Merge remote-tracking branch 'remotes/marcandre/tags/misc-pull-request' into staging

chardev & doc misc

# gpg: Signature made Tue 14 Sep 2021 13:59:10 BST
# gpg:                using RSA key 87A9BD933F87C606D276F62DDAE8E10975969CE5
# gpg:                issuer "marcandre.lureau@redhat.com"
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>" [full]
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>" [full]
# Primary key fingerprint: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/marcandre/tags/misc-pull-request:
  chardev: add some comments about the class methods
  chardev: remove needless class method
  chardev: Propagate error from logfile opening
  meson.build: fix comment typo
  docs: add supported host CPU architectures section

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 73 insertions, 11 deletions

diff --git a/chardev/char-mux.c b/chardev/char-mux.c
index 5baf419..ada0c68 100644
--- a/chardev/char-mux.c
+++ b/chardev/char-mux.c
@@ -386,10 +386,9 @@ void suspend_mux_open(void)
 static int chardev_options_parsed_cb(Object *child, void *opaque)
 {
     Chardev *chr = (Chardev *)child;
-    ChardevClass *class = CHARDEV_GET_CLASS(chr);
 
-    if (!chr->be_open && class->chr_options_parsed) {
-        class->chr_options_parsed(chr);
+    if (!chr->be_open && CHARDEV_IS_MUX(chr)) {
+        open_muxes(chr);
     }
 
     return 0;
@@ -412,7 +411,6 @@ static void char_mux_class_init(ObjectClass *oc, void *data)
     cc->chr_accept_input = mux_chr_accept_input;
     cc->chr_add_watch = mux_chr_add_watch;
     cc->chr_be_event = mux_chr_be_event;
-    cc->chr_options_parsed = open_muxes;
     cc->chr_update_read_handler = mux_chr_update_read_handlers;
 }
 
diff --git a/chardev/char.c b/chardev/char.c
index 4595a8d..0169d8d 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -241,18 +241,15 @@ static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
     ChardevCommon *common = backend ? backend->u.null.data : NULL;
 
     if (common && common->has_logfile) {
-        int flags = O_WRONLY | O_CREAT;
+        int flags = O_WRONLY;
         if (common->has_logappend &&
             common->logappend) {
             flags |= O_APPEND;
         } else {
             flags |= O_TRUNC;
         }
-        chr->logfd = qemu_open_old(common->logfile, flags, 0666);
+        chr->logfd = qemu_create(common->logfile, flags, 0666, errp);
         if (chr->logfd < 0) {
-            error_setg_errno(errp, errno,
-                             "Unable to open logfile %s",
-                             common->logfile);
             return;
         }
     }
diff --git a/docs/about/build-platforms.rst b/docs/about/build-platforms.rst
index 6923236..bcb1549 100644
--- a/docs/about/build-platforms.rst
+++ b/docs/about/build-platforms.rst
@@ -29,6 +29,39 @@ The `Repology`_ site is a useful resource to identify
 currently shipped versions of software in various operating systems,
 though it does not cover all distros listed below.
 
+Supported host architectures
+----------------------------
+
+Those hosts are officially supported, with various accelerators:
+
+  .. list-table::
+   :header-rows: 1
+
+   * - CPU Architecture
+     - Accelerators
+   * - Arm
+     - kvm (64 bit only), tcg, xen
+   * - MIPS
+     - kvm, tcg
+   * - PPC
+     - kvm, tcg
+   * - RISC-V
+     - tcg
+   * - s390x
+     - kvm, tcg
+   * - SPARC
+     - tcg
+   * - x86
+     - hax, hvf (64 bit only), kvm, nvmm, tcg, whpx (64 bit only), xen
+
+Other host architectures are not supported. It is possible to build QEMU on an
+unsupported host architecture using the configure ``--enable-tcg-interpreter``
+option to enable the experimental TCI support, but note that this is very slow
+and is not recommended.
+
+Non-supported architectures may be removed in the future following the
+:ref:`deprecation process<Deprecated features>`.
+
 Linux OS, macOS, FreeBSD, NetBSD, OpenBSD
 -----------------------------------------
 
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 9ee355e..3c2be84 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -1,3 +1,5 @@
+.. _Deprecated features:
+
 Deprecated features
 ===================
 
diff --git a/include/chardev/char.h b/include/chardev/char.h
index 7c0444f..a319b5f 100644
--- a/include/chardev/char.h
+++ b/include/chardev/char.h
@@ -254,26 +254,58 @@ struct ChardevClass {
 
     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
     bool supports_yank;
+
+    /* parse command line options and populate QAPI @backend */
     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 
+    /* called after construction, open/starts the backend */
     void (*open)(Chardev *chr, ChardevBackend *backend,
                  bool *be_opened, Error **errp);
 
+    /* write buf to the backend */
     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
+
+    /*
+     * Read from the backend (blocking). A typical front-end will instead rely
+     * on chr_can_read/chr_read being called when polling/looping.
+     */
     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
+
+    /* create a watch on the backend */
     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
+
+    /* update the backend internal sources */
     void (*chr_update_read_handler)(Chardev *s);
+
+    /* send an ioctl to the backend */
     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
+
+    /* get ancillary-received fds during last read */
     int (*get_msgfds)(Chardev *s, int* fds, int num);
+
+    /* set ancillary fds to be sent with next write */
     int (*set_msgfds)(Chardev *s, int *fds, int num);
+
+    /* accept the given fd */
     int (*chr_add_client)(Chardev *chr, int fd);
+
+    /* wait for a connection */
     int (*chr_wait_connected)(Chardev *chr, Error **errp);
+
+    /* disconnect a connection */
     void (*chr_disconnect)(Chardev *chr);
+
+    /* called by frontend when it can read */
     void (*chr_accept_input)(Chardev *chr);
+
+    /* set terminal echo */
     void (*chr_set_echo)(Chardev *chr, bool echo);
+
+    /* notify the backend of frontend open state */
     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
+
+    /* handle various events */
     void (*chr_be_event)(Chardev *s, QEMUChrEvent event);
-    void (*chr_options_parsed)(Chardev *chr);
 };
 
 Chardev *qemu_chardev_new(const char *id, const char *typename,
diff --git a/meson.build b/meson.build
index 7d7d14a..2711cbb 100644
--- a/meson.build
+++ b/meson.build
@@ -78,7 +78,7 @@ endif
 
 accelerator_targets = { 'CONFIG_KVM': kvm_targets }
 if cpu in ['x86', 'x86_64', 'arm', 'aarch64']
-  # i368 emulator provides xenpv machine type for multiple architectures
+  # i386 emulator provides xenpv machine type for multiple architectures
   accelerator_targets += {
     'CONFIG_XEN': ['i386-softmmu', 'x86_64-softmmu'],
   }