Re: [PATCH v2] KVM: s390: reset crypto attributes for all vcpus

From: Janosch Frank
Date: Mon Apr 23 2018 - 02:18:53 EST


On 22.04.2018 17:37, 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.

And this time for real: Thanks, applied


>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> Reported-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
> ---
> v2 Changes:
> Fixed compile error, kvm_s390_vcpu_crypto_setup before declaration
>
> arch/s390/kvm/kvm-s390.c | 17 ++++++++++++-----
> arch/s390/kvm/kvm-s390.h | 13 +++++++++++++
> 2 files changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index fa355a6..e629ae1 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -791,11 +791,21 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
>
> 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)
> +void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm)
> {
> struct kvm_vcpu *vcpu;
> int i;
>
> + 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);
> +}
> +
> +static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
> +{
> if (!test_kvm_facility(kvm, 76))
> return -EINVAL;
>
> @@ -832,10 +842,7 @@ 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
>


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