[PATCH v5 31/69] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting

[Marc Zyngier]

On Mon, 20 Dec 2021 07:18:51 +0000,
Ganapatrao Kulkarni <gankulkarni at os.amperecomputing.com> wrote:
> 
> 
> 
> On 30-11-2021 01:31 am, Marc Zyngier wrote:
> > From: Jintack Lim <jintack at cs.columbia.edu>
> > 
> > Forward ELR_EL1, SPSR_EL1 and VBAR_EL1 traps to the virtual EL2 if the
> > virtual HCR_EL2.NV bit is set.
> > 
> > This is for recursive nested virtualization.
> > 
> > Signed-off-by: Jintack Lim <jintack at cs.columbia.edu>
> > Signed-off-by: Marc Zyngier <maz at kernel.org>
> > ---
> >   arch/arm64/include/asm/kvm_arm.h |  1 +
> >   arch/arm64/kvm/sys_regs.c        | 28 +++++++++++++++++++++++++++-
> >   2 files changed, 28 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
> > index 9759bc893a51..68af5509e4b0 100644
> > --- a/arch/arm64/include/asm/kvm_arm.h
> > +++ b/arch/arm64/include/asm/kvm_arm.h
> > @@ -20,6 +20,7 @@
> >   #define HCR_AMVOFFEN	(UL(1) << 51)
> >   #define HCR_FIEN	(UL(1) << 47)
> >   #define HCR_FWB		(UL(1) << 46)
> > +#define HCR_NV1		(UL(1) << 43)
> >   #define HCR_NV		(UL(1) << 42)
> >   #define HCR_API		(UL(1) << 41)
> >   #define HCR_APK		(UL(1) << 40)
> > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> > index e96877fc3b2a..511e06b6f603 100644
> > --- a/arch/arm64/kvm/sys_regs.c
> > +++ b/arch/arm64/kvm/sys_regs.c
> > @@ -288,6 +288,22 @@ static bool access_rw(struct kvm_vcpu *vcpu,
> >   	return true;
> >   }
> >   +/* This function is to support the recursive nested
> > virtualization */
> > +static bool forward_nv1_traps(struct kvm_vcpu *vcpu, struct sys_reg_params *p)
> > +{
> > +	return forward_traps(vcpu, HCR_NV1);
> > +}
> > +
> 
> Shall we move this helper to emulate-nested.c?

Sure, that shouldn't be a problem.

	M.

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