On 1/10/20 1:11 PM, Thomas Huth wrote: > On 10/01/2020 12.45, Janosch Frank wrote: >> The architecture states that we need to reset local IRQs for all CPU >> resets. Because the old reset interface did not support the normal CPU >> reset we never did that on a normal reset. >> >> Let's implement an interface for the missing normal and clear resets >> and reset all local IRQs, registers and control structures as stated >> in the architecture. >> >> Userspace might already reset the registers via the vcpu run struct, >> but as we need the interface for the interrupt clearing part anyway, >> we implement the resets fully and don't rely on userspace to reset the >> rest. >> >> Signed-off-by: Janosch Frank >> Reviewed-by: Cornelia Huck >> --- >> Documentation/virt/kvm/api.txt | 43 +++++++++++++ >> arch/s390/kvm/kvm-s390.c | 112 +++++++++++++++++++++++---------- >> include/uapi/linux/kvm.h | 5 ++ >> 3 files changed, 127 insertions(+), 33 deletions(-) >> >> diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt >> index ebb37b34dcfc..73448764f544 100644 >> --- a/Documentation/virt/kvm/api.txt >> +++ b/Documentation/virt/kvm/api.txt >> @@ -4168,6 +4168,42 @@ This ioctl issues an ultravisor call to terminate the secure guest, >> unpins the VPA pages and releases all the device pages that are used to >> track the secure pages by hypervisor. >> >> +4.122 KVM_S390_NORMAL_RESET >> + >> +Capability: KVM_CAP_S390_VCPU_RESETS >> +Architectures: s390 >> +Type: vcpu ioctl >> +Parameters: none >> +Returns: 0 >> + >> +This ioctl resets VCPU registers and control structures according to >> +the cpu reset definition in the POP (Principles Of Operation). >> + >> +4.123 KVM_S390_INITIAL_RESET >> + >> +Capability: none >> +Architectures: s390 >> +Type: vcpu ioctl >> +Parameters: none >> +Returns: 0 >> + >> +This ioctl resets VCPU registers and control structures according to >> +the initial cpu reset definition in the POP. However, the cpu is not >> +put into ESA mode. This reset is a superset of the normal reset. >> + >> +4.124 KVM_S390_CLEAR_RESET >> + >> +Capability: KVM_CAP_S390_VCPU_RESETS >> +Architectures: s390 >> +Type: vcpu ioctl >> +Parameters: none >> +Returns: 0 >> + >> +This ioctl resets VCPU registers and control structures according to >> +the clear cpu reset definition in the POP. However, the cpu is not put >> +into ESA mode. This reset is a superset of the initial reset. >> + >> + >> 5. The kvm_run structure >> ------------------------ >> >> @@ -5396,3 +5432,10 @@ handling by KVM (as some KVM hypercall may be mistakenly treated as TLB >> flush hypercalls by Hyper-V) so userspace should disable KVM identification >> in CPUID and only exposes Hyper-V identification. In this case, guest >> thinks it's running on Hyper-V and only use Hyper-V hypercalls. >> + >> +8.22 KVM_CAP_S390_VCPU_RESETS >> + >> +Architectures: s390 >> + >> +This capability indicates that the KVM_S390_NORMAL_RESET and >> +KVM_S390_CLEAR_RESET ioctls are available. >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index d9e6bf3d54f0..5640f3d6f98d 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -529,6 +529,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) >> case KVM_CAP_S390_CMMA_MIGRATION: >> case KVM_CAP_S390_AIS: >> case KVM_CAP_S390_AIS_MIGRATION: >> + case KVM_CAP_S390_VCPU_RESETS: >> r = 1; >> break; >> case KVM_CAP_S390_HPAGE_1M: >> @@ -2844,35 +2845,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) >> >> } >> >> -static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu) >> -{ >> - /* this equals initial cpu reset in pop, but we don't switch to ESA */ >> - vcpu->arch.sie_block->gpsw.mask = 0UL; >> - vcpu->arch.sie_block->gpsw.addr = 0UL; >> - kvm_s390_set_prefix(vcpu, 0); >> - kvm_s390_set_cpu_timer(vcpu, 0); >> - vcpu->arch.sie_block->ckc = 0UL; >> - vcpu->arch.sie_block->todpr = 0; >> - memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64)); >> - vcpu->arch.sie_block->gcr[0] = CR0_UNUSED_56 | >> - CR0_INTERRUPT_KEY_SUBMASK | >> - CR0_MEASUREMENT_ALERT_SUBMASK; >> - vcpu->arch.sie_block->gcr[14] = CR14_UNUSED_32 | >> - CR14_UNUSED_33 | >> - CR14_EXTERNAL_DAMAGE_SUBMASK; >> - /* make sure the new fpc will be lazily loaded */ >> - save_fpu_regs(); >> - current->thread.fpu.fpc = 0; >> - vcpu->arch.sie_block->gbea = 1; >> - vcpu->arch.sie_block->pp = 0; >> - vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >> - vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID; >> - kvm_clear_async_pf_completion_queue(vcpu); >> - if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) >> - kvm_s390_vcpu_stop(vcpu); >> - kvm_s390_clear_local_irqs(vcpu); >> -} >> - >> void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) >> { >> mutex_lock(&vcpu->kvm->lock); >> @@ -3287,10 +3259,75 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, >> return r; >> } >> >> -static int kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >> +static void kvm_arch_vcpu_ioctl_normal_reset(struct kvm_vcpu *vcpu) >> { >> - kvm_s390_vcpu_initial_reset(vcpu); >> - return 0; >> + vcpu->arch.sie_block->gpsw.mask = ~PSW_MASK_RI; >> + vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID; >> + memset(vcpu->run->s.regs.riccb, 0, sizeof(vcpu->run->s.regs.riccb)); >> + >> + kvm_clear_async_pf_completion_queue(vcpu); >> + if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) >> + kvm_s390_vcpu_stop(vcpu); >> + kvm_s390_clear_local_irqs(vcpu); >> +} >> + >> +static void kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu) >> +{ >> + /* Initial reset is a superset of the normal reset */ >> + kvm_arch_vcpu_ioctl_normal_reset(vcpu); >> + >> + /* this equals initial cpu reset in pop, but we don't switch to ESA */ >> + vcpu->arch.sie_block->gpsw.mask = 0UL; >> + vcpu->arch.sie_block->gpsw.addr = 0UL; >> + kvm_s390_set_prefix(vcpu, 0); >> + kvm_s390_set_cpu_timer(vcpu, 0); >> + vcpu->arch.sie_block->ckc = 0UL; >> + vcpu->arch.sie_block->todpr = 0; >> + memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64)); >> + vcpu->arch.sie_block->gcr[0] = CR0_UNUSED_56 | >> + CR0_INTERRUPT_KEY_SUBMASK | >> + CR0_MEASUREMENT_ALERT_SUBMASK; >> + vcpu->arch.sie_block->gcr[14] = CR14_UNUSED_32 | >> + CR14_UNUSED_33 | >> + CR14_EXTERNAL_DAMAGE_SUBMASK; >> + /* make sure the new fpc will be lazily loaded */ >> + save_fpu_regs(); >> + current->thread.fpu.fpc = 0; >> + vcpu->arch.sie_block->gbea = 1; >> + vcpu->arch.sie_block->pp = 0; >> + vcpu->arch.sie_block->fpf &= ~FPF_BPBC; >> +} >> + >> +static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu) >> +{ >> + struct kvm_sync_regs *regs = &vcpu->run->s.regs; >> + >> + /* Clear reset is a superset of the initial reset */ >> + kvm_arch_vcpu_ioctl_normal_reset(vcpu); > > s/kvm_arch_vcpu_ioctl_normal_reset/kvm_arch_vcpu_ioctl_initial_reset/ -_- It seems like my vacation was not enough... > >> + memset(®s->gprs, 0, sizeof(regs->gprs)); >> + /* Will be picked up because of save_fpu_regs() in the initial reset */ >> + memset(¤t->thread.fpu.vxrs, 0, sizeof(current->thread.fpu.vxrs)); > > I'm still not 100% sure about whether current->thread.fpu.vxrs is always > fine here? But I hope Christian can give an ACK for that... > > Thomas >