similar to: [PATCH] vhost: disable metadata prefetch optimization

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) && \

On 2019/7/26 ??7:51, Michael S. Tsirkin wrote: > This seems to cause guest and host memory corruption. > Disable for now until we get a better handle on that. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > --- > > I put this in linux-next, we'll re-enable if we can fix > the outstanding issues in a short order. Btw, is this more suitable to e.g

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

From: "Michael S. Tsirkin" <mst at redhat.com> This seems to cause guest and host memory corruption. Disable for now until we get a better handle on that. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the range is overlapped with metadata Jason Wang (9):

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: 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 +++++++++++++++++++++++++-----------------

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

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

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Jason Wang (6): vhost: don't set uaddr for invalid address vhost: validate MMU notifier registration vhost: fix vhost map leak vhost: reset invalidate_count in vhost_set_vring_num_addr() vhost: mark dirty pages during map uninit vhost: don't do synchronize_rcu() in

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 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

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 Tue, Jul 23, 2019 at 03:57:14AM -0400, Jason Wang wrote: > The return value of mmu_notifier_register() is not checked in > vhost_vring_set_num_addr(). This will cause an out of sync between mm > and MMU notifier thus a double free. To solve this, introduce a > boolean flag to track whether MMU notifier is registered and only do > unregistering when it was true. > >

Hi all: This series try to fix several issues introduced by meta data accelreation series. Please review. Changes from V3: - remove the unnecessary patch Changes from V2: - use seqlck helper to synchronize MMU notifier with vhost worker Changes from V1: - try not use RCU to syncrhonize MMU notifier with vhost worker - set dirty pages after no readers - return -EAGAIN only when we find the