Re: [Xen-devel] [PATCH] x86: make SMEP/SMAP suppression tolerate NMI/MCE at the "wrong" time

2016-05-17 Thread Wei Liu
On Tue, May 17, 2016 at 07:43:34AM -0600, Jan Beulich wrote: > There is one instruction boundary where any kind of interruption would > break the assumptions cr4_pv32_restore's debug mode checking makes on > the correlation between the CR4 register value and its in-memory cache. > Correct this

Re: [Xen-devel] [PATCH] x86: make SMEP/SMAP suppression tolerate NMI/MCE at the "wrong" time

2016-05-17 Thread Andrew Cooper
On 17/05/16 14:43, Jan Beulich wrote: > There is one instruction boundary where any kind of interruption would > break the assumptions cr4_pv32_restore's debug mode checking makes on > the correlation between the CR4 register value and its in-memory cache. > Correct this (see the code comment)

[Xen-devel] [PATCH] x86: make SMEP/SMAP suppression tolerate NMI/MCE at the "wrong" time

2016-05-17 Thread Jan Beulich
There is one instruction boundary where any kind of interruption would break the assumptions cr4_pv32_restore's debug mode checking makes on the correlation between the CR4 register value and its in-memory cache. Correct this (see the code comment) even in non-debug mode, or else a subsequent