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.

3 files changed, 20 insertions, 3 deletions

diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
index 4dbdadd39e..8276e53683 100644
--- a/include/sysemu/hostmem.h
+++ b/include/sysemu/hostmem.h
@@ -27,6 +27,22 @@
 #define MEMORY_BACKEND_CLASS(klass) \
     OBJECT_CLASS_CHECK(HostMemoryBackendClass, (klass), TYPE_MEMORY_BACKEND)
 
+/* hostmem-ram.c */
+/**
+ * @TYPE_MEMORY_BACKEND_RAM:
+ * name of backend that uses mmap on the anonymous RAM
+ */
+
+#define TYPE_MEMORY_BACKEND_RAM "memory-backend-ram"
+
+/* hostmem-file.c */
+/**
+ * @TYPE_MEMORY_BACKEND_FILE:
+ * name of backend that uses mmap on a file descriptor
+ */
+#define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
+
+typedef struct HostMemoryBackend HostMemoryBackend;
 typedef struct HostMemoryBackendClass HostMemoryBackendClass;
 
 /**
@@ -45,6 +61,7 @@ struct HostMemoryBackendClass {
  * @parent: opaque parent object container
  * @size: amount of memory backend provides
  * @mr: MemoryRegion representing host memory belonging to backend
+ * @prealloc_threads: number of threads to be used for preallocatining RAM
  */
 struct HostMemoryBackend {
     /* private */
@@ -53,7 +70,8 @@ struct HostMemoryBackend {
     /* protected */
     uint64_t size;
     bool merge, dump, use_canonical_path;
-    bool prealloc, force_prealloc, is_mapped, share;
+    bool prealloc, is_mapped, share;
+    uint32_t prealloc_threads;
     DECLARE_BITMAP(host_nodes, MAX_NODES + 1);
     HostMemPolicy policy;
 
diff --git a/include/sysemu/numa.h b/include/sysemu/numa.h
index ba693cc80b..ad58ee88f7 100644
--- a/include/sysemu/numa.h
+++ b/include/sysemu/numa.h
@@ -112,5 +112,6 @@ void numa_default_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
                                   int nb_nodes, ram_addr_t size);
 void numa_cpu_pre_plug(const struct CPUArchId *slot, DeviceState *dev,
                        Error **errp);
+bool numa_uses_legacy_mem(void);
 
 #endif
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index dec64fcc17..479d90bcea 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -50,8 +50,6 @@ extern uint8_t *boot_splash_filedata;
 extern bool enable_mlock;
 extern bool enable_cpu_pm;
 extern QEMUClockType rtc_clock;
-extern const char *mem_path;
-extern int mem_prealloc;
 
 #define MAX_OPTION_ROMS 16
 typedef struct QEMUOptionRom {