Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-21 Thread George Dunlap
On Fri, Feb 16, 2018 at 5:02 PM, Andrew Cooper wrote: > On 16/02/18 16:21, Jan Beulich wrote: > On 16.02.18 at 16:50, wrote: >>> On 16/02/18 08:00, Jan Beulich wrote: >>> On 15.02.18 at 17:53, wrote: > On 15/02/18 16:03, Jan Beulich wrote: >> --- a/xen/arch/x86/pv/emul-priv-op.c

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-19 Thread Andrew Cooper
On 19/02/18 07:50, Jan Beulich wrote: On 16.02.18 at 18:02, wrote: >> On 16/02/18 16:21, Jan Beulich wrote: >> On 16.02.18 at 16:50, wrote: On 16/02/18 08:00, Jan Beulich wrote: On 15.02.18 at 17:53, wrote: >> On 15/02/18 16:03, Jan Beulich wrote: >>> --- a/xen/arc

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-18 Thread Jan Beulich
>>> On 16.02.18 at 18:02, wrote: > On 16/02/18 16:21, Jan Beulich wrote: > On 16.02.18 at 16:50, wrote: >>> On 16/02/18 08:00, Jan Beulich wrote: >>> On 15.02.18 at 17:53, wrote: > On 15/02/18 16:03, Jan Beulich wrote: >> --- a/xen/arch/x86/pv/emul-priv-op.c >> +++ b/xen/arch

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-16 Thread Andrew Cooper
On 16/02/18 16:21, Jan Beulich wrote: On 16.02.18 at 16:50, wrote: >> On 16/02/18 08:00, Jan Beulich wrote: >> On 15.02.18 at 17:53, wrote: On 15/02/18 16:03, Jan Beulich wrote: > --- a/xen/arch/x86/pv/emul-priv-op.c > +++ b/xen/arch/x86/pv/emul-priv-op.c > @@ -73,55 +73

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-16 Thread Jan Beulich
>>> On 16.02.18 at 16:50, wrote: > On 16/02/18 08:00, Jan Beulich wrote: > On 15.02.18 at 17:53, wrote: >>> On 15/02/18 16:03, Jan Beulich wrote: --- a/xen/arch/x86/pv/emul-priv-op.c +++ b/xen/arch/x86/pv/emul-priv-op.c @@ -73,55 +73,42 @@ void (*pv_post_outb_hook)(unsigned int

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-16 Thread Andrew Cooper
On 16/02/18 08:00, Jan Beulich wrote: On 15.02.18 at 17:53, wrote: >> On 15/02/18 16:03, Jan Beulich wrote: >>> --- a/xen/arch/x86/pv/emul-priv-op.c >>> +++ b/xen/arch/x86/pv/emul-priv-op.c >>> @@ -73,55 +73,42 @@ void (*pv_post_outb_hook)(unsigned int p >>> >>> typedef void io_emul_stub_t

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-16 Thread Jan Beulich
>>> On 15.02.18 at 17:53, wrote: > On 15/02/18 16:03, Jan Beulich wrote: >> --- a/xen/arch/x86/pv/emul-priv-op.c >> +++ b/xen/arch/x86/pv/emul-priv-op.c >> @@ -73,55 +73,42 @@ void (*pv_post_outb_hook)(unsigned int p >> >> typedef void io_emul_stub_t(struct cpu_user_regs *); >> >> -void __x86

Re: [Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-15 Thread Andrew Cooper
On 15/02/18 16:03, Jan Beulich wrote: > The stub is within reach from the .text section, so there's no point > using an indirect call here. This has the added benefit of there no > longer being two sufficiently different approaches, breaking one of > which people may not even notice. > > Signed-off

[Xen-devel] [PATCH] x86/PV: avoid indirect call/thunk in I/O emulation

2018-02-15 Thread Jan Beulich
The stub is within reach from the .text section, so there's no point using an indirect call here. This has the added benefit of there no longer being two sufficiently different approaches, breaking one of which people may not even notice. Signed-off-by: Jan Beulich --- a/xen/arch/x86/pv/emul-pri