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, 5 insertions, 7 deletions

diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index d23485108d..38d8e51703 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -167,7 +167,7 @@ static void microvm_memory_init(MicrovmMachineState *mms)
 {
     MachineState *machine = MACHINE(mms);
     X86MachineState *x86ms = X86_MACHINE(mms);
-    MemoryRegion *ram, *ram_below_4g, *ram_above_4g;
+    MemoryRegion *ram_below_4g, *ram_above_4g;
     MemoryRegion *system_memory = get_system_memory();
     FWCfgState *fw_cfg;
     ram_addr_t lowmem;
@@ -214,12 +214,8 @@ static void microvm_memory_init(MicrovmMachineState *mms)
         x86ms->below_4g_mem_size = machine->ram_size;
     }
 
-    ram = g_malloc(sizeof(*ram));
-    memory_region_allocate_system_memory(ram, NULL, "microvm.ram",
-                                         machine->ram_size);
-
     ram_below_4g = g_malloc(sizeof(*ram_below_4g));
-    memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", ram,
+    memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", machine->ram,
                              0, x86ms->below_4g_mem_size);
     memory_region_add_subregion(system_memory, 0, ram_below_4g);
 
@@ -227,7 +223,8 @@ static void microvm_memory_init(MicrovmMachineState *mms)
 
     if (x86ms->above_4g_mem_size > 0) {
         ram_above_4g = g_malloc(sizeof(*ram_above_4g));
-        memory_region_init_alias(ram_above_4g, NULL, "ram-above-4g", ram,
+        memory_region_init_alias(ram_above_4g, NULL, "ram-above-4g",
+                                 machine->ram,
                                  x86ms->below_4g_mem_size,
                                  x86ms->above_4g_mem_size);
         memory_region_add_subregion(system_memory, 0x100000000ULL,
@@ -502,6 +499,7 @@ static void microvm_class_init(ObjectClass *oc, void *data)
     mc->auto_enable_numa_with_memhp = false;
     mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
     mc->nvdimm_supported = false;
+    mc->default_ram_id = "microvm.ram";
 
     /* Avoid relying too much on kernel components */
     mc->default_kernel_irqchip_split = true;