From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [RFC v4 23/58] vga: convert vga and its derivatives to the memory API Date: Wed, 20 Jul 2011 16:45:35 +0200 Message-ID: <4E26EA0F.40302@siemens.com> References: <1310901265-32051-1-git-send-email-avi@redhat.com> <1310901265-32051-24-git-send-email-avi@redhat.com> <4E26E0AF.9040503@siemens.com> <4E26E8CF.2080205@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from david.siemens.de ([192.35.17.14]:33979 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751778Ab1GTOpl (ORCPT ); Wed, 20 Jul 2011 10:45:41 -0400 In-Reply-To: <4E26E8CF.2080205@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2011-07-20 16:40, Avi Kivity wrote: > On 07/20/2011 05:05 PM, Jan Kiszka wrote: >> On 2011-07-17 13:13, Avi Kivity wrote: >>> Convert all vga memory to the memory API. Note we need to fall back to >>> get_system_memory(), since the various buses don't pass the vga window >>> as a memory region. >>> >> >>> >>> if (limit> 0) { >>> - /* Thinking about changing bank base? First, drop the dirty bitmap information >>> - * on the current location, otherwise we lose this pointer forever */ >>> - if (s->vga.lfb_vram_mapped) { >>> - target_phys_addr_t base_addr = isa_mem_base + 0xa0000 + bank_index * 0x8000; >>> - cpu_physical_sync_dirty_bitmap(base_addr, base_addr + 0x8000); >>> - } >> >> Why is it safe to drop this? >> > > The memory API will sync the dirty bitmap once it becomes invisible. OK, maybe add a short note to the commit log in the next release? > > (that's the whole point - it can be made invisible by something outside > the cirrus card's knowledge). > > Note - with kvm, there is still a race between syncing the bitmap and > removing the region. However that is a bug in the kvm API; it is not > possible to work around it in qemu. > Dirty log off, reconfigure, dirty log on? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux