From: Paolo Abeni pabeni@redhat.com Sent: Thursday, February 2, 2023 12:31 AM
On Thu, 2023-02-02 at 05:20 +0000, Michael Kelley (LINUX) wrote:
From: Jakub Kicinski kuba@kernel.org Sent: Wednesday, February 1, 2023 9:01 PM
On Mon, 30 Jan 2023 19:33:06 -0800 Michael Kelley wrote:
@@ -990,9 +987,7 @@ static int netvsc_dma_map(struct hv_device *hv_dev, struct hv_netvsc_packet *packet, struct hv_page_buffer *pb) {
- u32 page_count = packet->cp_partial ?
packet->page_buf_cnt - packet->rmsg_pgcnt :packet->page_buf_cnt;
- u32 page_count = packet->page_buf_cnt; dma_addr_t dma; int i;
Suspiciously, the caller still does:
if (packet->cp_partial) pb += packet->rmsg_pgcnt; ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);Shouldn't that if () pb +=... also go away?
No -- it's correct.
In netvsc_send(), cp_partial is tested and packet->page_buf_cnt is adjusted. But the pointer into the pagebuf array is not adjusted in netvsc_send(). Instead it is adjusted here in netvsc_send_pkt(), which brings it back in sync with packet->page_buf_cnt.
Ok
I don't know if there's a good reason for the adjustment being split across two different functions. It doesn't seem like the most straightforward approach. From a quick glance at the code it looks like this adjustment to 'pb' could move to netvsc_send() to be together with the adjustment to packet->page_buf_cnt, but maybe there's a reason for the split that I'm not familiar with.
Haiyang -- any insight?
While at that, please also have a look at the following allocation in netvsc_dma_map():
packet->dma_range = kcalloc(page_count, sizeof(*packet->dma_range), GFP_KERNEL);
which looks wrong - netvsc_dma_map() should be in atomic context.
Anyway it's a topic unrelated from this patch. I just stumbled upon it while reviewing.
Thanks for pointing this out. I've made a note to do a fix.
Michael