[Qemu-devel] [PATCH] qtest: ask endianness of the target in qtest_init()

[Laurent Vivier <lvivier@redhat.com>]

The target endianness is not deduced anymore from
the architecture name but asked directly to the guest,
using a new qtest command: "endianness". As it can't
change (this is the value of TARGET_WORDS_BIGENDIAN),
we store it to not have to ask every time we want to
know if we have to byte-swap a value.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
CC: Greg Kurz <groug@kaod.org>
CC: David Gibson <david@gibson.dropbear.id.au>
CC: Peter Maydell <peter.maydell@linaro.org>
---
Note: this patch can be seen as a v2 of
"qtest: evaluate endianness of the target in qtest_init()"
from the patch series "tests: enable virtio tests on SPAPR"
in which I have added the idea from Peter to ask the endianness
directly to the guest using a new qtest command.

 qtest.c                   |   7 ++
 tests/libqos/virtio-pci.c |   2 +-
 tests/libqtest.c          | 224 ++++++++++++++++++++--------------------------
 tests/libqtest.h          |  16 +++-
 tests/virtio-blk-test.c   |   2 +-
 5 files changed, 118 insertions(+), 133 deletions(-)

diff --git a/qtest.c b/qtest.c
index 22482cc..b53b39c 100644
--- a/qtest.c
+++ b/qtest.c
@@ -537,6 +537,13 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
 
         qtest_send_prefix(chr);
         qtest_send(chr, "OK\n");
+    } else if (strcmp(words[0], "endianness") == 0) {
+        qtest_send_prefix(chr);
+#if defined(TARGET_WORDS_BIGENDIAN)
+        qtest_sendf(chr, "OK big\n");
+#else
+        qtest_sendf(chr, "OK little\n");
+#endif
 #ifdef TARGET_PPC64
     } else if (strcmp(words[0], "rtas") == 0) {
         uint64_t res, args, ret;
diff --git a/tests/libqos/virtio-pci.c b/tests/libqos/virtio-pci.c
index 18b92b9..6e005c1 100644
--- a/tests/libqos/virtio-pci.c
+++ b/tests/libqos/virtio-pci.c
@@ -86,7 +86,7 @@ static uint64_t qvirtio_pci_config_readq(QVirtioDevice *d, uint64_t addr)
     int i;
     uint64_t u64 = 0;
 
-    if (qtest_big_endian()) {
+    if (target_big_endian()) {
         for (i = 0; i < 8; ++i) {
             u64 |= (uint64_t)qpci_io_readb(dev->pdev,
                                 (void *)(uintptr_t)addr + i) << (7 - i) * 8;
diff --git a/tests/libqtest.c b/tests/libqtest.c
index 6f6bdf1..27cf6b1 100644
--- a/tests/libqtest.c
+++ b/tests/libqtest.c
@@ -37,6 +37,7 @@ struct QTestState
     bool irq_level[MAX_IRQ];
     GString *rx;
     pid_t qemu_pid;  /* our child QEMU process */
+    bool big_endian;
 };
 
 static GHookList abrt_hooks;
@@ -146,89 +147,6 @@ void qtest_add_abrt_handler(GHookFunc fn, const void *data)
     g_hook_prepend(&abrt_hooks, hook);
 }
 
-QTestState *qtest_init(const char *extra_args)
-{
-    QTestState *s;
-    int sock, qmpsock, i;
-    gchar *socket_path;
-    gchar *qmp_socket_path;
-    gchar *command;
-    const char *qemu_binary;
-
-    qemu_binary = getenv("QTEST_QEMU_BINARY");
-    g_assert(qemu_binary != NULL);
-
-    s = g_malloc(sizeof(*s));
-
-    socket_path = g_strdup_printf("/tmp/qtest-%d.sock", getpid());
-    qmp_socket_path = g_strdup_printf("/tmp/qtest-%d.qmp", getpid());
-
-    sock = init_socket(socket_path);
-    qmpsock = init_socket(qmp_socket_path);
-
-    qtest_add_abrt_handler(kill_qemu_hook_func, s);
-
-    s->qemu_pid = fork();
-    if (s->qemu_pid == 0) {
-        setenv("QEMU_AUDIO_DRV", "none", true);
-        command = g_strdup_printf("exec %s "
-                                  "-qtest unix:%s,nowait "
-                                  "-qtest-log %s "
-                                  "-qmp unix:%s,nowait "
-                                  "-machine accel=qtest "
-                                  "-display none "
-                                  "%s", qemu_binary, socket_path,
-                                  getenv("QTEST_LOG") ? "/dev/fd/2" : "/dev/null",
-                                  qmp_socket_path,
-                                  extra_args ?: "");
-        execlp("/bin/sh", "sh", "-c", command, NULL);
-        exit(1);
-    }
-
-    s->fd = socket_accept(sock);
-    if (s->fd >= 0) {
-        s->qmp_fd = socket_accept(qmpsock);
-    }
-    unlink(socket_path);
-    unlink(qmp_socket_path);
-    g_free(socket_path);
-    g_free(qmp_socket_path);
-
-    g_assert(s->fd >= 0 && s->qmp_fd >= 0);
-
-    s->rx = g_string_new("");
-    for (i = 0; i < MAX_IRQ; i++) {
-        s->irq_level[i] = false;
-    }
-
-    /* Read the QMP greeting and then do the handshake */
-    qtest_qmp_discard_response(s, "");
-    qtest_qmp_discard_response(s, "{ 'execute': 'qmp_capabilities' }");
-
-    if (getenv("QTEST_STOP")) {
-        kill(s->qemu_pid, SIGSTOP);
-    }
-
-    return s;
-}
-
-void qtest_quit(QTestState *s)
-{
-    qtest_instances = g_list_remove(qtest_instances, s);
-    g_hook_destroy_link(&abrt_hooks, g_hook_find_data(&abrt_hooks, TRUE, s));
-
-    /* Uninstall SIGABRT handler on last instance */
-    if (!qtest_instances) {
-        cleanup_sigabrt_handler();
-    }
-
-    kill_qemu(s);
-    close(s->fd);
-    close(s->qmp_fd);
-    g_string_free(s->rx, true);
-    g_free(s);
-}
-
 static void socket_send(int fd, const char *buf, size_t size)
 {
     size_t offset;
@@ -347,6 +265,99 @@ typedef struct {
     QDict *response;
 } QMPResponseParser;
 
+QTestState *qtest_init(const char *extra_args)
+{
+    QTestState *s;
+    int sock, qmpsock, i;
+    gchar *socket_path;
+    gchar *qmp_socket_path;
+    gchar *command;
+    const char *qemu_binary;
+    gchar **args;
+
+    qemu_binary = getenv("QTEST_QEMU_BINARY");
+    g_assert(qemu_binary != NULL);
+
+    s = g_malloc(sizeof(*s));
+
+    socket_path = g_strdup_printf("/tmp/qtest-%d.sock", getpid());
+    qmp_socket_path = g_strdup_printf("/tmp/qtest-%d.qmp", getpid());
+
+    sock = init_socket(socket_path);
+    qmpsock = init_socket(qmp_socket_path);
+
+    qtest_add_abrt_handler(kill_qemu_hook_func, s);
+
+    s->qemu_pid = fork();
+    if (s->qemu_pid == 0) {
+        setenv("QEMU_AUDIO_DRV", "none", true);
+        command = g_strdup_printf("exec %s "
+                                  "-qtest unix:%s,nowait "
+                                  "-qtest-log %s "
+                                  "-qmp unix:%s,nowait "
+                                  "-machine accel=qtest "
+                                  "-display none "
+                                  "%s", qemu_binary, socket_path,
+                                  getenv("QTEST_LOG") ? "/dev/fd/2"
+                                                      : "/dev/null",
+                                  qmp_socket_path,
+                                  extra_args ?: "");
+        execlp("/bin/sh", "sh", "-c", command, NULL);
+        exit(1);
+    }
+
+    s->fd = socket_accept(sock);
+    if (s->fd >= 0) {
+        s->qmp_fd = socket_accept(qmpsock);
+    }
+    unlink(socket_path);
+    unlink(qmp_socket_path);
+    g_free(socket_path);
+    g_free(qmp_socket_path);
+
+    g_assert(s->fd >= 0 && s->qmp_fd >= 0);
+
+    s->rx = g_string_new("");
+    for (i = 0; i < MAX_IRQ; i++) {
+        s->irq_level[i] = false;
+    }
+
+    /* Read the QMP greeting and then do the handshake */
+    qtest_qmp_discard_response(s, "");
+    qtest_qmp_discard_response(s, "{ 'execute': 'qmp_capabilities' }");
+
+    if (getenv("QTEST_STOP")) {
+        kill(s->qemu_pid, SIGSTOP);
+    }
+
+    /* ask endianness of the target */
+
+    qtest_sendf(s, "endianness\n");
+    args = qtest_rsp(s, 1);
+    g_assert(strcmp(args[1], "big") == 0 || strcmp(args[1], "little") == 0);
+    s->big_endian = strcmp(args[1], "big") == 0;
+    g_strfreev(args);
+
+    return s;
+}
+
+void qtest_quit(QTestState *s)
+{
+    qtest_instances = g_list_remove(qtest_instances, s);
+    g_hook_destroy_link(&abrt_hooks, g_hook_find_data(&abrt_hooks, TRUE, s));
+
+    /* Uninstall SIGABRT handler on last instance */
+    if (!qtest_instances) {
+        cleanup_sigabrt_handler();
+    }
+
+    kill_qemu(s);
+    close(s->fd);
+    close(s->qmp_fd);
+    g_string_free(s->rx, true);
+    g_free(s);
+}
+
 static void qmp_response(JSONMessageParser *parser, GQueue *tokens)
 {
     QMPResponseParser *qmp = container_of(parser, QMPResponseParser, parser);
@@ -886,50 +897,7 @@ char *hmp(const char *fmt, ...)
     return ret;
 }
 
-bool qtest_big_endian(void)
+bool qtest_big_endian(QTestState *s)
 {
-    const char *arch = qtest_get_arch();
-    int i;
-
-    static const struct {
-        const char *arch;
-        bool big_endian;
-    } endianness[] = {
-        { "aarch64", false },
-        { "alpha", false },
-        { "arm", false },
-        { "cris", false },
-        { "i386", false },
-        { "lm32", true },
-        { "m68k", true },
-        { "microblaze", true },
-        { "microblazeel", false },
-        { "mips", true },
-        { "mips64", true },
-        { "mips64el", false },
-        { "mipsel", false },
-        { "moxie", true },
-        { "or32", true },
-        { "ppc", true },
-        { "ppc64", true },
-        { "ppcemb", true },
-        { "s390x", true },
-        { "sh4", false },
-        { "sh4eb", true },
-        { "sparc", true },
-        { "sparc64", true },
-        { "unicore32", false },
-        { "x86_64", false },
-        { "xtensa", false },
-        { "xtensaeb", true },
-        {},
-    };
-
-    for (i = 0; endianness[i].arch; i++) {
-        if (strcmp(endianness[i].arch, arch) == 0) {
-            return endianness[i].big_endian;
-        }
-    }
-
-    return false;
+    return s->big_endian;
 }
diff --git a/tests/libqtest.h b/tests/libqtest.h
index f7402e0..4be1f77 100644
--- a/tests/libqtest.h
+++ b/tests/libqtest.h
@@ -410,6 +410,14 @@ int64_t qtest_clock_step(QTestState *s, int64_t step);
 int64_t qtest_clock_set(QTestState *s, int64_t val);
 
 /**
+ * qtest_big_endian:
+ * @s: QTestState instance to operate on.
+ *
+ * Returns: True if the architecture under test has a big endian configuration.
+ */
+bool qtest_big_endian(QTestState *s);
+
+/**
  * qtest_get_arch:
  *
  * Returns: The architecture for the QEMU executable under test.
@@ -874,12 +882,14 @@ static inline int64_t clock_set(int64_t val)
 }
 
 /**
- * qtest_big_endian:
+ * target_big_endian:
  *
  * Returns: True if the architecture under test has a big endian configuration.
  */
-bool qtest_big_endian(void);
-
+static inline bool target_big_endian(void)
+{
+    return qtest_big_endian(global_qtest);
+}
 
 QDict *qmp_fd_receive(int fd);
 void qmp_fd_sendv(int fd, const char *fmt, va_list ap);
diff --git a/tests/virtio-blk-test.c b/tests/virtio-blk-test.c
index 3c4fecc..0506917 100644
--- a/tests/virtio-blk-test.c
+++ b/tests/virtio-blk-test.c
@@ -125,7 +125,7 @@ static inline void virtio_blk_fix_request(QVirtioBlkReq *req)
     bool host_endian = false;
 #endif
 
-    if (qtest_big_endian() != host_endian) {
+    if (target_big_endian() != host_endian) {
         req->type = bswap32(req->type);
         req->ioprio = bswap32(req->ioprio);
         req->sector = bswap64(req->sector);
-- 
2.7.4