From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40936 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726000AbfKSLkL (ORCPT ); Tue, 19 Nov 2019 06:40:11 -0500 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xAJBWufJ076823 for ; Tue, 19 Nov 2019 06:40:10 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wcf5p1j23-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 19 Nov 2019 06:40:09 -0500 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 19 Nov 2019 11:40:07 -0000 Subject: Re: [RFC 36/37] KVM: s390: protvirt: Support cmd 5 operation state References: <20191024114059.102802-1-frankja@linux.ibm.com> <20191024114059.102802-37-frankja@linux.ibm.com> <20191118183842.36688a81.cohuck@redhat.com> <44b320d8-604d-8497-59a3-defc41472ba5@linux.ibm.com> <20191119112316.0a421a01.cohuck@redhat.com> From: Janosch Frank Date: Tue, 19 Nov 2019 12:40:02 +0100 MIME-Version: 1.0 In-Reply-To: <20191119112316.0a421a01.cohuck@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="MBoE7p07IwHjDCn1yoh2tOEJDbN921Wpa" Message-Id: Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, thuth@redhat.com, david@redhat.com, borntraeger@de.ibm.com, imbrenda@linux.ibm.com, mihajlov@linux.ibm.com, mimu@linux.ibm.com, gor@linux.ibm.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --MBoE7p07IwHjDCn1yoh2tOEJDbN921Wpa Content-Type: multipart/mixed; boundary="PqRqh7TBYp86qHVFwckupNP7kyoj6NkGY" --PqRqh7TBYp86qHVFwckupNP7kyoj6NkGY Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 11/19/19 11:23 AM, Cornelia Huck wrote: > On Tue, 19 Nov 2019 09:13:11 +0100 > Janosch Frank wrote: >=20 >> On 11/18/19 6:38 PM, Cornelia Huck wrote: >>> On Thu, 24 Oct 2019 07:40:58 -0400 >>> Janosch Frank wrote: >>> =20 >>>> Code 5 for the set cpu state UV call tells the UV to load a PSW from= >>>> the SE header (first IPL) or from guest location 0x0 (diag 308 subco= de >>>> 0/1). Also it sets the cpu into operating state afterwards, so we ca= n >>>> start it. =20 >>> >>> I'm a bit confused by the patch description: Does this mean that the = UV >>> does the transition to operating state? Does the hypervisor get a >>> notification for that? =20 >> >> CMD 5 is defined as "load psw and set to operating". >> Currently QEMU will still go out and do a "set to operating" after the= >> cmd 5 because our current infrastructure does it and it's basically a >> nop, so I didn't want to put in the effort to remove it. >=20 > So, the "it" setting the cpu into operating state is QEMU, via the > mpstate interface, which triggers that call? Or is that implicit, but > it does not hurt to do it again (which would make more sense to me)? Qemu sets operating state via mpstate. I could fence that via env->pv checks but that would also mean more code and setting operating twice is just a nop. >=20 > Assuming the latter, what about the following description: >=20 > "KVM: s390: protvirt: support setting cpu state 5 >=20 > Setting code 5 ("load psw and set to operating") in the set cpu state > UV call tells the UV to load a PSW either from the SE header (first > IPL) or from guest location 0x0 (diag 308 subcode 0/1). Subsequently, > the cpu is set into operating state by the UV. >=20 > Note that we can still instruct the UV to set the cpu into operating > state explicitly afterwards." Sounds good >=20 >> >>> =20 >>>> >>>> Signed-off-by: Janosch Frank >>>> --- >>>> arch/s390/include/asm/uv.h | 1 + >>>> arch/s390/kvm/kvm-s390.c | 4 ++++ >>>> include/uapi/linux/kvm.h | 1 + >>>> 3 files changed, 6 insertions(+) >>>> >>>> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h= >>>> index 33b52ba306af..8d10ae731458 100644 >>>> --- a/arch/s390/include/asm/uv.h >>>> +++ b/arch/s390/include/asm/uv.h >>>> @@ -163,6 +163,7 @@ struct uv_cb_unp { >>>> #define PV_CPU_STATE_OPR 1 >>>> #define PV_CPU_STATE_STP 2 >>>> #define PV_CPU_STATE_CHKSTP 3 >>>> +#define PV_CPU_STATE_OPR_LOAD 5 >>>> =20 >>>> struct uv_cb_cpu_set_state { >>>> struct uv_cb_header header; >>>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>>> index cc5feb67f145..5cc9108c94e4 100644 >>>> --- a/arch/s390/kvm/kvm-s390.c >>>> +++ b/arch/s390/kvm/kvm-s390.c >>>> @@ -4652,6 +4652,10 @@ static int kvm_s390_handle_pv_vcpu(struct kvm= _vcpu *vcpu, >>>> r =3D kvm_s390_pv_destroy_cpu(vcpu); >>>> break; >>>> } >>>> + case KVM_PV_VCPU_SET_IPL_PSW: { >>>> + r =3D kvm_s390_pv_set_cpu_state(vcpu, PV_CPU_STATE_OPR_LOAD); >=20 > Also maybe add a comment here that setting into oper state (again) can > be done separately? >=20 >>>> + break; >>>> + } >>>> default: >>>> r =3D -ENOTTY; >>>> } >>>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >>>> index 2846ed5e5dd9..973007d27d55 100644 >>>> --- a/include/uapi/linux/kvm.h >>>> +++ b/include/uapi/linux/kvm.h >>>> @@ -1483,6 +1483,7 @@ enum pv_cmd_id { >>>> KVM_PV_VM_UNSHARE, >>>> KVM_PV_VCPU_CREATE, >>>> KVM_PV_VCPU_DESTROY, >>>> + KVM_PV_VCPU_SET_IPL_PSW, >>>> }; >>>> =20 >>>> struct kvm_pv_cmd { =20 >>> =20 >> >> >=20 --PqRqh7TBYp86qHVFwckupNP7kyoj6NkGY-- --MBoE7p07IwHjDCn1yoh2tOEJDbN921Wpa Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEwGNS88vfc9+v45Yq41TmuOI4ufgFAl3T1JIACgkQ41TmuOI4 ufgb+w/+O1S2/CILwR0MSsvfDWcyhYRGRWDFN/FBupiD2giKXJ/Q9nQZeOOqtvhe g3aeMBJ7NdMwsTn4b3nZFvPPkgQnDuAgKoq0724CNCRxEPSqR3hmbwab51Q7DC9U RE62I7wWo7qzY5pBgWJ0x08KybmslCstOAANjZZkZQDTkgZlmYQ2/MCH8WMFqvrj 7royXTKgmnRwfvBUK7hKHXU4jJFRfMsH+a2JJXv8xu3qH9VW769qQbu66zCmehYK E0u3jOCh18Zcb4iXmtgliT+wr4mljaENiMxJ1f3GY0iyDZaAHLwmAsC2j1piZI/C xJSRX9e25j2dlz7IRsWzZvOZFpv0kp57SBj0cmKgIUVvC0Tw6MvuEaqg5cnJuRYV gYgB4vA+9VVqrwpxY36+0iOlkzTpKj4Ue5IuOJhsU8yyJblvqcbUpHNlsulWtiQH jSlP+xX+43FacT7HCYfnbB5rn+hxCJXh3LVOBAG9MkVju1qw+aJNI9CGR4CvZkcl gQ4sFV8inoA9/UuzLeahOMCQDpt7u142/NpEwns539qD3WUo1cip5Eir3H5ErJg5 TaQXMlwChiQAWDwG23z4k2ad9QFMRDu7KqsaAjbvcdewtcyIaG1gYSg9v4DKpTdJ K1ivtD1QFy4mJ4bQDEHf3i3uUJqZcJjF//VhACDZx62aoRGCAJA= =ASdO -----END PGP SIGNATURE----- --MBoE7p07IwHjDCn1yoh2tOEJDbN921Wpa--