Messages in this thread Patch in this message | | | Date | Thu, 11 Nov 2010 16:04:38 -0800 | From | Jeremy Fitzhardinge <> | Subject | [PATCH] agp: use DMA API when compiled for Xen as well |
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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-gtt.c b/drivers/char/agp/intel-gtt.c index 75e0a34..ce63e5c 100644 --- a/drivers/char/agp/intel-gtt.c +++ b/drivers/char/agp/intel-gtt.c @@ -20,8 +20,12 @@ * 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
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