From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 636086B004F for ; Thu, 27 Aug 2009 06:12:26 -0400 (EDT) Date: Thu, 27 Aug 2009 13:10:26 +0300 From: "Michael S. Tsirkin" Subject: Re: [PATCHv4 2/2] vhost_net: a kernel-level virtio server Message-ID: <20090827101026.GA8545@redhat.com> References: <200908252140.41295.rusty@rustcorp.com.au> <20090825175016.GA15790@redhat.com> <200908261540.59900.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200908261540.59900.arnd@arndb.de> Sender: owner-linux-mm@kvack.org To: Arnd Bergmann Cc: virtualization@lists.linux-foundation.org, Rusty Russell , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, hpa@zytor.com, mingo@elte.hu, akpm@linux-foundation.org List-ID: On Wed, Aug 26, 2009 at 03:40:59PM +0200, Arnd Bergmann wrote: > On Tuesday 25 August 2009, Michael S. Tsirkin wrote: > > > I'd like to avoid that here, > > > though it's kind of ugly. We'd need VHOST_GET_FEATURES (and ACK) to take a > > > struct like: > > > > > > u32 feature_size; > > > u32 features[]; > > Hmm, variable length ioctl arguments, I'd rather not go there. > The ioctl infrastructure already has a length argument encoded > in the ioctl number. We can use that if we need more, e.g. > > /* now */ > #define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64) > /* > * uncomment if we run out of feature bits: > > struct vhost_get_features2 { > __u64 bits[2]; > }; > #define VHOST_GET_FEATURES2 _IOR(VHOST_VIRTIO, 0x00, \ > struct vhost_get_features2) > */ I thought so, too. Rusty, agree? -- MST -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org