block/nvme: don't touch the completion entries

Completion entries are meant to be only read by the host and written by the device.
The driver is supposed to scan the completions from the last point where it left,
and until it sees a completion with non flipped phase bit.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190716163020.13383-4-mlevitsk@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

diff --git a/block/nvme.c b/block/nvme.c
index 35ce10dc79540da46a62bc6f4f0f6b41c08e954d..c28755cc31914bfa9bb7920f3e427ed41178c5e2 100644 (file)
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -318,7 +318,7 @@ static bool nvme_process_completion(BDRVNVMeState *s, NVMeQueuePair *q)
     while (q->inflight) {
         int16_t cid;
         c = (NvmeCqe *)&q->cq.queue[q->cq.head * NVME_CQ_ENTRY_BYTES];
-        if (!c->cid || (le16_to_cpu(c->status) & 0x1) == q->cq_phase) {
+        if ((le16_to_cpu(c->status) & 0x1) == q->cq_phase) {
             break;
         }
         q->cq.head = (q->cq.head + 1) % NVME_QUEUE_SIZE;
@@ -342,10 +342,7 @@ static bool nvme_process_completion(BDRVNVMeState *s, NVMeQueuePair *q)
         qemu_mutex_unlock(&q->lock);
         req.cb(req.opaque, nvme_translate_error(c));
         qemu_mutex_lock(&q->lock);
-        c->cid = cpu_to_le16(0);
         q->inflight--;
-        /* Flip Phase Tag bit. */
-        c->status = cpu_to_le16(le16_to_cpu(c->status) ^ 0x1);
         progress = true;
     }
     if (progress) {