On 19.04.2018 23:13, Tony Krowiak wrote:
> Introduces a new function to reset the crypto attributes for all
> vcpus whether they are running or not. Each vcpu in KVM will
> be removed from SIE prior to resetting the crypto attributes in its
> SIE state description. After all vcpus have had their crypto attributes
> reset the vcpus will be restored to SIE.
>
> This function is incorporated into the kvm_s390_vm_set_crypto(kvm)
> function to fix a reported issue whereby the crypto key wrapping
> attributes could potentially get out of synch for running vcpus.
>
> Reported-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx>
A reported-by for a code refactoring is strange.
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
> ---
> arch/s390/kvm/kvm-s390.c | 18 ++++++++++++++----
> arch/s390/kvm/kvm-s390.h | 13 +++++++++++++
> 2 files changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index fa355a6..4fa3037 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -789,6 +789,19 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
> return ret;
> }
>
> +void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm)
> + {
> + int i;
> + struct kvm_vcpu *vcpu;
> +
> + kvm_s390_vcpu_block_all(kvm);
> +
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_s390_vcpu_crypto_setup(vcpu);
> +
> + kvm_s390_vcpu_unblock_all(kvm);
This code has to be protected by kvm->lock. Can that be guaranteed by
the caller?
> +}
> +
> static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu);
>
> static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
> @@ -832,10 +845,7 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
> return -ENXIO;
> }
>
> - kvm_for_each_vcpu(i, vcpu, kvm) {
> - kvm_s390_vcpu_crypto_setup(vcpu);
> - exit_sie(vcpu);
> - }
> + kvm_s390_vcpu_crypto_reset_all(kvm);
> mutex_unlock(&kvm->lock);
> return 0;
> }
> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
> index 1b5621f..981e3ba 100644
> --- a/arch/s390/kvm/kvm-s390.h
> +++ b/arch/s390/kvm/kvm-s390.h
> @@ -410,4 +410,17 @@ static inline int kvm_s390_use_sca_entries(void)
> }
> void kvm_s390_reinject_machine_check(struct kvm_vcpu *vcpu,
> struct mcck_volatile_info *mcck_info);
> +
> +/**
> + * kvm_s390_vcpu_crypto_reset_all
> + *
> + * Reset the crypto attributes for each vcpu. This can be done while the vcpus
> + * are running as each vcpu will be removed from SIE before resetting the crypt
> + * attributes and restored to SIE afterward.
> + *
> + * Note: The kvm->lock must be held while calling this function
> + *
> + * @kvm: the KVM guest
> + */
> +void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm);
> #endif
>
--
Thanks,
David / dhildenb
