[Qemu-devel] [RFC 3/5] hw/arm: add scattered RAM memory region support

[zhuyijun]

From: Zhu Yijun <address@hidden>

Dig out reserved memory holes and collect scattered RAM memory
regions by adding mem_list member in arm_boot_info struct.

Signed-off-by: Zhu Yijun <address@hidden>
---
 hw/arm/boot.c        |   8 ++++
 hw/arm/virt.c        | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 include/hw/arm/arm.h |   1 +
 3 files changed, 108 insertions(+), 2 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index c2720c8..30438f4 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -836,6 +836,14 @@ static void arm_load_kernel_notify(Notifier *notifier, 
void *data)
      */
     assert(!(info->secure_board_setup && kvm_enabled()));
 
+    /* If machine is not virt, the mem_list will empty. */
+    if (QLIST_EMPTY(&vms->bootinfo.mem_list)) {
+        RAMRegion *new = g_new(RAMRegion, 1);
+        new->base = info->loader_start;
+        new->size = info->ram_size;
+        QLIST_INSERT_HEAD(&vms->bootinfo.mem_list, new, next);
+    }
+
     info->dtb_filename = qemu_opt_get(qemu_get_machine_opts(), "dtb");
 
     /* Load the kernel.  */
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index ddde5e1..ff334c1 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -56,6 +56,7 @@
 #include "hw/smbios/smbios.h"
 #include "qapi/visitor.h"
 #include "standard-headers/linux/input.h"
+#include "hw/vfio/vfio-common.h"
 
 #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
     static void virt_##major##_##minor##_class_init(ObjectClass *oc, \
@@ -1225,6 +1226,98 @@ void virt_machine_done(Notifier *notifier, void *data)
     virt_build_smbios(vms);
 }
 
+static void handle_reserved_ram_region_overlap(void)
+{
+    hwaddr cur_end, next_end;
+    RAMRegion *reg, *next_reg, *tmp_reg;
+
+    QLIST_FOREACH(reg, &reserved_ram_regions, next) {
+        next_reg = QLIST_NEXT(reg, next);
+
+        while (next_reg && next_reg->base <= (reg->base + reg->size)) {
+            next_end = next_reg->base + next_reg->size;
+            cur_end = reg->base + reg->size;
+            if (next_end > cur_end) {
+                reg->size += (next_end - cur_end);
+            }
+
+            tmp_reg = QLIST_NEXT(next_reg, next);
+            QLIST_REMOVE(next_reg, next);
+            g_free(next_reg);
+            next_reg = tmp_reg;
+        }
+    }
+}
+
+static void update_memory_regions(VirtMachineState *vms, hwaddr ram_size)
+{
+
+    RAMRegion *new, *reg, *last = NULL;
+    hwaddr virt_start, virt_end;
+    virt_start = vms->memmap[VIRT_MEM].base;
+    virt_end = virt_start + ram_size - 1;
+
+    handle_reserved_ram_region_overlap();
+
+    QLIST_FOREACH(reg, &reserved_ram_regions, next) {
+        if (reg->base >= virt_start && reg->base < virt_end) {
+            if (reg->base == virt_start) {
+                virt_start += reg->size;
+                virt_end += reg->size;
+                continue;
+            } else {
+                new = g_new(RAMRegion, 1);
+                new->base = virt_start;
+                new->size = reg->base - virt_start;
+                virt_start = reg->base + reg->size;
+            }
+
+            if (QLIST_EMPTY(&vms->bootinfo.mem_list)) {
+                QLIST_INSERT_HEAD(&vms->bootinfo.mem_list, new, next);
+            } else {
+                QLIST_INSERT_AFTER(last, new, next);
+            }
+
+            last = new;
+            ram_size -= new->size;
+            virt_end += reg->size;
+        }
+    }
+
+    if (ram_size > 0) {
+        new = g_new(RAMRegion, 1);
+        new->base = virt_start;
+        new->size = ram_size;
+
+        if (QLIST_EMPTY(&vms->bootinfo.mem_list)) {
+            QLIST_INSERT_HEAD(&vms->bootinfo.mem_list, new, next);
+        } else {
+            QLIST_INSERT_AFTER(last, new, next);
+        }
+    }
+}
+
+static void create_ram_alias(VirtMachineState *vms,
+                             MemoryRegion *sysmem,
+                             MemoryRegion *ram)
+{
+    RAMRegion *reg;
+    MemoryRegion *ram_memory;
+    char *nodename;
+    hwaddr sz = 0;
+
+    QLIST_FOREACH(reg, &vms->bootinfo.mem_list, next) {
+        nodename = g_strdup_printf("address@hidden" PRIx64, reg->base);
+        ram_memory = g_new(MemoryRegion, 1);
+        memory_region_init_alias(ram_memory, NULL, nodename, ram, sz,
+                                 reg->size);
+        memory_region_add_subregion(sysmem, reg->base, ram_memory);
+        sz += reg->size;
+
+        g_free(nodename);
+    }
+}
+
 static void virt_ram_memory_region_init(Notifier *notifier, void *data)
 {
     MachineState *machine = MACHINE(qdev_get_machine());
@@ -1232,10 +1325,15 @@ static void virt_ram_memory_region_init(Notifier 
*notifier, void *data)
     MemoryRegion *ram = g_new(MemoryRegion, 1);
     VirtMachineState *vms = container_of(notifier, VirtMachineState,
                                          ram_memory_region_init);
+    RAMRegion *first_mem_reg;
 
     memory_region_allocate_system_memory(ram, NULL, "mach-virt.ram",
                                          machine->ram_size);
-    memory_region_add_subregion(sysmem, vms->memmap[VIRT_MEM].base, ram);
+    update_memory_regions(vms, machine->ram_size);
+    create_ram_alias(vms, sysmem, ram);
+
+    first_mem_reg = QLIST_FIRST(&vms->bootinfo.mem_list);
+    vms->bootinfo.loader_start = first_mem_reg->base;
 }
 
 static uint64_t virt_cpu_mp_affinity(VirtMachineState *vms, int idx)
@@ -1458,7 +1556,6 @@ static void machvirt_init(MachineState *machine)
     vms->bootinfo.initrd_filename = machine->initrd_filename;
     vms->bootinfo.nb_cpus = smp_cpus;
     vms->bootinfo.board_id = -1;
-    vms->bootinfo.loader_start = vms->memmap[VIRT_MEM].base;
     vms->bootinfo.get_dtb = machvirt_dtb;
     vms->bootinfo.firmware_loaded = firmware_loaded;
     arm_load_kernel(ARM_CPU(first_cpu), &vms->bootinfo);
diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h
index ce769bd..d953026 100644
--- a/include/hw/arm/arm.h
+++ b/include/hw/arm/arm.h
@@ -124,6 +124,7 @@ struct arm_boot_info {
     bool secure_board_setup;
 
     arm_endianness endianness;
+    QLIST_HEAD(, RAMRegion) mem_list;
 };
 
 /**
-- 
1.8.3.1