From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58796) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bZKVf-00019m-MX for qemu-devel@nongnu.org; Mon, 15 Aug 2016 12:13:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bZKVd-0004Ji-L6 for qemu-devel@nongnu.org; Mon, 15 Aug 2016 12:13:06 -0400 References: <1471067570-7503-1-git-send-email-wei@redhat.com> <1471253464.3003.5.camel@redhat.com> From: Wei Huang Message-ID: <57B1EA05.2050908@redhat.com> Date: Mon, 15 Aug 2016 11:12:53 -0500 MIME-Version: 1.0 In-Reply-To: <1471253464.3003.5.camel@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit 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: Andrea Bolognani , qemu-arm@nongnu.org Cc: peter.maydell@linaro.org, drjones@redhat.com, shannon.zhao@linaro.org, qemu-devel@nongnu.org On 8/15/16 04:31, Andrea Bolognani wrote: > > On Sat, 2016-08-13 at 00:52 -0500, Wei Huang wrote: >> This patch adds a pmu=[on/off] option to enable/disable host vPMU >> support in guest VM. There are several reasons to justify this option. >> First, host-backed vPMU can be problematic for cross-migration between >> different SoC as perf counters are architecture-dependent. It is more >> flexible to have an option to turn it on/off. Secondly this option >> matches the "pmu" option as supported in libvirt tool. >> >> Note that, like "has_el3", the "pmu" option is only made available on >> CPUs that support host-backed vPMU. They include: >> * cortex-a53 + kvm >> * cortex-a57 + kvm >> * host + kvm >> This option is removed in other configs where it doesn't make sense >> (e.g. cortex-a57 + TCG); and the default pmu support is off. This patch >> has been tested under both DT/ACPI modes. >> >> Signed-off-by: Wei Huang >> --- >> hw/arm/virt-acpi-build.c | 2 +- >> hw/arm/virt.c | 2 +- >> target-arm/cpu.c | 13 +++++++++++++ >> target-arm/cpu.h | 3 ++- >> target-arm/cpu64.c | 6 ++++++ >> target-arm/kvm64.c | 10 +++++----- >> 6 files changed, 28 insertions(+), 8 deletions(-) > > Did you already try driving this with libvirt? It should work > out of the box. > > If you haven't, I will do it :) No, I haven't. All tests were done based on command line to QEMU. :-) -Wei > > -- > Andrea Bolognani / Red Hat / Virtualization >