similar to: INFO: rcu detected stall in vhost_worker

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

On Thu, Sep 05, 2019 at 08:27:36PM +0800, Jason Wang wrote: > 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

On Thu, Sep 05, 2019 at 08:27:36PM +0800, Jason Wang wrote: > 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

On Fri, Jul 26, 2019 at 8:26 AM syzbot <syzbot+36e93b425cd6eb54fcc1 at syzkaller.appspotmail.com> wrote: > > syzbot has bisected this bug to: > > commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 > Author: Linus Torvalds <torvalds at linux-foundation.org> > Date: Sun Jul 7 22:41:56 2019 +0000 > > Linux 5.2 That seems very unlikely. That commit literally

Hi: Per request from Michael and Jason, the metadata accelreation is reverted in this version and rework in next version. Please review. Thanks Jason Wang (2): Revert "vhost: access vq metadata through kernel virtual address" vhost: re-introducing metadata acceleration through kernel virtual address drivers/vhost/vhost.c | 202 +++++++++++++++++++++++++-----------------

Hi: Per request from Michael and Jason, the metadata accelreation is reverted in this version and rework in next version. Please review. Thanks Jason Wang (2): Revert "vhost: access vq metadata through kernel virtual address" vhost: re-introducing metadata acceleration through kernel virtual address drivers/vhost/vhost.c | 202 +++++++++++++++++++++++++-----------------

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

On Mon, Sep 09, 2019 at 10:18:57AM +0800, Jason Wang wrote: > > On 2019/9/8 ??7:05, Michael S. Tsirkin wrote: > > On Thu, Sep 05, 2019 at 08:27:36PM +0800, Jason Wang wrote: > > > This is a rework on the commit 7f466032dc9e ("vhost: access vq > > > metadata through kernel virtual address"). > > > > > > It was noticed that the

On 2019/9/8 ??7:05, Michael S. Tsirkin wrote: > On Thu, Sep 05, 2019 at 08:27:36PM +0800, Jason Wang wrote: >> 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

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

Clang warns: drivers/vhost/vhost.c:2085:5: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined] #if VHOST_ARCH_CAN_ACCEL_UACCESS ^ drivers/vhost/vhost.h:98:38: note: expanded from macro 'VHOST_ARCH_CAN_ACCEL_UACCESS' #define VHOST_ARCH_CAN_ACCEL_UACCESS defined(CONFIG_MMU_NOTIFIER) && \

Clang warns: drivers/vhost/vhost.c:2085:5: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined] #if VHOST_ARCH_CAN_ACCEL_UACCESS ^ drivers/vhost/vhost.h:98:38: note: expanded from macro 'VHOST_ARCH_CAN_ACCEL_UACCESS' #define VHOST_ARCH_CAN_ACCEL_UACCESS defined(CONFIG_MMU_NOTIFIER) && \

This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM doesn't see obvious

Hi: This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling like SMAP. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM

Hi: This series tries to access virtqueue metadata through kernel virtual address instead of copy_user() friends since they had too much overheads like checks, spec barriers or even hardware feature toggling like SMAP. This is done through setup kernel address through direct mapping and co-opreate VM management with MMU notifiers. Test shows about 23% improvement on TX PPS. TCP_STREAM

On Thu, Jun 06, 2019 at 09:12:23AM -0700, Nathan Chancellor wrote: > Clang warns: > > drivers/vhost/vhost.c:2085:5: warning: macro expansion producing > 'defined' has undefined behavior [-Wexpansion-to-defined] > #if VHOST_ARCH_CAN_ACCEL_UACCESS > ^ > drivers/vhost/vhost.h:98:38: note: expanded from macro > 'VHOST_ARCH_CAN_ACCEL_UACCESS'

Hi: This small series try to fix several bugs of ptr_ring usage in vhost_net. Please review. Thanks Alexander Potapenko (1): vhost_net: initialize rx_ring in vhost_net_open() Jason Wang (2): vhost_net: keep private_data and rx_ring synced vhost_net: examine pointer types during un-producing drivers/net/tun.c | 3 ++- drivers/vhost/net.c | 8 +++++--- include/linux/if_tun.h | 4

From: Alexander Potapenko <glider at google.com> KMSAN reported a use of uninit memory in vhost_net_buf_unproduce() while trying to access n->vqs[VHOST_NET_VQ_TX].rx_ring: ================================================================== BUG: KMSAN: use of uninitialized memory in vhost_net_buf_unproduce+0x7bb/0x9a0 drivers/vho et.c:170 CPU: 0 PID: 3021 Comm: syz-fuzzer Not tainted

On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote: > This patch adds kcov_remote_start/kcov_remote_stop annotations to the > vhost_worker function, which is responsible for processing vhost works. > Since vhost_worker is spawned when a vhost device instance is created, > the common kcov handle is used for kcov_remote_start/stop annotations. > > Signed-off-by:

On Thu, Oct 17, 2019 at 09:00:18PM +0200, Andrey Konovalov wrote: > On Thu, Oct 17, 2019 at 8:18 PM Greg Kroah-Hartman > <gregkh at linuxfoundation.org> wrote: > > > > On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote: > > > This patch adds kcov_remote_start/kcov_remote_stop annotations to the > > > vhost_worker function, which is