On 05.12.2017 09:33, Christian Borntraeger wrote:
> From: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
>
> All skey functions call skey_check_enable at their start, which checks
> if we are in the PSTATE and injects a privileged operation exception
> if we are.
Correct thing to do, are we sure we even get an intercept?
(no documentation at hand :( )
>
> Unfortunately they continue processing afterwards and perform the
> operation anyhow as skey_check_enable does not deliver an error if the
> exception injection was successful.
>
> Let's move the PSTATE check into the skey functions and exit them on
> such an occasion, also we now do not enable skey handling anymore in
> such a case.
>
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Fixes: a7e19ab ("KVM: s390: handle missing storage-key facility")
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.8+
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/kvm/priv.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
> index 28b69ab..572496c 100644
> --- a/arch/s390/kvm/priv.c
> +++ b/arch/s390/kvm/priv.c
> @@ -232,8 +232,6 @@ static int try_handle_skey(struct kvm_vcpu *vcpu)
> VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
> return -EAGAIN;
> }
> - if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> - return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> return 0;
> }
>
> @@ -244,6 +242,9 @@ static int handle_iske(struct kvm_vcpu *vcpu)
> int reg1, reg2;
> int rc;
>
> + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> +
> rc = try_handle_skey(vcpu);
> if (rc)
> return rc != -EAGAIN ? rc : 0;
> @@ -273,6 +274,9 @@ static int handle_rrbe(struct kvm_vcpu *vcpu)
> int reg1, reg2;
> int rc;
>
> + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> +
> rc = try_handle_skey(vcpu);
> if (rc)
> return rc != -EAGAIN ? rc : 0;
> @@ -308,6 +312,9 @@ static int handle_sske(struct kvm_vcpu *vcpu)
> int reg1, reg2;
> int rc;
>
> + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> +
> rc = try_handle_skey(vcpu);
> if (rc)
> return rc != -EAGAIN ? rc : 0;
>
--
Thanks,
David / dhildenb
