m68k pull request 20220120

Fix virt-m68k reboot
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Merge remote-tracking branch 'remotes/vivier/tags/m68k-for-7.0-pull-request' into staging

m68k pull request 20220120

Fix virt-m68k reboot

# gpg: Signature made Thu 20 Jan 2022 08:35:50 GMT
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier/tags/m68k-for-7.0-pull-request:
  m68k: virt: correctly set the initial PC
  hw/elf_ops: clear uninitialized segment space
  exec/memory: Extract address_space_set() from dma_memory_set()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/core/loader.c

@@ -1164,9 +1164,13 @@ static void rom_reset(void *unused)
         if (rom->mr) {
             void *host = memory_region_get_ram_ptr(rom->mr);
             memcpy(host, rom->data, rom->datasize);
+            memset(host + rom->datasize, 0, rom->romsize - rom->datasize);
         } else {
             address_space_write_rom(rom->as, rom->addr, MEMTXATTRS_UNSPECIFIED,
                                     rom->data, rom->datasize);
+            address_space_set(rom->as, rom->addr + rom->datasize, 0,
+                              rom->romsize - rom->datasize,
+                              MEMTXATTRS_UNSPECIFIED);
         }
         if (rom->isrom) {
             /* rom needs to be written only once */

hw/m68k/virt.c

@@ -85,14 +85,21 @@
 #define VIRT_VIRTIO_MMIO_BASE 0xff010000     /* MMIO: 0xff010000 - 0xff01ffff */
 #define VIRT_VIRTIO_IRQ_BASE  PIC_IRQ(2, 1)  /* PIC: 2, 3, 4, 5, IRQ: ALL */
 
+typedef struct {
+    M68kCPU *cpu;
+    hwaddr initial_pc;
+    hwaddr initial_stack;
+} ResetInfo;
+
 static void main_cpu_reset(void *opaque)
 {
-    M68kCPU *cpu = opaque;
+    ResetInfo *reset_info = opaque;
+    M68kCPU *cpu = reset_info->cpu;
     CPUState *cs = CPU(cpu);
 
     cpu_reset(cs);
-    cpu->env.aregs[7] = ldl_phys(cs->as, 0);
+    cpu->env.aregs[7] = reset_info->initial_stack;
-    cpu->env.pc = ldl_phys(cs->as, 4);
+    cpu->env.pc = reset_info->initial_pc;
 }
 
 static void virt_init(MachineState *machine)
@@ -113,6 +120,7 @@ static void virt_init(MachineState *machine)
     SysBusDevice *sysbus;
     hwaddr io_base;
     int i;
+    ResetInfo *reset_info;
 
     if (ram_size > 3399672 * KiB) {
         /*
@@ -124,9 +132,13 @@ static void virt_init(MachineState *machine)
         exit(1);
     }
 
+    reset_info = g_malloc0(sizeof(ResetInfo));
+
     /* init CPUs */
     cpu = M68K_CPU(cpu_create(machine->cpu_type));
-    qemu_register_reset(main_cpu_reset, cpu);
+
+    reset_info->cpu = cpu;
+    qemu_register_reset(main_cpu_reset, reset_info);
 
     /* RAM */
     memory_region_add_subregion(get_system_memory(), 0, machine->ram);
@@ -206,7 +218,7 @@ static void virt_init(MachineState *machine)
             error_report("could not load kernel '%s'", kernel_filename);
             exit(1);
         }
-        stl_phys(cs->as, 4, elf_entry); /* reset initial PC */
+        reset_info->initial_pc = elf_entry;
         parameters_base = (high + 1) & ~1;
 
         BOOTINFO1(cs->as, parameters_base, BI_MACHTYPE, MACH_VIRT);

include/exec/memory.h

@@ -2908,6 +2908,22 @@ address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
     }
 }
 
+/**
+ * address_space_set: Fill address space with a constant byte.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @c: constant byte to fill the memory
+ * @len: the number of bytes to fill with the constant byte
+ * @attrs: memory transaction attributes
+ */
+MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+                              uint8_t c, hwaddr len, MemTxAttrs attrs);
+
 #ifdef NEED_CPU_H
 /* enum device_endian to MemOp.  */
 static inline MemOp devend_memop(enum device_endian end)

include/hw/elf_ops.h

@@ -555,6 +555,19 @@ static ssize_t glue(load_elf, SZ)(const char *name, int fd,
                     if (res != MEMTX_OK) {
                         goto fail;
                     }
+                    /*
+                     * We need to zero'ify the space that is not copied
+                     * from file
+                     */
+                    if (file_size < mem_size) {
+                        res = address_space_set(as ? as : &address_space_memory,
+                                                addr + file_size, 0,
+                                                mem_size - file_size,
+                                                MEMTXATTRS_UNSPECIFIED);
+                        if (res != MEMTX_OK) {
+                            goto fail;
+                        }
+                    }
                 }
             }
 

softmmu/dma-helpers.c

@@ -23,20 +23,7 @@ MemTxResult dma_memory_set(AddressSpace *as, dma_addr_t addr,
 {
     dma_barrier(as, DMA_DIRECTION_FROM_DEVICE);
 
-#define FILLBUF_SIZE 512
+    return address_space_set(as, addr, c, len, attrs);
-    uint8_t fillbuf[FILLBUF_SIZE];
-    int l;
-    MemTxResult error = MEMTX_OK;
-
-    memset(fillbuf, c, FILLBUF_SIZE);
-    while (len > 0) {
-        l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
-        error |= address_space_write(as, addr, attrs, fillbuf, l);
-        len -= l;
-        addr += l;
-    }
-
-    return error;
 }
 
 void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,

softmmu/physmem.c

@@ -2927,6 +2927,25 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
     }
 }
 
+MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+                              uint8_t c, hwaddr len, MemTxAttrs attrs)
+{
+#define FILLBUF_SIZE 512
+    uint8_t fillbuf[FILLBUF_SIZE];
+    int l;
+    MemTxResult error = MEMTX_OK;
+
+    memset(fillbuf, c, FILLBUF_SIZE);
+    while (len > 0) {
+        l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
+        error |= address_space_write(as, addr, attrs, fillbuf, l);
+        len -= l;
+        addr += l;
+    }
+
+    return error;
+}
+
 void cpu_physical_memory_rw(hwaddr addr, void *buf,
                             hwaddr len, bool is_write)
 {