search for: virt_xxx

drivers/xen/xenbus/xenbus_comms.c uses full memory barriers to communicate with the other side. For guests compiled with CONFIG_SMP, smp_wmb and smp_mb would be sufficient, so mb() and wmb() here are only needed if a non-SMP guest runs on an SMP host. Switch to virt_xxx barriers which serve this exact purpose. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/xen/xenbus/xenbus_comms.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index fdb0f3...

include/xen/interface/io/ring.h uses full memory barriers to communicate with the other side. For guests compiled with CONFIG_SMP, smp_wmb and smp_mb would be sufficient, so mb() and wmb() here are only needed if a non-SMP guest runs on an SMP host. Switch to virt_xxx barriers which serve this exact purpose. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/xen/interface/io/ring.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h index 7dc...

...__smp_xxx metag: define __smp_xxx mips: define __smp_xxx s390: define __smp_xxx sh: define __smp_xxx, fix smp_store_mb for !SMP sparc: define __smp_xxx tile: define __smp_xxx xtensa: define __smp_xxx x86: define __smp_xxx asm-generic: implement virt_xxx memory barriers Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" virtio_ring: update weak barriers to use virt_xxx sh: support 1 and 2 byte xchg sh: move xchg_cmpxchg to a header by itself virtio_ring: use virt_store_mb xenbus: use virt_xxx...

...__smp_xxx metag: define __smp_xxx mips: define __smp_xxx s390: define __smp_xxx sh: define __smp_xxx, fix smp_store_mb for !SMP sparc: define __smp_xxx tile: define __smp_xxx xtensa: define __smp_xxx x86: define __smp_xxx asm-generic: implement virt_xxx memory barriers Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" virtio_ring: update weak barriers to use virt_xxx sh: support 1 and 2 byte xchg sh: move xchg_cmpxchg to a header by itself virtio_ring: use virt_store_mb xenbus: use virt_xxx...

drivers/xen/events/events_fifo.c uses rmb() to communicate with the other side. For guests compiled with CONFIG_SMP, smp_rmb would be sufficient, so rmb() here is only needed if a non-SMP guest runs on an SMP host. Switch to the virt_rmb barrier which serves this exact purpose. Pull in asm/barrier.h here to make sure the file is self-contained. Suggested-by: David Vrabel <david.vrabel at

Fix build after API changes. Reported-by: Kamal Mostafa <kamal at canonical.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/asm/barrier.h | 22 +++++++++++++--------- tools/virtio/linux/compiler.h | 9 +++++++++ tools/virtio/linux/kernel.h | 1 + 3 files changed, 23 insertions(+), 9 deletions(-) create mode 100644 tools/virtio/linux/compiler.h

Fix build after API changes. Reported-by: Kamal Mostafa <kamal at canonical.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- tools/virtio/asm/barrier.h | 22 +++++++++++++--------- tools/virtio/linux/compiler.h | 9 +++++++++ tools/virtio/linux/kernel.h | 1 + 3 files changed, 23 insertions(+), 9 deletions(-) create mode 100644 tools/virtio/linux/compiler.h

...> mips: define __smp_xxx > s390: define __smp_xxx > sh: define __smp_xxx, fix smp_store_mb for !SMP > sparc: define __smp_xxx > tile: define __smp_xxx > xtensa: define __smp_xxx > x86: define __smp_xxx > asm-generic: implement virt_xxx memory barriers > Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" > virtio_ring: update weak barriers to use virt_xxx > sh: support 1 and 2 byte xchg > sh: move xchg_cmpxchg to a header by itself > virtio_ring: use virt_store_mb &...

...has the benefit of cleaning out a bunch of duplicated ifdefs on a bunch of architectures - this patchset brings about a net reduction in LOC, even with new barriers and extra documentation :) Then virt can use __smp_XXX when talking to an SMP host. To make those users explicit, this patchset adds virt_xxx wrappers for them. Touching all archs is a tad tedious, but its fairly straight forward. The rest of the patchset is structured as follows: -. Patch 1 fixes a bug in asm-generic. It is already in tip, included here for completeness. -. Patches 2-12 make sure barrier.h on all remaining ar...

...has the benefit of cleaning out a bunch of duplicated ifdefs on a bunch of architectures - this patchset brings about a net reduction in LOC, even with new barriers and extra documentation :) Then virt can use __smp_XXX when talking to an SMP host. To make those users explicit, this patchset adds virt_xxx wrappers for them. Touching all archs is a tad tedious, but its fairly straight forward. The rest of the patchset is structured as follows: -. Patch 1 fixes a bug in asm-generic. It is already in tip, included here for completeness. -. Patches 2-12 make sure barrier.h on all remaining ar...

...use the generic version - > in other words, it just might be that for s390 smp_ and virt_ > barriers must be equivalent. The definition of the memory barriers is independent from the fact if the system is running on an hypervisor or not. Is there really an architecture where you need special virt_xxx barriers?!? -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.

...use the generic version - > in other words, it just might be that for s390 smp_ and virt_ > barriers must be equivalent. The definition of the memory barriers is independent from the fact if the system is running on an hypervisor or not. Is there really an architecture where you need special virt_xxx barriers?!? -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.

For several reasons, it would be beneficial to kill off ACCESS_ONCE() tree-wide, in favour of {READ,WRITE}_ONCE(). These work with aggregate types, more obviously document their intended behaviour, and are necessary for tools like KTSAN to work correctly (as otherwise reads and writes cannot be instrumented separately). While it's possible to script the bulk of this tree-wide conversion, some

For several reasons, it would be beneficial to kill off ACCESS_ONCE() tree-wide, in favour of {READ,WRITE}_ONCE(). These work with aggregate types, more obviously document their intended behaviour, and are necessary for tools like KTSAN to work correctly (as otherwise reads and writes cannot be instrumented separately). While it's possible to script the bulk of this tree-wide conversion, some

...duplicated ifdefs on a bunch of architectures - this patchset brings about a net reduction in LOC, more than compensated for later by performance enhancements, extra documentation and tools :) Then virt can use __smp_XXX when talking to an SMP host. To make those users explicit, this patchset adds virt_xxx wrappers for them. Touching all archs is a tad tedious, but its fairly straight forward. The patchset is structured as follows: -. Patch 1 fixes a bug in asm-generic. It is already in tip, included here for completeness. -. Patches 2-12 make sure barrier.h on all remaining architectures...

...duplicated ifdefs on a bunch of architectures - this patchset brings about a net reduction in LOC, more than compensated for later by performance enhancements, extra documentation and tools :) Then virt can use __smp_XXX when talking to an SMP host. To make those users explicit, this patchset adds virt_xxx wrappers for them. Touching all archs is a tad tedious, but its fairly straight forward. The patchset is structured as follows: -. Patch 1 fixes a bug in asm-generic. It is already in tip, included here for completeness. -. Patches 2-12 make sure barrier.h on all remaining architectures...

...ers to 'val' for its cast, and thus won't work unless > there's a variable of the correct type that happens to be called 'var'. > > Fix this with s/var/val/, making READ_ONCE() work as expected regardless. > > Fixes: a7c490333df3cff5 ("tools/virtio: use virt_xxx barriers") > Signed-off-by: Mark Rutland <mark.rutland at arm.com> > Cc: Jason Wang <jasowang at redhat.com> > Cc: Michael S. Tsirkin <mst at redhat.com> > Cc: linux-kernel at vger.kernel.org > Cc: virtualization at lists.linux-foundation.org > --- > too...

...efers to 'val' for its cast, and thus won't work unless > there's a variable of the correct type that happens to be called 'var'. > > Fix this with s/var/val/, making READ_ONCE() work as expected regardless. > > Fixes: a7c490333df3cff5 ("tools/virtio: use virt_xxx barriers") > Signed-off-by: Mark Rutland <mark.rutland at arm.com> > Cc: Jason Wang <jasowang at redhat.com> > Cc: Michael S. Tsirkin <mst at redhat.com> > Cc: linux-kernel at vger.kernel.org > Cc: virtualization at lists.linux-foundation.org > --- > to...

...#39;, but erroneously refers to 'val' for its cast, and thus won't work unless there's a variable of the correct type that happens to be called 'var'. Fix this with s/var/val/, making READ_ONCE() work as expected regardless. Fixes: a7c490333df3cff5 ("tools/virtio: use virt_xxx barriers") Signed-off-by: Mark Rutland <mark.rutland at arm.com> Cc: Jason Wang <jasowang at redhat.com> Cc: Michael S. Tsirkin <mst at redhat.com> Cc: linux-kernel at vger.kernel.org Cc: virtualization at lists.linux-foundation.org Signed-off-by: Michael S. Tsirkin <mst a...

...#39;, but erroneously refers to 'val' for its cast, and thus won't work unless there's a variable of the correct type that happens to be called 'var'. Fix this with s/var/val/, making READ_ONCE() work as expected regardless. Fixes: a7c490333df3cff5 ("tools/virtio: use virt_xxx barriers") Signed-off-by: Mark Rutland <mark.rutland at arm.com> Cc: Jason Wang <jasowang at redhat.com> Cc: Michael S. Tsirkin <mst at redhat.com> Cc: linux-kernel at vger.kernel.org Cc: virtualization at lists.linux-foundation.org --- tools/virtio/linux/compiler.h | 2 +-...