vhost: reduce memory footprint when IOMMU is disabled
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Commit Message
If an application does not request IOMMU support, we can avoid
allocating a IOMMU pool.
This saves 112kB (IOTLB_CACHE_SIZE * sizeof(struct vhost_iotlb_entry))
per vq.
Signed-off-by: David Marchand <david.marchand@redhat.com>
---
lib/vhost/iotlb.c | 20 +++++++++++---------
lib/vhost/socket.c | 4 +++-
lib/vhost/vhost.c | 7 ++++++-
lib/vhost/vhost.h | 5 ++++-
4 files changed, 24 insertions(+), 12 deletions(-)
Comments
> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Friday, September 16, 2022 5:02 PM
> To: dev@dpdk.org
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; Xia, Chenbo
> <chenbo.xia@intel.com>
> Subject: [PATCH] vhost: reduce memory footprint when IOMMU is disabled
>
> If an application does not request IOMMU support, we can avoid
> allocating a IOMMU pool.
>
> This saves 112kB (IOTLB_CACHE_SIZE * sizeof(struct vhost_iotlb_entry))
> per vq.
>
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
> lib/vhost/iotlb.c | 20 +++++++++++---------
> lib/vhost/socket.c | 4 +++-
> lib/vhost/vhost.c | 7 ++++++-
> lib/vhost/vhost.h | 5 ++++-
> 4 files changed, 24 insertions(+), 12 deletions(-)
The compilation issue seems not related to this patch.
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia@intel.com>
> Sent: Thursday, September 22, 2022 9:09 PM
> To: David Marchand <david.marchand@redhat.com>; dev@dpdk.org
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: RE: [PATCH] vhost: reduce memory footprint when IOMMU is disabled
>
> > -----Original Message-----
> > From: David Marchand <david.marchand@redhat.com>
> > Sent: Friday, September 16, 2022 5:02 PM
> > To: dev@dpdk.org
> > Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; Xia, Chenbo
> > <chenbo.xia@intel.com>
> > Subject: [PATCH] vhost: reduce memory footprint when IOMMU is disabled
> >
> > If an application does not request IOMMU support, we can avoid
> > allocating a IOMMU pool.
> >
> > This saves 112kB (IOTLB_CACHE_SIZE * sizeof(struct vhost_iotlb_entry))
> > per vq.
> >
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
> > ---
> > lib/vhost/iotlb.c | 20 +++++++++++---------
> > lib/vhost/socket.c | 4 +++-
> > lib/vhost/vhost.c | 7 ++++++-
> > lib/vhost/vhost.h | 5 ++++-
> > 4 files changed, 24 insertions(+), 12 deletions(-)
>
> The compilation issue seems not related to this patch.
>
> Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
Applied to next-virtio/main, thanks
@@ -341,16 +341,18 @@ vhost_user_iotlb_init(struct virtio_net *dev, struct vhost_virtqueue *vq)
TAILQ_INIT(&vq->iotlb_list);
TAILQ_INIT(&vq->iotlb_pending_list);
- vq->iotlb_pool = rte_calloc_socket("iotlb", IOTLB_CACHE_SIZE,
- sizeof(struct vhost_iotlb_entry), 0, socket);
- if (!vq->iotlb_pool) {
- VHOST_LOG_CONFIG(dev->ifname, ERR,
- "Failed to create IOTLB cache pool for vq %"PRIu32"\n",
- vq->index);
- return -1;
+ if (dev->flags & VIRTIO_DEV_SUPPORT_IOMMU) {
+ vq->iotlb_pool = rte_calloc_socket("iotlb", IOTLB_CACHE_SIZE,
+ sizeof(struct vhost_iotlb_entry), 0, socket);
+ if (!vq->iotlb_pool) {
+ VHOST_LOG_CONFIG(dev->ifname, ERR,
+ "Failed to create IOTLB cache pool for vq %"PRIu32"\n",
+ vq->index);
+ return -1;
+ }
+ for (i = 0; i < IOTLB_CACHE_SIZE; i++)
+ vhost_user_iotlb_pool_put(vq, &vq->iotlb_pool[i]);
}
- for (i = 0; i < IOTLB_CACHE_SIZE; i++)
- vhost_user_iotlb_pool_put(vq, &vq->iotlb_pool[i]);
vq->iotlb_cache_nr = 0;
@@ -228,7 +228,8 @@ vhost_user_add_connection(int fd, struct vhost_user_socket *vsocket)
vhost_set_ifname(vid, vsocket->path, size);
vhost_setup_virtio_net(vid, vsocket->use_builtin_virtio_net,
- vsocket->net_compliant_ol_flags, vsocket->stats_enabled);
+ vsocket->net_compliant_ol_flags, vsocket->stats_enabled,
+ vsocket->iommu_support);
vhost_attach_vdpa_device(vid, vsocket->vdpa_dev);
@@ -905,6 +906,7 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
vsocket->async_copy = flags & RTE_VHOST_USER_ASYNC_COPY;
vsocket->net_compliant_ol_flags = flags & RTE_VHOST_USER_NET_COMPLIANT_OL_FLAGS;
vsocket->stats_enabled = flags & RTE_VHOST_USER_NET_STATS_ENABLE;
+ vsocket->iommu_support = flags & RTE_VHOST_USER_IOMMU_SUPPORT;
if (vsocket->async_copy &&
(flags & (RTE_VHOST_USER_IOMMU_SUPPORT |
@@ -771,7 +771,8 @@ vhost_set_ifname(int vid, const char *if_name, unsigned int if_len)
}
void
-vhost_setup_virtio_net(int vid, bool enable, bool compliant_ol_flags, bool stats_enabled)
+vhost_setup_virtio_net(int vid, bool enable, bool compliant_ol_flags, bool stats_enabled,
+ bool support_iommu)
{
struct virtio_net *dev = get_device(vid);
@@ -790,6 +791,10 @@ vhost_setup_virtio_net(int vid, bool enable, bool compliant_ol_flags, bool stats
dev->flags |= VIRTIO_DEV_STATS_ENABLED;
else
dev->flags &= ~VIRTIO_DEV_STATS_ENABLED;
+ if (support_iommu)
+ dev->flags |= VIRTIO_DEV_SUPPORT_IOMMU;
+ else
+ dev->flags &= ~VIRTIO_DEV_SUPPORT_IOMMU;
}
void
@@ -37,6 +37,8 @@
#define VIRTIO_DEV_LEGACY_OL_FLAGS ((uint32_t)1 << 5)
/* Used to indicate the application has requested statistics collection */
#define VIRTIO_DEV_STATS_ENABLED ((uint32_t)1 << 6)
+/* Used to indicate the application has requested iommu support */
+#define VIRTIO_DEV_SUPPORT_IOMMU ((uint32_t)1 << 7)
/* Backend value set by guest. */
#define VIRTIO_DEV_STOPPED -1
@@ -803,7 +805,8 @@ int alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx);
void vhost_attach_vdpa_device(int vid, struct rte_vdpa_device *dev);
void vhost_set_ifname(int, const char *if_name, unsigned int if_len);
-void vhost_setup_virtio_net(int vid, bool enable, bool legacy_ol_flags, bool stats_enabled);
+void vhost_setup_virtio_net(int vid, bool enable, bool legacy_ol_flags, bool stats_enabled,
+ bool support_iommu);
void vhost_enable_extbuf(int vid);
void vhost_enable_linearbuf(int vid);
int vhost_enable_guest_notification(struct virtio_net *dev,