On Mon, Feb 04, 2013 at 11:50:43AM +0800, Dongxiao Xu wrote: > Changes from v1 to v2: > - Modify commit message and comments according to Gleb's suggestions. > > SMEP is disabled if CPU is in non-paging mode in hardware. > However KVM always uses paging mode to emulate guest non-paging > mode with TDP. To emulate this behavior, SMEP needs to be manually > disabled when guest switches to non-paging mode. > > We met an issue that, SMP Linux guest with recent kernel (enable > SMEP support, for example, 3.5.3) would crash with triple fault if > setting unrestricted_guest=0. This is because KVM uses an identity > mapping page table to emulate the non-paging mode, where the page > table is set with USER flag. If SMEP is still enabled in this case, > guest will meet unhandlable page fault and then crash. > > Signed-off-by: Dongxiao Xu <dongxiao.xu@xxxxxxxxx> > Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx> > --- > arch/x86/kvm/vmx.c | 8 ++++++++ > 1 files changed, 8 insertions(+), 0 deletions(-) Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
