Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* RTC fixes (Artem)
* icount fixes (Artem)
* rr fixes (Pavel, myself)
* hotplug cleanup (Igor)
* SCSI fixes (myself)
* 4.20-rc1 KVM header update (myself)
* coalesced PIO support (Peng Hao)
* HVF fixes (Roman B.)
* Hyper-V refactoring (Roman K.)
* Support for Hyper-V IPI (Vitaly)

# gpg: Signature made Fri 19 Oct 2018 12:47:58 BST
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (47 commits)
  replay: pass raw icount value to replay_save_clock
  target/i386: kvm: just return after migrate_add_blocker failed
  hyperv_testdev: add SynIC message and event testmodes
  hyperv: process POST_MESSAGE hypercall
  hyperv: add support for KVM_HYPERV_EVENTFD
  hyperv: process SIGNAL_EVENT hypercall
  hyperv: add synic event flag signaling
  hyperv: add synic message delivery
  hyperv: make overlay pages for SynIC
  hyperv: only add SynIC in compatible configurations
  hyperv: qom-ify SynIC
  hyperv:synic: split capability testing and setting
  i386: add hyperv-stub for CONFIG_HYPERV=n
  default-configs: collect CONFIG_HYPERV* in hyperv.mak
  hyperv: factor out arch-independent API into hw/hyperv
  hyperv: make hyperv_vp_index inline
  hyperv: split hyperv-proto.h into x86 and arch-independent parts
  hyperv: rename kvm_hv_sint_route_set_sint
  hyperv: make HvSintRoute reference-counted
  hyperv: address HvSintRoute by X86CPU pointer
  ...

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

1 files changed, 9 insertions, 5 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index 0f2f65ee40..214ce396f9 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3458,25 +3458,29 @@ HXCOMM Silently ignored for compatibility
 DEF("clock", HAS_ARG, QEMU_OPTION_clock, "", QEMU_ARCH_ALL)
 
 DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
-    "-rtc [base=utc|localtime|date][,clock=host|rt|vm][,driftfix=none|slew]\n" \
+    "-rtc [base=utc|localtime|<datetime>][,clock=host|rt|vm][,driftfix=none|slew]\n" \
     "                set the RTC base and clock, enable drift fix for clock ticks (x86 only)\n",
     QEMU_ARCH_ALL)
 
 STEXI
 
-@item -rtc [base=utc|localtime|@var{date}][,clock=host|vm][,driftfix=none|slew]
+@item -rtc [base=utc|localtime|@var{datetime}][,clock=host|rt|vm][,driftfix=none|slew]
 @findex -rtc
 Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
 UTC or local time, respectively. @code{localtime} is required for correct date in
-MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
+MS-DOS or Windows. To start at a specific point in time, provide @var{datetime} in the
 format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
 
 By default the RTC is driven by the host system time. This allows using of the
 RTC as accurate reference clock inside the guest, specifically if the host
 time is smoothly following an accurate external reference clock, e.g. via NTP.
 If you want to isolate the guest time from the host, you can set @option{clock}
-to @code{rt} instead.  To even prevent it from progressing during suspension,
-you can set it to @code{vm}.
+to @code{rt} instead, which provides a host monotonic clock if host support it.
+To even prevent the RTC from progressing during suspension, you can set @option{clock}
+to @code{vm} (virtual clock). @samp{clock=vm} is recommended especially in
+icount mode in order to preserve determinism; however, note that in icount mode
+the speed of the virtual clock is variable and can in general differ from the
+host clock.
 
 Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
 specifically with Windows' ACPI HAL. This option will try to figure out how