From e514379de52573131ccc47441787e5fab6dbfc08 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 25 Nov 2016 03:06:58 -0700 Subject: [PATCH] xen: ignore direction in bufioreq handling There's no way to communicate back read data, so only writes can ever be usefully specified. Ignore the field, paving the road for eventually re-using the bit for something else in a few (many?) years time. Signed-off-by: Jan Beulich Reviewed-by: Paul Durrant Acked-by: Stefano Stabellini Signed-off-by: Stefano Stabellini --- xen-hvm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/xen-hvm.c b/xen-hvm.c index 124ae10b5d..0892361cc2 100644 --- a/xen-hvm.c +++ b/xen-hvm.c @@ -997,6 +997,7 @@ static int handle_buffered_iopage(XenIOState *state) memset(&req, 0x00, sizeof(req)); req.state = STATE_IOREQ_READY; req.count = 1; + req.dir = IOREQ_WRITE; for (;;) { uint32_t rdptr = buf_page->read_pointer, wrptr; @@ -1014,7 +1015,6 @@ static int handle_buffered_iopage(XenIOState *state) req.size = 1U << buf_req->size; req.addr = buf_req->addr; req.data = buf_req->data; - req.dir = buf_req->dir; req.type = buf_req->type; xen_rmb(); qw = (req.size == 8); @@ -1031,10 +1031,12 @@ static int handle_buffered_iopage(XenIOState *state) handle_ioreq(state, &req); /* Only req.data may get updated by handle_ioreq(), albeit even that - * should not happen as such data would never make it to the guest. + * should not happen as such data would never make it to the guest (we + * can only usefully see writes here after all). */ assert(req.state == STATE_IOREQ_READY); assert(req.count == 1); + assert(req.dir == IOREQ_WRITE); assert(!req.data_is_ptr); atomic_add(&buf_page->read_pointer, qw + 1);