lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 23 Jan 2017 12:18:07 -0800 (PST)
From:   Shivappa Vikas <>
To:     Thomas Gleixner <>
cc:     Vikas Shivappa <>,,,,,,,,,,
Subject: Re: [PATCH 8/8] x86/intel_rdt: rmdir,umount and hotcpu updates for

On Mon, 16 Jan 2017, Thomas Gleixner wrote:

> On Tue, 10 Jan 2017, Vikas Shivappa wrote:
>> During rmdir only reset the ctrl values for the rdtgroup's closid. This
>> is done so that that next time when the closid is reused they dont
>> reflect old values.
> How on earth is that related to MBA?

This is not specific to MBA so i put it as x86/intel_rdt in the subject but will 
send this as part of seperate series which you mentioned.

>> Remove the closid update during cpuonline in cqm as its
>> already in the CAT code. Since both cqm and CAT want the rmid and closid
>> to be zero when cpu is online, remove the PQR MSR write to zero during
>> cpuonline because the MSRs are at zero after cpu reset and also during
> Are you sure that the MSRs are zero when the cpu goes offline and then
> online again? That's not a reset.

Thats right - I was removing this since at the first sched_in the new CLOSID 
would be updated anyways. I know this prevents from having a 0 CLOSid at the 
time all the hot plug code is run, but we already have run the __cpu_disable and 
all the hotplug code when going down on the last used CLOSid. (if the kernel 
thread that handles the offline/online should have a 0 CLOS then thats fine 
So may be the right way is to actually zero the CLOS in PQR_MSR when we are 
going down/offline ?


> Thanks,
> 	tglx

Powered by blists - more mailing lists