From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57394) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UZijO-0001RE-Nl for qemu-devel@nongnu.org; Tue, 07 May 2013 10:19:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UZijJ-0006Mw-Dl for qemu-devel@nongnu.org; Tue, 07 May 2013 10:19:02 -0400 Received: from mail-we0-x236.google.com ([2a00:1450:400c:c03::236]:48492) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UZijJ-0006Mi-7G for qemu-devel@nongnu.org; Tue, 07 May 2013 10:18:57 -0400 Received: by mail-we0-f182.google.com with SMTP id t60so572853wes.27 for ; Tue, 07 May 2013 07:18:56 -0700 (PDT) Sender: Paolo Bonzini From: Paolo Bonzini Date: Tue, 7 May 2013 16:17:15 +0200 Message-Id: <1367936238-12196-38-git-send-email-pbonzini@redhat.com> In-Reply-To: <1367936238-12196-1-git-send-email-pbonzini@redhat.com> References: <1367936238-12196-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 37/40] 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: aik@ozlabs.ru, jan.kiszka@siemens.com, qemulist@gmail.com, stefanha@redhat.com, david@gibson.dropbear.id.au 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 63123e0..1efcde4 100644 --- a/exec.c +++ b/exec.c @@ -2085,6 +2085,7 @@ void cpu_physical_memory_write_rom(hwaddr addr, } typedef struct { + MemoryRegion *mr; void *buffer; hwaddr addr; hwaddr len; @@ -2179,15 +2180,18 @@ 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; @@ -2212,8 +2216,12 @@ 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; @@ -2227,6 +2235,7 @@ 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) { @@ -2234,6 +2243,7 @@ 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