* [dpdk-dev] [PATCH] vhost: fix vhost interrupt support
@ 2018-09-04 23:55 Tiwei Bie
2018-09-10 7:22 ` Maxime Coquelin
2018-09-10 13:47 ` [dpdk-dev] " Maxime Coquelin
0 siblings, 2 replies; 7+ messages in thread
From: Tiwei Bie @ 2018-09-04 23:55 UTC (permalink / raw)
To: maxime.coquelin, zhihong.wang, dev; +Cc: stable
When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to
update the avail event to enable the notification.
Fixes: 3f8ff12821e4 ("vhost: support interrupt mode")
Cc: stable@dpdk.org
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
lib/librte_vhost/Makefile | 1 +
lib/librte_vhost/vhost.c | 18 ++++++++++++------
lib/librte_vhost/vhost.h | 2 ++
3 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
index de431fbb7..531cf4832 100644
--- a/lib/librte_vhost/Makefile
+++ b/lib/librte_vhost/Makefile
@@ -13,6 +13,7 @@ LIBABIVER := 4
CFLAGS += -DALLOW_EXPERIMENTAL_API
CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64
CFLAGS += -I vhost_user
+CFLAGS += -fno-strict-aliasing
LDLIBS += -lpthread
ifeq ($(CONFIG_RTE_LIBRTE_VHOST_NUMA),y)
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 3c9be10a0..88b1781d5 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -646,12 +646,18 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
}
static inline void
-vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable)
+vhost_enable_notify_split(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, int enable)
{
- if (enable)
- vq->used->flags &= ~VRING_USED_F_NO_NOTIFY;
- else
- vq->used->flags |= VRING_USED_F_NO_NOTIFY;
+ if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) {
+ if (enable)
+ vq->used->flags &= ~VRING_USED_F_NO_NOTIFY;
+ else
+ vq->used->flags |= VRING_USED_F_NO_NOTIFY;
+ } else {
+ if (enable)
+ vhost_avail_event(vq) = vq->last_avail_idx;
+ }
}
static inline void
@@ -689,7 +695,7 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
if (vq_is_packed(dev))
vhost_enable_notify_packed(dev, vq, enable);
else
- vhost_enable_notify_split(vq, enable);
+ vhost_enable_notify_split(dev, vq, enable);
return 0;
}
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 760a09c0d..25ffd7614 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -648,6 +648,8 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
return __vhost_iova_to_vva(dev, vq, iova, len, perm);
}
+#define vhost_avail_event(vr) \
+ (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size])
#define vhost_used_event(vr) \
(*(volatile uint16_t*)&(vr)->avail->ring[(vr)->size])
--
2.18.0
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [dpdk-dev] [PATCH] vhost: fix vhost interrupt support 2018-09-04 23:55 [dpdk-dev] [PATCH] vhost: fix vhost interrupt support Tiwei Bie @ 2018-09-10 7:22 ` Maxime Coquelin 2018-09-10 7:36 ` Tiwei Bie 2018-09-10 13:47 ` [dpdk-dev] " Maxime Coquelin 1 sibling, 1 reply; 7+ messages in thread From: Maxime Coquelin @ 2018-09-10 7:22 UTC (permalink / raw) To: Tiwei Bie, zhihong.wang, dev; +Cc: stable Hi Tiwei, On 09/05/2018 01:55 AM, Tiwei Bie wrote: > When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to > update the avail event to enable the notification. > > Fixes: 3f8ff12821e4 ("vhost: support interrupt mode") > Cc: stable@dpdk.org > > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> > --- > lib/librte_vhost/Makefile | 1 + > lib/librte_vhost/vhost.c | 18 ++++++++++++------ > lib/librte_vhost/vhost.h | 2 ++ > 3 files changed, 15 insertions(+), 6 deletions(-) > > diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile > index de431fbb7..531cf4832 100644 > --- a/lib/librte_vhost/Makefile > +++ b/lib/librte_vhost/Makefile > @@ -13,6 +13,7 @@ LIBABIVER := 4 > CFLAGS += -DALLOW_EXPERIMENTAL_API > CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 > CFLAGS += -I vhost_user > +CFLAGS += -fno-strict-aliasing I'm not clear why this is needed looking at the code below, could you please explain? > LDLIBS += -lpthread > > ifeq ($(CONFIG_RTE_LIBRTE_VHOST_NUMA),y) > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c > index 3c9be10a0..88b1781d5 100644 > --- a/lib/librte_vhost/vhost.c > +++ b/lib/librte_vhost/vhost.c > @@ -646,12 +646,18 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id) > } > > static inline void > -vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable) > +vhost_enable_notify_split(struct virtio_net *dev, > + struct vhost_virtqueue *vq, int enable) > { > - if (enable) > - vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; > - else > - vq->used->flags |= VRING_USED_F_NO_NOTIFY; > + if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) { > + if (enable) > + vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; > + else > + vq->used->flags |= VRING_USED_F_NO_NOTIFY; > + } else { > + if (enable) > + vhost_avail_event(vq) = vq->last_avail_idx; > + } > } > > static inline void > @@ -689,7 +695,7 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable) > if (vq_is_packed(dev)) > vhost_enable_notify_packed(dev, vq, enable); > else > - vhost_enable_notify_split(vq, enable); > + vhost_enable_notify_split(dev, vq, enable); > > return 0; > } > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > index 760a09c0d..25ffd7614 100644 > --- a/lib/librte_vhost/vhost.h > +++ b/lib/librte_vhost/vhost.h > @@ -648,6 +648,8 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq, > return __vhost_iova_to_vva(dev, vq, iova, len, perm); > } > > +#define vhost_avail_event(vr) \ > + (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > #define vhost_used_event(vr) \ > (*(volatile uint16_t*)&(vr)->avail->ring[(vr)->size]) > > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix vhost interrupt support 2018-09-10 7:22 ` Maxime Coquelin @ 2018-09-10 7:36 ` Tiwei Bie 2018-09-10 7:48 ` Maxime Coquelin 2018-09-14 12:10 ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit 0 siblings, 2 replies; 7+ messages in thread From: Tiwei Bie @ 2018-09-10 7:36 UTC (permalink / raw) To: Maxime Coquelin; +Cc: zhihong.wang, dev, stable Hi Maxime, On Mon, Sep 10, 2018 at 09:22:00AM +0200, Maxime Coquelin wrote: > Hi Tiwei, > > On 09/05/2018 01:55 AM, Tiwei Bie wrote: > > When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to > > update the avail event to enable the notification. > > > > Fixes: 3f8ff12821e4 ("vhost: support interrupt mode") > > Cc: stable@dpdk.org > > > > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> > > --- > > lib/librte_vhost/Makefile | 1 + > > lib/librte_vhost/vhost.c | 18 ++++++++++++------ > > lib/librte_vhost/vhost.h | 2 ++ > > 3 files changed, 15 insertions(+), 6 deletions(-) > > > > diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile > > index de431fbb7..531cf4832 100644 > > --- a/lib/librte_vhost/Makefile > > +++ b/lib/librte_vhost/Makefile > > @@ -13,6 +13,7 @@ LIBABIVER := 4 > > CFLAGS += -DALLOW_EXPERIMENTAL_API > > CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 > > CFLAGS += -I vhost_user > > +CFLAGS += -fno-strict-aliasing > > I'm not clear why this is needed looking at the code below, > could you please explain? Without this, we will get below build error: lib/librte_vhost/vhost.c: In function ‘vhost_enable_notify_split’: lib/librte_vhost/vhost.h:656:4: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/librte_vhost/vhost.c:659:4: note: in expansion of macro ‘vhost_avail_event’ vhost_avail_event(vq) = vq->last_avail_idx; ^~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors > > > LDLIBS += -lpthread > > ifeq ($(CONFIG_RTE_LIBRTE_VHOST_NUMA),y) > > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c > > index 3c9be10a0..88b1781d5 100644 > > --- a/lib/librte_vhost/vhost.c > > +++ b/lib/librte_vhost/vhost.c > > @@ -646,12 +646,18 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id) > > } > > static inline void > > -vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable) > > +vhost_enable_notify_split(struct virtio_net *dev, > > + struct vhost_virtqueue *vq, int enable) > > { > > - if (enable) > > - vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; > > - else > > - vq->used->flags |= VRING_USED_F_NO_NOTIFY; > > + if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) { > > + if (enable) > > + vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; > > + else > > + vq->used->flags |= VRING_USED_F_NO_NOTIFY; > > + } else { > > + if (enable) > > + vhost_avail_event(vq) = vq->last_avail_idx; > > + } > > } > > static inline void > > @@ -689,7 +695,7 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable) > > if (vq_is_packed(dev)) > > vhost_enable_notify_packed(dev, vq, enable); > > else > > - vhost_enable_notify_split(vq, enable); > > + vhost_enable_notify_split(dev, vq, enable); > > return 0; > > } > > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > > index 760a09c0d..25ffd7614 100644 > > --- a/lib/librte_vhost/vhost.h > > +++ b/lib/librte_vhost/vhost.h > > @@ -648,6 +648,8 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq, > > return __vhost_iova_to_vva(dev, vq, iova, len, perm); > > } > > +#define vhost_avail_event(vr) \ > > + (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > > #define vhost_used_event(vr) \ > > (*(volatile uint16_t*)&(vr)->avail->ring[(vr)->size]) > > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix vhost interrupt support 2018-09-10 7:36 ` Tiwei Bie @ 2018-09-10 7:48 ` Maxime Coquelin 2018-09-14 12:10 ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit 1 sibling, 0 replies; 7+ messages in thread From: Maxime Coquelin @ 2018-09-10 7:48 UTC (permalink / raw) To: Tiwei Bie; +Cc: zhihong.wang, dev, stable On 09/10/2018 09:36 AM, Tiwei Bie wrote: > Hi Maxime, > > On Mon, Sep 10, 2018 at 09:22:00AM +0200, Maxime Coquelin wrote: >> Hi Tiwei, >> >> On 09/05/2018 01:55 AM, Tiwei Bie wrote: >>> When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to >>> update the avail event to enable the notification. >>> >>> Fixes: 3f8ff12821e4 ("vhost: support interrupt mode") >>> Cc: stable@dpdk.org >>> >>> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> >>> --- >>> lib/librte_vhost/Makefile | 1 + >>> lib/librte_vhost/vhost.c | 18 ++++++++++++------ >>> lib/librte_vhost/vhost.h | 2 ++ >>> 3 files changed, 15 insertions(+), 6 deletions(-) >>> >>> diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile >>> index de431fbb7..531cf4832 100644 >>> --- a/lib/librte_vhost/Makefile >>> +++ b/lib/librte_vhost/Makefile >>> @@ -13,6 +13,7 @@ LIBABIVER := 4 >>> CFLAGS += -DALLOW_EXPERIMENTAL_API >>> CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 >>> CFLAGS += -I vhost_user >>> +CFLAGS += -fno-strict-aliasing >> >> I'm not clear why this is needed looking at the code below, >> could you please explain? > > Without this, we will get below build error: > > lib/librte_vhost/vhost.c: In function ‘vhost_enable_notify_split’: > lib/librte_vhost/vhost.h:656:4: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] > (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > lib/librte_vhost/vhost.c:659:4: note: in expansion of macro ‘vhost_avail_event’ > vhost_avail_event(vq) = vq->last_avail_idx; > ^~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors OK, thanks for the info. Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> Maxime ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [dpdk-dev] [dpdk-stable] [PATCH] vhost: fix vhost interrupt support 2018-09-10 7:36 ` Tiwei Bie 2018-09-10 7:48 ` Maxime Coquelin @ 2018-09-14 12:10 ` Ferruh Yigit 2018-09-14 14:51 ` Tiwei Bie 1 sibling, 1 reply; 7+ messages in thread From: Ferruh Yigit @ 2018-09-14 12:10 UTC (permalink / raw) To: Tiwei Bie, Maxime Coquelin; +Cc: zhihong.wang, dev, stable On 9/10/2018 8:36 AM, Tiwei Bie wrote: > Hi Maxime, > > On Mon, Sep 10, 2018 at 09:22:00AM +0200, Maxime Coquelin wrote: >> Hi Tiwei, >> >> On 09/05/2018 01:55 AM, Tiwei Bie wrote: >>> When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to >>> update the avail event to enable the notification. >>> >>> Fixes: 3f8ff12821e4 ("vhost: support interrupt mode") >>> Cc: stable@dpdk.org >>> >>> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> >>> --- >>> lib/librte_vhost/Makefile | 1 + >>> lib/librte_vhost/vhost.c | 18 ++++++++++++------ >>> lib/librte_vhost/vhost.h | 2 ++ >>> 3 files changed, 15 insertions(+), 6 deletions(-) >>> >>> diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile >>> index de431fbb7..531cf4832 100644 >>> --- a/lib/librte_vhost/Makefile >>> +++ b/lib/librte_vhost/Makefile >>> @@ -13,6 +13,7 @@ LIBABIVER := 4 >>> CFLAGS += -DALLOW_EXPERIMENTAL_API >>> CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 >>> CFLAGS += -I vhost_user >>> +CFLAGS += -fno-strict-aliasing >> >> I'm not clear why this is needed looking at the code below, >> could you please explain? > > Without this, we will get below build error: > > lib/librte_vhost/vhost.c: In function ‘vhost_enable_notify_split’: > lib/librte_vhost/vhost.h:656:4: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] > (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > lib/librte_vhost/vhost.c:659:4: note: in expansion of macro ‘vhost_avail_event’ > vhost_avail_event(vq) = vq->last_avail_idx; > ^~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > Getting this error with meson build system, since "-fno-strict-aliasing" is not added to meson build file. BUT instead of disabling compiler warning, first element of the "struct vring_used_elem ring[0]" is "uint32_t id;", so it should be accessed as uint32_t. What about following: #define vhost_avail_event(vr) \ - (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) + (*(volatile uint32_t*)&(vr)->used->ring[(vr)->size]) And for "vhost_avail_event(vq) = vq->last_avail_idx;", "last_avail_idx" is uint16_t, so assigning from uint16_t to uint32_t should be ok too. If above works for you please send a patch for update also removing "-fno-strict-aliasing", this can be rebased on existing patch. If not works, please at least send a patch to add flag to meson build file Thanks, ferruh >> >>> LDLIBS += -lpthread >>> ifeq ($(CONFIG_RTE_LIBRTE_VHOST_NUMA),y) >>> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c >>> index 3c9be10a0..88b1781d5 100644 >>> --- a/lib/librte_vhost/vhost.c >>> +++ b/lib/librte_vhost/vhost.c >>> @@ -646,12 +646,18 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id) >>> } >>> static inline void >>> -vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable) >>> +vhost_enable_notify_split(struct virtio_net *dev, >>> + struct vhost_virtqueue *vq, int enable) >>> { >>> - if (enable) >>> - vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; >>> - else >>> - vq->used->flags |= VRING_USED_F_NO_NOTIFY; >>> + if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) { >>> + if (enable) >>> + vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; >>> + else >>> + vq->used->flags |= VRING_USED_F_NO_NOTIFY; >>> + } else { >>> + if (enable) >>> + vhost_avail_event(vq) = vq->last_avail_idx; >>> + } >>> } >>> static inline void >>> @@ -689,7 +695,7 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable) >>> if (vq_is_packed(dev)) >>> vhost_enable_notify_packed(dev, vq, enable); >>> else >>> - vhost_enable_notify_split(vq, enable); >>> + vhost_enable_notify_split(dev, vq, enable); >>> return 0; >>> } >>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h >>> index 760a09c0d..25ffd7614 100644 >>> --- a/lib/librte_vhost/vhost.h >>> +++ b/lib/librte_vhost/vhost.h >>> @@ -648,6 +648,8 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq, >>> return __vhost_iova_to_vva(dev, vq, iova, len, perm); >>> } >>> +#define vhost_avail_event(vr) \ >>> + (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) >>> #define vhost_used_event(vr) \ >>> (*(volatile uint16_t*)&(vr)->avail->ring[(vr)->size]) >>> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [dpdk-dev] [dpdk-stable] [PATCH] vhost: fix vhost interrupt support 2018-09-14 12:10 ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit @ 2018-09-14 14:51 ` Tiwei Bie 0 siblings, 0 replies; 7+ messages in thread From: Tiwei Bie @ 2018-09-14 14:51 UTC (permalink / raw) To: Ferruh Yigit; +Cc: Maxime Coquelin, zhihong.wang, dev, stable On Fri, Sep 14, 2018 at 01:10:07PM +0100, Ferruh Yigit wrote: > On 9/10/2018 8:36 AM, Tiwei Bie wrote: > > Hi Maxime, > > > > On Mon, Sep 10, 2018 at 09:22:00AM +0200, Maxime Coquelin wrote: > >> Hi Tiwei, > >> > >> On 09/05/2018 01:55 AM, Tiwei Bie wrote: > >>> When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to > >>> update the avail event to enable the notification. > >>> > >>> Fixes: 3f8ff12821e4 ("vhost: support interrupt mode") > >>> Cc: stable@dpdk.org > >>> > >>> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> > >>> --- > >>> lib/librte_vhost/Makefile | 1 + > >>> lib/librte_vhost/vhost.c | 18 ++++++++++++------ > >>> lib/librte_vhost/vhost.h | 2 ++ > >>> 3 files changed, 15 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile > >>> index de431fbb7..531cf4832 100644 > >>> --- a/lib/librte_vhost/Makefile > >>> +++ b/lib/librte_vhost/Makefile > >>> @@ -13,6 +13,7 @@ LIBABIVER := 4 > >>> CFLAGS += -DALLOW_EXPERIMENTAL_API > >>> CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 > >>> CFLAGS += -I vhost_user > >>> +CFLAGS += -fno-strict-aliasing > >> > >> I'm not clear why this is needed looking at the code below, > >> could you please explain? > > > > Without this, we will get below build error: > > > > lib/librte_vhost/vhost.c: In function ‘vhost_enable_notify_split’: > > lib/librte_vhost/vhost.h:656:4: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] > > (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > lib/librte_vhost/vhost.c:659:4: note: in expansion of macro ‘vhost_avail_event’ > > vhost_avail_event(vq) = vq->last_avail_idx; > > ^~~~~~~~~~~~~~~~~ > > cc1: all warnings being treated as errors > > > > Getting this error with meson build system, since "-fno-strict-aliasing" is not > added to meson build file. Thanks! I didn't notice this. I just tried the meson build manually. The warning isn't treated as errors on my side. So it was not caught by the build script.. > BUT instead of disabling compiler warning, > > first element of the "struct vring_used_elem ring[0]" is "uint32_t id;", so it > should be accessed as uint32_t. What about following: > > #define vhost_avail_event(vr) \ > - (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > + (*(volatile uint32_t*)&(vr)->used->ring[(vr)->size]) > > And for "vhost_avail_event(vq) = vq->last_avail_idx;", "last_avail_idx" is > uint16_t, so assigning from uint16_t to uint32_t should be ok too. At the end of used ring, there is a 16bits event_idx. It can't be interpreted as a vring_used_elem and it's also not part of a vring_used_elem. This is the traditional way how we access it: https://github.com/torvalds/linux/blob/a06b0c82a049/drivers/vhost/vhost.c#L50 https://github.com/freebsd/freebsd/blob/209b94df8701/sys/dev/virtio/virtio_ring.h#L133 > > If above works for you please send a patch for update also removing > "-fno-strict-aliasing", this can be rebased on existing patch. > > If not works, please at least send a patch to add flag to meson build file I'll send a patch to add flag to meson build file. Thanks! > > Thanks, > ferruh > > >> > >>> LDLIBS += -lpthread > >>> ifeq ($(CONFIG_RTE_LIBRTE_VHOST_NUMA),y) > >>> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c > >>> index 3c9be10a0..88b1781d5 100644 > >>> --- a/lib/librte_vhost/vhost.c > >>> +++ b/lib/librte_vhost/vhost.c > >>> @@ -646,12 +646,18 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id) > >>> } > >>> static inline void > >>> -vhost_enable_notify_split(struct vhost_virtqueue *vq, int enable) > >>> +vhost_enable_notify_split(struct virtio_net *dev, > >>> + struct vhost_virtqueue *vq, int enable) > >>> { > >>> - if (enable) > >>> - vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; > >>> - else > >>> - vq->used->flags |= VRING_USED_F_NO_NOTIFY; > >>> + if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) { > >>> + if (enable) > >>> + vq->used->flags &= ~VRING_USED_F_NO_NOTIFY; > >>> + else > >>> + vq->used->flags |= VRING_USED_F_NO_NOTIFY; > >>> + } else { > >>> + if (enable) > >>> + vhost_avail_event(vq) = vq->last_avail_idx; > >>> + } > >>> } > >>> static inline void > >>> @@ -689,7 +695,7 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable) > >>> if (vq_is_packed(dev)) > >>> vhost_enable_notify_packed(dev, vq, enable); > >>> else > >>> - vhost_enable_notify_split(vq, enable); > >>> + vhost_enable_notify_split(dev, vq, enable); > >>> return 0; > >>> } > >>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > >>> index 760a09c0d..25ffd7614 100644 > >>> --- a/lib/librte_vhost/vhost.h > >>> +++ b/lib/librte_vhost/vhost.h > >>> @@ -648,6 +648,8 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq, > >>> return __vhost_iova_to_vva(dev, vq, iova, len, perm); > >>> } > >>> +#define vhost_avail_event(vr) \ > >>> + (*(volatile uint16_t*)&(vr)->used->ring[(vr)->size]) > >>> #define vhost_used_event(vr) \ > >>> (*(volatile uint16_t*)&(vr)->avail->ring[(vr)->size]) > >>> > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix vhost interrupt support 2018-09-04 23:55 [dpdk-dev] [PATCH] vhost: fix vhost interrupt support Tiwei Bie 2018-09-10 7:22 ` Maxime Coquelin @ 2018-09-10 13:47 ` Maxime Coquelin 1 sibling, 0 replies; 7+ messages in thread From: Maxime Coquelin @ 2018-09-10 13:47 UTC (permalink / raw) To: Tiwei Bie, zhihong.wang, dev; +Cc: stable On 09/05/2018 01:55 AM, Tiwei Bie wrote: > When VIRTIO_RING_F_EVENT_IDX is negotiated, we need to > update the avail event to enable the notification. > > Fixes: 3f8ff12821e4 ("vhost: support interrupt mode") > Cc:stable@dpdk.org > > Signed-off-by: Tiwei Bie<tiwei.bie@intel.com> > --- > lib/librte_vhost/Makefile | 1 + > lib/librte_vhost/vhost.c | 18 ++++++++++++------ > lib/librte_vhost/vhost.h | 2 ++ > 3 files changed, 15 insertions(+), 6 deletions(-) Applied to dpdk-next-virtio/master. Thanks! Maxime ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-09-14 14:52 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-09-04 23:55 [dpdk-dev] [PATCH] vhost: fix vhost interrupt support Tiwei Bie 2018-09-10 7:22 ` Maxime Coquelin 2018-09-10 7:36 ` Tiwei Bie 2018-09-10 7:48 ` Maxime Coquelin 2018-09-14 12:10 ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit 2018-09-14 14:51 ` Tiwei Bie 2018-09-10 13:47 ` [dpdk-dev] " Maxime Coquelin
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