From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] kvm-all.c: Move init of irqchip_inject_ioctl out of kvm_irqchip_create() Date: Tue, 14 Aug 2012 13:05:11 +0200 Message-ID: <502A30E7.9090504@siemens.com> References: <1344272705-17825-1-git-send-email-peter.maydell@linaro.org> <5029FF4B.8040001@web.de> <502A2FFA.1080604@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Peter Maydell , Marcelo Tosatti , qemu-devel@nongnu.org, kvm@vger.kernel.org, patches@linaro.org To: Avi Kivity Return-path: In-Reply-To: <502A2FFA.1080604@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On 2012-08-14 13:01, Avi Kivity wrote: > On 08/14/2012 10:33 AM, Jan Kiszka wrote: >> >> KVM_IRQ_LINE is old-style, deprecated, KVM_IRQ_LINE_STATUS (i.e >> injection with feedback to allow lost-tick compensation) is the current >> standard that other archs should pick up. > > KVM_IRQ_LINE_STATUS may not make sense on all architectures. > > I don't think we're really deprecating KVM_IRQ_LINE or discouraging its > use. It's not like the kernel-allocated memory slot ioctls. I do not think it makes sense to provide both interfaces long term (provided we ever do a cut). Also, it's almost trivial to provide the add-on feature of KVM_IRQ_LINE_STATUS, and it keeps the door open for IRQ decoalescing. If there is no way for an arch to detect coalescing, it can still return >0 unconditionally. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux