wxx patch queue

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Merge remote-tracking branch 'remotes/weil/tags/pull-wxx-20150924' into staging

wxx patch queue

# gpg: Signature made Thu 24 Sep 2015 20:24:50 BST using RSA key ID 677450AD
# gpg: Good signature from "Stefan Weil <sw@weilnetz.de>"
# gpg:                 aka "Stefan Weil <stefan.weil@weilnetz.de>"
# gpg:                 aka "Stefan Weil <stefan.weil@bib.uni-mannheim.de>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 4923 6FEA 75C9 5D69 8EC2  B78A E08C 21D5 6774 50AD

* remotes/weil/tags/pull-wxx-20150924:
  oslib-win32: only provide localtime_r/gmtime_r if missing
  gtk: avoid redefining _WIN32_WINNT macro
  qemu-thread: add a fast path to the Win32 QemuEvent
  slirp: Fix non blocking connect for w32
  nsis: Add QEMU version information to Windows registry

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

Makefile

@@ -623,6 +623,7 @@ endif # SIGNCODE
                 $(if $(DLL_PATH),-DDLLDIR="$(DLL_PATH)") \
                 -DSRCDIR="$(SRC_PATH)" \
                 -DOUTFILE="$(INSTALLER)" \
+                -DDISPLAYVERSION="$(VERSION)" \
                 $(SRC_PATH)/qemu.nsi
 	rm -r ${INSTDIR}
 ifdef SIGNCODE

configure

@@ -1736,6 +1736,37 @@ else
   l2tpv3=no
 fi
 
+##########################################
+# MinGW / Mingw-w64 localtime_r/gmtime_r check
+
+if test "$mingw32" = "yes"; then
+    # Some versions of MinGW / Mingw-w64 lack localtime_r
+    # and gmtime_r entirely.
+    #
+    # Some versions of Mingw-w64 define a macro for
+    # localtime_r/gmtime_r.
+    #
+    # Some versions of Mingw-w64 will define functions
+    # for localtime_r/gmtime_r, but only if you have
+    # _POSIX_THREAD_SAFE_FUNCTIONS defined. For fun
+    # though, unistd.h and pthread.h both define
+    # that for you.
+    #
+    # So this #undef localtime_r and #include <unistd.h>
+    # are not in fact redundant.
+cat > $TMPC << EOF
+#include <unistd.h>
+#include <time.h>
+#undef localtime_r
+int main(void) { localtime_r(NULL, NULL); return 0; }
+EOF
+    if compile_prog "" "" ; then
+        localtime_r="yes"
+    else
+        localtime_r="no"
+    fi
+fi
+
 ##########################################
 # pkg-config probe
 
@@ -5034,6 +5065,9 @@ fi
 if test "$zero_malloc" = "yes" ; then
   echo "CONFIG_ZERO_MALLOC=y" >> $config_host_mak
 fi
+if test "$localtime_r" = "yes" ; then
+  echo "CONFIG_LOCALTIME_R=y" >> $config_host_mak
+fi
 if test "$qom_cast_debug" = "yes" ; then
   echo "CONFIG_QOM_CAST_DEBUG=y" >> $config_host_mak
 fi

docs/win32-qemu-event.promela

@@ -0,0 +1,98 @@
+/*
+ * This model describes the implementation of QemuEvent in
+ * util/qemu-thread-win32.c.
+ *
+ * Author: Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * This file is in the public domain.  If you really want a license,
+ * the WTFPL will do.
+ *
+ * To verify it:
+ *     spin -a docs/event.promela
+ *     gcc -O2 pan.c -DSAFETY
+ *     ./a.out
+ */
+
+bool event;
+int value;
+
+/* Primitives for a Win32 event */
+#define RAW_RESET event = false
+#define RAW_SET   event = true
+#define RAW_WAIT  do :: event -> break; od
+
+#if 0
+/* Basic sanity checking: test the Win32 event primitives */
+#define RESET     RAW_RESET
+#define SET       RAW_SET
+#define WAIT      RAW_WAIT
+#else
+/* Full model: layer a userspace-only fast path on top of the RAW_*
+ * primitives.  SET/RESET/WAIT have exactly the same semantics as
+ * RAW_SET/RAW_RESET/RAW_WAIT, but try to avoid invoking them.
+ */
+#define EV_SET 0
+#define EV_FREE 1
+#define EV_BUSY -1
+
+int state = EV_FREE;
+
+int xchg_result;
+#define SET   if :: state != EV_SET ->                                      \
+                    atomic { /* xchg_result=xchg(state, EV_SET) */          \
+                        xchg_result = state;                                \
+                        state = EV_SET;                                     \
+                    }                                                       \
+                    if :: xchg_result == EV_BUSY -> RAW_SET;                \
+                       :: else -> skip;                                     \
+                    fi;                                                     \
+                 :: else -> skip;                                           \
+              fi
+
+#define RESET if :: state == EV_SET -> atomic { state = state | EV_FREE; }  \
+                 :: else            -> skip;                                \
+              fi
+
+int tmp1, tmp2;
+#define WAIT  tmp1 = state;                                                 \
+              if :: tmp1 != EV_SET ->                                       \
+                    if :: tmp1 == EV_FREE ->                                \
+                          RAW_RESET;                                        \
+                          atomic { /* tmp2=cas(state, EV_FREE, EV_BUSY) */  \
+                              tmp2 = state;                                 \
+                              if :: tmp2 == EV_FREE -> state = EV_BUSY;     \
+                                 :: else            -> skip;                \
+                              fi;                                           \
+                          }                                                 \
+                          if :: tmp2 == EV_SET -> tmp1 = EV_SET;            \
+                             :: else           -> tmp1 = EV_BUSY;           \
+                          fi;                                               \
+                       :: else -> skip;                                     \
+                    fi;                                                     \
+                    assert(tmp1 != EV_FREE);                                \
+                    if :: tmp1 == EV_BUSY -> RAW_WAIT;                      \
+                       :: else -> skip;                                     \
+                    fi;                                                     \
+                 :: else -> skip;                                           \
+              fi
+#endif
+
+active proctype waiter()
+{
+     if
+         :: !value ->
+             RESET;
+             if
+                 :: !value -> WAIT;
+                 :: else   -> skip;
+             fi;
+        :: else -> skip;
+    fi;
+    assert(value);
+}
+
+active proctype notifier()
+{
+    value = true;
+    SET;
+}

include/qemu/osdep.h

@@ -38,10 +38,12 @@
 #include <strings.h>
 #include <inttypes.h>
 #include <limits.h>
+/* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
+ * function availability on recentish Mingw-w64 platforms. */
+#include <unistd.h>
 #include <time.h>
 #include <ctype.h>
 #include <errno.h>
-#include <unistd.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/time.h>

include/qemu/thread-win32.h

@@ -18,6 +18,7 @@ struct QemuSemaphore {
 };
 
 struct QemuEvent {
+    int value;
     HANDLE event;
 };
 

include/sysemu/os-win32.h

@@ -73,10 +73,12 @@
 #define siglongjmp(env, val) longjmp(env, val)
 
 /* Missing POSIX functions. Don't use MinGW-w64 macros. */
+#ifndef CONFIG_LOCALTIME_R
 #undef gmtime_r
 struct tm *gmtime_r(const time_t *timep, struct tm *result);
 #undef localtime_r
 struct tm *localtime_r(const time_t *timep, struct tm *result);
+#endif /* CONFIG_LOCALTIME_R */
 
 
 static inline void os_setup_signal_handling(void) {}

include/ui/gtk.h

@@ -1,10 +1,6 @@
 #ifndef UI_GTK_H
 #define UI_GTK_H
 
-#ifdef _WIN32
-# define _WIN32_WINNT 0x0601 /* needed to get definition of MAPVK_VK_TO_VSC */
-#endif
-
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
 /* Work around an -Wstrict-prototypes warning in GTK headers */
 #pragma GCC diagnostic push

qemu.nsi

@@ -139,6 +139,9 @@ Section "${PRODUCT} (required)"
 
     ; Write the uninstall keys for Windows
     WriteRegStr HKLM "${UNINST_KEY}" "DisplayName" "QEMU"
+!ifdef DISPLAYVERSION
+    WriteRegStr HKLM "${UNINST_KEY}" "DisplayVersion" "${DISPLAYVERSION}"
+!endif
     WriteRegStr HKLM "${UNINST_KEY}" "UninstallString" '"${UNINST_EXE}"'
     WriteRegDWORD HKLM "${UNINST_KEY}" "NoModify" 1
     WriteRegDWORD HKLM "${UNINST_KEY}" "NoRepair" 1

slirp/tcp_input.c

@@ -584,7 +584,13 @@ findso:
 	    goto cont_input;
 	  }
 
-	  if((tcp_fconnect(so) == -1) && (errno != EINPROGRESS) && (errno != EWOULDBLOCK)) {
+          if ((tcp_fconnect(so) == -1) &&
+#if defined(_WIN32)
+              socket_error() != WSAEWOULDBLOCK
+#else
+              (errno != EINPROGRESS) && (errno != EWOULDBLOCK)
+#endif
+          ) {
 	    u_char code=ICMP_UNREACH_NET;
 	    DEBUG_MISC((dfd, " tcp fconnect errno = %d-%s\n",
 			errno,strerror(errno)));

ui/gtk.c

@@ -104,6 +104,15 @@
 #define GDK_KEY_Pause GDK_Pause
 #endif
 
+/* Some older mingw versions lack this constant or have
+ * it conditionally defined */
+#ifdef _WIN32
+# ifndef MAPVK_VK_TO_VSC
+#  define MAPVK_VK_TO_VSC 0
+# endif
+#endif
+
+
 #define HOTKEY_MODIFIERS        (GDK_CONTROL_MASK | GDK_MOD1_MASK)
 
 static const int modifier_keycode[] = {

util/oslib-win32.c

@@ -95,6 +95,7 @@ void qemu_anon_ram_free(void *ptr, size_t size)
     }
 }
 
+#ifndef CONFIG_LOCALTIME_R
 /* FIXME: add proper locking */
 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 {
@@ -118,6 +119,7 @@ struct tm *localtime_r(const time_t *timep, struct tm *result)
     }
     return p;
 }
+#endif /* CONFIG_LOCALTIME_R */
 
 void qemu_set_block(int fd)
 {

util/qemu-thread-win32.c

@@ -238,10 +238,34 @@ void qemu_sem_wait(QemuSemaphore *sem)
     }
 }
 
+/* Wrap a Win32 manual-reset event with a fast userspace path.  The idea
+ * is to reset the Win32 event lazily, as part of a test-reset-test-wait
+ * sequence.  Such a sequence is, indeed, how QemuEvents are used by
+ * RCU and other subsystems!
+ *
+ * Valid transitions:
+ * - free->set, when setting the event
+ * - busy->set, when setting the event, followed by futex_wake
+ * - set->free, when resetting the event
+ * - free->busy, when waiting
+ *
+ * set->busy does not happen (it can be observed from the outside but
+ * it really is set->free->busy).
+ *
+ * busy->free provably cannot happen; to enforce it, the set->free transition
+ * is done with an OR, which becomes a no-op if the event has concurrently
+ * transitioned to free or busy (and is faster than cmpxchg).
+ */
+
+#define EV_SET         0
+#define EV_FREE        1
+#define EV_BUSY       -1
+
 void qemu_event_init(QemuEvent *ev, bool init)
 {
     /* Manual reset.  */
-    ev->event = CreateEvent(NULL, TRUE, init, NULL);
+    ev->event = CreateEvent(NULL, TRUE, TRUE, NULL);
+    ev->value = (init ? EV_SET : EV_FREE);
 }
 
 void qemu_event_destroy(QemuEvent *ev)
@@ -251,17 +275,51 @@ void qemu_event_destroy(QemuEvent *ev)
 
 void qemu_event_set(QemuEvent *ev)
 {
+    if (atomic_mb_read(&ev->value) != EV_SET) {
+        if (atomic_xchg(&ev->value, EV_SET) == EV_BUSY) {
+            /* There were waiters, wake them up.  */
             SetEvent(ev->event);
+        }
+    }
 }
 
 void qemu_event_reset(QemuEvent *ev)
 {
-    ResetEvent(ev->event);
+    if (atomic_mb_read(&ev->value) == EV_SET) {
+        /* If there was a concurrent reset (or even reset+wait),
+         * do nothing.  Otherwise change EV_SET->EV_FREE.
+         */
+        atomic_or(&ev->value, EV_FREE);
+    }
 }
 
 void qemu_event_wait(QemuEvent *ev)
 {
+    unsigned value;
+
+    value = atomic_mb_read(&ev->value);
+    if (value != EV_SET) {
+        if (value == EV_FREE) {
+            /* qemu_event_set is not yet going to call SetEvent, but we are
+             * going to do another check for EV_SET below when setting EV_BUSY.
+             * At that point it is safe to call WaitForSingleObject.
+             */
+            ResetEvent(ev->event);
+
+            /* Tell qemu_event_set that there are waiters.  No need to retry
+             * because there cannot be a concurent busy->free transition.
+             * After the CAS, the event will be either set or busy.
+             */
+            if (atomic_cmpxchg(&ev->value, EV_FREE, EV_BUSY) == EV_SET) {
+                value = EV_SET;
+            } else {
+                value = EV_BUSY;
+            }
+        }
+        if (value == EV_BUSY) {
             WaitForSingleObject(ev->event, INFINITE);
+        }
+    }
 }
 
 struct QemuThreadData {