Hi Mike,
On 4/17/23 21:39, Mike Pattrick wrote:
Hi Maxime,
On Fri, Mar 31, 2023 at 11:43 AM Maxime Coquelin
<maxime.coque...@redhat.com> wrote:
This patch introduces a helper to check whether two IOTLB
entries share a page.
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
lib/vhost/iotlb.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/lib/vhost/iotlb.c b/lib/vhost/iotlb.c
index e8f1cb661e..d919f74704 100644
--- a/lib/vhost/iotlb.c
+++ b/lib/vhost/iotlb.c
@@ -23,6 +23,23 @@ struct vhost_iotlb_entry {
#define IOTLB_CACHE_SIZE 2048
+static bool
+vhost_user_iotlb_share_page(struct vhost_iotlb_entry *a, struct
vhost_iotlb_entry *b,
+ uint64_t align)
+{
+ uint64_t a_end, b_start;
+
+ if (a == NULL || b == NULL)
+ return false;
+
+ /* Assumes entry a lower than entry b */
+ RTE_ASSERT(a->uaddr < b->uaddr);
+ a_end = RTE_ALIGN_CEIL(a->uaddr + a->size, align);
+ b_start = RTE_ALIGN_FLOOR(b->uaddr, align);
+
+ return a_end > b_start;
This may be a very minor detail, but it might improve readability if
the a_end calculation used addr + size - 1 and the return conditional
used >=.
That's actually how I initially implemented it, but discussing with
David we agreed it would be better that way for consistency with
vhost_user_iotlb_clear_dump().
Regards,
Maxime
Cheers,
M
+}
+
static void
vhost_user_iotlb_set_dump(struct virtio_net *dev, struct vhost_iotlb_entry
*node)
{
@@ -37,16 +54,14 @@ static void
vhost_user_iotlb_clear_dump(struct virtio_net *dev, struct vhost_iotlb_entry
*node,
struct vhost_iotlb_entry *prev, struct vhost_iotlb_entry *next)
{
- uint64_t align, mask;
+ uint64_t align;
align = hua_to_alignment(dev->mem, (void *)(uintptr_t)node->uaddr);
- mask = ~(align - 1);
/* Don't disable coredump if the previous node is in the same page */
- if (prev == NULL || (node->uaddr & mask) != ((prev->uaddr + prev->size - 1)
& mask)) {
+ if (!vhost_user_iotlb_share_page(prev, node, align)) {
/* Don't disable coredump if the next node is in the same page
*/
- if (next == NULL ||
- ((node->uaddr + node->size - 1) & mask) !=
(next->uaddr & mask))
+ if (!vhost_user_iotlb_share_page(node, next, align))
mem_set_dump((void *)(uintptr_t)node->uaddr,
node->size, false, align);
}
}
--
2.39.2
