Re: [PATCH v7 21/27] KVM: arm/arm64: Add hook for arch-specific KVM initialisation

Dave Martin
2019-04-04T14:54:06Z

On Thu, Apr 04, 2019 at 04:25:28PM +0200, Andrew Jones wrote:
> On Fri, Mar 29, 2019 at 01:00:46PM +0000, Dave Martin wrote:
> > This patch adds a kvm_arm_init_arch_resources() hook to perform
> > subarch-specific initialisation when starting up KVM.
> >
> > This will be used in a subsequent patch for global SVE-related
> > setup on arm64.
> >
> > No functional change.
> >
> > Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> > Reviewed-by: Julien Thierry <julien.thierry@arm.com>
> > Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
> > ---
> > arch/arm/include/asm/kvm_host.h | 2 ++
> > arch/arm64/include/asm/kvm_host.h | 2 ++
> > virt/kvm/arm/arm.c | 4 ++++
> > 3 files changed, 8 insertions(+)
> >
> > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> > index 770d732..a49ee01 100644
> > --- a/arch/arm/include/asm/kvm_host.h
> > +++ b/arch/arm/include/asm/kvm_host.h
> > @@ -53,6 +53,8 @@
> >
> > DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
> >
> > +static inline int kvm_arm_init_arch_resources(void) { return 0; }
> > +
> > u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
> > int __attribute_const__ kvm_target_cpu(void);
> > int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
> > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> > index 205438a..3e89509 100644
> > --- a/arch/arm64/include/asm/kvm_host.h
> > +++ b/arch/arm64/include/asm/kvm_host.h
> > @@ -58,6 +58,8 @@
> >
> > DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
> >
> > +static inline int kvm_arm_init_arch_resources(void) { return 0; }
> > +
> > int __attribute_const__ kvm_target_cpu(void);
> > int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
> > int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext);
> > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> > index 99c3738..c69e137 100644
> > --- a/virt/kvm/arm/arm.c
> > +++ b/virt/kvm/arm/arm.c
> > @@ -1664,6 +1664,10 @@ int kvm_arch_init(void *opaque)
> > if (err)
> > return err;
> >
> > + err = kvm_arm_init_arch_resources();
> > + if (err)
> > + return err;
> > +
> > if (!in_hyp_mode) {
> > err = init_hyp_mode();
> > if (err)
> > --
> > 2.1.4
> >
>
> It's not clear to me from the commit message why init_common_resources()
> won't work for this. Maybe it'll be more clear as I continue the review.

init_common_resources() is for stuff common to arm and arm64.

kvm_arm_init_arch_resources() is intended for stuff specific to the
particular arch backend.

Maybe there is a better name for this.

Cheers
---Dave