From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39645) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bZLEq-00052d-4r for qemu-devel@nongnu.org; Mon, 15 Aug 2016 12:59:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bZLEo-0004T8-Cc for qemu-devel@nongnu.org; Mon, 15 Aug 2016 12:59:47 -0400 Message-ID: <1471280374.3003.10.camel@redhat.com> From: Andrea Bolognani Date: Mon, 15 Aug 2016 18:59:34 +0200 In-Reply-To: <20160815100938.vve6hknieytt2ys7@kamzik.localdomain> References: <1471067570-7503-1-git-send-email-wei@redhat.com> <20160815100938.vve6hknieytt2ys7@kamzik.localdomain> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH V1 1/1] arm64: Add an option to turn on/off host-backed vPMU support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Jones , Wei Huang Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org, peter.maydell@linaro.org, shannon.zhao@linaro.org On Mon, 2016-08-15 at 12:09 +0200, Andrew Jones wrote: > Hmm... so now if the user doesn't specify pmu=3Don (off by default) the= n we > silently disable it (I think that's a 2.6 compat issue), and if they do > specify pmu=3Don, but KVM doesn't support it, then it's silently disabl= ed, > which isn't nice. I think QEMU should error out in that case, explainin= g > that the user specified incompatible options, i.e. they selected accel=3D= kvm > and pmu=3Don, but their KVM version (or cpu model) doesn't support PMU > emulation. I agree. Asking qemu to provide a feature that it can't provide should definitely result in a big fat error. --=C2=A0 Andrea Bolognani / Red Hat / Virtualization