From: Pavel Fedin <p.fedin@samsung.com>
To: 'Paolo Bonzini' <pbonzini@redhat.com>,
'Peter Maydell' <peter.maydell@linaro.org>
Cc: kvmarm@lists.cs.columbia.edu, 'kvm-devel' <kvm@vger.kernel.org>,
'Marc Zyngier' <marc.zyngier@arm.com>
Subject: RE: [RFC] Handling CP15 timer without in-kernel irqchip
Date: Fri, 02 Oct 2015 13:22:54 +0300 [thread overview]
Message-ID: <00cd01d0fcfc$4de250e0$e9a6f2a0$@samsung.com> (raw)
In-Reply-To: <560E59FA.9070205@redhat.com>
Hello!
> I mean in the device tree. Does the boot loader realize it's under a
> hypervisor, and provide different device trees to the kernel?
This has nothing to do with the device tree. Device tree is static. The logic sits inside Linux kernel itself:
a) If we are running in HYP mode (we are host) - use physical timer
b) If there's no virtual timer IRQ specified - use physical timer
c) Otherwise - use virtual vimer.
On systems without virtualization support virtual timer is simply aliased to physical timer, this is architectural requirement. Therefore this logic just works everywhere.
Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia
next prev parent reply other threads:[~2015-10-02 10:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-02 7:28 [RFC] Handling CP15 timer without in-kernel irqchip Pavel Fedin
2015-10-02 9:30 ` Paolo Bonzini
2015-10-02 9:41 ` Pavel Fedin
2015-10-02 9:58 ` Peter Maydell
2015-10-02 10:05 ` Paolo Bonzini
2015-10-02 10:16 ` Peter Maydell
2015-10-02 10:18 ` Paolo Bonzini
2015-10-02 10:22 ` Pavel Fedin [this message]
2015-10-02 10:23 ` Peter Maydell
2015-10-02 10:18 ` Pavel Fedin
2015-10-02 10:22 ` Marc Zyngier
2015-10-02 10:22 ` Marc Zyngier
2015-10-02 10:33 ` Pavel Fedin
2015-10-02 14:54 ` Pavel Fedin
2015-10-02 20:26 ` Christoffer Dall
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