Do all accesses within rcu read side critical section, and synchronize on release. Since callbacks are always invoked from bh, synchronize_...

vhost_zerocopy_callback accesses VQ right after it drops a ubuf reference. In theory, this could race with device removal which waits on the ubuf kref, and crash on use after free. Do all accesses within rcu read side critical section, and synchronize on release. Since callbacks are always invoked from bh, synchronize_...

...> drivers/vhost/net.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index ff60c2a..d09c17c 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -308,6 +308,11 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) > struct vhost_virtqueue *vq = ubufs->vq; > int cnt = atomic_read(&ubufs->kref.refcount); > > + /* set len to mark this desc buffers done DMA */ > + vq->heads[ubuf->desc].len = success ? > + VHOST_DMA_DONE_LEN : VHOST_DM...

...> drivers/vhost/net.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index ff60c2a..d09c17c 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -308,6 +308,11 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) > struct vhost_virtqueue *vq = ubufs->vq; > int cnt = atomic_read(&ubufs->kref.refcount); > > + /* set len to mark this desc buffers done DMA */ > + vq->heads[ubuf->desc].len = success ? > + VHOST_DMA_DONE_LEN : VHOST_DM...

Hi all: This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V1: - Fix the zerocopy enabling check by changing the check of upend_idx != done_idx to (upend_idx + 1) % UIO_MAXIOV == done_idx. - Switch to use put_user() in

Hi all: This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V1: - Fix the zerocopy enabling check by changing the check of upend_idx != done_idx to (upend_idx + 1) % UIO_MAXIOV == done_idx. - Switch to use put_user() in

tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b, however you can only enable this mode if you know your workload does not trigger heavy guest to host/host to guest traffic - otherwise you get a (minor) performance regression. This patchset addresses this problem by notifying the owner device when callback is invoked because of a data copy. This makes it possible to

tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b, however you can only enable this mode if you know your workload does not trigger heavy guest to host/host to guest traffic - otherwise you get a (minor) performance regression. This patchset addresses this problem by notifying the owner device when callback is invoked because of a data copy. This makes it possible to

This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V2: - Typo fixes and code style fix - Add performance gain in the commit log of patch 2/6 - Retest the update the result in patch 6/6 Changes from V1: - Fix the zerocopy enabling check

This series tries to unify and simplify vhost codes especially for zerocopy. With this series, 5% - 10% improvement for per cpu throughput were seen during netperf guest sending test. Plase review. Changes from V2: - Typo fixes and code style fix - Add performance gain in the commit log of patch 2/6 - Retest the update the result in patch 6/6 Changes from V1: - Fix the zerocopy enabling check

tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b, however you can only enable this mode if you know your workload does not trigger heavy guest to host/host to guest traffic - otherwise you get a (minor) performance regression. This patchset addresses this problem by notifying the owner device when callback is invoked because of a data copy. This makes it possible to

tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b, however you can only enable this mode if you know your workload does not trigger heavy guest to host/host to guest traffic - otherwise you get a (minor) performance regression. This patchset addresses this problem by notifying the owner device when callback is invoked because of a data copy. This makes it possible to

tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b, however you can only enable this mode if you know your workload does not trigger heavy guest to host/host to guest traffic - otherwise you get a (minor) performance regression. This patchset addresses this problem by notifying the owner device when callback is invoked because of a data copy. This makes it possible to

tun supports zero copy transmit since 0690899b4d4501b3505be069b9a687e68ccbe15b, however you can only enable this mode if you know your workload does not trigger heavy guest to host/host to guest traffic - otherwise you get a (minor) performance regression. This patchset addresses this problem by notifying the owner device when callback is invoked because of a data copy. This makes it possible to

...> drivers/vhost/net.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index ff60c2a..d09c17c 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -308,6 +308,11 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) > struct vhost_virtqueue *vq = ubufs->vq; > int cnt = atomic_read(&ubufs->kref.refcount); > > + /* set len to mark this desc buffers done DMA */ > + vq->heads[ubuf->desc].len = success ? > + VHOST_DMA_DONE_LEN : VHOST_DM...

...> drivers/vhost/net.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index ff60c2a..d09c17c 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -308,6 +308,11 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) > struct vhost_virtqueue *vq = ubufs->vq; > int cnt = atomic_read(&ubufs->kref.refcount); > > + /* set len to mark this desc buffers done DMA */ > + vq->heads[ubuf->desc].len = success ? > + VHOST_DMA_DONE_LEN : VHOST_DM...

...> drivers/vhost/net.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 70cab75..a035a89 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -308,6 +308,11 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) > struct vhost_virtqueue *vq = ubufs->vq; > int cnt = atomic_read(&ubufs->kref.refcount); > > + /* set len to mark this desc buffers done DMA */ > + vq->heads[ubuf->desc].len = success ? > + VHOST_DMA_DONE_LEN : VHOST_DM...

...> drivers/vhost/net.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 70cab75..a035a89 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -308,6 +308,11 @@ static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) > struct vhost_virtqueue *vq = ubufs->vq; > int cnt = atomic_read(&ubufs->kref.refcount); > > + /* set len to mark this desc buffers done DMA */ > + vq->heads[ubuf->desc].len = success ? > + VHOST_DMA_DONE_LEN : VHOST_DM...

...ontrol = NULL; > - msg.msg_controllen = 0; > - ubufs = NULL; > - } else { > - struct ubuf_info *ubuf; > - ubuf = nvq->ubuf_info + nvq->upend_idx; > - > - vq->heads[nvq->upend_idx].len = > - VHOST_DMA_IN_PROGRESS; > - ubuf->callback = vhost_zerocopy_callback; > - ubuf->ctx = nvq->ubufs; > - ubuf->desc = nvq->upend_idx; > - msg.msg_control = ubuf; > - msg.msg_controllen = sizeof(ubuf); > - ubufs = nvq->ubufs; > - kref_get(&ubufs->kref); > - } > + vq->heads[nvq->upend_idx].len = VH...

...ontrol = NULL; > - msg.msg_controllen = 0; > - ubufs = NULL; > - } else { > - struct ubuf_info *ubuf; > - ubuf = nvq->ubuf_info + nvq->upend_idx; > - > - vq->heads[nvq->upend_idx].len = > - VHOST_DMA_IN_PROGRESS; > - ubuf->callback = vhost_zerocopy_callback; > - ubuf->ctx = nvq->ubufs; > - ubuf->desc = nvq->upend_idx; > - msg.msg_control = ubuf; > - msg.msg_controllen = sizeof(ubuf); > - ubufs = nvq->ubufs; > - kref_get(&ubufs->kref); > - } > + vq->heads[nvq->upend_idx].len = VH...