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 <walling@xxxxxxxxxxxxx> >> --- >> 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
