Re: [PATCH v10 02/26] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART

Christian Borntraeger
2018-09-24T10:49:38Z

On 09/12/2018 09:42 PM, Tony Krowiak wrote:
> From: David Hildenbrand <david@redhat.com>
>
> When we change the crycb (or execution controls), we also have to make sure
> that the vSIE shadow datastructures properly consider the changed
> values before rerunning the vSIE. We can achieve that by simply using a
> VCPU request now.
>
> This has to be a synchronous request (== handled before entering the
> (v)SIE again).
>
> The request will make sure that the vSIE handler is left, and that the
> request will be processed (NOP), therefore forcing a reload of all
> vSIE data (including rebuilding the crycb) when re-entering the vSIE
> interception handler the next time.
>
> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

same here? First David then Tomy?

otherwise
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>

> ---
> arch/s390/include/asm/kvm_host.h | 1 +
> arch/s390/kvm/kvm-s390.c | 7 ++++++-
> 2 files changed, 7 insertions(+), 1 deletions(-)
>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index 29c940b..75d3962 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -44,6 +44,7 @@
> #define KVM_REQ_ICPT_OPEREXC KVM_ARCH_REQ(2)
> #define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)
> #define KVM_REQ_STOP_MIGRATION KVM_ARCH_REQ(4)
> +#define KVM_REQ_VSIE_RESTART KVM_ARCH_REQ(5)
>
> #define SIGP_CTRL_C 0x80
> #define SIGP_CTRL_SCN_MASK 0x3f
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 0b5aff0..876fbb2 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -844,8 +844,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm)
>
> kvm_s390_vcpu_block_all(kvm);
>
> - kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_for_each_vcpu(i, vcpu, kvm) {
> kvm_s390_vcpu_crypto_setup(vcpu);
> + /* recreate the shadow crycb by leaving the VSIE handler */
> + kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
> + }
>
> kvm_s390_vcpu_unblock_all(kvm);
> }
> @@ -3203,6 +3206,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>
> /* nothing to do, just clear the request */
> kvm_clear_request(KVM_REQ_UNHALT, vcpu);
> + /* we left the vsie handler, nothing to do, just clear the request */
> + kvm_clear_request(KVM_REQ_VSIE_RESTART, vcpu);
>
> return 0;
> }
>