From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41207) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UZMMX-0004Wc-JW for qemu-devel@nongnu.org; Mon, 06 May 2013 10:26:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UZMMS-0005TE-2d for qemu-devel@nongnu.org; Mon, 06 May 2013 10:25:57 -0400 Received: from mail-ee0-f48.google.com ([74.125.83.48]:46348) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UZMMR-0005T2-Fc for qemu-devel@nongnu.org; Mon, 06 May 2013 10:25:51 -0400 Received: by mail-ee0-f48.google.com with SMTP id d4so1834540eek.21 for ; Mon, 06 May 2013 07:25:50 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Mon, 6 May 2013 16:25:17 +0200 Message-Id: <1367850321-1732-5-git-send-email-pbonzini@redhat.com> In-Reply-To: <1367850321-1732-1-git-send-email-pbonzini@redhat.com> References: <1367850321-1732-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [RFC PATCH 4/8] memory: ref/unref memory across address_space_map/unmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: jan.kiszka@siemens.com, qemulist@gmail.com, stefanha@redhat.com The iothread mutex might be released between map and unmap, so the mapped region might disappear. Signed-off-by: Paolo Bonzini --- 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