Merge tag 'patchew/20200219160953.13771-1-imammedo@redhat.com' of https://github.com/patchew-project/qemu into HEAD

This series removes ad hoc RAM allocation API (memory_region_allocate_system_memory)
and consolidates it around hostmem backend. It allows to

* resolve conflicts between global -mem-prealloc and hostmem's "policy" option,
  fixing premature allocation before binding policy is applied

* simplify complicated memory allocation routines which had to deal with 2 ways
  to allocate RAM.

* reuse hostmem backends of a choice for main RAM without adding extra CLI
  options to duplicate hostmem features.  A recent case was -mem-shared, to
  enable vhost-user on targets that don't support hostmem backends [1] (ex: s390)

* move RAM allocation from individual boards into generic machine code and
  provide them with prepared MemoryRegion.

* clean up deprecated NUMA features which were tied to the old API (see patches)
  - "numa: remove deprecated -mem-path fallback to anonymous RAM"
  - (POSTPONED, waiting on libvirt side) "forbid '-numa node,mem' for 5.0 and newer machine types"
  - (POSTPONED) "numa: remove deprecated implicit RAM distribution between nodes"

Introduce a new machine.memory-backend property and wrapper code that aliases
global -mem-path and -mem-alloc into automatically created hostmem backend
properties (provided memory-backend was not set explicitly given by user).
A bulk of trivial patches then follow to incrementally convert individual
boards to using machine.memory-backend provided MemoryRegion.

Board conversion typically involves:

* providing MachineClass::default_ram_size and MachineClass::default_ram_id
  so generic code could create default backend if user didn't explicitly provide
  memory-backend or -m options

* dropping memory_region_allocate_system_memory() call

* using convenience MachineState::ram MemoryRegion, which points to MemoryRegion
   allocated by ram-memdev

On top of that for some boards:

* missing ram_size checks are added (typically it were boards with fixed ram size)

* ram_size fixups are replaced by checks and hard errors, forcing user to
  provide correct "-m" values instead of ignoring it and continuing running.

After all boards are converted, the old API is removed and memory allocation
routines are cleaned up.

1 files changed, 39 insertions, 14 deletions

diff --git a/backends/hostmem.c b/backends/hostmem.c
index e773bdfa6e..a70867b255 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -215,7 +215,7 @@ static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
 {
     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
 
-    return backend->prealloc || backend->force_prealloc;
+    return backend->prealloc;
 }
 
 static void host_memory_backend_set_prealloc(Object *obj, bool value,
@@ -223,15 +223,6 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value,
 {
     Error *local_err = NULL;
     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
-    MachineState *ms = MACHINE(qdev_get_machine());
-
-    if (backend->force_prealloc) {
-        if (value) {
-            error_setg(errp,
-                       "remove -mem-prealloc to use the prealloc property");
-            return;
-        }
-    }
 
     if (!host_memory_backend_mr_inited(backend)) {
         backend->prealloc = value;
@@ -243,7 +234,7 @@ 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, ms->smp.cpus, &local_err);
+        os_mem_prealloc(fd, ptr, sz, backend->prealloc_threads, &local_err);
         if (local_err) {
             error_propagate(errp, local_err);
             return;
@@ -252,14 +243,43 @@ static void host_memory_backend_set_prealloc(Object *obj, bool value,
     }
 }
 
+static void host_memory_backend_get_prealloc_threads(Object *obj, Visitor *v,
+    const char *name, void *opaque, Error **errp)
+{
+    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
+    visit_type_uint32(v, name, &backend->prealloc_threads, errp);
+}
+
+static void host_memory_backend_set_prealloc_threads(Object *obj, Visitor *v,
+    const char *name, void *opaque, Error **errp)
+{
+    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
+    Error *local_err = NULL;
+    uint32_t value;
+
+    visit_type_uint32(v, name, &value, &local_err);
+    if (local_err) {
+        goto out;
+    }
+    if (value <= 0) {
+        error_setg(&local_err,
+                   "property '%s' of %s doesn't take value '%d'",
+                   name, object_get_typename(obj), value);
+        goto out;
+    }
+    backend->prealloc_threads = value;
+out:
+    error_propagate(errp, local_err);
+}
+
 static void host_memory_backend_init(Object *obj)
 {
     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
     MachineState *machine = MACHINE(qdev_get_machine());
 
+    /* TODO: convert access to globals to compat properties */
     backend->merge = machine_mem_merge(machine);
     backend->dump = machine_dump_guest_core(machine);
-    backend->prealloc = mem_prealloc;
 }
 
 static void host_memory_backend_post_init(Object *obj)
@@ -313,7 +333,6 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
 {
     HostMemoryBackend *backend = MEMORY_BACKEND(uc);
     HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
-    MachineState *ms = MACHINE(qdev_get_machine());
     Error *local_err = NULL;
     void *ptr;
     uint64_t sz;
@@ -378,7 +397,7 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
          */
         if (backend->prealloc) {
             os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
-                            ms->smp.cpus, &local_err);
+                            backend->prealloc_threads, &local_err);
             if (local_err) {
                 goto out;
             }
@@ -456,6 +475,12 @@ host_memory_backend_class_init(ObjectClass *oc, void *data)
         host_memory_backend_set_prealloc, &error_abort);
     object_class_property_set_description(oc, "prealloc",
         "Preallocate memory", &error_abort);
+    object_class_property_add(oc, "prealloc-threads", "int",
+        host_memory_backend_get_prealloc_threads,
+        host_memory_backend_set_prealloc_threads,
+        NULL, NULL, &error_abort);
+    object_class_property_set_description(oc, "prealloc-threads",
+        "Number of CPU threads to use for prealloc", &error_abort);
     object_class_property_add(oc, "size", "int",
         host_memory_backend_get_size,
         host_memory_backend_set_size,