* xsetbv fix (x86 targets TCG)

* remove unused functions
 * qht segfault and memory leak fixes
 * NBD fixes
 * Fix for non-power-of-2 discard granularity
 * Memory hotplug fixes
 * Migration regressions
 * IOAPIC fixes and (disabled by default) EOI register support
 * Various other small fixes
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQExBAABCAAbBQJXoiNRFBxwYm9uemluaUByZWRoYXQuY29tAAoJEL/70l94x66D
 ZwMH/1HmEYIAyyd9T8z2sNjdN7vKCNsphS7OXALDnwTp+VX4icUbf41NC6Eeg/e+
 6OKA90KSBTquG3wxsXrUK5Nwy7EKMoCXVQrdYw5T04OidQLtJosKgPx4MrvPSx8h
 caFUXo9WynT/aGRNc14gnZZiooQxsy/JoNhuml/WL0nupEmoUb/Ns3Yo++HRHntR
 rFmJvvD9SrQsWzd9+aJ8zm+Qi09gXsbj1grr6LHCLVmwDWAJooFev6MqBvplkL50
 OLqCJfAXJ2srUoEboVdg3V+sFtB8Eru+iMdpZyLwo07V4BBK7heEsXx6JJkTObMC
 90MSnMo6BauUO/R/bMvvLlNWykU=
 =XqbI
 -----END PGP SIGNATURE-----

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

* xsetbv fix (x86 targets TCG)
* remove unused functions
* qht segfault and memory leak fixes
* NBD fixes
* Fix for non-power-of-2 discard granularity
* Memory hotplug fixes
* Migration regressions
* IOAPIC fixes and (disabled by default) EOI register support
* Various other small fixes

# gpg: Signature made Wed 03 Aug 2016 18:01:05 BST
# gpg:                using RSA key 0xBFFBD25F78C7AE83
# 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: (25 commits)
  util: Fix assertion in iov_copy() upon zero 'bytes' and non-zero 'offset'
  qdev: Fix use after free in qdev_init_nofail error path
  Reorganize help output of '-display' option
  x86: ioapic: add support for explicit EOI
  x86: ioapic: ignore level irq during processing
  apic: fix broken migration for kvm-apic
  fw_cfg: Make base type "fw_cfg" abstract
  block: Cater to iscsi with non-power-of-2 discard
  osdep: Document differences in rounding macros
  nbd: Limit nbdflags to 16 bits
  nbd: Fix bad flag detection on server
  i2c: fix migration regression introduced by broadcast support
  mptsas: really fix migration compatibility
  qdist: return "(empty)" instead of NULL when printing an empty dist
  qdist: use g_renew and g_new instead of g_realloc and g_malloc.
  qdist: fix memory leak during binning
  target-i386: fix typo in xsetbv implementation
  qht: do not segfault when gathering stats from an uninitialized qht
  util: Drop inet_listen()
  util: drop unix_nonblocking_connect()
  ...

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

backends/hostmem.c

@@ -203,6 +203,7 @@ static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
 static void host_memory_backend_set_prealloc(Object *obj, bool value,
                                              Error **errp)
 {
+    Error *local_err = NULL;
     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
 
     if (backend->force_prealloc) {
@@ -223,7 +224,11 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value,
         void *ptr = memory_region_get_ram_ptr(&backend->mr);
         uint64_t sz = memory_region_size(&backend->mr);
 
-        os_mem_prealloc(fd, ptr, sz);
+        os_mem_prealloc(fd, ptr, sz, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
         backend->prealloc = true;
     }
 }
@@ -286,8 +291,7 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
     if (bc->alloc) {
         bc->alloc(backend, &local_err);
         if (local_err) {
-            error_propagate(errp, local_err);
+            goto out;
-            return;
         }
 
         ptr = memory_region_get_ram_ptr(&backend->mr);
@@ -343,10 +347,16 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
          * specified NUMA policy in place.
          */
         if (backend->prealloc) {
-            os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
+            os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
+                            &local_err);
+            if (local_err) {
+                goto out;
             }
         }
     }
+out:
+    error_propagate(errp, local_err);
+}
 
 static bool
 host_memory_backend_can_be_deleted(UserCreatable *uc, Error **errp)

block/io.c

@@ -1180,10 +1180,11 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int alignment = MAX(bs->bl.pwrite_zeroes_alignment,
                         bs->bl.request_alignment);
 
-    assert(is_power_of_2(alignment));
+    assert(alignment % bs->bl.request_alignment == 0);
-    head = offset & (alignment - 1);
+    head = offset % alignment;
-    tail = (offset + count) & (alignment - 1);
+    tail = (offset + count) % alignment;
-    max_write_zeroes &= ~(alignment - 1);
+    max_write_zeroes = QEMU_ALIGN_DOWN(max_write_zeroes, alignment);
+    assert(max_write_zeroes >= bs->bl.request_alignment);
 
     while (count > 0 && !ret) {
         int num = count;
@@ -2429,9 +2430,10 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
 
     /* Discard is advisory, so ignore any unaligned head or tail */
     align = MAX(bs->bl.pdiscard_alignment, bs->bl.request_alignment);
-    assert(is_power_of_2(align));
+    assert(align % bs->bl.request_alignment == 0);
-    head = MIN(count, -offset & (align - 1));
+    head = offset % align;
     if (head) {
+        head = MIN(count, align - head);
         count -= head;
         offset += head;
     }
@@ -2449,6 +2451,7 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
 
     max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT_MAX),
                                    align);
+    assert(max_pdiscard);
 
     while (count > 0) {
         int ret;

block/nbd-client.h

@@ -20,7 +20,7 @@
 typedef struct NbdClientSession {
     QIOChannelSocket *sioc; /* The master data channel */
     QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
-    uint32_t nbdflags;
+    uint16_t nbdflags;
     off_t size;
 
     CoMutex send_mutex;

exec.c

@@ -1226,7 +1226,7 @@ static void *file_ram_alloc(RAMBlock *block,
     char *filename;
     char *sanitized_name;
     char *c;
-    void *area;
+    void *area = MAP_FAILED;
     int fd = -1;
     int64_t page_size;
 
@@ -1314,13 +1314,19 @@ static void *file_ram_alloc(RAMBlock *block,
     }
 
     if (mem_prealloc) {
-        os_mem_prealloc(fd, area, memory);
+        os_mem_prealloc(fd, area, memory, errp);
+        if (errp && *errp) {
+            goto error;
+        }
     }
 
     block->fd = fd;
     return area;
 
 error:
+    if (area != MAP_FAILED) {
+        qemu_ram_munmap(area, memory);
+    }
     if (unlink_on_error) {
         unlink(path);
     }

hw/core/qdev.c

@@ -354,12 +354,14 @@ void qdev_init_nofail(DeviceState *dev)
 
     assert(!dev->realized);
 
+    object_ref(OBJECT(dev));
     object_property_set_bool(OBJECT(dev), true, "realized", &err);
     if (err) {
         error_reportf_err(err, "Initialization of device %s failed: ",
                           object_get_typename(OBJECT(dev)));
         exit(1);
     }
+    object_unref(OBJECT(dev));
 }
 
 void qdev_machine_creation_done(void)

hw/i2c/core.c

@@ -17,6 +17,8 @@ struct I2CNode {
     QLIST_ENTRY(I2CNode) next;
 };
 
+#define I2C_BROADCAST 0x00
+
 struct I2CBus
 {
     BusState qbus;
@@ -47,6 +49,8 @@ static void i2c_bus_pre_save(void *opaque)
     if (!QLIST_EMPTY(&bus->current_devs)) {
         if (!bus->broadcast) {
             bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
+        } else {
+            bus->saved_address = I2C_BROADCAST;
         }
     }
 }
@@ -58,7 +62,6 @@ static const VMStateDescription vmstate_i2c_bus = {
     .pre_save = i2c_bus_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(saved_address, I2CBus),
-        VMSTATE_BOOL(broadcast, I2CBus),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -93,7 +96,7 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
     I2CSlaveClass *sc;
     I2CNode *node;
 
-    if (address == 0x00) {
+    if (address == I2C_BROADCAST) {
         /*
          * This is a broadcast, the current_devs will be all the devices of the
          * bus.
@@ -221,7 +224,8 @@ static int i2c_slave_post_load(void *opaque, int version_id)
     I2CNode *node;
 
     bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
-    if ((bus->saved_address == dev->address) || (bus->broadcast)) {
+    if ((bus->saved_address == dev->address) ||
+        (bus->saved_address == I2C_BROADCAST)) {
         node = g_malloc(sizeof(struct I2CNode));
         node->elt = dev;
         QLIST_INSERT_HEAD(&bus->current_devs, node, next);

hw/intc/ioapic.c

@@ -21,6 +21,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/error-report.h"
 #include "monitor/monitor.h"
 #include "hw/hw.h"
 #include "hw/i386/pc.h"
@@ -117,21 +118,25 @@ static void ioapic_service(IOAPICCommonState *s)
                     s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
                 }
 
+                if (coalesce) {
+                    /* We are level triggered interrupts, and the
+                     * guest should be still working on previous one,
+                     * so skip it. */
+                    continue;
+                }
+
 #ifdef CONFIG_KVM
                 if (kvm_irqchip_is_split()) {
                     if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
                         kvm_set_irq(kvm_state, i, 1);
                         kvm_set_irq(kvm_state, i, 0);
                     } else {
-                        if (!coalesce) {
                         kvm_set_irq(kvm_state, i, 1);
                     }
-                    }
                     continue;
                 }
-#else
-                (void)coalesce;
 #endif
+
                 /* No matter whether IR is enabled, we translate
                  * the IOAPIC message into a MSI one, and its
                  * address space will decide whether we need a
@@ -265,7 +270,7 @@ ioapic_mem_read(void *opaque, hwaddr addr, unsigned int size)
             val = s->id << IOAPIC_ID_SHIFT;
             break;
         case IOAPIC_REG_VER:
-            val = IOAPIC_VERSION |
+            val = s->version |
                 ((IOAPIC_NUM_PINS - 1) << IOAPIC_VER_ENTRIES_SHIFT);
             break;
         default:
@@ -354,6 +359,13 @@ ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val,
             }
         }
         break;
+    case IOAPIC_EOI:
+        /* Explicit EOI is only supported for IOAPIC version 0x20 */
+        if (size != 4 || s->version != 0x20) {
+            break;
+        }
+        ioapic_eoi_broadcast(val);
+        break;
     }
 
     ioapic_update_kvm_routes(s);
@@ -387,6 +399,12 @@ static void ioapic_realize(DeviceState *dev, Error **errp)
 {
     IOAPICCommonState *s = IOAPIC_COMMON(dev);
 
+    if (s->version != 0x11 && s->version != 0x20) {
+        error_report("IOAPIC only supports version 0x11 or 0x20 "
+                     "(default: 0x11).");
+        exit(1);
+    }
+
     memory_region_init_io(&s->io_memory, OBJECT(s), &ioapic_io_ops, s,
                           "ioapic", 0x1000);
 
@@ -397,6 +415,11 @@ static void ioapic_realize(DeviceState *dev, Error **errp)
     qemu_add_machine_init_done_notifier(&s->machine_done);
 }
 
+static Property ioapic_properties[] = {
+    DEFINE_PROP_UINT8("version", IOAPICCommonState, version, 0x11),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void ioapic_class_init(ObjectClass *klass, void *data)
 {
     IOAPICCommonClass *k = IOAPIC_COMMON_CLASS(klass);
@@ -404,6 +427,7 @@ static void ioapic_class_init(ObjectClass *klass, void *data)
 
     k->realize = ioapic_realize;
     dc->reset = ioapic_reset_common;
+    dc->props = ioapic_properties;
 }
 
 static const TypeInfo ioapic_info = {

hw/nvram/fw_cfg.c

@@ -990,6 +990,7 @@ static void fw_cfg_class_init(ObjectClass *klass, void *data)
 static const TypeInfo fw_cfg_info = {
     .name          = TYPE_FW_CFG,
     .parent        = TYPE_SYS_BUS_DEVICE,
+    .abstract      = true,
     .instance_size = sizeof(FWCfgState),
     .class_init    = fw_cfg_class_init,
 };

hw/scsi/mptsas.c

@@ -1295,6 +1295,8 @@ static void mptsas_scsi_init(PCIDevice *dev, Error **errp)
         /* With msi=auto, we fall back to MSI off silently */
         error_free(err);
 
+        /* Only used for migration.  */
+        s->msi_in_use = (ret == 0);
     }
 
     memory_region_init_io(&s->mmio_io, OBJECT(s), &mptsas_mmio_ops, s,
@@ -1370,7 +1372,7 @@ static const VMStateDescription vmstate_mptsas = {
     .post_load = mptsas_post_load,
     .fields      = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(dev, MPTSASState),
-        VMSTATE_UNUSED(sizeof(bool)), /* Was msi_in_use */
+        VMSTATE_BOOL(msi_in_use, MPTSASState),
         VMSTATE_UINT32(state, MPTSASState),
         VMSTATE_UINT8(who_init, MPTSASState),
         VMSTATE_UINT8(doorbell_state, MPTSASState),

hw/scsi/mptsas.h

@@ -31,6 +31,8 @@ struct MPTSASState {
     OnOffAuto msi;
     uint64_t sas_addr;
 
+    bool msi_in_use;
+
     /* Doorbell register */
     uint32_t state;
     uint8_t who_init;

include/block/block_int.h

@@ -330,36 +330,39 @@ typedef struct BlockLimits {
      * otherwise. */
     uint32_t request_alignment;
 
-    /* maximum number of bytes that can be discarded at once (since it
+    /* Maximum number of bytes that can be discarded at once (since it
-     * is signed, it must be < 2G, if set), should be multiple of
+     * is signed, it must be < 2G, if set). Must be multiple of
      * pdiscard_alignment, but need not be power of 2. May be 0 if no
      * inherent 32-bit limit */
     int32_t max_pdiscard;
 
-    /* optimal alignment for discard requests in bytes, must be power
+    /* Optimal alignment for discard requests in bytes. A power of 2
-     * of 2, less than max_pdiscard if that is set, and multiple of
+     * is best but not mandatory.  Must be a multiple of
-     * bl.request_alignment. May be 0 if bl.request_alignment is good
+     * bl.request_alignment, and must be less than max_pdiscard if
-     * enough */
+     * that is set. May be 0 if bl.request_alignment is good enough */
     uint32_t pdiscard_alignment;
 
-    /* maximum number of bytes that can zeroized at once (since it is
+    /* Maximum number of bytes that can zeroized at once (since it is
-     * signed, it must be < 2G, if set), should be multiple of
+     * signed, it must be < 2G, if set). Must be multiple of
      * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
     int32_t max_pwrite_zeroes;
 
-    /* optimal alignment for write zeroes requests in bytes, must be
+    /* Optimal alignment for write zeroes requests in bytes. A power
-     * power of 2, less than max_pwrite_zeroes if that is set, and
+     * of 2 is best but not mandatory.  Must be a multiple of
-     * multiple of bl.request_alignment. May be 0 if
+     * bl.request_alignment, and must be less than max_pwrite_zeroes
-     * bl.request_alignment is good enough */
+     * if that is set. May be 0 if bl.request_alignment is good
+     * enough */
     uint32_t pwrite_zeroes_alignment;
 
-    /* optimal transfer length in bytes (must be power of 2, and
+    /* Optimal transfer length in bytes.  A power of 2 is best but not
-     * multiple of bl.request_alignment), or 0 if no preferred size */
+     * mandatory.  Must be a multiple of bl.request_alignment, or 0 if
+     * no preferred size */
     uint32_t opt_transfer;
 
-    /* maximal transfer length in bytes (need not be power of 2, but
+    /* Maximal transfer length in bytes.  Need not be power of 2, but
-     * should be multiple of opt_transfer), or 0 for no 32-bit limit.
+     * must be multiple of opt_transfer and bl.request_alignment, or 0
-     * For now, anything larger than INT_MAX is clamped down. */
+     * for no 32-bit limit.  For now, anything larger than INT_MAX is
+     * clamped down. */
     uint32_t max_transfer;
 
     /* memory alignment, in bytes so that no bounce buffer is needed */

include/block/nbd.h

@@ -90,11 +90,11 @@ ssize_t nbd_wr_syncv(QIOChannel *ioc,
                      size_t niov,
                      size_t length,
                      bool do_read);
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
+int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
                           QCryptoTLSCreds *tlscreds, const char *hostname,
                           QIOChannel **outioc,
                           off_t *size, Error **errp);
-int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size);
+int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size);
 ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request);
 ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply);
 int nbd_client(int fd);
@@ -104,7 +104,7 @@ typedef struct NBDExport NBDExport;
 typedef struct NBDClient NBDClient;
 
 NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size,
-                          uint32_t nbdflags, void (*close)(NBDExport *),
+                          uint16_t nbdflags, void (*close)(NBDExport *),
                           Error **errp);
 void nbd_export_close(NBDExport *exp);
 void nbd_export_get(NBDExport *exp);

include/hw/i386/ioapic_internal.h

@@ -29,8 +29,6 @@
 
 #define MAX_IOAPICS                     1
 
-#define IOAPIC_VERSION                  0x11
-
 #define IOAPIC_LVT_DEST_SHIFT           56
 #define IOAPIC_LVT_DEST_IDX_SHIFT       48
 #define IOAPIC_LVT_MASKED_SHIFT         16
@@ -71,6 +69,7 @@
 
 #define IOAPIC_IOREGSEL                 0x00
 #define IOAPIC_IOWIN                    0x10
+#define IOAPIC_EOI                      0x40
 
 #define IOAPIC_REG_ID                   0x00
 #define IOAPIC_REG_VER                  0x01
@@ -109,6 +108,7 @@ struct IOAPICCommonState {
     uint32_t irr;
     uint64_t ioredtbl[IOAPIC_NUM_PINS];
     Notifier machine_done;
+    uint8_t version;
 };
 
 void ioapic_reset_common(DeviceState *dev);

include/hw/i386/pc.h

@@ -388,7 +388,7 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
         .value = "off",\
     },\
     {\
-        .driver   = "apic",\
+        .driver   = "apic-common",\
         .property = "legacy-instance-id",\
         .value    = "on",\
     },

include/qemu/osdep.h

@@ -158,7 +158,8 @@ extern int daemon(int, int);
 /* Round number down to multiple */
 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
 
-/* Round number up to multiple */
+/* Round number up to multiple. Safe when m is not a power of 2 (see
+ * ROUND_UP for a faster version when a power of 2 is guaranteed) */
 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
 
 /* Check if n is a multiple of m */
@@ -175,6 +176,9 @@ extern int daemon(int, int);
 /* Check if pointer p is n-bytes aligned */
 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
 
+/* Round number up to multiple. Requires that d be a power of 2 (see
+ * QEMU_ALIGN_UP for a safer but slower version on arbitrary
+ * numbers) */
 #ifndef ROUND_UP
 #define ROUND_UP(n,d) (((n) + (d) - 1) & -(d))
 #endif
@@ -379,7 +383,7 @@ unsigned long qemu_getauxval(unsigned long type);
 
 void qemu_set_tty_echo(int fd, bool echo);
 
-void os_mem_prealloc(int fd, char *area, size_t sz);
+void os_mem_prealloc(int fd, char *area, size_t sz, Error **errp);
 
 int qemu_read_password(char *buf, int buf_size);
 

include/qemu/qht.h

@@ -69,6 +69,9 @@ void qht_destroy(struct qht *ht);
  * Attempting to insert a NULL @p is a bug.
  * Inserting the same pointer @p with different @hash values is a bug.
  *
+ * In case of successful operation, smp_wmb() is implied before the pointer is
+ * inserted into the hash table.
+ *
  * Returns true on sucess.
  * Returns false if the @p-@hash pair already exists in the hash table.
  */
@@ -83,6 +86,8 @@ bool qht_insert(struct qht *ht, void *p, uint32_t hash);
  *
  * Needs to be called under an RCU read-critical section.
  *
+ * smp_read_barrier_depends() is implied before the call to @func.
+ *
  * The user-provided @func compares pointers in QHT against @userp.
  * If the function returns true, a match has been found.
  *

include/qemu/sockets.h

@@ -33,20 +33,12 @@ int socket_set_fast_reuse(int fd);
 typedef void NonBlockingConnectHandler(int fd, Error *err, void *opaque);
 
 InetSocketAddress *inet_parse(const char *str, Error **errp);
-int inet_listen(const char *str, char *ostr, int olen,
-                int socktype, int port_offset, Error **errp);
 int inet_connect(const char *str, Error **errp);
-int inet_nonblocking_connect(const char *str,
-                             NonBlockingConnectHandler *callback,
-                             void *opaque, Error **errp);
 
 NetworkAddressFamily inet_netfamily(int family);
 
 int unix_listen(const char *path, char *ostr, int olen, Error **errp);
 int unix_connect(const char *path, Error **errp);
-int unix_nonblocking_connect(const char *str,
-                             NonBlockingConnectHandler *callback,
-                             void *opaque, Error **errp);
 
 SocketAddress *socket_parse(const char *str, Error **errp);
 int socket_connect(SocketAddress *addr, Error **errp,

nbd/client.c

@@ -408,7 +408,7 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
 }
 
 
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
+int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
                           QCryptoTLSCreds *tlscreds, const char *hostname,
                           QIOChannel **outioc,
                           off_t *size, Error **errp)
@@ -468,7 +468,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
         uint32_t opt;
         uint32_t namesize;
         uint16_t globalflags;
-        uint16_t exportflags;
         bool fixedNewStyle = false;
 
         if (read_sync(ioc, &globalflags, sizeof(globalflags)) !=
@@ -477,7 +476,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
             goto fail;
         }
         globalflags = be16_to_cpu(globalflags);
-        *flags = globalflags << 16;
         TRACE("Global flags are %" PRIx32, globalflags);
         if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
             fixedNewStyle = true;
@@ -545,17 +543,15 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
             goto fail;
         }
         *size = be64_to_cpu(s);
-        TRACE("Size is %" PRIu64, *size);
 
-        if (read_sync(ioc, &exportflags, sizeof(exportflags)) !=
+        if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
-            sizeof(exportflags)) {
             error_setg(errp, "Failed to read export flags");
             goto fail;
         }
-        exportflags = be16_to_cpu(exportflags);
+        be16_to_cpus(flags);
-        *flags |= exportflags;
-        TRACE("Export flags are %" PRIx16, exportflags);
     } else if (magic == NBD_CLIENT_MAGIC) {
+        uint32_t oldflags;
+
         if (name) {
             error_setg(errp, "Server does not support export names");
             goto fail;
@@ -572,16 +568,22 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
         *size = be64_to_cpu(s);
         TRACE("Size is %" PRIu64, *size);
 
-        if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
+        if (read_sync(ioc, &oldflags, sizeof(oldflags)) != sizeof(oldflags)) {
             error_setg(errp, "Failed to read export flags");
             goto fail;
         }
-        *flags = be32_to_cpu(*flags);
+        be32_to_cpus(&oldflags);
+        if (oldflags & ~0xffff) {
+            error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
+            goto fail;
+        }
+        *flags = oldflags;
     } else {
         error_setg(errp, "Bad magic received");
         goto fail;
     }
 
+    TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags);
     if (read_sync(ioc, &buf, 124) != 124) {
         error_setg(errp, "Failed to read reserved block");
         goto fail;
@@ -593,7 +595,7 @@ fail:
 }
 
 #ifdef __linux__
-int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size)
+int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size)
 {
     unsigned long sectors = size / BDRV_SECTOR_SIZE;
     if (size / BDRV_SECTOR_SIZE != sectors) {
@@ -689,7 +691,7 @@ int nbd_disconnect(int fd)
 }
 
 #else
-int nbd_init(int fd, QIOChannelSocket *ioc, uint32_t flags, off_t size)
+int nbd_init(int fd, QIOChannelSocket *ioc, uint16_t flags, off_t size)
 {
     return -ENOTSUP;
 }

nbd/server.c

@@ -63,7 +63,7 @@ struct NBDExport {
     char *name;
     off_t dev_offset;
     off_t size;
-    uint32_t nbdflags;
+    uint16_t nbdflags;
     QTAILQ_HEAD(, NBDClient) clients;
     QTAILQ_ENTRY(NBDExport) next;
 
@@ -544,7 +544,7 @@ static coroutine_fn int nbd_negotiate(NBDClientNewData *data)
     NBDClient *client = data->client;
     char buf[8 + 8 + 8 + 128];
     int rc;
-    const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
+    const uint16_t myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
                               NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
     bool oldStyle;
 
@@ -575,7 +575,6 @@ static coroutine_fn int nbd_negotiate(NBDClientNewData *data)
 
     oldStyle = client->exp != NULL && !client->tlscreds;
     if (oldStyle) {
-        assert ((client->exp->nbdflags & ~65535) == 0);
         TRACE("advertising size %" PRIu64 " and flags %x",
               client->exp->size, client->exp->nbdflags | myflags);
         stq_be_p(buf + 8, NBD_CLIENT_MAGIC);
@@ -606,7 +605,6 @@ static coroutine_fn int nbd_negotiate(NBDClientNewData *data)
             goto fail;
         }
 
-        assert ((client->exp->nbdflags & ~65535) == 0);
         TRACE("advertising size %" PRIu64 " and flags %x",
               client->exp->size, client->exp->nbdflags | myflags);
         stq_be_p(buf + 18, client->exp->size);
@@ -810,7 +808,7 @@ static void nbd_eject_notifier(Notifier *n, void *data)
 }
 
 NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size,
-                          uint32_t nbdflags, void (*close)(NBDExport *),
+                          uint16_t nbdflags, void (*close)(NBDExport *),
                           Error **errp)
 {
     NBDExport *exp = g_malloc0(sizeof(NBDExport));
@@ -1057,7 +1055,8 @@ static ssize_t nbd_co_receive_request(NBDRequest *req,
     if (request->type & ~NBD_CMD_MASK_COMMAND & ~NBD_CMD_FLAG_FUA) {
         LOG("unsupported flags (got 0x%x)",
             request->type & ~NBD_CMD_MASK_COMMAND);
-        return -EINVAL;
+        rc = -EINVAL;
+        goto out;
     }
 
     rc = 0;

numa.c

@@ -463,6 +463,7 @@ void memory_region_allocate_system_memory(MemoryRegion *mr, Object *owner,
             exit(1);
         }
 
+        host_memory_backend_set_mapped(backend, true);
         memory_region_add_subregion(mr, addr, seg);
         vmstate_register_ram_global(seg);
         addr += size;

qemu-nbd.c

@@ -251,7 +251,7 @@ static void *nbd_client_thread(void *arg)
 {
     char *device = arg;
     off_t size;
-    uint32_t nbdflags;
+    uint16_t nbdflags;
     QIOChannelSocket *sioc;
     int fd;
     int ret;
@@ -465,7 +465,7 @@ int main(int argc, char **argv)
     BlockBackend *blk;
     BlockDriverState *bs;
     off_t dev_offset = 0;
-    uint32_t nbdflags = 0;
+    uint16_t nbdflags = 0;
     bool disconnect = false;
     const char *bindto = "0.0.0.0";
     const char *port = NULL;

qemu-options.hx

@@ -927,10 +927,25 @@ ETEXI
 
 DEF("display", HAS_ARG, QEMU_OPTION_display,
     "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
-    "            [,window_close=on|off]|curses|none|\n"
+    "            [,window_close=on|off][,gl=on|off]|curses|none|\n"
-    "            gtk[,grab_on_hover=on|off]|\n"
+    "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
-    "            vnc=<display>[,<optargs>]\n"
+    "-display vnc=<display>[,<optargs>]\n"
-    "                select display type\n", QEMU_ARCH_ALL)
+    "-display curses\n"
+    "-display none"
+    "                select display type\n"
+    "The default display is equivalent to\n"
+#if defined(CONFIG_GTK)
+            "\t\"-display gtk\"\n"
+#elif defined(CONFIG_SDL)
+            "\t\"-display sdl\"\n"
+#elif defined(CONFIG_COCOA)
+            "\t\"-display cocoa\"\n"
+#elif defined(CONFIG_VNC)
+            "\t\"-vnc localhost:0,to=99,id=default\"\n"
+#else
+            "\t\"-display none\"\n"
+#endif
+    , QEMU_ARCH_ALL)
 STEXI
 @item -display @var{type}
 @findex -display
@@ -977,7 +992,7 @@ the console and monitor.
 ETEXI
 
 DEF("curses", 0, QEMU_OPTION_curses,
-    "-curses         use a curses/ncurses interface instead of SDL\n",
+    "-curses         shorthand for -display curses\n",
     QEMU_ARCH_ALL)
 STEXI
 @item -curses
@@ -1027,7 +1042,7 @@ Disable SDL window close capability.
 ETEXI
 
 DEF("sdl", 0, QEMU_OPTION_sdl,
-    "-sdl            enable SDL\n", QEMU_ARCH_ALL)
+    "-sdl            shorthand for -display sdl\n", QEMU_ARCH_ALL)
 STEXI
 @item -sdl
 @findex -sdl
@@ -1224,7 +1239,7 @@ Set the initial graphical resolution and depth (PPC, SPARC only).
 ETEXI
 
 DEF("vnc", HAS_ARG, QEMU_OPTION_vnc ,
-    "-vnc display    start a VNC server on display\n", QEMU_ARCH_ALL)
+    "-vnc <display>  shorthand for -display vnc=<display>\n", QEMU_ARCH_ALL)
 STEXI
 @item -vnc @var{display}[,@var{option}[,@var{option}[,...]]]
 @findex -vnc

scripts/checkpatch.pl

@@ -2544,7 +2544,7 @@ sub process {
 		}
 	}
 
-# check for non-portable ffs() calls that have portable alternatives in QEMU
+# check for non-portable libc calls that have portable alternatives in QEMU
 		if ($line =~ /\bffs\(/) {
 			ERROR("use ctz32() instead of ffs()\n" . $herecurr);
 		}
@@ -2554,6 +2554,9 @@ sub process {
 		if ($line =~ /\bffsll\(/) {
 			ERROR("use ctz64() instead of ffsll()\n" . $herecurr);
 		}
+		if ($line =~ /\bbzero\(/) {
+			ERROR("use memset() instead of bzero()\n" . $herecurr);
+		}
 	}
 
 	# If we have no input at all, then there is nothing to report on

target-i386/translate.c

@@ -7176,7 +7176,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
             tcg_gen_trunc_tl_i32(cpu_tmp2_i32, cpu_regs[R_ECX]);
             gen_helper_xsetbv(cpu_env, cpu_tmp2_i32, cpu_tmp1_i64);
             /* End TB because translation flags may change.  */
-            gen_jmp_im(s->pc - pc_start);
+            gen_jmp_im(s->pc - s->cs_base);
             gen_eob(s);
             break;
 

tests/test-qdist.c

@@ -360,10 +360,16 @@ static void test_none(void)
     g_assert(isnan(qdist_xmax(&dist)));
 
     pr = qdist_pr_plain(&dist, 0);
-    g_assert(pr == NULL);
+    g_assert_cmpstr(pr, ==, "(empty)");
+    g_free(pr);
 
     pr = qdist_pr_plain(&dist, 2);
-    g_assert(pr == NULL);
+    g_assert_cmpstr(pr, ==, "(empty)");
+    g_free(pr);
+
+    pr = qdist_pr(&dist, 0, QDIST_PR_BORDER);
+    g_assert_cmpstr(pr, ==, "(empty)");
+    g_free(pr);
 
     qdist_destroy(&dist);
 }

tests/test-qht.c

@@ -95,8 +95,12 @@ static void iter_check(unsigned int count)
 
 static void qht_do_test(unsigned int mode, size_t init_entries)
 {
+    /* under KVM we might fetch stats from an uninitialized qht */
+    check_n(0);
+
     qht_init(&ht, 0, mode);
 
+    check_n(0);
     insert(0, N);
     check(0, N, true);
     check_n(N);

translate-all.c

@@ -1663,15 +1663,50 @@ void tb_flush_jmp_cache(CPUState *cpu, target_ulong addr)
            TB_JMP_PAGE_SIZE * sizeof(TranslationBlock *));
 }
 
+static void print_qht_statistics(FILE *f, fprintf_function cpu_fprintf,
+                                 struct qht_stats hst)
+{
+    uint32_t hgram_opts;
+    size_t hgram_bins;
+    char *hgram;
+
+    if (!hst.head_buckets) {
+        return;
+    }
+    cpu_fprintf(f, "TB hash buckets     %zu/%zu (%0.2f%% head buckets used)\n",
+                hst.used_head_buckets, hst.head_buckets,
+                (double)hst.used_head_buckets / hst.head_buckets * 100);
+
+    hgram_opts =  QDIST_PR_BORDER | QDIST_PR_LABELS;
+    hgram_opts |= QDIST_PR_100X   | QDIST_PR_PERCENT;
+    if (qdist_xmax(&hst.occupancy) - qdist_xmin(&hst.occupancy) == 1) {
+        hgram_opts |= QDIST_PR_NODECIMAL;
+    }
+    hgram = qdist_pr(&hst.occupancy, 10, hgram_opts);
+    cpu_fprintf(f, "TB hash occupancy   %0.2f%% avg chain occ. Histogram: %s\n",
+                qdist_avg(&hst.occupancy) * 100, hgram);
+    g_free(hgram);
+
+    hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
+    hgram_bins = qdist_xmax(&hst.chain) - qdist_xmin(&hst.chain);
+    if (hgram_bins > 10) {
+        hgram_bins = 10;
+    } else {
+        hgram_bins = 0;
+        hgram_opts |= QDIST_PR_NODECIMAL | QDIST_PR_NOBINRANGE;
+    }
+    hgram = qdist_pr(&hst.chain, hgram_bins, hgram_opts);
+    cpu_fprintf(f, "TB hash avg chain   %0.3f buckets. Histogram: %s\n",
+                qdist_avg(&hst.chain), hgram);
+    g_free(hgram);
+}
+
 void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
 {
     int i, target_code_size, max_target_code_size;
     int direct_jmp_count, direct_jmp2_count, cross_page;
     TranslationBlock *tb;
     struct qht_stats hst;
-    uint32_t hgram_opts;
-    size_t hgram_bins;
-    char *hgram;
 
     target_code_size = 0;
     max_target_code_size = 0;
@@ -1724,34 +1759,7 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
                         tcg_ctx.tb_ctx.nb_tbs : 0);
 
     qht_statistics_init(&tcg_ctx.tb_ctx.htable, &hst);
-
+    print_qht_statistics(f, cpu_fprintf, hst);
-    cpu_fprintf(f, "TB hash buckets     %zu/%zu (%0.2f%% head buckets used)\n",
-                hst.used_head_buckets, hst.head_buckets,
-                (double)hst.used_head_buckets / hst.head_buckets * 100);
-
-    hgram_opts =  QDIST_PR_BORDER | QDIST_PR_LABELS;
-    hgram_opts |= QDIST_PR_100X   | QDIST_PR_PERCENT;
-    if (qdist_xmax(&hst.occupancy) - qdist_xmin(&hst.occupancy) == 1) {
-        hgram_opts |= QDIST_PR_NODECIMAL;
-    }
-    hgram = qdist_pr(&hst.occupancy, 10, hgram_opts);
-    cpu_fprintf(f, "TB hash occupancy   %0.2f%% avg chain occ. Histogram: %s\n",
-                qdist_avg(&hst.occupancy) * 100, hgram);
-    g_free(hgram);
-
-    hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
-    hgram_bins = qdist_xmax(&hst.chain) - qdist_xmin(&hst.chain);
-    if (hgram_bins > 10) {
-        hgram_bins = 10;
-    } else {
-        hgram_bins = 0;
-        hgram_opts |= QDIST_PR_NODECIMAL | QDIST_PR_NOBINRANGE;
-    }
-    hgram = qdist_pr(&hst.chain, hgram_bins, hgram_opts);
-    cpu_fprintf(f, "TB hash avg chain   %0.3f buckets. Histogram: %s\n",
-                qdist_avg(&hst.chain), hgram);
-    g_free(hgram);
-
     qht_statistics_destroy(&hst);
 
     cpu_fprintf(f, "\nStatistics:\n");

util/iov.c

@@ -247,7 +247,8 @@ unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt,
 {
     size_t len;
     unsigned int i, j;
-    for (i = 0, j = 0; i < iov_cnt && j < dst_iov_cnt && bytes; i++) {
+    for (i = 0, j = 0;
+         i < iov_cnt && j < dst_iov_cnt && (offset || bytes); i++) {
         if (offset >= iov[i].iov_len) {
             offset -= iov[i].iov_len;
             continue;

util/oslib-posix.c

@@ -318,7 +318,7 @@ static void sigbus_handler(int signal)
     siglongjmp(sigjump, 1);
 }
 
-void os_mem_prealloc(int fd, char *area, size_t memory)
+void os_mem_prealloc(int fd, char *area, size_t memory, Error **errp)
 {
     int ret;
     struct sigaction act, oldact;
@@ -330,8 +330,9 @@ void os_mem_prealloc(int fd, char *area, size_t memory)
 
     ret = sigaction(SIGBUS, &act, &oldact);
     if (ret) {
-        perror("os_mem_prealloc: failed to install signal handler");
+        error_setg_errno(errp, errno,
-        exit(1);
+            "os_mem_prealloc: failed to install signal handler");
+        return;
     }
 
     /* unblock SIGBUS */
@@ -340,9 +341,8 @@ void os_mem_prealloc(int fd, char *area, size_t memory)
     pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
 
     if (sigsetjmp(sigjump, 1)) {
-        fprintf(stderr, "os_mem_prealloc: Insufficient free host memory "
+        error_setg(errp, "os_mem_prealloc: Insufficient free host memory "
             "pages available to allocate guest RAM\n");
-        exit(1);
     } else {
         int i;
         size_t hpagesize = qemu_fd_getpagesize(fd);
@@ -352,16 +352,16 @@ void os_mem_prealloc(int fd, char *area, size_t memory)
         for (i = 0; i < numpages; i++) {
             memset(area + (hpagesize * i), 0, 1);
         }
+    }
 
     ret = sigaction(SIGBUS, &oldact, NULL);
     if (ret) {
+        /* Terminate QEMU since it can't recover from error */
         perror("os_mem_prealloc: failed to reinstall signal handler");
         exit(1);
     }
-
     pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 }
-}
 
 
 static struct termios oldtty;

util/oslib-win32.c

@@ -539,7 +539,7 @@ int getpagesize(void)
     return system_info.dwPageSize;
 }
 
-void os_mem_prealloc(int fd, char *area, size_t memory)
+void os_mem_prealloc(int fd, char *area, size_t memory, Error **errp)
 {
     int i;
     size_t pagesize = getpagesize();

util/qdist.c

@@ -14,9 +14,11 @@
 #define NAN (0.0 / 0.0)
 #endif
 
+#define QDIST_EMPTY_STR "(empty)"
+
 void qdist_init(struct qdist *dist)
 {
-    dist->entries = g_malloc(sizeof(*dist->entries));
+    dist->entries = g_new(struct qdist_entry, 1);
     dist->size = 1;
     dist->n = 0;
 }
@@ -62,8 +64,7 @@ void qdist_add(struct qdist *dist, double x, long count)
 
     if (unlikely(dist->n == dist->size)) {
         dist->size *= 2;
-        dist->entries = g_realloc(dist->entries,
+        dist->entries = g_renew(struct qdist_entry, dist->entries, dist->size);
-                                  sizeof(*dist->entries) * (dist->size));
     }
     dist->n++;
     entry = &dist->entries[dist->n - 1];
@@ -188,7 +189,7 @@ void qdist_bin__internal(struct qdist *to, const struct qdist *from, size_t n)
             }
         }
         /* they're equally spaced, so copy the dist and bail out */
-        to->entries = g_new(struct qdist_entry, from->n);
+        to->entries = g_renew(struct qdist_entry, to->entries, n);
         to->n = from->n;
         memcpy(to->entries, from->entries, sizeof(*to->entries) * to->n);
         return;
@@ -234,7 +235,7 @@ char *qdist_pr_plain(const struct qdist *dist, size_t n)
     char *ret;
 
     if (dist->n == 0) {
-        return NULL;
+        return g_strdup(QDIST_EMPTY_STR);
     }
     qdist_bin__internal(&binned, dist, n);
     ret = qdist_pr_internal(&binned);
@@ -309,7 +310,7 @@ char *qdist_pr(const struct qdist *dist, size_t n_bins, uint32_t opt)
     GString *s;
 
     if (dist->n == 0) {
-        return NULL;
+        return g_strdup(QDIST_EMPTY_STR);
     }
 
     s = g_string_new("");

util/qemu-sockets.c

@@ -624,34 +624,6 @@ fail:
     return NULL;
 }
 
-int inet_listen(const char *str, char *ostr, int olen,
-                int socktype, int port_offset, Error **errp)
-{
-    char *optstr;
-    int sock = -1;
-    InetSocketAddress *addr;
-
-    addr = inet_parse(str, errp);
-    if (addr != NULL) {
-        sock = inet_listen_saddr(addr, port_offset, true, errp);
-        if (sock != -1 && ostr) {
-            optstr = strchr(str, ',');
-            if (addr->ipv6) {
-                snprintf(ostr, olen, "[%s]:%s%s",
-                         addr->host,
-                         addr->port,
-                         optstr ? optstr : "");
-            } else {
-                snprintf(ostr, olen, "%s:%s%s",
-                         addr->host,
-                         addr->port,
-                         optstr ? optstr : "");
-            }
-        }
-        qapi_free_InetSocketAddress(addr);
-    }
-    return sock;
-}
 
 /**
  * Create a blocking socket and connect it to an address.
@@ -674,36 +646,6 @@ int inet_connect(const char *str, Error **errp)
     return sock;
 }
 
-/**
- * Create a non-blocking socket and connect it to an address.
- * Calls the callback function with fd in case of success or -1 in case of
- * error.
- *
- * @str: address string
- * @callback: callback function that is called when connect completes,
- *            cannot be NULL.
- * @opaque: opaque for callback function
- * @errp: set in case of an error
- *
- * Returns: -1 on immediate error, file descriptor on success.
- **/
-int inet_nonblocking_connect(const char *str,
-                             NonBlockingConnectHandler *callback,
-                             void *opaque, Error **errp)
-{
-    int sock = -1;
-    InetSocketAddress *addr;
-
-    g_assert(callback != NULL);
-
-    addr = inet_parse(str, errp);
-    if (addr != NULL) {
-        sock = inet_connect_saddr(addr, errp, callback, opaque);
-        qapi_free_InetSocketAddress(addr);
-    }
-    return sock;
-}
-
 #ifndef _WIN32
 
 static int unix_listen_saddr(UnixSocketAddress *saddr,
@@ -893,22 +835,6 @@ int unix_connect(const char *path, Error **errp)
 }
 
 
-int unix_nonblocking_connect(const char *path,
-                             NonBlockingConnectHandler *callback,
-                             void *opaque, Error **errp)
-{
-    UnixSocketAddress *saddr;
-    int sock = -1;
-
-    g_assert(callback != NULL);
-
-    saddr = g_new0(UnixSocketAddress, 1);
-    saddr->path = g_strdup(path);
-    sock = unix_connect_saddr(saddr, errp, callback, opaque);
-    qapi_free_UnixSocketAddress(saddr);
-    return sock;
-}
-
 SocketAddress *socket_parse(const char *str, Error **errp)
 {
     SocketAddress *addr;

util/qht.c

@@ -445,7 +445,11 @@ void *qht_do_lookup(struct qht_bucket *head, qht_lookup_func_t func,
     do {
         for (i = 0; i < QHT_BUCKET_ENTRIES; i++) {
             if (b->hashes[i] == hash) {
-                void *p = atomic_read(&b->pointers[i]);
+                /* The pointer is dereferenced before seqlock_read_retry,
+                 * so (unlike qht_insert__locked) we need to use
+                 * atomic_rcu_read here.
+                 */
+                void *p = atomic_rcu_read(&b->pointers[i]);
 
                 if (likely(p) && likely(func(p, userp))) {
                     return p;
@@ -535,6 +539,7 @@ static bool qht_insert__locked(struct qht *ht, struct qht_map *map,
         atomic_rcu_set(&prev->next, b);
     }
     b->hashes[i] = hash;
+    /* smp_wmb() implicit in seqlock_write_begin.  */
     atomic_set(&b->pointers[i], p);
     seqlock_write_end(&head->sequence);
     return true;
@@ -784,11 +789,16 @@ void qht_statistics_init(struct qht *ht, struct qht_stats *stats)
 
     map = atomic_rcu_read(&ht->map);
 
-    stats->head_buckets = map->n_buckets;
     stats->used_head_buckets = 0;
     stats->entries = 0;
     qdist_init(&stats->chain);
     qdist_init(&stats->occupancy);
+    /* bail out if the qht has not yet been initialized */
+    if (unlikely(map == NULL)) {
+        stats->head_buckets = 0;
+        return;
+    }
+    stats->head_buckets = map->n_buckets;
 
     for (i = 0; i < map->n_buckets; i++) {
         struct qht_bucket *head = &map->buckets[i];