From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eamon Walsh Subject: Re: Fbdev graphics broken in xen/next dom0 Date: Fri, 12 Mar 2010 19:44:11 -0500 Message-ID: <4B9ADFDB.1070300@tycho.nsa.gov> References: <4B9AA301.6090303@tycho.nsa.gov> <4B9AB559.1070709@goop.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------090100060806090400070409" Return-path: In-Reply-To: <4B9AB559.1070709@goop.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jeremy Fitzhardinge Cc: George Coker , Xen-devel , Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org This is a multi-part message in MIME format. --------------090100060806090400070409 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 03/12/2010 04:42 PM, Jeremy Fitzhardinge wrote: > On 03/12/2010 12:24 PM, Eamon Walsh wrote: > >> I work in the same group as Dave Quigley and George Coker. I'm working >> on a graphical switcher application for Xen which uses the DirectFB >> library on top of Linux VESA fbdev. This runs in dom0 at the moment. >> I'm using the latest xen/next pvops dom0 and xen-unstable hypervisor >> compiled from source, with vga=ask so I can boot dom0 in a graphical mode. >> >> The problem I'm having is illustrated by the attached test program that >> displays a green background with a white square for 10 seconds when run >> as root. It doesn't work on the xen/next / xen-unstable combo. The >> program runs and exits normally but all I see is a black screen. >> >> The program *does* work on xen/next running on the bare metal. It also >> works using the xen-unstable hypervisor with an older dom0, the 2.6.31.4 >> kernel with Novell patches. So I think the issue is in the xen/next >> kernel. I've run the test program on different machines and observed >> the same behavior. >> >> The xen-unstable / 2.6.31.4 dom0 combination works and I'm using that >> for the moment but I'd like to be using pvops. I would be happy to run >> more tests / provide more data if needed. >> >> > What's the hardware? Do any messages appear either on the dom0 console > or the Xen console? Does booting with a vga console help? > The hardware is a Dell Latitude E6500 with nvidia graphics. I also see the issue on a Dell Optiplex 960 desktop with Intel graphics. No obvious messages on the consoles. I am booting in VGA mode. I have narrowed the problem down: it has something to do with mmap of /dev/fb0 not syncing. The attached C code mmaps /dev/fb0 and writes some random bits. On a configuration that does work (2.6.31.4 on 4.0-rc6, or xen/next on bare metal) the random bits are visible on the screen. With xen/next on 4.0-rc6, nothing is visible. Calling msync() before the sleep has no effect. Also, using write() on /dev/fb0 always works so it appears to be mmap related. -- Eamon Walsh National Security Agency --------------090100060806090400070409 Content-Type: text/plain; name="mmaptest.c" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="mmaptest.c" I2luY2x1ZGUgPHN5cy90eXBlcy5oPgojaW5jbHVkZSA8c3lzL21tYW4uaD4KI2luY2x1ZGUg PHN0ZGlvLmg+CiNpbmNsdWRlIDxzdGRsaWIuaD4KI2luY2x1ZGUgPHN0cmluZy5oPgojaW5j bHVkZSA8dW5pc3RkLmg+CiNpbmNsdWRlIDxmY250bC5oPgoKc3RhdGljIHZvaWQgYmFpbChp bnQgY29uZCwgY29uc3QgY2hhciAqbXNnKQp7CglpZiAoY29uZCkgewoJCXBlcnJvcihtc2cp OwoJCWV4aXQoMSk7Cgl9Cn0KCmludCBtYWluKHZvaWQpCnsKCWludCBpZCA9IG9wZW4oIi9k ZXYvdXJhbmRvbSIsIE9fUkRPTkxZKSwgZmQgPSBvcGVuKCIvZGV2L2ZiMCIsIE9fUkRXUik7 Cgl1bnNpZ25lZCAqYWRkcjsKCWNoYXIgYnVmWzQwOTZdOwoKCWJhaWwoZmQgPCAwLCAiL2Rl di9mYjAiKTsKCWJhaWwoaWQgPCAwLCAiL2Rldi91cmFuZG9tIik7CgoJYWRkciA9IG1tYXAo TlVMTCwgc2l6ZW9mKGJ1ZiksIFBST1RfUkVBRHxQUk9UX1dSSVRFLCBNQVBfU0hBUkVELCBm ZCwgMCk7CgliYWlsKGFkZHIgPT0gTUFQX0ZBSUxFRCwgIm1tYXAiKTsKCglyZWFkKGlkLCBi dWYsIHNpemVvZihidWYpKTsKCW1lbWNweShhZGRyLCBidWYsIHNpemVvZihidWYpKTsKCS8v IHdyaXRlKGZkLCBidWYsIHNpemVvZihidWYpKTsKCglzbGVlcCgxMCk7CgoJY2xvc2UoaWQp OwoJY2xvc2UoZmQpOwoKCXJldHVybiAwOwp9Cg== --------------090100060806090400070409 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel --------------090100060806090400070409--