From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50756) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecBTS-0005iD-4g for qemu-devel@nongnu.org; Thu, 18 Jan 2018 09:47:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecBTP-0008LR-I5 for qemu-devel@nongnu.org; Thu, 18 Jan 2018 09:47:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36554) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ecBTP-0008LH-Bm for qemu-devel@nongnu.org; Thu, 18 Jan 2018 09:47:23 -0500 References: <20180112125854.18261-1-kraxel@redhat.com> <20180112125854.18261-11-kraxel@redhat.com> <20180118133643.GP19695@redhat.com> <20180118141256.GS19695@redhat.com> From: Paolo Bonzini Message-ID: <85686228-03dd-a7fc-1477-f27d09de5007@redhat.com> Date: Thu, 18 Jan 2018 15:46:54 +0100 MIME-Version: 1.0 In-Reply-To: <20180118141256.GS19695@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 10/14] ui: fix VNC client throttling when audio capture is active List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Peter Maydell , Gerd Hoffmann , QEMU Developers On 18/01/2018 15:12, Daniel P. Berrange wrote: >> In addition to that, do we support a >= 2 GiB framebuffer at all? (Even >> with unsigned ints, Coverity would rightly complain about a truncated >> 32-bit multiplication being assigned to a 64-bit value). > client_width/client_height are values that are initialized from the > graphics card frontend config, and thus limited by amount of video > RAM QEMU allows. bytes_per_pixel is limited to 8/16/32. > > So I think we're safe from 2GB overflow in any normal case. > > That said, VGA RAM size is configurable, so I'm curious what would happen > if someone configured an insanely large VGA RAM and asked for a big frame > buffer in guest. > > VNC is protocol limited to uint16 for width/height size, and so is X11 > so I imagine some exploding behavour would follow :-) Indeed, and even 2^16 x 2^16 * 32bpp is already 34 bits. So perhaps we should limit VNC to 16384 pixels on each axis (maximum frame buffer size 1 GiB). Paolo