similar to: [PATCH] vhost-net: utilize PUBLISH_USED_IDX feature

With PUBLISH_USED_IDX, guest tells us which used entries it has consumed. This can be used to reduce the number of interrupts: after we write a used entry, if the guest has not yet consumed the previous entry, or if the guest has already consumed the new entry, we do not need to interrupt. This imporves bandwidth by 30% under some workflows. Signed-off-by: Michael S. Tsirkin <mst at

With PUBLISH_USED_IDX, guest tells us which used entries it has consumed. This can be used to reduce the number of interrupts: after we write a used entry, if the guest has not yet consumed the previous entry, or if the guest has already consumed the new entry, we do not need to interrupt. This imporves bandwidth by 30% under some workflows. Signed-off-by: Michael S. Tsirkin <mst at

Currently vhost *_access_ok() functions return int. This is error-prone because there are two popular conventions: 1. 0 means failure, 1 means success 2. -errno means failure, 0 means success Although vhost mostly uses #1, it does not do so consistently. umem_access_ok() uses #2. This patch changes the return type from int to bool so that false means failure and true means success. This

Currently vhost *_access_ok() functions return int. This is error-prone because there are two popular conventions: 1. 0 means failure, 1 means success 2. -errno means failure, 0 means success Although vhost mostly uses #1, it does not do so consistently. umem_access_ok() uses #2. This patch changes the return type from int to bool so that false means failure and true means success. This

On biarch kernels, it is not safe to do copy from/to user, even with use_mm, unless we checked the address range with access_ok previously. Implement these checks to enforce safe memory accesses. Reported-by: Al Viro <viro at zeniv.linux.org.uk> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/net.c | 17 ++++++- drivers/vhost/vhost.c | 111

On biarch kernels, it is not safe to do copy from/to user, even with use_mm, unless we checked the address range with access_ok previously. Implement these checks to enforce safe memory accesses. Reported-by: Al Viro <viro at zeniv.linux.org.uk> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/net.c | 17 ++++++- drivers/vhost/vhost.c | 111

This fixes two issues with recent access checking patch: 1. if (&d->vqs[i].private_data) -> if (d->vqs[i].private_data) 2. we can't forbid log base changes while ring is running, because host needs to resize log in rare cases (e.g. when memory is added with a baloon) and in that case it needs to increase log size with realloc, which might move the log address.

This fixes two issues with recent access checking patch: 1. if (&d->vqs[i].private_data) -> if (d->vqs[i].private_data) 2. we can't forbid log base changes while ring is running, because host needs to resize log in rare cases (e.g. when memory is added with a baloon) and in that case it needs to increase log size with realloc, which might move the log address.

I did an audit for potential integer overflows of values which get passed to access_ok() and here are the results. Signed-off-by: Dan Carpenter <error27 at gmail.com> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index dd3d6f7..c2aa12c 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -429,6 +429,14 @@ static int vq_access_ok(unsigned int num, struct

I did an audit for potential integer overflows of values which get passed to access_ok() and here are the results. Signed-off-by: Dan Carpenter <error27 at gmail.com> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index dd3d6f7..c2aa12c 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -429,6 +429,14 @@ static int vq_access_ok(unsigned int num, struct

Refactor code to make sure features are only accessed under VQ mutex. This makes everything simpler, no need for RCU here anymore. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Note: this is on top of my last pull request drivers/vhost/vhost.h | 11 +++-------- drivers/vhost/net.c | 8 +++----- drivers/vhost/scsi.c | 22 +++++++++++++--------- drivers/vhost/test.c | 9

Refactor code to make sure features are only accessed under VQ mutex. This makes everything simpler, no need for RCU here anymore. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Note: this is on top of my last pull request drivers/vhost/vhost.h | 11 +++-------- drivers/vhost/net.c | 8 +++----- drivers/vhost/scsi.c | 22 +++++++++++++--------- drivers/vhost/test.c | 9

On Sun, Jul 07, 2013 at 02:37:10PM +0300, Michael S. Tsirkin wrote: > On Mon, May 06, 2013 at 08:10:03PM +0800, Asias He wrote: > > On Mon, May 06, 2013 at 01:03:42PM +0300, Michael S. Tsirkin wrote: > > > On Mon, May 06, 2013 at 04:38:21PM +0800, Asias He wrote: > > > > Currently, vhost-net and vhost-scsi are sharing the vhost core code. > > > > However,

Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 2025543..1015464 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -413,6 +413,27 @@ static void vhost_dev_free_iovecs(struct

On 2019/3/7 ??2:43, Souptick Joarder wrote: > On Wed, Mar 6, 2019 at 12:48 PM Jason Wang <jasowang at redhat.com> wrote: >> Signed-off-by: Jason Wang <jasowang at redhat.com> > Is the change log left with any particular reason ? Nope, will add the log. Thanks >> --- >> drivers/vhost/vhost.c | 46 ++++++++++++++++++++++++++++------------------ >> 1

> On 6 Mar 2019, at 08:18, Jason Wang <jasowang at redhat.com> wrote: > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/vhost.c | 46 ++++++++++++++++++++++++++++------------------ > 1 file changed, 28 insertions(+), 18 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 2025543..1015464 100644 >

> On 6 Mar 2019, at 08:18, Jason Wang <jasowang at redhat.com> wrote: > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/vhost.c | 46 ++++++++++++++++++++++++++++------------------ > 1 file changed, 28 insertions(+), 18 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 2025543..1015464 100644 >

Refactor code to make sure features are only accessed under VQ mutex. This makes everything simpler, no need for RCU here anymore. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- This is on top of the recent pull request that I sent. drivers/vhost/vhost.h | 11 +++-------- drivers/vhost/net.c | 8 +++----- drivers/vhost/scsi.c | 22 +++++++++++++---------

Refactor code to make sure features are only accessed under VQ mutex. This makes everything simpler, no need for RCU here anymore. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- This is on top of the recent pull request that I sent. drivers/vhost/vhost.h | 11 +++-------- drivers/vhost/net.c | 8 +++----- drivers/vhost/scsi.c | 22 +++++++++++++---------

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace(qemu) implementation of DMA remapping. The idea is simple, cache the translation in a software device IOTLB (which was implemented as interval tree) in vhost and use vhost_net file descriptor for reporting IOTLB miss and IOTLB update/invalidation. When vhost meets an IOTLB miss, the