diff mbox

[RFC,v2,2/8] virtio: memory cache for packed ring

Message ID 1528225683-11413-3-git-send-email-wexu@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wei Xu June 5, 2018, 7:07 p.m. UTC 
From: Wei Xu <wexu@redhat.com>

Mostly reuse memory cache with 1.0 except for the offset calculation.

Signed-off-by: Wei Xu <wexu@redhat.com>
---
 hw/virtio/virtio.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

Comments

Jason Wang June 6, 2018, 2:53 a.m. UTC | #1 
On 2018年06月06日 03:07, wexu@redhat.com wrote:
> From: Wei Xu <wexu@redhat.com>
>
> Mostly reuse memory cache with 1.0 except for the offset calculation.
>
> Signed-off-by: Wei Xu <wexu@redhat.com>
> ---
>   hw/virtio/virtio.c | 29 ++++++++++++++++++++---------
>   1 file changed, 20 insertions(+), 9 deletions(-)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index e192a9a..f6c0689 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -150,11 +150,8 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>       VRingMemoryRegionCaches *old = vq->vring.caches;
>       VRingMemoryRegionCaches *new;
>       hwaddr addr, size;
> -    int event_size;
>       int64_t len;
>   
> -    event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> -
>       addr = vq->vring.desc;
>       if (!addr) {
>           return;
> @@ -168,7 +165,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>           goto err_desc;
>       }
>   
> -    size = virtio_queue_get_used_size(vdev, n) + event_size;
> +    size = virtio_queue_get_used_size(vdev, n);
>       len = address_space_cache_init(&new->used, vdev->dma_as,
>                                      vq->vring.used, size, true);
>       if (len < size) {
> @@ -176,7 +173,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>           goto err_used;
>       }
>   
> -    size = virtio_queue_get_avail_size(vdev, n) + event_size;
> +    size = virtio_queue_get_avail_size(vdev, n);
>       len = address_space_cache_init(&new->avail, vdev->dma_as,
>                                      vq->vring.avail, size, false);
>       if (len < size) {
> @@ -2320,14 +2317,28 @@ hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
>   
>   hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)

I would rather rename this to virtio_queue_get_driver_size().

>   {
> -    return offsetof(VRingAvail, ring) +
> -        sizeof(uint16_t) * vdev->vq[n].vring.num;
> +    int s;
> +
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        return sizeof(struct VRingPackedDescEvent);
> +    } else {
> +        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> +        return offsetof(VRingAvail, ring) +
> +            sizeof(uint16_t) * vdev->vq[n].vring.num + s;
> +    }
>   }
>   
>   hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)

virtio_queue_get_device_size().

Thanks

>   {
> -    return offsetof(VRingUsed, ring) +
> -        sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
> +    int s;
> +
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        return sizeof(struct VRingPackedDescEvent);
> +    } else {
> +        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> +        return offsetof(VRingUsed, ring) +
> +            sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s;
> +    }
>   }
>   
>   uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
Paolo Bonzini June 13, 2018, 12:27 p.m. UTC | #2 
On 05/06/2018 21:07, wexu@redhat.com wrote:
> From: Wei Xu <wexu@redhat.com>
> 
> Mostly reuse memory cache with 1.0 except for the offset calculation.
> 
> Signed-off-by: Wei Xu <wexu@redhat.com>
> ---
>  hw/virtio/virtio.c | 29 ++++++++++++++++++++---------
>  1 file changed, 20 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index e192a9a..f6c0689 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -150,11 +150,8 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>      VRingMemoryRegionCaches *old = vq->vring.caches;
>      VRingMemoryRegionCaches *new;
>      hwaddr addr, size;
> -    int event_size;
>      int64_t len;
>  
> -    event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> -
>      addr = vq->vring.desc;
>      if (!addr) {
>          return;
> @@ -168,7 +165,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>          goto err_desc;
>      }
>  
> -    size = virtio_queue_get_used_size(vdev, n) + event_size;
> +    size = virtio_queue_get_used_size(vdev, n);
>      len = address_space_cache_init(&new->used, vdev->dma_as,
>                                     vq->vring.used, size, true);
>      if (len < size) {
> @@ -176,7 +173,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>          goto err_used;
>      }
>  
> -    size = virtio_queue_get_avail_size(vdev, n) + event_size;
> +    size = virtio_queue_get_avail_size(vdev, n);
>      len = address_space_cache_init(&new->avail, vdev->dma_as,
>                                     vq->vring.avail, size, false);
>      if (len < size) {
> @@ -2320,14 +2317,28 @@ hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
>  
>  hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
>  {
> -    return offsetof(VRingAvail, ring) +
> -        sizeof(uint16_t) * vdev->vq[n].vring.num;
> +    int s;
> +
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        return sizeof(struct VRingPackedDescEvent);
> +    } else {
> +        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> +        return offsetof(VRingAvail, ring) +
> +            sizeof(uint16_t) * vdev->vq[n].vring.num + s;
> +    }
>  }
>  
>  hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
>  {
> -    return offsetof(VRingUsed, ring) +
> -        sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
> +    int s;
> +
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        return sizeof(struct VRingPackedDescEvent);
> +    } else {
> +        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> +        return offsetof(VRingUsed, ring) +
> +            sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s;
> +    }
>  }
>  
>  uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Wei Xu June 19, 2018, 7:39 a.m. UTC | #3 
On Wed, Jun 06, 2018 at 10:53:07AM +0800, Jason Wang wrote:
> 
> 
> On 2018年06月06日 03:07, wexu@redhat.com wrote:
> >From: Wei Xu <wexu@redhat.com>
> >
> >Mostly reuse memory cache with 1.0 except for the offset calculation.
> >
> >Signed-off-by: Wei Xu <wexu@redhat.com>
> >---
> >  hw/virtio/virtio.c | 29 ++++++++++++++++++++---------
> >  1 file changed, 20 insertions(+), 9 deletions(-)
> >
> >diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> >index e192a9a..f6c0689 100644
> >--- a/hw/virtio/virtio.c
> >+++ b/hw/virtio/virtio.c
> >@@ -150,11 +150,8 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
> >      VRingMemoryRegionCaches *old = vq->vring.caches;
> >      VRingMemoryRegionCaches *new;
> >      hwaddr addr, size;
> >-    int event_size;
> >      int64_t len;
> >-    event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> >-
> >      addr = vq->vring.desc;
> >      if (!addr) {
> >          return;
> >@@ -168,7 +165,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
> >          goto err_desc;
> >      }
> >-    size = virtio_queue_get_used_size(vdev, n) + event_size;
> >+    size = virtio_queue_get_used_size(vdev, n);
> >      len = address_space_cache_init(&new->used, vdev->dma_as,
> >                                     vq->vring.used, size, true);
> >      if (len < size) {
> >@@ -176,7 +173,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
> >          goto err_used;
> >      }
> >-    size = virtio_queue_get_avail_size(vdev, n) + event_size;
> >+    size = virtio_queue_get_avail_size(vdev, n);
> >      len = address_space_cache_init(&new->avail, vdev->dma_as,
> >                                     vq->vring.avail, size, false);
> >      if (len < size) {
> >@@ -2320,14 +2317,28 @@ hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
> >  hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
> 
> I would rather rename this to virtio_queue_get_driver_size().

Would this confuse 1.0 if it is shared by both? Otherwise I will take it to next version, thanks.

Wei

> 
> >  {
> >-    return offsetof(VRingAvail, ring) +
> >-        sizeof(uint16_t) * vdev->vq[n].vring.num;
> >+    int s;
> >+
> >+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> >+        return sizeof(struct VRingPackedDescEvent);
> >+    } else {
> >+        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> >+        return offsetof(VRingAvail, ring) +
> >+            sizeof(uint16_t) * vdev->vq[n].vring.num + s;
> >+    }
> >  }
> >  hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
> 
> virtio_queue_get_device_size().
> 
> Thanks
> 
> >  {
> >-    return offsetof(VRingUsed, ring) +
> >-        sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
> >+    int s;
> >+
> >+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> >+        return sizeof(struct VRingPackedDescEvent);
> >+    } else {
> >+        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> >+        return offsetof(VRingUsed, ring) +
> >+            sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s;
> >+    }
> >  }
> >  uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
>
Maxime Coquelin Sept. 20, 2018, 2:18 p.m. UTC | #4 
On 06/05/2018 09:07 PM, wexu@redhat.com wrote:
> From: Wei Xu <wexu@redhat.com>
> 
> Mostly reuse memory cache with 1.0 except for the offset calculation.
> 
> Signed-off-by: Wei Xu <wexu@redhat.com>
> ---
>   hw/virtio/virtio.c | 29 ++++++++++++++++++++---------
>   1 file changed, 20 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index e192a9a..f6c0689 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -150,11 +150,8 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>       VRingMemoryRegionCaches *old = vq->vring.caches;
>       VRingMemoryRegionCaches *new;
>       hwaddr addr, size;
> -    int event_size;
>       int64_t len;
>   
> -    event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> -
>       addr = vq->vring.desc;
>       if (!addr) {
>           return;
> @@ -168,7 +165,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>           goto err_desc;
>       }
>   

In the case of packed ring layout, the region's cache for the descs has
to be initialized as write-able, as the descriptors are written-back by
the device.

Following patch fixes the assert I'm facing, but we might want to
differentiate the split and packed cases as it is read-only in split
case:

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 012c0925f2..4b165aaf2c 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -173,7 +173,7 @@ static void virtio_init_region_cache(VirtIODevice 
*vdev, int n)
      new = g_new0(VRingMemoryRegionCaches, 1);
      size = virtio_queue_get_desc_size(vdev, n);
      len = address_space_cache_init(&new->desc, vdev->dma_as,
-                                   addr, size, false);
+                                   addr, size, true);
      if (len < size) {
          virtio_error(vdev, "Cannot map desc");
          goto err_desc;


> -    size = virtio_queue_get_used_size(vdev, n) + event_size;
> +    size = virtio_queue_get_used_size(vdev, n);
>       len = address_space_cache_init(&new->used, vdev->dma_as,
>                                      vq->vring.used, size, true);
>       if (len < size) {
> @@ -176,7 +173,7 @@ static void virtio_init_region_cache(VirtIODevice *vdev, int n)
>           goto err_used;
>       }
>   
> -    size = virtio_queue_get_avail_size(vdev, n) + event_size;
> +    size = virtio_queue_get_avail_size(vdev, n);
>       len = address_space_cache_init(&new->avail, vdev->dma_as,
>                                      vq->vring.avail, size, false);
>       if (len < size) {
> @@ -2320,14 +2317,28 @@ hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
>   
>   hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
>   {
> -    return offsetof(VRingAvail, ring) +
> -        sizeof(uint16_t) * vdev->vq[n].vring.num;
> +    int s;
> +
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        return sizeof(struct VRingPackedDescEvent);
> +    } else {
> +        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> +        return offsetof(VRingAvail, ring) +
> +            sizeof(uint16_t) * vdev->vq[n].vring.num + s;
> +    }
>   }
>   
>   hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
>   {
> -    return offsetof(VRingUsed, ring) +
> -        sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
> +    int s;
> +
> +    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
> +        return sizeof(struct VRingPackedDescEvent);
> +    } else {
> +        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
> +        return offsetof(VRingUsed, ring) +
> +            sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s;
> +    }
>   }
>   
>   uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
>
diff mbox

Patch

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index e192a9a..f6c0689 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -150,11 +150,8 @@  static void virtio_init_region_cache(VirtIODevice *vdev, int n)
     VRingMemoryRegionCaches *old = vq->vring.caches;
     VRingMemoryRegionCaches *new;
     hwaddr addr, size;
-    int event_size;
     int64_t len;
 
-    event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
-
     addr = vq->vring.desc;
     if (!addr) {
         return;
@@ -168,7 +165,7 @@  static void virtio_init_region_cache(VirtIODevice *vdev, int n)
         goto err_desc;
     }
 
-    size = virtio_queue_get_used_size(vdev, n) + event_size;
+    size = virtio_queue_get_used_size(vdev, n);
     len = address_space_cache_init(&new->used, vdev->dma_as,
                                    vq->vring.used, size, true);
     if (len < size) {
@@ -176,7 +173,7 @@  static void virtio_init_region_cache(VirtIODevice *vdev, int n)
         goto err_used;
     }
 
-    size = virtio_queue_get_avail_size(vdev, n) + event_size;
+    size = virtio_queue_get_avail_size(vdev, n);
     len = address_space_cache_init(&new->avail, vdev->dma_as,
                                    vq->vring.avail, size, false);
     if (len < size) {
@@ -2320,14 +2317,28 @@  hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n)
 
 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n)
 {
-    return offsetof(VRingAvail, ring) +
-        sizeof(uint16_t) * vdev->vq[n].vring.num;
+    int s;
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+        return sizeof(struct VRingPackedDescEvent);
+    } else {
+        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+        return offsetof(VRingAvail, ring) +
+            sizeof(uint16_t) * vdev->vq[n].vring.num + s;
+    }
 }
 
 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n)
 {
-    return offsetof(VRingUsed, ring) +
-        sizeof(VRingUsedElem) * vdev->vq[n].vring.num;
+    int s;
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+        return sizeof(struct VRingPackedDescEvent);
+    } else {
+        s = virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+        return offsetof(VRingUsed, ring) +
+            sizeof(VRingUsedElem) * vdev->vq[n].vring.num + s;
+    }
 }
 
 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)