s390x: fix memory detection for guests > 64GB

the s390 memory detection has a 16bit field that specifies the amount of
increments. This patch adopts the memory size to always fit into that
scheme. This also fixes virtio detection for these guests, since the
descriptor page is located after the main memory.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
index 698ff6f34512f52133def1653b26f52f6ff773f0..3eba7ea1e815366445a84d98ff8f443370c6337e 100644 (file)
--- a/hw/s390-virtio.c
+++ b/hw/s390-virtio.c
@@ -131,7 +131,7 @@ int s390_virtio_hypercall(CPUState *env, uint64_t mem, uint64_t hypercall)
 }
 
 /* PC hardware initialisation */
-static void s390_init(ram_addr_t ram_size,
+static void s390_init(ram_addr_t my_ram_size,
                       const char *boot_device,
                       const char *kernel_filename,
                       const char *kernel_cmdline,
@@ -143,19 +143,29 @@ static void s390_init(ram_addr_t ram_size,
     ram_addr_t kernel_size = 0;
     ram_addr_t initrd_offset;
     ram_addr_t initrd_size = 0;
+    int shift = 0;
     uint8_t *storage_keys;
     int i;
 
+    /* s390x ram size detection needs a 16bit multiplier + an increment. So
+       guests > 64GB can be specified in 2MB steps etc. */
+    while ((my_ram_size >> (20 + shift)) > 65535) {
+        shift++;
+    }
+    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
+
+    /* lets propagate the changed ram size into the global variable. */
+    ram_size = my_ram_size;
 
     /* get a BUS */
-    s390_bus = s390_virtio_bus_init(&ram_size);
+    s390_bus = s390_virtio_bus_init(&my_ram_size);
 
     /* allocate RAM */
-    ram_addr = qemu_ram_alloc(NULL, "s390.ram", ram_size);
-    cpu_register_physical_memory(0, ram_size, ram_addr);
+    ram_addr = qemu_ram_alloc(NULL, "s390.ram", my_ram_size);
+    cpu_register_physical_memory(0, my_ram_size, ram_addr);
 
     /* allocate storage keys */
-    storage_keys = qemu_mallocz(ram_size / TARGET_PAGE_SIZE);
+    storage_keys = qemu_mallocz(my_ram_size / TARGET_PAGE_SIZE);
 
     /* init CPUs */
     if (cpu_model == NULL) {

diff --git a/target-s390x/op_helper.c b/target-s390x/op_helper.c
index 91539405402cc5da7a08ef24e5fab865f61e8a2e..49760a40a251133ad00d387cde224aac7daf80b4 100644 (file)
--- a/target-s390x/op_helper.c
+++ b/target-s390x/op_helper.c
@@ -2361,6 +2361,7 @@ static void ext_interrupt(CPUState *env, int type, uint32_t param,
 int sclp_service_call(CPUState *env, uint32_t sccb, uint64_t code)
 {
     int r = 0;
+    int shift = 0;
 
 #ifdef DEBUG_HELPER
     printf("sclp(0x%x, 0x%" PRIx64 ")\n", sccb, code);
@@ -2375,8 +2376,11 @@ int sclp_service_call(CPUState *env, uint32_t sccb, uint64_t code)
     switch(code) {
         case SCLP_CMDW_READ_SCP_INFO:
         case SCLP_CMDW_READ_SCP_INFO_FORCED:
-            stw_phys(sccb + SCP_MEM_CODE, ram_size >> 20);
-            stb_phys(sccb + SCP_INCREMENT, 1);
+            while ((ram_size >> (20 + shift)) > 65535) {
+                shift++;
+            }
+            stw_phys(sccb + SCP_MEM_CODE, ram_size >> (20 + shift));
+            stb_phys(sccb + SCP_INCREMENT, 1 << shift);
             stw_phys(sccb + SCP_RESPONSE_CODE, 0x10);
 
             if (kvm_enabled()) {