Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-04 Thread Borislav Petkov
On Mon, Feb 29, 2016 at 03:50:19PM -0800, Andy Lutomirski wrote: > x86_64 has very clean espfix handling on paravirt: espfix64 is set > up in native_iret, so paravirt systems that override iret bypass > espfix64 automatically. This is robust and straightforward. > > x86_32 is messier. espfix is

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-02 Thread Luis R. Rodriguez
On Wed, Mar 02, 2016 at 04:33:06PM -0800, Andy Lutomirski wrote: > On Tue, Mar 1, 2016 at 4:15 PM, Luis R. Rodriguez wrote: > > Ingo, your feedback appreciated at the end here, regarding quirks. > > > > On Tue, Mar 01, 2016 at 09:00:53AM -0500, Boris Ostrovsky wrote: > >> On

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-02 Thread Andy Lutomirski
On Tue, Mar 1, 2016 at 4:15 PM, Luis R. Rodriguez wrote: > Ingo, your feedback appreciated at the end here, regarding quirks. > > On Tue, Mar 01, 2016 at 09:00:53AM -0500, Boris Ostrovsky wrote: >> On 02/29/2016 06:50 PM, Andy Lutomirski wrote: >> >diff --git

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-01 Thread Luis R. Rodriguez
Ingo, your feedback appreciated at the end here, regarding quirks. On Tue, Mar 01, 2016 at 09:00:53AM -0500, Boris Ostrovsky wrote: > On 02/29/2016 06:50 PM, Andy Lutomirski wrote: > >diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > >index 91ddae732a36..c6ef4da8e4f4

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-01 Thread Luis R. Rodriguez
On Mon, Feb 29, 2016 at 03:50:19PM -0800, Andy Lutomirski wrote: > x86_64 has very clean espfix handling on paravirt: espfix64 is set > up in native_iret, so paravirt systems that override iret bypass > espfix64 automatically. This is robust and straightforward. This I think I get as all the ESP

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-01 Thread Luis R. Rodriguez
On Tue, Mar 01, 2016 at 07:44:10AM -0800, Andy Lutomirski wrote: > On Tue, Mar 1, 2016 at 6:00 AM, Boris Ostrovsky > wrote: > > On 02/29/2016 06:50 PM, Andy Lutomirski wrote: > >> > >> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > >> index

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-01 Thread Andy Lutomirski
On Tue, Mar 1, 2016 at 6:00 AM, Boris Ostrovsky wrote: > On 02/29/2016 06:50 PM, Andy Lutomirski wrote: >> >> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c >> index 91ddae732a36..c6ef4da8e4f4 100644 >> --- a/arch/x86/kernel/cpu/common.c >>

Re: [Xen-devel] [PATCH v2 1/2] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

2016-03-01 Thread Boris Ostrovsky
On 02/29/2016 06:50 PM, Andy Lutomirski wrote: diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 91ddae732a36..c6ef4da8e4f4 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -979,6 +979,31 @@ static void identify_cpu(struct cpuinfo_x86