Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

vhost, pc, virtio features, fixes, cleanups

New features:
    VT-d support for devices behind a bridge
    vhost-user migration support

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 22 Oct 2015 12:39:19 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream: (37 commits)
  hw/isa/lpc_ich9: inject the SMI on the VCPU that is writing to APM_CNT
  i386: keep cpu_model field in MachineState uptodate
  vhost: set the correct queue index in case of migration with multiqueue
  piix: fix resource leak reported by Coverity
  seccomp: add memfd_create to whitelist
  vhost-user-test: check ownership during migration
  vhost-user-test: add live-migration test
  vhost-user-test: learn to tweak various qemu arguments
  vhost-user-test: wrap server in TestServer struct
  vhost-user-test: remove useless static check
  vhost-user-test: move wait_for_fds() out
  vhost: add migration block if memfd failed
  vhost-user: use an enum helper for features mask
  vhost user: add rarp sending after live migration for legacy guest
  vhost user: add support of live migration
  net: add trace_vhost_user_event
  vhost-user: document migration log
  vhost: use a function for each call
  vhost-user: add a migration blocker
  vhost-user: send log shm fd along with log_base
  ...

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

1 files changed, 71 insertions, 0 deletions

diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
new file mode 100644
index 0000000000..13942694cc
--- /dev/null
+++ b/util/mmap-alloc.c
@@ -0,0 +1,71 @@
+/*
+ * Support for RAM backed by mmaped host memory.
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * Authors:
+ *  Michael S. Tsirkin <mst@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+#include <qemu/mmap-alloc.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <assert.h>
+
+void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
+{
+    /*
+     * Note: this always allocates at least one extra page of virtual address
+     * space, even if size is already aligned.
+     */
+    size_t total = size + align;
+    void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+    size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
+    void *ptr1;
+
+    if (ptr == MAP_FAILED) {
+        return NULL;
+    }
+
+    /* Make sure align is a power of 2 */
+    assert(!(align & (align - 1)));
+    /* Always align to host page size */
+    assert(align >= getpagesize());
+
+    ptr1 = mmap(ptr + offset, size, PROT_READ | PROT_WRITE,
+                MAP_FIXED |
+                (fd == -1 ? MAP_ANONYMOUS : 0) |
+                (shared ? MAP_SHARED : MAP_PRIVATE),
+                fd, 0);
+    if (ptr1 == MAP_FAILED) {
+        munmap(ptr, total);
+        return NULL;
+    }
+
+    ptr += offset;
+    total -= offset;
+
+    if (offset > 0) {
+        munmap(ptr - offset, offset);
+    }
+
+    /*
+     * Leave a single PROT_NONE page allocated after the RAM block, to serve as
+     * a guard page guarding against potential buffer overflows.
+     */
+    if (total > size + getpagesize()) {
+        munmap(ptr + size + getpagesize(), total - size - getpagesize());
+    }
+
+    return ptr;
+}
+
+void qemu_ram_munmap(void *ptr, size_t size)
+{
+    if (ptr) {
+        /* Unmap both the RAM block and the guard page */
+        munmap(ptr, size + getpagesize());
+    }
+}