On Wed, Nov 18, 2015 at 12:21:56PM -0800, Andy Lutomirski wrote:
> Could we make this a little less subtle:
>
> ALTERNATIVE "testl %eax, %eax; lz .Lsyscall_32_done", "jmp
> .Lsyscasll_32_done", X86_FEATURE_XENPV
>
> Borislav, what do you think?
I don't mind either.
I would've said your version
After 32-bit syscall rewrite, and specifically after commit 5f310f739b4c
("x86/entry/32: Re-implement SYSENTER using the new C path"), the stack
frame that is passed to xen_sysexit is no longer a "standard" one (i.e.
it's not pt_regs).
Since we end up calling xen_iret from xen_sysexit we don't
On Wed, Nov 18, 2015 at 12:06 PM, Boris Ostrovsky
wrote:
> After 32-bit syscall rewrite, and specifically after commit 5f310f739b4c
> ("x86/entry/32: Re-implement SYSENTER using the new C path"), the stack
> frame that is passed to xen_sysexit is no longer a "standard"
On Wed, Nov 18, 2015 at 12:50 PM, Brian Gerst wrote:
> On Wed, Nov 18, 2015 at 3:21 PM, Andy Lutomirski wrote:
>> On Wed, Nov 18, 2015 at 12:06 PM, Boris Ostrovsky
>> wrote:
>>> After 32-bit syscall rewrite, and specifically
On Wed, Nov 18, 2015 at 12:21:56PM -0800, Andy Lutomirski wrote:
> > diff --git a/arch/x86/include/asm/cpufeature.h
> > b/arch/x86/include/asm/cpufeature.h
> > index e4f8010..0e4fe5b 100644
> > --- a/arch/x86/include/asm/cpufeature.h
> > +++ b/arch/x86/include/asm/cpufeature.h
> > @@ -216,6
On 11/18/2015 03:58 PM, Andy Lutomirski wrote:
On Wed, Nov 18, 2015 at 12:50 PM, Brian Gerst wrote:
Can you just add !xen_pv_domain() to the opportunistic SYSRET check
instead? Bury the alternatives in that macro, ie.
static_cpu_has(X86_FEATURE_XENPV). That would likely
On Wed, Nov 18, 2015 at 3:21 PM, Andy Lutomirski wrote:
> On Wed, Nov 18, 2015 at 12:06 PM, Boris Ostrovsky
> wrote:
>> After 32-bit syscall rewrite, and specifically after commit 5f310f739b4c
>> ("x86/entry/32: Re-implement SYSENTER using the new