exec: Don't abort when we can't allocate guest memory

We abort() on memory allocation failure.  abort() is appropriate for
programming errors.  Maybe most memory allocation failures are
programming errors, maybe not.  But guest memory allocation failure
isn't, and aborting when the user asks for more memory than we can
provide is not nice.  exit(1) instead, and do it in just one place, so
the error message is consistent.

Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1375276272-15988-8-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <anthony@codemonkey.ws>

exec.c

@@ -1150,6 +1150,11 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
         }
         if (!new_block->host) {
             new_block->host = phys_mem_alloc(size);
+            if (!new_block->host) {
+                fprintf(stderr, "Cannot set up guest memory '%s': %s\n",
+                        new_block->mr->name, strerror(errno));
+                exit(1);
+            }
             memory_try_enable_merging(new_block->host, size);
         }
     }

target-s390x/kvm.c

@@ -332,11 +332,7 @@ static void *legacy_s390_alloc(ram_addr_t size)
     mem = mmap((void *) 0x800000000ULL, size,
                PROT_EXEC|PROT_READ|PROT_WRITE,
                MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
-    if (mem == MAP_FAILED) {
-        fprintf(stderr, "Allocating RAM failed\n");
-        abort();
-    }
-    return mem;
+    return mem == MAP_FAILED ? NULL : mem;
 }
 
 int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)

util/oslib-posix.c

@@ -112,9 +112,7 @@ void *qemu_anon_ram_alloc(size_t size)
     size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
 
     if (ptr == MAP_FAILED) {
-        fprintf(stderr, "Failed to allocate %zu B: %s\n",
-                size, strerror(errno));
-        abort();
+        return NULL;
     }
 
     ptr += offset;

util/oslib-win32.c

@@ -65,10 +65,7 @@ void *qemu_anon_ram_alloc(size_t size)
     /* FIXME: this is not exactly optimal solution since VirtualAlloc
        has 64Kb granularity, but at least it guarantees us that the
        memory is page aligned. */
-    if (!size) {
-        abort();
-    }
-    ptr = qemu_oom_check(VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE));
+    ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
     trace_qemu_anon_ram_alloc(size, ptr);
     return ptr;
 }