From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:35212) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QqNBC-0005Fe-9x for qemu-devel@nongnu.org; Mon, 08 Aug 2011 06:35:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QqNBB-0003Bl-28 for qemu-devel@nongnu.org; Mon, 08 Aug 2011 06:35:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56625) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QqNBA-0003Bc-R3 for qemu-devel@nongnu.org; Mon, 08 Aug 2011 06:35:29 -0400 Date: Mon, 8 Aug 2011 13:36:06 +0300 From: "Michael S. Tsirkin" Message-ID: <20110808103606.GA10372@redhat.com> References: <1312463195-13605-1-git-send-email-avi@redhat.com> <1312463195-13605-2-git-send-email-avi@redhat.com> <4E3BF599.4050207@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E3BF599.4050207@codemonkey.ws> Subject: Re: [Qemu-devel] [PATCH v3 01/39] virtio-pci: get config on init List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Avi Kivity , kvm@vger.kernel.org, qemu-devel@nongnu.org On Fri, Aug 05, 2011 at 08:52:25AM -0500, Anthony Liguori wrote: > On 08/04/2011 08:05 AM, Avi Kivity wrote: > >From: "Michael S. Tsirkin" > > > >We originally did get config on map, so that > >following write accesses are done on an updated config. > >New memory API doesn't give us a callback > >on map, and arguably, devices don't know when > >cpu really can access there. So updating on > >init seems cleaner. > > > >Signed-off-by: Michael S. Tsirkin > >Signed-off-by: Avi Kivity > >--- > > hw/virtio-pci.c | 7 ++++--- > > 1 files changed, 4 insertions(+), 3 deletions(-) > > > >diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c > >index d685243..ca1f12f 100644 > >--- a/hw/virtio-pci.c > >+++ b/hw/virtio-pci.c > >@@ -506,9 +506,6 @@ static void virtio_map(PCIDevice *pci_dev, int region_num, > > register_ioport_read(addr, config_len, 1, virtio_pci_config_readb, proxy); > > register_ioport_read(addr, config_len, 2, virtio_pci_config_readw, proxy); > > register_ioport_read(addr, config_len, 4, virtio_pci_config_readl, proxy); > >- > >- if (vdev->config_len) > >- vdev->get_config(vdev, vdev->config); > > } > > > > static void virtio_write_config(PCIDevice *pci_dev, uint32_t address, > >@@ -689,6 +686,10 @@ void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev) > > proxy->host_features |= 0x1<< VIRTIO_F_NOTIFY_ON_EMPTY; > > proxy->host_features |= 0x1<< VIRTIO_F_BAD_FEATURE; > > proxy->host_features = vdev->get_features(vdev, proxy->host_features); > >+ > >+ if (vdev->config_len) { > >+ vdev->get_config(vdev, vdev->config); > >+ } > > Thinking more closely, I don't think this right. > > Updating on map ensured that the config was refreshed after each > time the bar was mapped. In the very least, the config needs to be > refreshed during reset because the guest may write to the guest > space which should get cleared after reset. > > Regards, > > Anthony Liguori Not sure I understand. Which register, for example, do you have in mind? Could you clarify please? > > } > > > > static int virtio_blk_init_pci(PCIDevice *pci_dev)