From: Paolo Bonzini Date: Thu, 12 Feb 2015 16:04:47 +0000 (+0100) Subject: KVM: emulate: fix CMPXCHG8B on 32-bit hosts X-Git-Tag: omap-for-v4.1/wl12xx-dt~64^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ff6f8e61eb7f96d3ca535c6d240f863ccd6fb7d;p=pandora-kernel.git KVM: emulate: fix CMPXCHG8B on 32-bit hosts This has been broken for a long time: it broke first in 2.6.35, then was almost fixed in 2.6.36 but this one-liner slipped through the cracks. The bug shows up as an infinite loop in Windows 7 (and newer) boot on 32-bit hosts without EPT. Windows uses CMPXCHG8B to write to page tables, which causes a page fault if running without EPT; the emulator is then called from kvm_mmu_page_fault. The loop then happens if the higher 4 bytes are not 0; the common case for this is that the NX bit (bit 63) is 1. Fixes: 6550e1f165f384f3a46b60a1be9aba4bc3c2adad Fixes: 16518d5ada690643453eb0aef3cc7841d3623c2d Cc: stable@vger.kernel.org # 2.6.35+ Reported-by: Erik Rull Tested-by: Erik Rull Signed-off-by: Paolo Bonzini --- Reading git-diff-tree failed