lists.openwall.net | 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
| ||
|
Date: Thu, 9 Nov 2017 17:00:30 +0100 From: Radim Krcmar <rkrcmar@...hat.com> To: Wanpeng Li <kernellwp@...il.com> Cc: Eduardo Valentin <eduval@...zon.com>, Paolo Bonzini <pbonzini@...hat.com>, Matt Wilson <msw@...zon.com>, Jonathan Corbet <corbet@....net>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>, the arch/x86 maintainers <x86@...nel.org>, Peter Zijlstra <peterz@...radead.org>, Waiman Long <longman@...hat.com>, kvm <kvm@...r.kernel.org>, linux-doc@...r.kernel.org, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "Jan H . Schoenherr" <jschoenh@...zon.de>, Anthony Liguori <aliguori@...zon.com> Subject: Re: [PATCHv3 1/1] locking/qspinlock/x86: Avoid test-and-set when PV_DEDICATED is set 2017-11-09 20:43+0800, Wanpeng Li: > 2017-11-07 4:26 GMT+08:00 Eduardo Valentin <eduval@...zon.com>: > > Currently, the existing qspinlock implementation will fallback to > > test-and-set if the hypervisor has not set the PV_UNHALT flag. > > > > This patch gives the opportunity to guest kernels to select > > between test-and-set and the regular queueu fair lock implementation > > based on the PV_DEDICATED KVM feature flag. When the PV_DEDICATED > > flag is not set, the code will still fall back to test-and-set, > > but when the PV_DEDICATED flag is set, the code will use > > the regular queue spinlock implementation. > > > > With this patch, when in autoselect mode, the guest will > > use the default spinlock implementation based on host feature > > flags as follows: > > > > PV_DEDICATED = 1, PV_UNHALT = anything: default is qspinlock > > PV_DEDICATED = 0, PV_UNHALT = 1: default is pvqspinlock > > PV_DEDICATED = 0, PV_UNHALT = 0: default is tas > > > > Cc: Paolo Bonzini <pbonzini@...hat.com> > > Cc: "Radim Krčmář" <rkrcmar@...hat.com> > > Cc: Jonathan Corbet <corbet@....net> > > Cc: Thomas Gleixner <tglx@...utronix.de> > > Cc: Ingo Molnar <mingo@...hat.com> > > Cc: "H. Peter Anvin" <hpa@...or.com> > > Cc: x86@...nel.org > > Cc: Peter Zijlstra <peterz@...radead.org> > > Cc: Waiman Long <longman@...hat.com> > > Cc: kvm@...r.kernel.org > > Cc: linux-doc@...r.kernel.org > > Cc: linux-kernel@...r.kernel.org > > Cc: Jan H. Schoenherr <jschoenh@...zon.de> > > Cc: Anthony Liguori <aliguori@...zon.com> > > Suggested-by: Matt Wilson <msw@...zon.com> > > Signed-off-by: Eduardo Valentin <eduval@...zon.com> > > --- > > You should also add a cpuid flag in kvm part. It is better without that. The flag has no dependency on KVM (kernel hypervisor) code.
Powered by blists - more mailing lists