These two are almost the same as memory_region_init_ram() and
memory_region_init_ram_ptr() except that they have an extra errp
parameter to let callers handle error. The purpose is to fix the bug
described below.
We should have added errp directly to memory_region_ram(), but that
mixes updates to calls to memory_region_ram() and this bug fix and make
it hard to review.
We will rename _may_fail variants later so that we will have two versions
of API: one with errp parameter(memory_region_init_ram(),
memory_region_init_ram_ptr()), one without errp parameter and with
suffix _nofail.
In hostmem-ram.c we call memory_region_init_ram_may_fail() now rather
than memory_region_init_ram() so that error can be handled. This
solves a problem that qemu just exits when using monitor command
object_add to add a memory backend whose size is way too large. In the
case we'd better give an error message and keep guest running.
The problem can be reproduced as follows:
1. run qemu
2. (monitor)object_add memory-backend-ram,size=100000G,id=ram0
Signed-off-by: Hu Tao <hu...@cn.fujitsu.com>
---
backends/hostmem-ram.c | 4 +--
exec.c | 32 +++++++++++++++++-------
include/exec/memory.h | 37 +++++++++++++++++++++++++++
include/exec/ram_addr.h | 4 +--
memory.c | 66 ++++++++++++++++++++++++++++++++++++++++---------
5 files changed, 119 insertions(+), 24 deletions(-)
diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c
index d9a8290..d0e92ad 100644
--- a/backends/hostmem-ram.c
+++ b/backends/hostmem-ram.c
@@ -26,8 +26,8 @@ ram_backend_memory_alloc(HostMemoryBackend *backend, Error
**errp)
}
path = object_get_canonical_path_component(OBJECT(backend));
- memory_region_init_ram(&backend->mr, OBJECT(backend), path,
- backend->size);
+ memory_region_init_ram_may_fail(&backend->mr, OBJECT(backend), path,
+ backend->size, errp);
g_free(path);
}
diff --git a/exec.c b/exec.c
index 765bd94..7e60a44 100644
--- a/exec.c
+++ b/exec.c
@@ -1224,7 +1224,7 @@ static int memory_try_enable_merging(void *addr, size_t
len)
return qemu_madvise(addr, len, QEMU_MADV_MERGEABLE);
}
-static ram_addr_t ram_block_add(RAMBlock *new_block)
+static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
{
RAMBlock *block;
ram_addr_t old_ram_size, new_ram_size;
@@ -1241,9 +1241,11 @@ static ram_addr_t ram_block_add(RAMBlock *new_block)
} else {
new_block->host = phys_mem_alloc(new_block->length);
if (!new_block->host) {
- fprintf(stderr, "Cannot set up guest memory '%s': %s\n",
- new_block->mr->name, strerror(errno));
- exit(1);
+ error_setg_errno(errp, errno,
+ "cannot set up guest memory '%s'",
+ new_block->mr->name);
+ qemu_mutex_unlock_ramlist();
+ return -1;
}
memory_try_enable_merging(new_block->host, new_block->length);
}
@@ -1294,6 +1296,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
Error **errp)
{
RAMBlock *new_block;
+ ram_addr_t addr;
if (xen_enabled()) {
error_setg(errp, "-mem-path not supported with Xen");
@@ -1323,14 +1326,20 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
return -1;
}
- return ram_block_add(new_block);
+ addr = ram_block_add(new_block, errp);
+ if (errp && *errp) {
+ g_free(new_block);
+ return -1;
+ }
+ return addr;
}
#endif
ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
- MemoryRegion *mr)
+ MemoryRegion *mr, Error **errp)
{
RAMBlock *new_block;
+ ram_addr_t addr;
size = TARGET_PAGE_ALIGN(size);
new_block = g_malloc0(sizeof(*new_block));
@@ -1341,12 +1350,17 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size,
void *host,
if (host) {
new_block->flags |= RAM_PREALLOC;
}
- return ram_block_add(new_block);
+ addr = ram_block_add(new_block, errp);
+ if (errp && *errp) {
+ g_free(new_block);
+ return -1;
+ }
+ return addr;
}
-ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr)
+ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp)
{
- return qemu_ram_alloc_from_ptr(size, NULL, mr);
+ return qemu_ram_alloc_from_ptr(size, NULL, mr, errp);
}
void qemu_ram_free_from_ptr(ram_addr_t addr)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index e2c8e3e..7ebcea6 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -304,6 +304,23 @@ void memory_region_init_io(MemoryRegion *mr,
uint64_t size);
/**
+ * memory_region_init_ram_may_fail: Initialize RAM memory region. Accesses
+ * into the region will modify memory
+ * directly.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: the name of the region.
+ * @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
+ */
+void memory_region_init_ram_may_fail(MemoryRegion *mr,
+ struct Object *owner,
+ const char *name,
+ uint64_t size,
+ Error **errp);
+
+/**
* memory_region_init_ram: Initialize RAM memory region. Accesses into the
* region will modify memory directly.
*
@@ -340,6 +357,25 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
#endif
/**
+ * memory_region_init_ram_ptr_may_fail: Initialize RAM memory region from a
+ * user-provided pointer. Accesses into
+ * the region will modify memory
directly.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: the name of the region.
+ * @size: size of the region.
+ * @ptr: memory to be mapped; must contain at least @size bytes.
+ * @errp: pointer to Error*, to store an error if it happens.
+ */
+void memory_region_init_ram_ptr_may_fail(MemoryRegion *mr,
+ struct Object *owner,
+ const char *name,
+ uint64_t size,
+ void *ptr,
+ Error **errp);
+
+/**
* memory_region_init_ram_ptr: Initialize RAM memory region from a
* user-provided pointer. Accesses into the
* region will modify memory directly.
@@ -384,6 +420,7 @@ void memory_region_init_alias(MemoryRegion *mr,
* @ops: callbacks for write access handling.
* @name: the name of the region.
* @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
*/
void memory_region_init_rom_device(MemoryRegion *mr,
struct Object *owner,
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 6593be1..cf1d4c7 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -26,8 +26,8 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
bool share, const char *mem_path,
Error **errp);
ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
- MemoryRegion *mr);
-ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr);
+ MemoryRegion *mr, Error **errp);
+ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp);
int qemu_get_ram_fd(ram_addr_t addr);
void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
void *qemu_get_ram_ptr(ram_addr_t addr);
diff --git a/memory.c b/memory.c
index 64d7176..f55f098 100644
--- a/memory.c
+++ b/memory.c
@@ -25,6 +25,7 @@
#include "exec/memory-internal.h"
#include "exec/ram_addr.h"
#include "sysemu/sysemu.h"
+#include "qemu/error-report.h"
//#define DEBUG_UNASSIGNED
@@ -1160,16 +1161,33 @@ void memory_region_init_io(MemoryRegion *mr,
mr->ram_addr = ~(ram_addr_t)0;
}
-void memory_region_init_ram(MemoryRegion *mr,
- Object *owner,
- const char *name,
- uint64_t size)
+void memory_region_init_ram_may_fail(MemoryRegion *mr,
+ Object *owner,
+ const char *name,
+ uint64_t size,
+ Error **errp)
{
memory_region_init(mr, owner, name, size);
mr->ram = true;
mr->terminates = true;
mr->destructor = memory_region_destructor_ram;
- mr->ram_addr = qemu_ram_alloc(size, mr);
+ mr->ram_addr = qemu_ram_alloc(size, mr, errp);
+}
+
+void memory_region_init_ram(MemoryRegion *mr,
+ Object *owner,
+ const char *name,
+ uint64_t size)
+{
+ Error *local_err = NULL;
+
+ memory_region_init_ram_may_fail(mr, owner, name, size, &local_err);
+
+ if (local_err) {
+ error_report("%s", error_get_pretty(local_err));
+ error_free(local_err);
+ exit(EXIT_FAILURE);
+ }
}
#ifdef __linux__
@@ -1189,17 +1207,35 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
}
#endif
+void memory_region_init_ram_ptr_may_fail(MemoryRegion *mr,
+ Object *owner,
+ const char *name,
+ uint64_t size,
+ void *ptr,
+ Error **errp)
+{
+ memory_region_init(mr, owner, name, size);
+ mr->ram = true;
+ mr->terminates = true;
+ mr->destructor = memory_region_destructor_ram_from_ptr;
+ mr->ram_addr = qemu_ram_alloc_from_ptr(size, ptr, mr, errp);
+}
+
void memory_region_init_ram_ptr(MemoryRegion *mr,
Object *owner,
const char *name,
uint64_t size,
void *ptr)
{
- memory_region_init(mr, owner, name, size);
- mr->ram = true;
- mr->terminates = true;
- mr->destructor = memory_region_destructor_ram_from_ptr;
- mr->ram_addr = qemu_ram_alloc_from_ptr(size, ptr, mr);
+ Error *local_err = NULL;
+
+ memory_region_init_ram_ptr_may_fail(mr, owner, name, size, ptr,
&local_err);
+
+ if (local_err) {
+ error_report("%s", error_get_pretty(local_err));
+ error_free(local_err);
+ exit(EXIT_FAILURE);
+ }
}
void memory_region_init_alias(MemoryRegion *mr,
@@ -1223,13 +1259,21 @@ void memory_region_init_rom_device(MemoryRegion *mr,
const char *name,
uint64_t size)
{
+ Error *local_err = NULL;
+
memory_region_init(mr, owner, name, size);
mr->ops = ops;
mr->opaque = opaque;
mr->terminates = true;
mr->rom_device = true;
mr->destructor = memory_region_destructor_rom_device;
- mr->ram_addr = qemu_ram_alloc(size, mr);
+ mr->ram_addr = qemu_ram_alloc(size, mr, &local_err);
+
+ if (local_err) {
+ error_report("%s", error_get_pretty(local_err));
+ error_free(local_err);
+ exit(EXIT_FAILURE);
+ }
}
void memory_region_init_iommu(MemoryRegion *mr,
--
1.9.3
