Commit e514379d authored by Jan Beulich's avatar Jan Beulich Committed by Stefano Stabellini
Browse files

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: default avatarJan Beulich <jbeulich@suse.com>
Reviewed-by: default avatarPaul Durrant <paul.durrant@citrix.com>
Acked-by: default avatarStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: default avatarStefano Stabellini <sstabellini@kernel.org>
parent f37f29d3

xen-hvm.c

+4 −2
Original line number Diff line number Diff line
@@ -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);