From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:59382 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405364AbgFYOmV (ORCPT ); Thu, 25 Jun 2020 10:42:21 -0400 Subject: Re: [PATCH 1/2] docs: kvm: add documentation for KVM_CAP_S390_DIAG318 References: <20200624202200.28209-1-walling@linux.ibm.com> <20200624202200.28209-2-walling@linux.ibm.com> <151bb070-f083-5011-2f04-291058bc9cc2@linux.ibm.com> From: Collin Walling Message-ID: <0503ff8d-21ad-1e6c-783b-3857bda76161@linux.ibm.com> Date: Thu, 25 Jun 2020 10:42:15 -0400 MIME-Version: 1.0 In-Reply-To: <151bb070-f083-5011-2f04-291058bc9cc2@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Janosch Frank , kvm@vger.kernel.org, linux-s390@vger.kernel.org Cc: pbonzini@redhat.com, borntraeger@de.ibm.com, david@redhat.com, cohuck@redhat.com, imbrenda@linux.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com, thuth@redhat.com On 6/25/20 3:16 AM, Janosch Frank wrote: > On 6/24/20 10:21 PM, Collin Walling wrote: >> Documentation for the s390 DIAGNOSE 0x318 instruction handling. >> >> Signed-off-by: Collin Walling >> --- >> Documentation/virt/kvm/api.rst | 19 +++++++++++++++++++ >> 1 file changed, 19 insertions(+) >> >> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst >> index 426f94582b7a..056608e8f243 100644 >> --- a/Documentation/virt/kvm/api.rst >> +++ b/Documentation/virt/kvm/api.rst >> @@ -6150,3 +6150,22 @@ KVM can therefore start protected VMs. >> This capability governs the KVM_S390_PV_COMMAND ioctl and the >> KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected >> guests when the state change is invalid. >> + >> +8.24 KVM_CAP_S390_DIAG318 >> +------------------------- >> + >> +:Architecture: s390 >> + >> +This capability allows for information regarding the control program that may >> +be observed via system/firmware service events. The availability of this > > I'm not sure if control program is understood universally, it's a rather > old term to say guest kernel. > > How about: > > This capability allows a guest to set information about its control > program (i.e. guest kernel type and version). The information is helpful > on system/firmware service events, providing additional data about what > environments are running on the machine. > > Fair point. I'll add some clarity to this. >> +capability indicates that KVM handling of the register synchronization, reset, >> +and VSIE shadowing of the DIAGNOSE 0x318 related information is present. >> + >> +The information associated with the instruction is an 8-byte value consisting >> +of a one-byte Control Program Name Code (CPNC), and a 7-byte Control Program >> +Version Code (CPVC). The CPNC determines what environment the control program >> +is running in (e.g. Linux, z/VM...), and the CPVC is used for extraneous >> +information specific to OS (e.g. Linux version, Linux distribution...) >> + >> +If this capability is available, then the CPNC and CPVC can be synchronized >> +between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). >> > > -- Regards, Collin Stay safe and stay healthy