Re: [PATCH 28/59] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting

Julien Thierry
2019-06-26T07:23:15Z

On 06/21/2019 10:38 AM, Marc Zyngier wrote:
> From: Jintack Lim <jintack@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@cs.columbia.edu>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> arch/arm64/include/asm/kvm_arm.h | 1 +
> arch/arm64/kvm/sys_regs.c | 19 +++++++++++++++++--
> 2 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
> index d21486274eeb..55f4525c112c 100644
> --- a/arch/arm64/include/asm/kvm_arm.h
> +++ b/arch/arm64/include/asm/kvm_arm.h
> @@ -24,6 +24,7 @@
>
> /* Hyp Configuration Register (HCR) bits */
> #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 0f74b9277a86..beadebcfc888 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -473,8 +473,10 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
> if (el12_reg(p) && forward_nv_traps(vcpu))
> return false;
>
> - if (!el12_reg(p) && forward_vm_traps(vcpu, p))
> - return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu));
> + if (!el12_reg(p) && forward_vm_traps(vcpu, p)) {
> + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu));
> + return false;

I feel like this change is actually intended to be part of the previous
patch.

Cheers,

Julien