linux-kernel - Re: [RFC PATCH v1 1/5] KVM Guest: Add VCPU running/pre-empted state for guest

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 linux-cve-announce 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]

Message-ID: <4F9F367F.8090603@linux.vnet.ibm.com>
Date:	Tue, 01 May 2012 06:33:59 +0530
From:	Raghavendra K T <raghavendra.kt@...ux.vnet.ibm.com>
To:	"Nikunj A. Dadhania" <nikunj@...ux.vnet.ibm.com>
CC:	peterz@...radead.org, mingo@...e.hu, jeremy@...p.org,
	mtosatti@...hat.com, kvm@...r.kernel.org, x86@...nel.org,
	vatsa@...ux.vnet.ibm.com, linux-kernel@...r.kernel.org,
	avi@...hat.com, hpa@...or.com
Subject: Re: [RFC PATCH v1 1/5] KVM Guest: Add VCPU running/pre-empted state
 for guest

On 04/27/2012 09:53 PM, Nikunj A. Dadhania wrote:
> The patch adds guest code for msr between guest and hypervisor. The
> msr will export the vcpu running/pre-empted information to the guest
> from host. This will enable guest to intelligently send ipi to running
> vcpus and set flag for pre-empted vcpus. This will prevent waiting for
> vcpus that are not running.
>
> Suggested-by: Peter Zijlstra<a.p.zijlstra@...llo.nl>
> Signed-off-by: Nikunj A. Dadhania<nikunj@...ux.vnet.ibm.com>
> ---
>   arch/x86/include/asm/kvm_para.h |   10 ++++++++++
>   arch/x86/kernel/kvm.c           |   33 +++++++++++++++++++++++++++++++++
>   2 files changed, 43 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
> index 77266d3..f57b5cc 100644
> --- a/arch/x86/include/asm/kvm_para.h
> +++ b/arch/x86/include/asm/kvm_para.h
> @@ -24,6 +24,7 @@
>   #define KVM_FEATURE_ASYNC_PF		4
>   #define KVM_FEATURE_STEAL_TIME		5
>   #define KVM_FEATURE_PV_UNHALT		6
> +#define KVM_FEATURE_VCPU_STATE          7

I think you intended to use KVM_FEATURE_VCPU_STATE to address
guest/host compatibility issue so that host/guest does not break
when one of them run older kernel?

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/