Re: [PATCH v9 14/22] KVM: s390: interfaces to clear CRYCB masks

Cornelia Huck
2018-08-15T13:10:39Z

On Mon, 13 Aug 2018 17:48:11 -0400
Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:

> From: Tony Krowiak <akrowiak@linux.ibm.com>
>
> Introduces two new KVM interface to clear the APM, AQM and ADM masks in
> the guest's CRYCB. The VCPUs are taken out of SIE to ensure the VCPUs do
> not get out of sync.
>
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Acked-by: Halil Pasic <pasic@linux.ibm.com>
> Tested-by: Michael Mueller <mimu@linux.ibm.com>
> Tested-by: Farhan Ali <alifm@linux.ibm.com>
> Tested-by: Pierre Morel <pmorel@linux.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> arch/s390/include/asm/kvm_host.h | 3 +++
> arch/s390/kvm/kvm-s390.c | 15 +++++++++++++++
> 2 files changed, 18 insertions(+), 0 deletions(-)
>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index 4a739d4..07e58d8 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -258,6 +258,7 @@ struct kvm_s390_sie_block {
> __u64 tecmc; /* 0x00e8 */
> __u8 reservedf0[12]; /* 0x00f0 */
> #define CRYCB_FORMAT_MASK 0x00000003
> +#define CRYCB_FORMAT0 0x00000000

This should probably go into a different patch (define is not used
here)?

> #define CRYCB_FORMAT1 0x00000001
> #define CRYCB_FORMAT2 0x00000003
> __u32 crycbd; /* 0x00fc */
> @@ -861,6 +862,8 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
> void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
> struct kvm_async_pf *work);
>
> +void kvm_arch_crypto_clear_masks(struct kvm *kvm);
> +
> extern int sie64a(struct kvm_s390_sie_block *, u64 *);
> extern char sie_exit;
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index f7de123..8d8a65a 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -1919,6 +1919,21 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm)
> kvm->arch.crypto.crycbd |= CRYCB_FORMAT1;
> }
>
> +void kvm_arch_crypto_clear_masks(struct kvm *kvm)
> +{
> + mutex_lock(&kvm->lock);
> + kvm_s390_vcpu_block_all(kvm);
> +
> + memset(&kvm->arch.crypto.crycb->apcb0, 0,
> + sizeof(kvm->arch.crypto.crycb->apcb0));
> + memset(&kvm->arch.crypto.crycb->apcb1, 0,
> + sizeof(kvm->arch.crypto.crycb->apcb1));
> +
> + kvm_s390_vcpu_unblock_all(kvm);
> + mutex_unlock(&kvm->lock);
> +}
> +EXPORT_SYMBOL(kvm_arch_crypto_clear_masks);

A quick grep shows that kvm-related exports tend to be
EXPORT_SYMBOL_GPL. Should that also be done here?

> +
> static u64 kvm_s390_get_initial_cpuid(void)
> {
> struct cpuid cpuid;