Re: pvops: i915 kms crashs with corrupt page table

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 02/24/2010 09:55 AM, Bastian Blank wrote:
> Hi
>
> I run a 2.6.32 dom0 kernel (the Debian distribution config). If I enable
> KMS in the intel driver, Xorg crashs with corrupt page table.
>    

Does this help?

 From d36d7863f86b2d7a786abf60ea37c75438b448d5 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com>
Date: Wed, 24 Feb 2010 11:10:45 -0800
Subject: [PATCH] agp: use DMA API when compiled for Xen as well

Xen guests need translation between pseudo-physical and real machine
physical addresses when accessing graphics devices, so use the DMA API
in that case too.

Signed-off-by: Jeremy Fitzhardinge<jeremy.fitzhardinge@citrix.com>

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 3cb56a0..efa7213 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -15,8 +15,12 @@
   * an Intel IOMMU. So make the correct use of the PCI DMA API contingent
   * on the Intel IOMMU support (CONFIG_DMAR).
   * Only newer chipsets need to bother with this, of course.
+ *
+ * Xen guests accessing graphics hardware also need proper translation
+ * between pseudo-physical addresses and real machine addresses, which
+ * is also achieved by using the DMA API.
   */
-#ifdef CONFIG_DMAR
+#if defined(CONFIG_DMAR) || defined(CONFIG_XEN)
  #define USE_PCI_DMA_API 1
  #endif