Commit 0095e2b9 authored Nov 08, 2016 by Jim Harris

bdev/nvme: account for 2MB straddle in queued_next_sge()



This function needs to check for SGEs that straddle a
2MB page boundary, and ensure it does not return
a length that will cross that boundary.

This cannot happen in practice currently with SPDK
since all buffers are allocated using rte_malloc(),
but an upcoming vhost-scsi target may produce
SGEs from a guest VM's physical memory that span
a 2MB boundary.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I8b83c7c39c4cf33815abb22ff2ebc90941b21e28

parent aac30ff3

lib/bdev/nvme/blockdev_nvme.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -639,6 +639,10 @@ queued_reset_sgl(void *ref, uint32_t sgl_offset)
		}
		}

		#define min(a, b) (((a)<(b))?(a):(b))

		#define _2MB_OFFSET(ptr) (((uintptr_t)ptr) & (0x200000 - 1))

		static int
		queued_next_sge(void ref, void address, uint32_t length)
		{
		@@ -658,6 +662,8 @@ queued_next_sge(void ref, void address, uint32_t length)
		*length -= bio->iov_offset;
		}

		length = min(length, 0x200000 - _2MB_OFFSET(*address));

		bio->iov_offset += *length;
		if (bio->iov_offset == iov->iov_len) {
		bio->iovpos++;