Re: [PATCH 4/4] x86/asm: Change sync_core() to use MOV to CR2 to serialize

2016-12-01 Thread Ingo Molnar
* Borislav Petkov wrote: > On Wed, Nov 30, 2016 at 12:34:55PM -0800, Andy Lutomirski wrote: > > Aside from being excessively slow, CPUID is problematic: Linux runs > > on a handful of CPUs that don't have CPUID. MOV to CR2 is always > > available, so use it instead. > > > > Signed-off-by: Andy

Re: [PATCH 4/4] x86/asm: Change sync_core() to use MOV to CR2 to serialize

2016-12-01 Thread Andrew Cooper
On 01/12/16 17:08, Andy Lutomirski wrote: > On Thu, Dec 1, 2016 at 1:22 AM, Borislav Petkov wrote: >> On Wed, Nov 30, 2016 at 12:34:55PM -0800, Andy Lutomirski wrote: >>> Aside from being excessively slow, CPUID is problematic: Linux runs >>> on a handful of CPUs that don't have CPUID. MOV to CR2

Re: [PATCH 4/4] x86/asm: Change sync_core() to use MOV to CR2 to serialize

2016-12-01 Thread Andy Lutomirski
On Thu, Dec 1, 2016 at 1:22 AM, Borislav Petkov wrote: > On Wed, Nov 30, 2016 at 12:34:55PM -0800, Andy Lutomirski wrote: >> Aside from being excessively slow, CPUID is problematic: Linux runs >> on a handful of CPUs that don't have CPUID. MOV to CR2 is always >> available, so use it instead. >>

Re: [PATCH 4/4] x86/asm: Change sync_core() to use MOV to CR2 to serialize

2016-12-01 Thread Borislav Petkov
On Wed, Nov 30, 2016 at 12:34:55PM -0800, Andy Lutomirski wrote: > Aside from being excessively slow, CPUID is problematic: Linux runs > on a handful of CPUs that don't have CPUID. MOV to CR2 is always > available, so use it instead. > > Signed-off-by: Andy Lutomirski > --- > arch/x86/include/a

[PATCH 4/4] x86/asm: Change sync_core() to use MOV to CR2 to serialize

2016-11-30 Thread Andy Lutomirski
Aside from being excessively slow, CPUID is problematic: Linux runs on a handful of CPUs that don't have CPUID. MOV to CR2 is always available, so use it instead. Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/processor.h | 31 --- 1 file changed, 8 insertio