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[Qemu-devel] [RFC PATCH 4/8] memory: ref/unref memory across address_spa
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [RFC PATCH 4/8] memory: ref/unref memory across address_space_map/unmap |
Date: |
Mon, 6 May 2013 16:25:17 +0200 |
The iothread mutex might be released between map and unmap, so the
mapped region might disappear.
Signed-off-by: Paolo Bonzini <address@hidden>
---
exec.c | 12 +++++++++++-
1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/exec.c b/exec.c
index 54b57fc..54ed203 100644
--- a/exec.c
+++ b/exec.c
@@ -2077,6 +2077,7 @@ void cpu_physical_memory_write_rom(hwaddr addr,
}
typedef struct {
+ MemoryRegion *mr;
void *buffer;
hwaddr addr;
hwaddr len;
@@ -2171,15 +2172,18 @@ void *address_space_map(AddressSpace *as,
bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, TARGET_PAGE_SIZE);
bounce.addr = addr;
bounce.len = l;
+ bounce.mr = section->mr;
if (!is_write) {
address_space_read(as, addr, bounce.buffer, l);
}
*plen = l;
+ memory_region_ref(section->mr);
return bounce.buffer;
}
if (!todo) {
raddr = memory_region_get_ram_addr(section->mr) + xlat;
+ memory_region_ref(section->mr);
} else {
if (memory_region_get_ram_addr(section->mr) + xlat != raddr +
todo) {
break;
@@ -2204,8 +2208,12 @@ void address_space_unmap(AddressSpace *as, void *buffer,
hwaddr len,
int is_write, hwaddr access_len)
{
if (buffer != bounce.buffer) {
+ MemoryRegion *mr;
+ ram_addr_t addr1;
+
+ mr = qemu_ram_addr_from_host(buffer, &addr1);
+ assert(mr);
if (is_write) {
- ram_addr_t addr1 = qemu_ram_addr_from_host_nofail(buffer);
while (access_len) {
unsigned l;
l = TARGET_PAGE_SIZE;
@@ -2219,6 +2227,7 @@ void address_space_unmap(AddressSpace *as, void *buffer,
hwaddr len,
if (xen_enabled()) {
xen_invalidate_map_cache_entry(buffer);
}
+ memory_region_unref(mr);
return;
}
if (is_write) {
@@ -2226,6 +2235,7 @@ void address_space_unmap(AddressSpace *as, void *buffer,
hwaddr len,
}
qemu_vfree(bounce.buffer);
bounce.buffer = NULL;
+ memory_region_unref(bounce.mr);
cpu_notify_map_clients();
}
--
1.7.1
- [Qemu-devel] [RFC PATCH 0/8] MemoryRegion and FlatView refcounting, replace hostmem with memory_region_find, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 2/8] exec: check MRU in qemu_ram_addr_from_host, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 1/8] memory: add ref/unref calls, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 4/8] memory: ref/unref memory across address_space_map/unmap,
Paolo Bonzini <=
- [Qemu-devel] [RFC PATCH 3/8] memory: return MemoryRegion from qemu_ram_addr_from_host, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 5/8] memory: access FlatView from a local variable, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 6/8] memory: use a new FlatView pointer on every topology update, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 7/8] memory: add reference counting to FlatView, Paolo Bonzini, 2013/05/06
- [Qemu-devel] [RFC PATCH 8/8] dataplane: replace hostmem with memory_region_find, Paolo Bonzini, 2013/05/06
- Re: [Qemu-devel] [RFC PATCH 0/8] MemoryRegion and FlatView refcounting, replace hostmem with memory_region_find, liu ping fan, 2013/05/08