From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33705) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bz5Kl-000595-9h for qemu-devel@nongnu.org; Tue, 25 Oct 2016 13:16:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bz5Kk-0004qt-Dq for qemu-devel@nongnu.org; Tue, 25 Oct 2016 13:16:19 -0400 References: <1477086782-10479-1-git-send-email-wei@redhat.com> <20161024084920.5qrrwa3wfdyr5kn5@hawk.localdomain> <155d69d3-c8fb-4ff1-7de9-ca72d4086ccb@redhat.com> <20161025073327.kbbabkrdsgfuypzt@kamzik.brq.redhat.com> From: Wei Huang Message-ID: Date: Tue, 25 Oct 2016 12:16:11 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V7 0/2] Add option to configure guest vPMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Andrew Jones Cc: qemu-arm , Shannon Zhao , Andrea Bolognani , QEMU Developers On 10/25/2016 10:59 AM, Peter Maydell wrote: > On 25 October 2016 at 16:26, Peter Maydell wrote: >> On 25 October 2016 at 08:33, Andrew Jones wrote: >>> Yes, I prefer it to not being able to easily switch a command line from >>> KVM to TCG. Granted, right now we mostly need to run with -cpu host for >>> KVM, which also needs to be switched for TCG. However that will hopefully >>> change with Shannon's work. >> >> If the TCG default is different from the KVM default then you >> will have problems with switching it anyway, because it will >> silently change behaviour underfoot. I think we should avoid that... > > So here's my suggestion: we should just not worry about printing > a warning for not actually honouring the "please give me a PMU" > flag under TCG. At some point we'll actually implement it, > at which point the problem goes away. In the meantime (a) not > providing a PMU and not bothering to say so is what we were > doing before, and (b) there's lots of bits of the CPU that we > don't actually yet implement in TCG but which will appear as > we fix bugs in the emulation. This is easy to implement. If Drew is OK with silence under TCG mode, I will send V8 out. > > thanks > -- PMM >