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  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, 6 Sep 2010 10:59:03 +0200
From:	Alexander Graf <>
To:	Avi Kivity <>
Cc:	Xiao Guangrong <>,
	Marcelo Tosatti <>,
	LKML <>, KVM <>
Subject: Re: [PATCH] KVM: don't sent IPI if the vcpu is not online

On 06.09.2010, at 10:55, Avi Kivity wrote:

> On 09/06/2010 11:51 AM, Alexander Graf wrote:
>>> I think guest_mode makes sense for the other archs for reducing IPIs, so let's leave it common and recommend that they implement it.  Alex, if you're ever bored.
>> What does the bit do? Do we have documentation on it ;)? No seriously, what's the intent of the field?
> It indicates that the vcpu is currently executing guest code.  Which in turn is important if you need to force it out of guest mode in order to inject an interrupt or flush the tlb.

Well, a vcpu is either offline in halt state or in guest mode, no? So we can conclude that guest_mode == !offline && !halt_state.

When in halt state, we are active on the wakeup waitqueue:

static void kvmppc_decrementer_func(unsigned long data)
        struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;


        if (waitqueue_active(&vcpu->wq)) {

Shouldn't that be enough information already?


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists