[RFC PATCH 13/13] machine: Add 'private-memory-backend' property
From: Chao Peng
Date: Thu Nov 11 2021 - 09:17:29 EST
Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
---
hw/core/machine.c | 38 ++++++++++++++++++++++++++++++++++++++
hw/i386/pc.c | 22 ++++++++++++++++------
include/hw/boards.h | 2 ++
softmmu/vl.c | 16 ++++++++++------
4 files changed, 66 insertions(+), 12 deletions(-)
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 067f42b528..d092bf400b 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -589,6 +589,22 @@ static void machine_set_memdev(Object *obj, const char *value, Error **errp)
ms->ram_memdev_id = g_strdup(value);
}
+static char *machine_get_private_memdev(Object *obj, Error **errp)
+{
+ MachineState *ms = MACHINE(obj);
+
+ return g_strdup(ms->private_ram_memdev_id);
+}
+
+static void machine_set_private_memdev(Object *obj, const char *value,
+ Error **errp)
+{
+ MachineState *ms = MACHINE(obj);
+
+ g_free(ms->private_ram_memdev_id);
+ ms->private_ram_memdev_id = g_strdup(value);
+}
+
static void machine_init_notify(Notifier *notifier, void *data)
{
MachineState *machine = MACHINE(qdev_get_machine());
@@ -962,6 +978,13 @@ static void machine_class_init(ObjectClass *oc, void *data)
object_class_property_set_description(oc, "memory-backend",
"Set RAM backend"
"Valid value is ID of hostmem based backend");
+
+ object_class_property_add_str(oc, "private-memory-backend",
+ machine_get_private_memdev,
+ machine_set_private_memdev);
+ object_class_property_set_description(oc, "private-memory-backend",
+ "Set guest private RAM backend"
+ "Valid value is ID of hostmem based backend");
}
static void machine_class_base_init(ObjectClass *oc, void *data)
@@ -1208,6 +1231,21 @@ void machine_run_board_init(MachineState *machine)
machine->ram = machine_consume_memdev(machine, MEMORY_BACKEND(o));
}
+ if (machine->private_ram_memdev_id) {
+ Object *o;
+ HostMemoryBackend *backend;
+ o = object_resolve_path_type(machine->private_ram_memdev_id,
+ TYPE_MEMORY_BACKEND, NULL);
+ backend = MEMORY_BACKEND(o);
+ if (backend->guest_private) {
+ machine->private_ram = machine_consume_memdev(machine, backend);
+ } else {
+ error_report("memorybaend %s is not guest private memory.",
+ object_get_canonical_path_component(OBJECT(backend)));
+ exit(EXIT_FAILURE);
+ }
+ }
+
if (machine->numa_state) {
numa_complete_configuration(machine);
if (machine->numa_state->num_nodes) {
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 1276bfeee4..e6209428c1 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -865,30 +865,40 @@ void pc_memory_init(PCMachineState *pcms,
MachineClass *mc = MACHINE_GET_CLASS(machine);
PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
X86MachineState *x86ms = X86_MACHINE(pcms);
+ MemoryRegion *ram, *root_region;
assert(machine->ram_size == x86ms->below_4g_mem_size +
x86ms->above_4g_mem_size);
linux_boot = (machine->kernel_filename != NULL);
+ *ram_memory = machine->ram;
+
+ /* Map private memory if set. Shared memory will be mapped per request. */
+ if (machine->private_ram) {
+ ram = machine->private_ram;
+ root_region = get_system_private_memory();
+ } else {
+ ram = machine->ram;
+ root_region = system_memory;
+ }
+
/*
* Split single memory region and use aliases to address portions of it,
* done for backwards compatibility with older qemus.
*/
- *ram_memory = machine->ram;
ram_below_4g = g_malloc(sizeof(*ram_below_4g));
- memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", machine->ram,
+ memory_region_init_alias(ram_below_4g, NULL, "ram-below-4g", ram,
0, x86ms->below_4g_mem_size);
- memory_region_add_subregion(system_memory, 0, ram_below_4g);
+ memory_region_add_subregion(root_region, 0, ram_below_4g);
e820_add_entry(0, x86ms->below_4g_mem_size, E820_RAM);
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",
- machine->ram,
+ ram,
x86ms->below_4g_mem_size,
x86ms->above_4g_mem_size);
- memory_region_add_subregion(system_memory, 0x100000000ULL,
- ram_above_4g);
+ memory_region_add_subregion(root_region, 0x100000000ULL, ram_above_4g);
e820_add_entry(0x100000000ULL, x86ms->above_4g_mem_size, E820_RAM);
}
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 463a5514f9..dd6a3a3e03 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -313,11 +313,13 @@ struct MachineState {
bool enable_graphics;
ConfidentialGuestSupport *cgs;
char *ram_memdev_id;
+ char *private_ram_memdev_id;
/*
* convenience alias to ram_memdev_id backend memory region
* or to numa container memory region
*/
MemoryRegion *ram;
+ MemoryRegion *private_ram;
DeviceMemoryState *device_memory;
ram_addr_t ram_size;
diff --git a/softmmu/vl.c b/softmmu/vl.c
index ea05bb39c5..9665ccdb16 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1985,17 +1985,15 @@ static bool have_custom_ram_size(void)
return !!qemu_opt_get_size(opts, "size", 0);
}
-static void qemu_resolve_machine_memdev(void)
+static void check_memdev(char *id)
{
- if (current_machine->ram_memdev_id) {
+ if (id) {
Object *backend;
ram_addr_t backend_size;
- backend = object_resolve_path_type(current_machine->ram_memdev_id,
- TYPE_MEMORY_BACKEND, NULL);
+ backend = object_resolve_path_type(id, TYPE_MEMORY_BACKEND, NULL);
if (!backend) {
- error_report("Memory backend '%s' not found",
- current_machine->ram_memdev_id);
+ error_report("Memory backend '%s' not found", id);
exit(EXIT_FAILURE);
}
backend_size = object_property_get_uint(backend, "size", &error_abort);
@@ -2011,6 +2009,12 @@ static void qemu_resolve_machine_memdev(void)
}
ram_size = backend_size;
}
+}
+
+static void qemu_resolve_machine_memdev(void)
+{
+ check_memdev(current_machine->ram_memdev_id);
+ check_memdev(current_machine->private_ram_memdev_id);
if (!xen_enabled()) {
/* On 32-bit hosts, QEMU is limited by virtual address space */
--
2.17.1