14 files changed, 280 insertions, 26 deletions
diff --git a/include/qemu/cacheflush.h b/include/qemu/cacheflush.h
index ae20bcd..76eb55d 100644
--- a/include/qemu/cacheflush.h
+++ b/include/qemu/cacheflush.h
@@ -26,6 +26,13 @@ static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
     /* icache is coherent and does not require flushing. */
 }
 
+#elif defined(EMSCRIPTEN)
+
+static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
+{
+    /* Wasm doesn't have executable region of memory. */
+}
+
 #else
 
 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len);
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 496dac5..65b8995 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -208,6 +208,26 @@
 #endif
 
 /*
+ * Disable -ftrivial-auto-var-init on a local variable.
+ *
+ * Use this in cases where there a method in the device I/O path (or other
+ * important hot paths), that has large variables on the stack. A rule of
+ * thumb is that "large" means a method with 4kb data in the local stack
+ * frame. Any variables which are KB in size, should be annotated with this
+ * attribute, to pre-emptively eliminate any potential overhead from the
+ * compiler's implicit zero'ing of memory.
+ *
+ * Given that this turns off a security hardening feature, when using this
+ * to flag variables, it is important that the code is double-checked to
+ * ensure there is no possible use of uninitialized data in the method.
+ */
+#if __has_attribute(uninitialized)
+# define QEMU_UNINITIALIZED __attribute__((uninitialized))
+#else
+# define QEMU_UNINITIALIZED
+#endif
+
+/*
  * http://clang.llvm.org/docs/ThreadSafetyAnalysis.html
  *
  * TSA is available since clang 3.6-ish.
diff --git a/include/qemu/futex.h b/include/qemu/futex.h
index 91ae889..607613e 100644
--- a/include/qemu/futex.h
+++ b/include/qemu/futex.h
@@ -1,5 +1,5 @@
 /*
- * Wrappers around Linux futex syscall
+ * Wrappers around Linux futex syscall and similar
  *
  * Copyright Red Hat, Inc. 2017
  *
@@ -11,17 +11,35 @@
  *
  */
 
+/*
+ * Note that a wake-up can also be caused by common futex usage patterns in
+ * unrelated code that happened to have previously used the futex word's
+ * memory location (e.g., typical futex-based implementations of Pthreads
+ * mutexes can cause this under some conditions).  Therefore, qemu_futex_wait()
+ * callers should always conservatively assume that it is a spurious wake-up,
+ * and use the futex word's value (i.e., the user-space synchronization scheme)
+ * to decide whether to continue to block or not.
+ */
+
 #ifndef QEMU_FUTEX_H
 #define QEMU_FUTEX_H
 
+#define HAVE_FUTEX
+
+#ifdef CONFIG_LINUX
 #include <sys/syscall.h>
 #include <linux/futex.h>
 
 #define qemu_futex(...)              syscall(__NR_futex, __VA_ARGS__)
 
-static inline void qemu_futex_wake(void *f, int n)
+static inline void qemu_futex_wake_all(void *f)
 {
-    qemu_futex(f, FUTEX_WAKE, n, NULL, NULL, 0);
+    qemu_futex(f, FUTEX_WAKE, INT_MAX, NULL, NULL, 0);
+}
+
+static inline void qemu_futex_wake_single(void *f)
+{
+    qemu_futex(f, FUTEX_WAKE, 1, NULL, NULL, 0);
 }
 
 static inline void qemu_futex_wait(void *f, unsigned val)
@@ -37,5 +55,25 @@ static inline void qemu_futex_wait(void *f, unsigned val)
         }
     }
 }
+#elif defined(CONFIG_WIN32)
+#include <synchapi.h>
+
+static inline void qemu_futex_wake_all(void *f)
+{
+    WakeByAddressAll(f);
+}
+
+static inline void qemu_futex_wake_single(void *f)
+{
+    WakeByAddressSingle(f);
+}
+
+static inline void qemu_futex_wait(void *f, unsigned val)
+{
+    WaitOnAddress(f, &val, sizeof(val), INFINITE);
+}
+#else
+#undef HAVE_FUTEX
+#endif
 
 #endif /* QEMU_FUTEX_H */
diff --git a/include/qemu/host-pci-mmio.h b/include/qemu/host-pci-mmio.h
new file mode 100644
index 0000000..a8ed993
--- /dev/null
+++ b/include/qemu/host-pci-mmio.h
@@ -0,0 +1,136 @@
+/*
+ * API for host PCI MMIO accesses (e.g. Linux VFIO BARs)
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Farhan Ali <alifm@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HOST_PCI_MMIO_H
+#define HOST_PCI_MMIO_H
+
+#include "qemu/bswap.h"
+#include "qemu/s390x_pci_mmio.h"
+
+static inline uint8_t host_pci_ldub_p(const void *ioaddr)
+{
+    uint8_t ret = 0;
+#ifdef __s390x__
+    ret = s390x_pci_mmio_read_8(ioaddr);
+#else
+    ret = ldub_p(ioaddr);
+#endif
+
+    return ret;
+}
+
+static inline uint16_t host_pci_lduw_le_p(const void *ioaddr)
+{
+    uint16_t ret = 0;
+#ifdef __s390x__
+    ret = le16_to_cpu(s390x_pci_mmio_read_16(ioaddr));
+#else
+    ret = lduw_le_p(ioaddr);
+#endif
+
+    return ret;
+}
+
+static inline uint32_t host_pci_ldl_le_p(const void *ioaddr)
+{
+    uint32_t ret = 0;
+#ifdef __s390x__
+    ret = le32_to_cpu(s390x_pci_mmio_read_32(ioaddr));
+#else
+    ret = ldl_le_p(ioaddr);
+#endif
+
+    return ret;
+}
+
+static inline uint64_t host_pci_ldq_le_p(const void *ioaddr)
+{
+    uint64_t ret = 0;
+#ifdef __s390x__
+    ret = le64_to_cpu(s390x_pci_mmio_read_64(ioaddr));
+#else
+    ret = ldq_le_p(ioaddr);
+#endif
+
+    return ret;
+}
+
+static inline void host_pci_stb_p(void *ioaddr, uint8_t val)
+{
+#ifdef __s390x__
+    s390x_pci_mmio_write_8(ioaddr, val);
+#else
+    stb_p(ioaddr, val);
+#endif
+}
+
+static inline void host_pci_stw_le_p(void *ioaddr, uint16_t val)
+{
+#ifdef __s390x__
+    s390x_pci_mmio_write_16(ioaddr, cpu_to_le16(val));
+#else
+    stw_le_p(ioaddr, val);
+#endif
+}
+
+static inline void host_pci_stl_le_p(void *ioaddr, uint32_t val)
+{
+#ifdef __s390x__
+    s390x_pci_mmio_write_32(ioaddr, cpu_to_le32(val));
+#else
+    stl_le_p(ioaddr, val);
+#endif
+}
+
+static inline void host_pci_stq_le_p(void *ioaddr, uint64_t val)
+{
+#ifdef __s390x__
+    s390x_pci_mmio_write_64(ioaddr, cpu_to_le64(val));
+#else
+    stq_le_p(ioaddr, val);
+#endif
+}
+
+static inline uint64_t host_pci_ldn_le_p(const void *ioaddr, int sz)
+{
+    switch (sz) {
+    case 1:
+        return host_pci_ldub_p(ioaddr);
+    case 2:
+        return host_pci_lduw_le_p(ioaddr);
+    case 4:
+        return host_pci_ldl_le_p(ioaddr);
+    case 8:
+        return host_pci_ldq_le_p(ioaddr);
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static inline void host_pci_stn_le_p(void *ioaddr, int sz, uint64_t v)
+{
+    switch (sz) {
+    case 1:
+        host_pci_stb_p(ioaddr, v);
+        break;
+    case 2:
+        host_pci_stw_le_p(ioaddr, v);
+        break;
+    case 4:
+        host_pci_stl_le_p(ioaddr, v);
+        break;
+    case 8:
+        host_pci_stq_le_p(ioaddr, v);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+#endif
diff --git a/include/qemu/lockcnt.h b/include/qemu/lockcnt.h
index f4b62a3..5a2800e 100644
--- a/include/qemu/lockcnt.h
+++ b/include/qemu/lockcnt.h
@@ -17,7 +17,7 @@
 typedef struct QemuLockCnt QemuLockCnt;
 
 struct QemuLockCnt {
-#ifndef CONFIG_LINUX
+#ifndef HAVE_FUTEX
     QemuMutex mutex;
 #endif
     unsigned count;
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 4397a90..96fe51b 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -8,7 +8,7 @@
  * To avoid getting into possible circular include dependencies, this
  * file should not include any other QEMU headers, with the exceptions
  * of config-host.h, config-target.h, qemu/compiler.h,
- * system/os-posix.h, system/os-win32.h, glib-compat.h and
+ * system/os-posix.h, system/os-win32.h, system/os-wasm.h, glib-compat.h and
  * qemu/typedefs.h, all of which are doing a similar job to this file
  * and are under similar constraints.
  *
@@ -164,10 +164,14 @@ QEMU_EXTERN_C int daemon(int, int);
 #include "system/os-win32.h"
 #endif
 
-#ifdef CONFIG_POSIX
+#if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
 #include "system/os-posix.h"
 #endif
 
+#if defined(EMSCRIPTEN)
+#include "system/os-wasm.h"
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/include/qemu/rcu.h b/include/qemu/rcu.h
index fea058a..020dbe4 100644
--- a/include/qemu/rcu.h
+++ b/include/qemu/rcu.h
@@ -17,8 +17,8 @@
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * License along with this library; if not, see
+ * <https://www.gnu.org/licenses/>.
  *
  * IBM's contributions to this file may be relicensed under LGPLv2 or later.
  */
diff --git a/include/qemu/rcu_queue.h b/include/qemu/rcu_queue.h
index 4e6298d..bfd5900 100644
--- a/include/qemu/rcu_queue.h
+++ b/include/qemu/rcu_queue.h
@@ -17,8 +17,8 @@
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * License along with this library; if not, see
+ * <https://www.gnu.org/licenses/>.
  *
  * Copyright (c) 2013 Mike D. Day, IBM Corporation.
  *
diff --git a/include/qemu/s390x_pci_mmio.h b/include/qemu/s390x_pci_mmio.h
new file mode 100644
index 0000000..c5f63ec
--- /dev/null
+++ b/include/qemu/s390x_pci_mmio.h
@@ -0,0 +1,24 @@
+/*
+ * s390x PCI MMIO definitions
+ *
+ * Copyright 2025 IBM Corp.
+ * Author(s): Farhan Ali <alifm@linux.ibm.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef S390X_PCI_MMIO_H
+#define S390X_PCI_MMIO_H
+
+#ifdef __s390x__
+uint8_t s390x_pci_mmio_read_8(const void *ioaddr);
+uint16_t s390x_pci_mmio_read_16(const void *ioaddr);
+uint32_t s390x_pci_mmio_read_32(const void *ioaddr);
+uint64_t s390x_pci_mmio_read_64(const void *ioaddr);
+
+void s390x_pci_mmio_write_8(void *ioaddr, uint8_t val);
+void s390x_pci_mmio_write_16(void *ioaddr, uint16_t val);
+void s390x_pci_mmio_write_32(void *ioaddr, uint32_t val);
+void s390x_pci_mmio_write_64(void *ioaddr, uint64_t val);
+#endif /* __s390x__ */
+
+#endif /* S390X_PCI_MMIO_H */
diff --git a/include/qemu/target-info-impl.h b/include/qemu/target-info-impl.h
index d30805f..1b51cbc 100644
--- a/include/qemu/target-info-impl.h
+++ b/include/qemu/target-info-impl.h
@@ -14,6 +14,12 @@
 typedef struct TargetInfo {
     /* runtime equivalent of TARGET_NAME definition */
     const char *target_name;
+    /* runtime equivalent of TARGET_LONG_BITS definition */
+    unsigned long_bits;
+    /* runtime equivalent of CPU_RESOLVING_TYPE definition */
+    const char *cpu_type;
+    /* QOM typename machines for this binary must implement */
+    const char *machine_typename;
 } TargetInfo;
 
 /**
diff --git a/include/qemu/target-info.h b/include/qemu/target-info.h
index 58d4136..850a295 100644
--- a/include/qemu/target-info.h
+++ b/include/qemu/target-info.h
@@ -17,6 +17,21 @@
 const char *target_name(void);
 
 /**
+ * target_long_bits:
+ *
+ * Returns: number of bits in a long type for this target (i.e. 64).
+ */
+unsigned target_long_bits(void);
+
+/**
+ * target_machine_typename:
+ *
+ * Returns: Name of the QOM interface implemented by machines
+ *          usable on this target binary.
+ */
+const char *target_machine_typename(void);
+
+/**
  * target_cpu_type:
  *
  * Returns: target CPU base QOM type name (i.e. TYPE_X86_CPU).
diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
index 5f2f3d1..758808b 100644
--- a/include/qemu/thread-posix.h
+++ b/include/qemu/thread-posix.h
@@ -32,15 +32,6 @@ struct QemuSemaphore {
     unsigned int count;
 };
 
-struct QemuEvent {
-#ifndef __linux__
-    pthread_mutex_t lock;
-    pthread_cond_t cond;
-#endif
-    unsigned value;
-    bool initialized;
-};
-
 struct QemuThread {
     pthread_t thread;
 };
diff --git a/include/qemu/thread-win32.h b/include/qemu/thread-win32.h
index d95af44..da9e732 100644
--- a/include/qemu/thread-win32.h
+++ b/include/qemu/thread-win32.h
@@ -28,12 +28,6 @@ struct QemuSemaphore {
     bool initialized;
 };
 
-struct QemuEvent {
-    int value;
-    HANDLE event;
-    bool initialized;
-};
-
 typedef struct QemuThreadData QemuThreadData;
 struct QemuThread {
     QemuThreadData *data;
diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index 6f800aa..f0302ed 100644
--- a/include/qemu/thread.h
+++ b/include/qemu/thread.h
@@ -3,13 +3,32 @@
 
 #include "qemu/processor.h"
 #include "qemu/atomic.h"
+#include "qemu/futex.h"
 
 typedef struct QemuCond QemuCond;
 typedef struct QemuSemaphore QemuSemaphore;
-typedef struct QemuEvent QemuEvent;
 typedef struct QemuLockCnt QemuLockCnt;
 typedef struct QemuThread QemuThread;
 
+/*
+ * QemuEvent
+ * =========
+ *
+ * QemuEvent is an implementation of Win32 manual-reset event object.
+ * For details, refer to:
+ * https://learn.microsoft.com/en-us/windows/win32/sync/using-event-objects
+ *
+ * QemuEvent is more lightweight than QemuSemaphore when HAVE_FUTEX is defined.
+ */
+typedef struct QemuEvent {
+#ifndef HAVE_FUTEX
+    pthread_mutex_t lock;
+    pthread_cond_t cond;
+#endif
+    unsigned value;
+    bool initialized;
+} QemuEvent;
+
 #ifdef _WIN32
 #include "qemu/thread-win32.h"
 #else