[PATCH v4 0/2] arch_timers patches to enable KVM support
marc.zyngier at arm.com
Tue Sep 4 13:38:47 EDT 2012
This series is aimed at offering the minimum level of support that KVM
needs when it comes to architected timers.
The first patch changes the driver to use the virtual timer by default
instead of the physical one (access to the later is conditioned by the
hypervisor settings, while the former is always available). This could
be required even if the kernel is not running as a guest.
The second patch exposes a clockcycle counter that can be used by
Tested on A15 (VE+TC2), both as a host and a KVM guest. Patches
* From v3:
- Use %Q/%R qualifiers to read 64bit registers, and move accessors
into a separate function.
- Some minor cleanup.
* From v2:
- Trick the compiler into generating really nice code, at the expense
of a certain lack of abstraction
- Don't mandate physical timer non-secure PPI, in order to stay
compatible with existing and possibly incomplete DTs.
Marc Zyngier (2):
ARM: arch_timers: enable the use of the virtual timer
ARM: arch_timers: register a time/cycle counter
arch/arm/include/asm/arch_timer.h | 7 +
arch/arm/kernel/arch_timer.c | 368 +++++++++++++++++++++++++++-----------
2 files changed, 273 insertions(+), 102 deletions(-)
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