On 06/11/18 07:53, Christoffer Dall wrote:
> On Mon, Nov 05, 2018 at 02:36:14PM +0000, Marc Zyngier wrote:
>> Some implementations may be forced to use VHE to work around HW
>> errata, for example. Let's introduce a helper that checks for
>> these cases.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>> ---
>> arch/arm/include/asm/kvm_host.h | 1 +
>> arch/arm64/include/asm/kvm_host.h | 6 ++++++
>> virt/kvm/arm/arm.c | 5 +++++
>> 3 files changed, 12 insertions(+)
>>
>> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
>> index c3469729f40c..0f2f782548cb 100644
>> --- a/arch/arm/include/asm/kvm_host.h
>> +++ b/arch/arm/include/asm/kvm_host.h
>> @@ -286,6 +286,7 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
>> struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
>>
>> static inline bool kvm_arch_sve_requires_vhe(void) { return false; }
>> +static inline bool kvm_arch_impl_requires_vhe(void) { return false; }
>> static inline void kvm_arch_hardware_unsetup(void) {}
>> static inline void kvm_arch_sync_events(struct kvm *kvm) {}
>> static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
>> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
>> index ca1714148400..7d6e974d024a 100644
>> --- a/arch/arm64/include/asm/kvm_host.h
>> +++ b/arch/arm64/include/asm/kvm_host.h
>> @@ -432,6 +432,12 @@ static inline bool kvm_arch_sve_requires_vhe(void)
>> return system_supports_sve();
>> }
>>
>> +static inline bool kvm_arch_impl_requires_vhe(void)
>> +{
>> + /* Some implementations have defects that confine them to VHE */
>> + return false;
>> +}
>> +
>> static inline void kvm_arch_hardware_unsetup(void) {}
>> static inline void kvm_arch_sync_events(struct kvm *kvm) {}
>> static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
>> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
>> index 66de2efddfca..bc90a1cdd27f 100644
>> --- a/virt/kvm/arm/arm.c
>> +++ b/virt/kvm/arm/arm.c
>> @@ -1647,6 +1647,11 @@ int kvm_arch_init(void *opaque)
>> kvm_pr_unimpl("SVE system without VHE unsupported. Broken cpu?");
>> return -ENODEV;
>> }
>> +
>> + if (kvm_arch_impl_requires_vhe()) {
>> + kvm_pr_unimpl("CPU requiring VHE in non-VHE mode");
>> + return -ENODEV;
>> + }
>
> So as per my previous comment, I'd prefer this function to only issue a
> single call, and have the function in kvm_host.h check for all the
> conditions, do the printing, etc.
>
> Thoughts?
Indeed, this seems a sensible alternative.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
