Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-13 Thread Stefano Stabellini
On Tue, 13 Feb 2018, Julien Grall wrote: > On 02/09/2018 07:12 PM, Julien Grall wrote: > > Hi, > > > > On 02/09/2018 07:10 PM, Stefano Stabellini wrote: > > > On Fri, 9 Feb 2018, Julien Grall wrote: > > > > On 02/09/2018 07:02 PM, Stefano Stabellini wrote: > > > > > On Fri, 9 Feb 2018, Julien

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-13 Thread Julien Grall
On 02/09/2018 07:12 PM, Julien Grall wrote: Hi, On 02/09/2018 07:10 PM, Stefano Stabellini wrote: On Fri, 9 Feb 2018, Julien Grall wrote: On 02/09/2018 07:02 PM, Stefano Stabellini wrote: On Fri, 9 Feb 2018, Julien Grall wrote: Hi, On 02/08/2018 11:49 PM, Stefano Stabellini wrote: On

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-09 Thread Julien Grall
Hi, On 02/09/2018 07:10 PM, Stefano Stabellini wrote: On Fri, 9 Feb 2018, Julien Grall wrote: On 02/09/2018 07:02 PM, Stefano Stabellini wrote: On Fri, 9 Feb 2018, Julien Grall wrote: Hi, On 02/08/2018 11:49 PM, Stefano Stabellini wrote: On Thu, 1 Feb 2018, Julien Grall wrote: On 1

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-09 Thread Stefano Stabellini
On Fri, 9 Feb 2018, Julien Grall wrote: > On 02/09/2018 07:02 PM, Stefano Stabellini wrote: > > On Fri, 9 Feb 2018, Julien Grall wrote: > > > Hi, > > > > > > On 02/08/2018 11:49 PM, Stefano Stabellini wrote: > > > > On Thu, 1 Feb 2018, Julien Grall wrote: > > > > > On 1 February 2018 at 19:37,

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-09 Thread Julien Grall
On 02/09/2018 07:02 PM, Stefano Stabellini wrote: On Fri, 9 Feb 2018, Julien Grall wrote: Hi, On 02/08/2018 11:49 PM, Stefano Stabellini wrote: On Thu, 1 Feb 2018, Julien Grall wrote: On 1 February 2018 at 19:37, Stefano Stabellini wrote: On Tue, 30 Jan 2018,

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-09 Thread Stefano Stabellini
On Fri, 9 Feb 2018, Julien Grall wrote: > Hi, > > On 02/08/2018 11:49 PM, Stefano Stabellini wrote: > > On Thu, 1 Feb 2018, Julien Grall wrote: > > > On 1 February 2018 at 19:37, Stefano Stabellini > > > wrote: > > > > On Tue, 30 Jan 2018, Julien Grall wrote: > > > > >

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-01 Thread Julien Grall
On 1 February 2018 at 19:37, Stefano Stabellini wrote: > On Tue, 30 Jan 2018, Julien Grall wrote: >> Xen does not properly support big.LITTLE platform. All vCPUs of a guest >> will always have the MIDR of the boot CPU (see arch_domain_create). >> At best the guest may see

Re: [Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-01 Thread Stefano Stabellini
On Tue, 30 Jan 2018, Julien Grall wrote: > Xen does not properly support big.LITTLE platform. All vCPUs of a guest > will always have the MIDR of the boot CPU (see arch_domain_create). > At best the guest may see unreliable performance (vCPU switching between > big and LITTLE), at worst the guest

[Xen-devel] [PATCH] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-01-30 Thread Julien Grall
Xen does not properly support big.LITTLE platform. All vCPUs of a guest will always have the MIDR of the boot CPU (see arch_domain_create). At best the guest may see unreliable performance (vCPU switching between big and LITTLE), at worst the guest will become unreliable or insecure. This is