From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: [PATCH RFC 0/4] Paravirt-spinlock implementation for KVM guests
 (Version 0)
Date: Wed, 28 Jul 2010 18:10:59 -0400
Message-ID: <20100728221059.GA32739@phenom.dumpdata.com>
References: <20100726061150.GB21699@linux.vnet.ibm.com>
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Cc: avi@redhat.com, Marcelo Tosatti <mtosatti@redhat.com>,
	Gleb Natapov <gleb@redhat.com>, linux-kernel@vger.kernel.org,
	npiggin@suse.de, Jeremy Fitzhardinge <jeremy@goop.org>,
	kvm@vger.kernel.org, bharata@in.ibm.com,
	Balbir Singh <balbir@in.ibm.com>,
	Jan Beulich <JBeulich@novell.com>
To: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
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On Mon, Jul 26, 2010 at 11:41:50AM +0530, Srivatsa Vaddagiri wrote:
> This patch-series implements paravirt-spinlock implementation for KVM guests,
> based heavily on Xen's implementation. I tried to refactor Xen's spinlock
> implementation to make it common for both Xen and KVM - but found that 
> few differences between Xen and KVM (Xen has the ability to block on a
> particular event/irq for example) _and_ the fact that the guest kernel 
> can be compiled to support both Xen and KVM hypervisors (CONFIG_XEN and
> CONFIG_KVM_GUEST can both be turned on) makes the "common" code a eye-sore.
> There will have to be:
> 
> 	if (xen) {
> 		...
> 	} else if (kvm) {
> 		..
> 	}
> 
> or possibly:
> 
> 	alternative(NOP, some_xen_specific_call, ....)

Why not utilize the pvops path?