similar to: [PATCH V2] vhost: introduce O(1) vq metadata cache

When device IOTLB is enabled, all address translations were stored in interval tree. O(lgN) searching time could be slow for virtqueue metadata (avail, used and descriptors) since they were accessed much often than other addresses. So this patch introduces an O(1) array which points to the interval tree nodes that store the translations of vq metadata. Those array were update during vq IOTLB

When device IOTLB is enabled, all address translations were stored in interval tree. O(lgN) searching time could be slow for virtqueue metadata (avail, used and descriptors) since they were accessed much often than other addresses. So this patch introduces an O(1) array which points to the interval tree nodes that store the translations of vq metadata. Those array were update during vq IOTLB

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

On 2019/12/13 ??5:15, Leonardo Bras wrote: > There is no need for this else statement, given that if block will return. > This change is not supposed to change the output binary. > > It reduces identation level on most lines in this function, and also > fixes an split string on vq_err(). > > Signed-off-by: Leonardo Bras <leonardo at linux.ibm.com> > --- >

It was reported that metadata acceleration introduces several issues, so this patch reverts commit ff466032dc9e5a61217f22ea34b2df932786bbfc, 73f628ec9e6bcc45b77c53fe6d0c0ec55eaf82af and 0b4a7092ffe568a55bf8f3cefdf79ff666586d91. We will rework it on the next version. Cc: Jason Gunthorpe <jgg at mellanox.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c

This is a rework on the commit 7f466032dc9e ("vhost: access vq metadata through kernel virtual address"). It was noticed that the copy_to/from_user() friends that was used to access virtqueue metdata tends to be very expensive for dataplane implementation like vhost since it involves lots of software checks, speculation barriers, hardware feature toggling (e.g SMAP). The extra cost will

It was noticed that the copy_user() friends that was used to access virtqueue metdata tends to be very expensive for dataplane implementation like vhost since it involves lots of software checks, speculation barrier, hardware feature toggling (e.g SMAP). The extra cost will be more obvious when transferring small packets since the time spent on metadata accessing become significant.. This patch

On Thu, Sep 05, 2019 at 08:27:35PM +0800, Jason Wang wrote: > It was reported that metadata acceleration introduces several issues, > so this patch reverts commit ff466032dc9e5a61217f22ea34b2df932786bbfc, > 73f628ec9e6bcc45b77c53fe6d0c0ec55eaf82af and > 0b4a7092ffe568a55bf8f3cefdf79ff666586d91. > > We will rework it on the next version. > > Cc: Jason Gunthorpe <jgg at

This patch factors out IOTLB into a dedicated module in order to be reused by other modules like vringh. User may choose to enable the automatic retiring by specifying VHOST_IOTLB_FLAG_RETIRE flag to fit for the case of vhost device IOTLB implementation. Signed-off-by: Jason Wang <jasowang at redhat.com> --- MAINTAINERS | 1 + drivers/vhost/Kconfig | 7 ++

It was noticed that the copy_user() friends that was used to access virtqueue metdata tends to be very expensive for dataplane implementation like vhost since it involves lots of software checks, speculation barrier, hardware feature toggling (e.g SMAP). The extra cost will be more obvious when transferring small packets since the time spent on metadata accessing become significant.. This patch

vhost logging uses of vq_err has a few defects and style inconsistencies. o pr_debug already uses pr_fmt so its use in vq_err is defective however no #defines of pr_fmt exist in this code so no actual defects exist o vq_err uses need terminating newlines so add the missing ones o Coalesce formats and realign arguments Signed-off-by: Joe Perches <joe at perches.com> ---

vhost logging uses of vq_err has a few defects and style inconsistencies. o pr_debug already uses pr_fmt so its use in vq_err is defective however no #defines of pr_fmt exist in this code so no actual defects exist o vq_err uses need terminating newlines so add the missing ones o Coalesce formats and realign arguments Signed-off-by: Joe Perches <joe at perches.com> ---

This patch introduces support for event suppression. This is done by have a two areas: device area and driver area. One side could then try to disable or enable (delayed) notification from other side by using a boolean hint or event index interface in the areas. For more information, please refer Virtio spec. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c |

This patch introduces basic support for event suppression aka driver and device area. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c | 168 ++++++++++++++++++++++++++++++++++++--- drivers/vhost/vhost.h | 10 ++- include/uapi/linux/virtio_ring.h | 19 +++++ 3 files changed, 182 insertions(+), 15 deletions(-) diff --git

This patch introduces basic support for event suppression aka driver and device area. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++--- drivers/vhost/vhost.h | 10 +- include/uapi/linux/virtio_ring.h | 19 ++++ 3 files changed, 204 insertions(+), 16 deletions(-) diff --git

It was noticed that the copy_user() friends that was used to access virtqueue metdata tends to be very expensive for dataplane implementation like vhost since it involves lots of software checks, speculation barrier, hardware feature toggling (e.g SMAP). The extra cost will be more obvious when transferring small packets since the time spent on metadata accessing become more significant. This

This patch introduces basic support for event suppression aka driver and device area. Compile tested only. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c | 169 ++++++++++++++++++++++++++++++++++++--- drivers/vhost/vhost.h | 10 ++- include/uapi/linux/virtio_ring.h | 19 +++++ 3 files changed, 183 insertions(+), 15 deletions(-) diff

On Tue, May 29, 2018 at 10:10:30AM +0800, Jason Wang wrote: > This patch introduces basic support for event suppression aka driver > and device area. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++--- > drivers/vhost/vhost.h | 10 +- >

On Tue, May 29, 2018 at 10:10:30AM +0800, Jason Wang wrote: > This patch introduces basic support for event suppression aka driver > and device area. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/vhost.c | 191 ++++++++++++++++++++++++++++++++++++--- > drivers/vhost/vhost.h | 10 +- >

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