On Thu, 14 Feb 2019 14:51:02 +0100 Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote: > This patch adds interception code for the PQAP instructions, > and a callback inside the KVM arch structure for s390. > > If a VFIO-AP drivers needs to intercept PQAP/AQIC or PQAP/TAPQ s/drivers/driver/ > instructions, the driver will initialize the callback inside > the kvm_arch structure to be called when the interception of a > PQAP instruction occurs. > > If the callback is not initialized, the code still returns > -EOPNOTSUPP to let userland handle the instruction as it used to. > > Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx> > Reviewed-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > --- > arch/s390/include/asm/kvm_host.h | 1 + > arch/s390/kvm/priv.c | 50 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index c5f5156..49cc8b0 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -719,6 +719,7 @@ struct kvm_s390_cpu_model { > > struct kvm_s390_crypto { > struct kvm_s390_crypto_cb *crycb; > + int (*pqap_hook)(struct kvm_vcpu *vcpu); > __u32 crycbd; > __u8 aes_kw; > __u8 dea_kw; > diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c > index 8679bd7..72fdc21 100644 > --- a/arch/s390/kvm/priv.c > +++ b/arch/s390/kvm/priv.c > @@ -27,6 +27,7 @@ > #include <asm/io.h> > #include <asm/ptrace.h> > #include <asm/sclp.h> > +#include <asm/ap.h> > #include "gaccess.h" > #include "kvm-s390.h" > #include "trace.h" > @@ -592,6 +593,53 @@ static int handle_io_inst(struct kvm_vcpu *vcpu) > } > } > > +/* > + * handle_pqap: Handling pqap interception > + * @vcpu: the vcpu having issue the pqap instruction s/issue/issued/ > + * > + * This callback only handles PQAP/AQIC instruction and Here you only talk about PQAP/AQIC, what about PQAP/TAPQ mentioned in the patch description? > + * calls a dedicated callback for this instruction if > + * a driver did register one in the CRYPTO satellite of the > + * SIE block. > + * > + * Do not change the behavior if, return -EOPNOTSUPP if: > + * - the hook is not used do not change the behavior. The hook is not used? Or not set? (I don't think you need to repeat "do not change the behavior".) > + * - AP instructions are not available or not available to the guest > + * - the instruction is not PQAP with function code indicating > + * AQIC do not change the previous behavior. > + * > + * For PQAP/AQIC instruction, verify privilege and specifications > + * > + * return the value returned by the callback. > + */ > +static int handle_pqap(struct kvm_vcpu *vcpu) > +{ > + uint8_t fc; > + > + /* Verify that the hook callback is registered */ > + if (!vcpu->kvm->arch.crypto.pqap_hook) > + return -EOPNOTSUPP; > + /* Verify that the AP instruction are available */ > + if (!ap_instructions_available()) > + return -EOPNOTSUPP; > + /* Verify that the guest is allowed to use AP instructions */ > + if (!(vcpu->arch.sie_block->eca & ECA_APIE)) > + return -EOPNOTSUPP; > + /* Verify that the function code is AQIC */ > + fc = vcpu->run->s.regs.gprs[0] >> 24; > + if (fc != 0x03) > + return -EOPNOTSUPP; > + > + /* PQAP instructions are allowed for guest kernel only */ > + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) > + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); > + /* AQIC instruction is allowed only if facility 65 is available */ > + if (!test_kvm_facility(vcpu->kvm, 65)) > + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); > + /* All right, call the callback */ > + return vcpu->kvm->arch.crypto.pqap_hook(vcpu); Can that callback also return -EOPNOTSUPP to order to drop to user space? > +} > + > static int handle_stfl(struct kvm_vcpu *vcpu) > { > int rc; > @@ -878,6 +926,8 @@ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu) > return handle_sthyi(vcpu); > case 0x7d: > return handle_stsi(vcpu); > + case 0xaf: > + return handle_pqap(vcpu); > case 0xb1: > return handle_stfl(vcpu); > case 0xb2: