| Message ID | 1558452877-27822-2-git-send-email-pmorel@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio: ap: AP Queue Interrupt Control | expand |
On 21.05.19 17:34, Pierre Morel wrote: > We prepare the interception of the PQAP/AQIC instruction for > the case the AQIC facility is enabled in the guest. > > First of all we do not want to change existing behavior when > intercepting AP instructions without the SIE allowing the guest > to use AP instructions. > > In this patch we only handle the AQIC interception allowed by > facility 65 which will be enabled when the complete interception > infrastructure will be present. > > We add a callback inside the KVM arch structure for s390 for > a VFIO driver to handle a specific response to the PQAP > instruction with the AQIC command and only this command. > > But we want to be able to return a correct answer to the guest > even there is no VFIO AP driver in the kernel. > Therefor, we inject the correct exceptions from inside KVM for the > case the callback is not initialized, which happens when the vfio_ap > driver is not loaded. > > We do consider the responsability of the driver to always initialize > the PQAP callback if it defines queues by initializing the CRYCB for > a guest. > If the callback has been setup we call it. > If not we setup an answer considering that no queue is available > for the guest when no callback has been setup. > > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> > --- > arch/s390/include/asm/kvm_host.h | 7 +++ > arch/s390/kvm/priv.c | 86 +++++++++++++++++++++++++++++++++++ > drivers/s390/crypto/vfio_ap_private.h | 2 + > 3 files changed, 95 insertions(+) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index faa7ebf..a0fc2f1 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -18,6 +18,7 @@ > #include <linux/kvm_host.h> > #include <linux/kvm.h> > #include <linux/seqlock.h> > +#include <linux/module.h> > #include <asm/debug.h> > #include <asm/cpu.h> > #include <asm/fpu/api.h> > @@ -723,8 +724,14 @@ struct kvm_s390_cpu_model { > unsigned short ibc; > }; > > +struct kvm_s390_module_hook { > + int (*hook)(struct kvm_vcpu *vcpu); > + struct module *owner; > +}; > + > struct kvm_s390_crypto { > struct kvm_s390_crypto_cb *crycb; > + struct kvm_s390_module_hook *pqap_hook; > __u32 crycbd; > __u8 aes_kw; > __u8 dea_kw; > diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c > index 8679bd7..ed52ffa 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 +593,89 @@ static int handle_io_inst(struct kvm_vcpu *vcpu) > } > } > > +/* > + * handle_pqap: Handling pqap interception > + * @vcpu: the vcpu having issue the pqap instruction > + * > + * We now support PQAP/AQIC instructions and we need to correctly > + * answer the guest even if no dedicated driver's hook is available. > + * > + * The intercepting code calls a dedicated callback for this instruction > + * if a driver did register one in the CRYPTO satellite of the > + * SIE block. > + * > + * If no callback is available, the queues are not available, return this > + * response code to the caller and set CC to 3. > + * Else return the response code returned by the callback. > + */ > +static int handle_pqap(struct kvm_vcpu *vcpu) > +{ > + struct ap_queue_status status = {}; > + unsigned long reg0; > + int ret; > + uint8_t fc; > + > + /* 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; > + /* > + * The only possibly intercepted functions when AP instructions are > + * available for the guest are AQIC and TAPQ with the t bit set > + * since we do not set IC.3 (FIII) we currently will only intercept > + * the AQIC function code. > + */ > + reg0 = vcpu->run->s.regs.gprs[0]; > + fc = (reg0 >> 24) & 0xff; > + if (WARN_ON_ONCE(fc != 0x03)) > + return -EOPNOTSUPP; > + > + /* PQAP instruction is 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); > + > + /* Common PQAP instruction specification exceptions */ > + /* bits 41-47 must all be zeros */ > + if (reg0 & 0x007f0000UL) > + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); > + /* APFT not install and T bit set */ > + if (!test_kvm_facility(vcpu->kvm, 15) && (reg0 & 0x00800000UL)) > + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); > + /* APXA not installed and APID greater 64 or APQI greater 16 */ > + if (!(vcpu->kvm->arch.crypto.crycbd & 0x02) && (reg0 & 0x0000c0f0UL)) > + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); > + > + /* AQIC function code specific exception */ > + /* facility 65 not present for AQIC function code */ > + if (!test_kvm_facility(vcpu->kvm, 65)) > + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); > + > + /* > + * Verify that the hook callback is registered, lock the owner > + * and call the hook. > + */ > + if (vcpu->kvm->arch.crypto.pqap_hook) { > + if (!try_module_get(vcpu->kvm->arch.crypto.pqap_hook->owner)) > + return -EOPNOTSUPP; > + ret = vcpu->kvm->arch.crypto.pqap_hook->hook(vcpu); > + module_put(vcpu->kvm->arch.crypto.pqap_hook->owner); > + if (!ret && vcpu->run->s.regs.gprs[1] & 0x00ff0000) > + kvm_s390_set_psw_cc(vcpu, 3); > + return ret; > + } > + /* > + * A vfio_driver must register a hook. > + * No hook means no driver to enable the SIE CRYCB and no queues. > + * We send this response to the guest. > + */ > + status.response_code = 0x01; > + memcpy(&vcpu->run->s.regs.gprs[1], &status, sizeof(status)); > + kvm_s390_set_psw_cc(vcpu, 3); > + return 0; > +} > + > static int handle_stfl(struct kvm_vcpu *vcpu) > { > int rc; > @@ -878,6 +962,8 @@ 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: > diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h > index 76b7f98..a910be1 100644 > --- a/drivers/s390/crypto/vfio_ap_private.h > +++ b/drivers/s390/crypto/vfio_ap_private.h > @@ -16,6 +16,7 @@ > #include <linux/mdev.h> > #include <linux/delay.h> > #include <linux/mutex.h> > +#include <linux/kvm_host.h> > > #include "ap_bus.h" > > @@ -81,6 +82,7 @@ struct ap_matrix_mdev { > struct ap_matrix matrix; > struct notifier_block group_notifier; > struct kvm *kvm; > + struct kvm_s390_module_hook pqap_hook; > }; > > extern int vfio_ap_mdev_register(void); acked-by: Harald Freudenberger <freude@linux.ibm.com>
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index faa7ebf..a0fc2f1 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -18,6 +18,7 @@ #include <linux/kvm_host.h> #include <linux/kvm.h> #include <linux/seqlock.h> +#include <linux/module.h> #include <asm/debug.h> #include <asm/cpu.h> #include <asm/fpu/api.h> @@ -723,8 +724,14 @@ struct kvm_s390_cpu_model { unsigned short ibc; }; +struct kvm_s390_module_hook { + int (*hook)(struct kvm_vcpu *vcpu); + struct module *owner; +}; + struct kvm_s390_crypto { struct kvm_s390_crypto_cb *crycb; + struct kvm_s390_module_hook *pqap_hook; __u32 crycbd; __u8 aes_kw; __u8 dea_kw; diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 8679bd7..ed52ffa 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 +593,89 @@ static int handle_io_inst(struct kvm_vcpu *vcpu) } } +/* + * handle_pqap: Handling pqap interception + * @vcpu: the vcpu having issue the pqap instruction + * + * We now support PQAP/AQIC instructions and we need to correctly + * answer the guest even if no dedicated driver's hook is available. + * + * The intercepting code calls a dedicated callback for this instruction + * if a driver did register one in the CRYPTO satellite of the + * SIE block. + * + * If no callback is available, the queues are not available, return this + * response code to the caller and set CC to 3. + * Else return the response code returned by the callback. + */ +static int handle_pqap(struct kvm_vcpu *vcpu) +{ + struct ap_queue_status status = {}; + unsigned long reg0; + int ret; + uint8_t fc; + + /* 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; + /* + * The only possibly intercepted functions when AP instructions are + * available for the guest are AQIC and TAPQ with the t bit set + * since we do not set IC.3 (FIII) we currently will only intercept + * the AQIC function code. + */ + reg0 = vcpu->run->s.regs.gprs[0]; + fc = (reg0 >> 24) & 0xff; + if (WARN_ON_ONCE(fc != 0x03)) + return -EOPNOTSUPP; + + /* PQAP instruction is 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); + + /* Common PQAP instruction specification exceptions */ + /* bits 41-47 must all be zeros */ + if (reg0 & 0x007f0000UL) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + /* APFT not install and T bit set */ + if (!test_kvm_facility(vcpu->kvm, 15) && (reg0 & 0x00800000UL)) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + /* APXA not installed and APID greater 64 or APQI greater 16 */ + if (!(vcpu->kvm->arch.crypto.crycbd & 0x02) && (reg0 & 0x0000c0f0UL)) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + + /* AQIC function code specific exception */ + /* facility 65 not present for AQIC function code */ + if (!test_kvm_facility(vcpu->kvm, 65)) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + + /* + * Verify that the hook callback is registered, lock the owner + * and call the hook. + */ + if (vcpu->kvm->arch.crypto.pqap_hook) { + if (!try_module_get(vcpu->kvm->arch.crypto.pqap_hook->owner)) + return -EOPNOTSUPP; + ret = vcpu->kvm->arch.crypto.pqap_hook->hook(vcpu); + module_put(vcpu->kvm->arch.crypto.pqap_hook->owner); + if (!ret && vcpu->run->s.regs.gprs[1] & 0x00ff0000) + kvm_s390_set_psw_cc(vcpu, 3); + return ret; + } + /* + * A vfio_driver must register a hook. + * No hook means no driver to enable the SIE CRYCB and no queues. + * We send this response to the guest. + */ + status.response_code = 0x01; + memcpy(&vcpu->run->s.regs.gprs[1], &status, sizeof(status)); + kvm_s390_set_psw_cc(vcpu, 3); + return 0; +} + static int handle_stfl(struct kvm_vcpu *vcpu) { int rc; @@ -878,6 +962,8 @@ 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: diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index 76b7f98..a910be1 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -16,6 +16,7 @@ #include <linux/mdev.h> #include <linux/delay.h> #include <linux/mutex.h> +#include <linux/kvm_host.h> #include "ap_bus.h" @@ -81,6 +82,7 @@ struct ap_matrix_mdev { struct ap_matrix matrix; struct notifier_block group_notifier; struct kvm *kvm; + struct kvm_s390_module_hook pqap_hook; }; extern int vfio_ap_mdev_register(void);