[PATCH v4 04/46] KVM: PPC: Book3S HV: Prevent radix guests from setting LPCR[TC]

[Alexey Kardashevskiy]

On 23/03/2021 12:02, Nicholas Piggin wrote:
> This bit only applies to hash partitions.
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>



Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>

> ---
>   arch/powerpc/kvm/book3s_hv.c        | 6 ++++++
>   arch/powerpc/kvm/book3s_hv_nested.c | 3 +--
>   2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index c5de7e3f22b6..1ffb0902e779 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1645,6 +1645,12 @@ static int kvm_arch_vcpu_ioctl_set_sregs_hv(struct kvm_vcpu *vcpu,
>    */
>   unsigned long kvmppc_filter_lpcr_hv(struct kvmppc_vcore *vc, unsigned long lpcr)
>   {
> +	struct kvm *kvm = vc->kvm;
> +
> +	/* LPCR_TC only applies to HPT guests */
> +	if (kvm_is_radix(kvm))
> +		lpcr &= ~LPCR_TC;
> +
>   	/* On POWER8 and above, userspace can modify AIL */
>   	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
>   		lpcr &= ~LPCR_AIL;
> diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
> index f7b441b3eb17..851e3f527eb2 100644
> --- a/arch/powerpc/kvm/book3s_hv_nested.c
> +++ b/arch/powerpc/kvm/book3s_hv_nested.c
> @@ -140,8 +140,7 @@ static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
>   	/*
>   	 * Don't let L1 change LPCR bits for the L2 except these:
>   	 */
> -	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
> -		LPCR_LPES | LPCR_MER;
> +	mask = LPCR_DPFD | LPCR_ILE | LPCR_AIL | LPCR_LD | LPCR_LPES | LPCR_MER;
>   	hr->lpcr = kvmppc_filter_lpcr_hv(vc,
>   			(vc->lpcr & ~mask) | (hr->lpcr & mask));
>   
> 

-- 
Alexey