[PATCH v4 01/66] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature

[Marc Zyngier]

On Thu, 20 May 2021 14:32:17 +0100,
Zenghui Yu <yuzenghui at huawei.com> wrote:
> 
> On 2021/5/11 0:58, Marc Zyngier wrote:
> > From: Jintack Lim <jintack.lim at linaro.org>
> > 
> > Add a new ARM64_HAS_NESTED_VIRT feature to indicate that the
> > CPU has the ARMv8.3 nested virtualization capability.
> > 
> > This will be used to support nested virtualization in KVM.
> > 
> > Signed-off-by: Jintack Lim <jintack.lim at linaro.org>
> > Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> > Signed-off-by: Christoffer Dall <christoffer.dall at arm.com>
> > Signed-off-by: Marc Zyngier <maz at kernel.org>
> > ---
> >  .../admin-guide/kernel-parameters.txt         |  4 +++
> >  arch/arm64/include/asm/cpucaps.h              |  1 +
> >  arch/arm64/kernel/cpufeature.c                | 25 +++++++++++++++++++
> >  3 files changed, 30 insertions(+)
> 
> [...]
> 
> > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> > index efed2830d141..056de86d7f6f 100644
> > --- a/arch/arm64/kernel/cpufeature.c
> > +++ b/arch/arm64/kernel/cpufeature.c
> > @@ -1645,6 +1645,21 @@ static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
> >  		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
> >  }
> >  +static bool nested_param;
> > +static bool has_nested_virt_support(const struct arm64_cpu_capabilities *cap,
> > +				    int scope)
> > +{
> > +	return has_cpuid_feature(cap, scope) &&
> > +		nested_param;
> > +}
> 
> Nitpick:
> 
> How about putting them into a single line (they still perfectly
> fit within the 80-colume limit)?

Fair enough.

	M.

-- 
Without deviation from the norm, progress is not possible.