Re: [Xen-devel] [PATCH v2] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-15 Thread Julien Grall
Hi Jan, On 15/02/18 09:03, Jan Beulich wrote: On 14.02.18 at 15:17, wrote: --- a/docs/misc/xen-command-line.markdown +++ b/docs/misc/xen-command-line.markdown @@ -1000,6 +1000,16 @@ supported only when compiled with XSM on x86. Control Xens use of the APEI Hardware Error Source Table, sho

Re: [Xen-devel] [PATCH v2] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-15 Thread Jan Beulich
>>> On 14.02.18 at 15:17, wrote: > --- a/docs/misc/xen-command-line.markdown > +++ b/docs/misc/xen-command-line.markdown > @@ -1000,6 +1000,16 @@ supported only when compiled with XSM on x86. > > Control Xens use of the APEI Hardware Error Source Table, should one be > found. > > +### hmp_un

Re: [Xen-devel] [PATCH v2] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-14 Thread Oleksandr Tyshchenko
Hi On Wed, Feb 14, 2018 at 4:47 PM, Oleksandr Tyshchenko wrote: > Hi, Julien. > > On Wed, Feb 14, 2018 at 4:17 PM, 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

Re: [Xen-devel] [PATCH v2] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-14 Thread Oleksandr Tyshchenko
Hi, Julien. On Wed, Feb 14, 2018 at 4:17 PM, 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 LIT

[Xen-devel] [PATCH v2] xen/arm: Park CPUs with a MIDR different from the boot CPU.

2018-02-14 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 becom