Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-06-06 Thread Julien Grall
Hi Konrad, On 06/06/16 15:17, Konrad Rzeszutek Wilk wrote: On Thu, Jun 02, 2016 at 04:14:04PM +0100, Julien Grall wrote: On 02/06/16 16:04, Julien Grall wrote: Hi Konrad, On 02/06/16 15:46, Konrad Rzeszutek Wilk wrote: On Tue, May 31, 2016 at 11:24:10AM +0100, Julien Grall wrote: On 31/05

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-06-06 Thread Konrad Rzeszutek Wilk
On Thu, Jun 02, 2016 at 04:14:04PM +0100, Julien Grall wrote: > > > On 02/06/16 16:04, Julien Grall wrote: > >Hi Konrad, > > > >On 02/06/16 15:46, Konrad Rzeszutek Wilk wrote: > >>On Tue, May 31, 2016 at 11:24:10AM +0100, Julien Grall wrote: > >>>On 31/05/16 10:21, Stefano Stabellini wrote: > >>>

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-06-02 Thread Julien Grall
On 02/06/16 16:04, Julien Grall wrote: Hi Konrad, On 02/06/16 15:46, Konrad Rzeszutek Wilk wrote: On Tue, May 31, 2016 at 11:24:10AM +0100, Julien Grall wrote: On 31/05/16 10:21, Stefano Stabellini wrote: On Mon, 30 May 2016, Julien Grall wrote: By spinning in __apply_alternatives_multi_st

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-06-02 Thread Julien Grall
Hi Konrad, On 02/06/16 15:46, Konrad Rzeszutek Wilk wrote: On Tue, May 31, 2016 at 11:24:10AM +0100, Julien Grall wrote: On 31/05/16 10:21, Stefano Stabellini wrote: On Mon, 30 May 2016, Julien Grall wrote: By spinning in __apply_alternatives_multi_stop we protect us against modification in t

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-06-02 Thread Konrad Rzeszutek Wilk
On Tue, May 31, 2016 at 11:24:10AM +0100, Julien Grall wrote: > Hi Stefano, > > On 31/05/16 10:21, Stefano Stabellini wrote: > >On Mon, 30 May 2016, Julien Grall wrote: > >>Hi Stefano, > >> > >>On 30/05/2016 15:45, Stefano Stabellini wrote: > >>>On Mon, 23 May 2016, Julien Grall wrote: > Hi St

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-31 Thread Julien Grall
Hi Stefano, On 31/05/16 10:21, Stefano Stabellini wrote: On Mon, 30 May 2016, Julien Grall wrote: Hi Stefano, On 30/05/2016 15:45, Stefano Stabellini wrote: On Mon, 23 May 2016, Julien Grall wrote: Hi Stefano, On 21/05/16 16:09, Stefano Stabellini wrote: On Thu, 5 May 2016, Julien Grall wr

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-31 Thread Stefano Stabellini
On Mon, 30 May 2016, Julien Grall wrote: > Hi Stefano, > > On 30/05/2016 15:45, Stefano Stabellini wrote: > > On Mon, 23 May 2016, Julien Grall wrote: > > > Hi Stefano, > > > > > > On 21/05/16 16:09, Stefano Stabellini wrote: > > > > On Thu, 5 May 2016, Julien Grall wrote: > > > > > +void __init

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-30 Thread Julien Grall
Hi Stefano, On 30/05/2016 15:45, Stefano Stabellini wrote: On Mon, 23 May 2016, Julien Grall wrote: Hi Stefano, On 21/05/16 16:09, Stefano Stabellini wrote: On Thu, 5 May 2016, Julien Grall wrote: +void __init apply_alternatives_all(void) +{ +int ret; + + /* better not try code pat

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-30 Thread Stefano Stabellini
On Mon, 23 May 2016, Julien Grall wrote: > Hi Stefano, > > On 21/05/16 16:09, Stefano Stabellini wrote: > > On Thu, 5 May 2016, Julien Grall wrote: > > > +void __init apply_alternatives_all(void) > > > +{ > > > +int ret; > > > + > > > + /* better not try code patching on a live SMP system */ >

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-23 Thread Julien Grall
Hi Stefano, On 21/05/16 16:09, Stefano Stabellini wrote: On Thu, 5 May 2016, Julien Grall wrote: +void __init apply_alternatives_all(void) +{ +int ret; + + /* better not try code patching on a live SMP system */ +ret = stop_machine_run(__apply_alternatives_multi_stop, NULL, NR_CPU

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-21 Thread Stefano Stabellini
On Thu, 5 May 2016, Julien Grall wrote: > Some of the processor erratum will require to modify code sequence. > As those modifications may impact the performance, they should only > be enabled on affected cores. Furthermore, Xen may also want to take > advantage of new hardware features coming up w

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-14 Thread Julien Grall
Hi Konrad, On 13/05/2016 21:26, Konrad Rzeszutek Wilk wrote: On Thu, May 05, 2016 at 05:34:19PM +0100, Julien Grall wrote: Some of the processor erratum will require to modify code sequence. As those modifications may impact the performance, they should only be enabled on affected cores. Furthe

Re: [Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-13 Thread Konrad Rzeszutek Wilk
On Thu, May 05, 2016 at 05:34:19PM +0100, Julien Grall wrote: > Some of the processor erratum will require to modify code sequence. > As those modifications may impact the performance, they should only > be enabled on affected cores. Furthermore, Xen may also want to take > advantage of new hardwar

[Xen-devel] [RFC 10/16] xen/arm: Introduce alternative runtime patching

2016-05-05 Thread Julien Grall
Some of the processor erratum will require to modify code sequence. As those modifications may impact the performance, they should only be enabled on affected cores. Furthermore, Xen may also want to take advantage of new hardware features coming up with v8.1 and v8.2. This patch adds an infrastru