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Violators will be prosecuted for from ; Fri, 10 Jan 2020 11:39:41 -0000 Subject: Re: [PATCH v6] KVM: s390: Add new reset vcpu API References: <20200110101906.54291-1-frankja@linux.ibm.com> <9b9c3e09-e3ec-0ef2-0aef-a31ff34df33b@redhat.com> From: Janosch Frank Date: Fri, 10 Jan 2020 12:39:37 +0100 MIME-Version: 1.0 In-Reply-To: <9b9c3e09-e3ec-0ef2-0aef-a31ff34df33b@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="eFr5w6XYX7VHZzFNb5mueUlackkmTyoC4" Message-Id: Sender: linux-s390-owner@vger.kernel.org List-ID: To: Thomas Huth , kvm@vger.kernel.org Cc: borntraeger@de.ibm.com, linux-s390@vger.kernel.org, david@redhat.com, cohuck@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --eFr5w6XYX7VHZzFNb5mueUlackkmTyoC4 Content-Type: multipart/mixed; boundary="E3oBMS9jL1rirgCKehsOCQ8Tq3QFpSdDg" --E3oBMS9jL1rirgCKehsOCQ8Tq3QFpSdDg Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 1/10/20 11:36 AM, Thomas Huth wrote: > On 10/01/2020 11.19, 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 >> --- > [...] >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index d9e6bf3d54f0..4936f9499291 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 =3D 1; >> break; >> case KVM_CAP_S390_HPAGE_1M: >> @@ -2844,35 +2845,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) >> =20 >> } >> =20 >> -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 =3D 0UL; >> - vcpu->arch.sie_block->gpsw.addr =3D 0UL; >> - kvm_s390_set_prefix(vcpu, 0); >> - kvm_s390_set_cpu_timer(vcpu, 0); >> - vcpu->arch.sie_block->ckc =3D 0UL; >> - vcpu->arch.sie_block->todpr =3D 0; >> - memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64)); >> - vcpu->arch.sie_block->gcr[0] =3D CR0_UNUSED_56 | >> - CR0_INTERRUPT_KEY_SUBMASK | >> - CR0_MEASUREMENT_ALERT_SUBMASK; >> - vcpu->arch.sie_block->gcr[14] =3D 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 =3D 0; >> - vcpu->arch.sie_block->gbea =3D 1; >> - vcpu->arch.sie_block->pp =3D 0; >> - vcpu->arch.sie_block->fpf &=3D ~FPF_BPBC; >> - vcpu->arch.pfault_token =3D 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 +3259,78 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(str= uct kvm_vcpu *vcpu, >> return r; >> } >> =20 >> -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 =3D ~PSW_MASK_RI; >> + vcpu->arch.pfault_token =3D 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 =3D 0UL; >> + vcpu->arch.sie_block->gpsw.addr =3D 0UL; >> + kvm_s390_set_prefix(vcpu, 0); >> + kvm_s390_set_cpu_timer(vcpu, 0); >> + vcpu->arch.sie_block->ckc =3D 0UL; >> + vcpu->arch.sie_block->todpr =3D 0; >> + memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64)); >> + vcpu->arch.sie_block->gcr[0] =3D CR0_UNUSED_56 | >> + CR0_INTERRUPT_KEY_SUBMASK | >> + CR0_MEASUREMENT_ALERT_SUBMASK; >> + vcpu->arch.sie_block->gcr[14] =3D 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 =3D 0; >> + vcpu->arch.sie_block->gbea =3D 1; >> + vcpu->arch.sie_block->pp =3D 0; >> + vcpu->arch.sie_block->fpf &=3D ~FPF_BPBC; >> +} >> + >> +static void kvm_arch_vcpu_ioctl_clear_reset(struct kvm_vcpu *vcpu) >> +{ >> + struct kvm_sync_regs *regs =3D &vcpu->run->s.regs; >> + >> + /* Clear reset is a superset of the initial reset */ >> + kvm_arch_vcpu_ioctl_normal_reset(vcpu); >> + >> + memset(®s->gprs, 0, sizeof(regs->gprs)); >> + /* >> + * Will be picked up via save_fpu_regs() in the initial reset >> + * fallthrough. >=20 > The word "fallthrough" now likely should be removed from the comment. >=20 > Also, I'm not an expert in this lazy-fpu stuff, but don't you rather > have to deal with current->thread.fpu.regs here instead? Yes, I'll need to fix that. >=20 >> + */ >> + memset(®s->vrs, 0, sizeof(regs->vrs)); >> + memset(®s->acrs, 0, sizeof(regs->acrs)); >> + >> + regs->etoken =3D 0; >> + regs->etoken_extension =3D 0; >> + >> + memset(®s->gscb, 0, sizeof(regs->gscb)); >> + if (MACHINE_HAS_GS) { >> + preempt_disable(); >> + __ctl_set_bit(2, 4); >> + if (current->thread.gs_cb) { >> + vcpu->arch.host_gscb =3D current->thread.gs_cb; >> + save_gs_cb(vcpu->arch.host_gscb); >> + } >> + if (vcpu->arch.gs_enabled) { >> + current->thread.gs_cb =3D (struct gs_cb *) >> + &vcpu->run->s.regs.gscb; >> + restore_gs_cb(current->thread.gs_cb); >> + } >> + preempt_enable(); >> + } >> } >=20 > Thomas >=20 --E3oBMS9jL1rirgCKehsOCQ8Tq3QFpSdDg-- --eFr5w6XYX7VHZzFNb5mueUlackkmTyoC4 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEwGNS88vfc9+v45Yq41TmuOI4ufgFAl4YYnkACgkQ41TmuOI4 ufiB2Q//e+eEjZZm+ERhmnJNP7hR1YF9NvZEKhISmUThBTehObV3owocFnEimcaj P73LlMb5re11y4CvackftMb2hTVyl975ijQnsUDyMN/f1a4VW1Kf09fdovtp3eIu KH02XVBut6l6zzdJx0t56sMIezOOPNqrj5Wv5TJveHt0mbxzdMvXOl0zE+uGCEld 689bkm0GpefGfe7tfta3lgviYzNMLEqR4q9Smztsk894GdQOiE2zgX2QfUlJQ9sJ hKTfF3Zu9YYcv31Lbd3Yugn6dCLVZ85UlLHmTgpsee7r8e/T4OQI3iOZ+Zwfv9Oa GiIRLkMLJFQqV3AJzN9+kzlUEpEhg6YdfdlMImdKfEZAXtfkyPa91qf7OZXFCvkO koDYpTJw3pjF3Wtd/v345v7S7Bbb9xVKNx2TsFIn+D9h4zLAIf9RurSxPx5XExJY hU56h4ppxuZfAyJAephM7ngE4TtZiv4UOiy/cXaxrUN4JnOmmqkEztPNmWOiqf9s Jxv9EIwaj5xPHPVBGmIUtCIKkuDd4ozLRknsZtb2yh9C0Ko+GfenbPFl7ezKzin8 xHbZUlzMGu3N5QtPgHwmSH49fIl1oCsHpj5+UZ+5nfSBc1+qW2ocV//wzidOxF7u VFqXmcvGHniOnon4YdaZDY9bhLLzHh5geFfyFhTOEagIHrQ7Mx4= =mCwg -----END PGP SIGNATURE----- --eFr5w6XYX7VHZzFNb5mueUlackkmTyoC4--