target/arm: Create tagged ram when MTE is enabled

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200626033144.790098-44-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 53 insertions, 2 deletions

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 402c362..22ce6d6 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1390,8 +1390,19 @@ static void create_platform_bus(VirtMachineState *vms)
                                 sysbus_mmio_get_region(s, 0));
 }
 
+static void create_tag_ram(MemoryRegion *tag_sysmem,
+                           hwaddr base, hwaddr size,
+                           const char *name)
+{
+    MemoryRegion *tagram = g_new(MemoryRegion, 1);
+
+    memory_region_init_ram(tagram, NULL, name, size / 32, &error_fatal);
+    memory_region_add_subregion(tag_sysmem, base / 32, tagram);
+}
+
 static void create_secure_ram(VirtMachineState *vms,
-                              MemoryRegion *secure_sysmem)
+                              MemoryRegion *secure_sysmem,
+                              MemoryRegion *secure_tag_sysmem)
 {
     MemoryRegion *secram = g_new(MemoryRegion, 1);
     char *nodename;
@@ -1409,6 +1420,10 @@ static void create_secure_ram(VirtMachineState *vms,
     qemu_fdt_setprop_string(vms->fdt, nodename, "status", "disabled");
     qemu_fdt_setprop_string(vms->fdt, nodename, "secure-status", "okay");
 
+    if (secure_tag_sysmem) {
+        create_tag_ram(secure_tag_sysmem, base, size, "mach-virt.secure-tag");
+    }
+
     g_free(nodename);
 }
 
@@ -1665,6 +1680,8 @@ static void machvirt_init(MachineState *machine)
     const CPUArchIdList *possible_cpus;
     MemoryRegion *sysmem = get_system_memory();
     MemoryRegion *secure_sysmem = NULL;
+    MemoryRegion *tag_sysmem = NULL;
+    MemoryRegion *secure_tag_sysmem = NULL;
     int n, virt_max_cpus;
     bool firmware_loaded;
     bool aarch64 = true;
@@ -1819,6 +1836,35 @@ static void machvirt_init(MachineState *machine)
                                      "secure-memory", &error_abort);
         }
 
+        /*
+         * The cpu adds the property if and only if MemTag is supported.
+         * If it is, we must allocate the ram to back that up.
+         */
+        if (object_property_find(cpuobj, "tag-memory", NULL)) {
+            if (!tag_sysmem) {
+                tag_sysmem = g_new(MemoryRegion, 1);
+                memory_region_init(tag_sysmem, OBJECT(machine),
+                                   "tag-memory", UINT64_MAX / 32);
+
+                if (vms->secure) {
+                    secure_tag_sysmem = g_new(MemoryRegion, 1);
+                    memory_region_init(secure_tag_sysmem, OBJECT(machine),
+                                       "secure-tag-memory", UINT64_MAX / 32);
+
+                    /* As with ram, secure-tag takes precedence over tag.  */
+                    memory_region_add_subregion_overlap(secure_tag_sysmem, 0,
+                                                        tag_sysmem, -1);
+                }
+            }
+
+            object_property_set_link(cpuobj, OBJECT(tag_sysmem),
+                                     "tag-memory", &error_abort);
+            if (vms->secure) {
+                object_property_set_link(cpuobj, OBJECT(secure_tag_sysmem),
+                                         "secure-tag-memory", &error_abort);
+            }
+        }
+
         qdev_realize(DEVICE(cpuobj), NULL, &error_fatal);
         object_unref(cpuobj);
     }
@@ -1857,10 +1903,15 @@ static void machvirt_init(MachineState *machine)
     create_uart(vms, VIRT_UART, sysmem, serial_hd(0));
 
     if (vms->secure) {
-        create_secure_ram(vms, secure_sysmem);
+        create_secure_ram(vms, secure_sysmem, secure_tag_sysmem);
         create_uart(vms, VIRT_SECURE_UART, secure_sysmem, serial_hd(1));
     }
 
+    if (tag_sysmem) {
+        create_tag_ram(tag_sysmem, vms->memmap[VIRT_MEM].base,
+                       machine->ram_size, "mach-virt.tag");
+    }
+
     vms->highmem_ecam &= vms->highmem && (!firmware_loaded || aarch64);
 
     create_rtc(vms);