diff options
Diffstat (limited to 'xen-hvm.c')
| -rw-r--r-- | xen-hvm.c | 22 |
1 files changed, 16 insertions, 6 deletions
@@ -995,6 +995,9 @@ 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; @@ -1009,18 +1012,16 @@ static int handle_buffered_iopage(XenIOState *state) break; } buf_req = &buf_page->buf_ioreq[rdptr % IOREQ_BUFFER_SLOT_NUM]; - req.size = 1UL << buf_req->size; - req.count = 1; + req.size = 1U << buf_req->size; req.addr = buf_req->addr; req.data = buf_req->data; - req.state = STATE_IOREQ_READY; - req.dir = buf_req->dir; - req.df = 1; req.type = buf_req->type; - req.data_is_ptr = 0; xen_rmb(); qw = (req.size == 8); if (qw) { + if (rdptr + 1 == wrptr) { + hw_error("Incomplete quad word buffered ioreq"); + } buf_req = &buf_page->buf_ioreq[(rdptr + 1) % IOREQ_BUFFER_SLOT_NUM]; req.data |= ((uint64_t)buf_req->data) << 32; @@ -1029,6 +1030,15 @@ 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 (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); } |