Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-6.0-pull-request' into staging

Pull request trivial-patches 20201214

# gpg: Signature made Mon 14 Dec 2020 15:52:07 GMT
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/trivial-branch-for-6.0-pull-request:
  configure / meson: Move check for linux/btrfs.h to meson.build
  configure / meson: Move check for sys/kcov.h to meson.build
  configure / meson: Move check for sys/signal.h to meson.build
  configure / meson: Move check for drm.h to meson.build
  configure / meson: Move check for pty.h to meson.build
  configure: Remove the obsolete check for ifaddrs.h
  blockdev: Fix a memleak in drive_backup_prepare()
  block/file-posix: fix a possible undefined behavior
  elf2dmp/pdb: Plug memleak in pdb_init_from_file
  elf2dmp/qemu_elf: Plug memleak in QEMU_Elf_init
  configure: Test if $make actually exists
  ads7846: moves from the hw/display folder to the hw/input folder.
  CODING_STYLE.rst: Be less strict about 80 character limit
  fsdev: open brace '{' following struct go on the same line
  hw/pci-host/pam: Replace magic number by PAM_REGIONS_COUNT definition
  hw/xen: Don't use '#' flag of printf format
  MAINTAINERS: update my email address
  qemu-options.hx: Fix minor issues in icount documentation
  target/i386: tracing: format length values as hex

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

1 files changed, 25 insertions, 19 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index e60ad42976..ae8872d1d6 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3958,30 +3958,34 @@ SRST
 ERST
 
 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
-    "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \
+    "-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=<filename>[,rrsnapshot=<snapshot>]]\n" \
     "                enable virtual instruction counter with 2^N clock ticks per\n" \
     "                instruction, enable aligning the host and virtual clocks\n" \
-    "                or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
+    "                or disable real time cpu sleeping, and optionally enable\n" \
+    "                record-and-replay mode\n", QEMU_ARCH_ALL)
 SRST
-``-icount [shift=N|auto][,rr=record|replay,rrfile=filename,rrsnapshot=snapshot]``
+``-icount [shift=N|auto][,align=on|off][,sleep=on|off][,rr=record|replay,rrfile=filename[,rrsnapshot=snapshot]]``
     Enable virtual instruction counter. The virtual cpu will execute one
     instruction every 2^N ns of virtual time. If ``auto`` is specified
     then the virtual cpu speed will be automatically adjusted to keep
     virtual time within a few seconds of real time.
 
-    When the virtual cpu is sleeping, the virtual time will advance at
-    default speed unless ``sleep=on|off`` is specified. With
-    ``sleep=on|off``, the virtual time will jump to the next timer
-    deadline instantly whenever the virtual cpu goes to sleep mode and
-    will not advance if no timer is enabled. This behavior give
-    deterministic execution times from the guest point of view.
-
     Note that while this option can give deterministic behavior, it does
     not provide cycle accurate emulation. Modern CPUs contain
     superscalar out of order cores with complex cache hierarchies. The
     number of instructions executed often has little or no correlation
     with actual performance.
 
+    When the virtual cpu is sleeping, the virtual time will advance at
+    default speed unless ``sleep=on`` is specified. With
+    ``sleep=on``, the virtual time will jump to the next timer
+    deadline instantly whenever the virtual cpu goes to sleep mode and
+    will not advance if no timer is enabled. This behavior gives
+    deterministic execution times from the guest point of view.
+    The default if icount is enabled is ``sleep=off``.
+    ``sleep=on`` cannot be used together with either ``shift=auto``
+    or ``align=on``.
+
     ``align=on`` will activate the delay algorithm which will try to
     synchronise the host clock and the virtual clock. The goal is to
     have a guest running at the real frequency imposed by the shift
@@ -3991,15 +3995,17 @@ SRST
     ``shift`` is ``auto``. Note: The sync algorithm will work for those
     shift values for which the guest clock runs ahead of the host clock.
     Typically this happens when the shift value is high (how high
-    depends on the host machine).
-
-    When ``rr`` option is specified deterministic record/replay is
-    enabled. Replay log is written into filename file in record mode and
-    read from this file in replay mode.
-
-    Option rrsnapshot is used to create new vm snapshot named snapshot
-    at the start of execution recording. In replay mode this option is
-    used to load the initial VM state.
+    depends on the host machine). The default if icount is enabled
+    is ``align=off``.
+
+    When the ``rr`` option is specified deterministic record/replay is
+    enabled. The ``rrfile=`` option must also be provided to
+    specify the path to the replay log. In record mode data is written
+    to this file, and in replay mode it is read back.
+    If the ``rrsnapshot`` option is given then it specifies a VM snapshot
+    name. In record mode, a new VM snapshot with the given name is created
+    at the start of execution recording. In replay mode this option
+    specifies the snapshot name used to load the initial VM state.
 ERST
 
 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \