[PATCH 2/2] tests/qtest/fuzz: Avoid QTest mmio serialization

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

We don't need to serialize over QTest chardev when we can
directly access the MMIO address space via the first
registered CPU view.

virtio-net-socket gets ~50% performance improvement.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 tests/qtest/fuzz/virtio_net_fuzz.c  | 6 ++++--
 tests/qtest/fuzz/virtio_scsi_fuzz.c | 6 +++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/tests/qtest/fuzz/virtio_net_fuzz.c b/tests/qtest/fuzz/virtio_net_fuzz.c
index d08a47e278..ec993c9d5f 100644
--- a/tests/qtest/fuzz/virtio_net_fuzz.c
+++ b/tests/qtest/fuzz/virtio_net_fuzz.c
@@ -19,6 +19,8 @@
 #include "fork_fuzz.h"
 #include "qos_fuzz.h"
 
+#include "exec/address-spaces.h"
+#include "hw/core/cpu.h"
 
 #define QVIRTIO_NET_TIMEOUT_US (30 * 1000 * 1000)
 #define QVIRTIO_RX_VQ 0
@@ -69,8 +71,8 @@ static void virtio_net_fuzz_multi(QTestState *s,
              * If checking used ring, ensure that the fuzzer doesn't trigger
              * trivial asserion failure on zero-zied buffer
              */
-            qtest_memwrite(s, req_addr, Data, vqa.length);
-
+            address_space_write(first_cpu->as, req_addr, MEMTXATTRS_UNSPECIFIED,
+                                &Data, vqa.length);
 
             free_head = qvirtqueue_add(s, q, req_addr, vqa.length,
                     vqa.write, vqa.next);
diff --git a/tests/qtest/fuzz/virtio_scsi_fuzz.c b/tests/qtest/fuzz/virtio_scsi_fuzz.c
index 3b95247f12..5096a5a730 100644
--- a/tests/qtest/fuzz/virtio_scsi_fuzz.c
+++ b/tests/qtest/fuzz/virtio_scsi_fuzz.c
@@ -23,6 +23,9 @@
 #include "fork_fuzz.h"
 #include "qos_fuzz.h"
 
+#include "exec/address-spaces.h"
+#include "hw/core/cpu.h"
+
 #define PCI_SLOT                0x02
 #define PCI_FN                  0x00
 #define QVIRTIO_SCSI_TIMEOUT_US (1 * 1000 * 1000)
@@ -108,7 +111,8 @@ static void virtio_scsi_fuzz(QTestState *s, QVirtioSCSIQueues* queues,
 
         /* Copy the data into ram, and place it on the virtqueue */
         uint64_t req_addr = guest_alloc(t_alloc, vqa.length);
-        qtest_memwrite(s, req_addr, Data, vqa.length);
+        address_space_write(first_cpu->as, req_addr, MEMTXATTRS_UNSPECIFIED,
+                            &Data, vqa.length);
         if (vq_touched[vqa.queue] == 0) {
             vq_touched[vqa.queue] = 1;
             free_head[vqa.queue] = qvirtqueue_add(s, q, req_addr, vqa.length,
-- 
2.21.3