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Re: [Qemu-arm] [PATCH V1 1/1] arm64: Add an option to turn on/off host-b
From: |
Andrea Bolognani |
Subject: |
Re: [Qemu-arm] [PATCH V1 1/1] arm64: Add an option to turn on/off host-backed vPMU support |
Date: |
Mon, 15 Aug 2016 11:31:04 +0200 |
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 <address@hidden>
> ---
> 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 :)
--
Andrea Bolognani / Red Hat / Virtualization