[Xen-changelog] [qemu-xen master] xen: ignore direction in bufioreq handling

[patchbot@xxxxxxx]

commit e514379de52573131ccc47441787e5fab6dbfc08
Author:     Jan Beulich <JBeulich@xxxxxxxx>
AuthorDate: Fri Nov 25 03:06:58 2016 -0700
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Mon Nov 28 11:26:29 2016 -0800

    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 <jbeulich@xxxxxxxx>
    Reviewed-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
    Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
    Signed-off-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen-hvm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/xen-hvm.c b/xen-hvm.c
index 124ae10..0892361 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);
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#master

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