From ef09f2ed2a8242e29e7f32b03d2d58d956929f69 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= Date: Wed, 16 Apr 2014 16:07:59 +0200 Subject: [PATCH] Disable PAT in linux VMs Apparently kernel patch "x86/cpa: Use pte_attrs instead of pte_flags on CPA/set_p.._wb/wc operations" (in out repo) doesn't fully solve the problem and sometimes qubes-gui agent crashes with message like "qubes-gui:664 map pfn expected mapping type write-back for [mem 0x00093000-0x00093fff], got uncached-minus". Because PAT we really need only in dom0 (lack of it dramatically decrease performance of some graphics drivers), we can simply disable it in VM - as it is currently done in upstream kernel. --- core/qubes.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/core/qubes.py b/core/qubes.py index bef2a4ea..b8833d64 100755 --- a/core/qubes.py +++ b/core/qubes.py @@ -80,8 +80,8 @@ vm_files = { defaults = { 'memory': 400, - 'kernelopts': "", - 'kernelopts_pcidevs': "iommu=soft swiotlb=4096", + 'kernelopts': "nopat", + 'kernelopts_pcidevs': "nopat iommu=soft swiotlb=4096", 'dom0_update_check_interval': 6*3600,