Messages in this thread | | | Date | Mon, 27 Jun 2022 19:40:25 +0200 | Subject | Re: [PATCH v10 2/3] KVM: s390: guest support for topology function | From | Pierre Morel <> |
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On 6/24/22 11:32, Claudio Imbrenda wrote: > On Mon, 20 Jun 2022 14:54:36 +0200 > Pierre Morel <pmorel@linux.ibm.com> wrote: > >> We report a topology change to the guest for any CPU hotplug. >> >> The reporting to the guest is done using the Multiprocessor >> Topology-Change-Report (MTCR) bit of the utility entry in the guest's >> SCA which will be cleared during the interpretation of PTF. >> >> On every vCPU creation we set the MCTR bit to let the guest know the >> next time he uses the PTF with command 2 instruction that the >> topology changed and that he should use the STSI(15.1.x) instruction >> to get the topology details. >> >> STSI(15.1.x) gives information on the CPU configuration topology. >> Let's accept the interception of STSI with the function code 15 and >> let the userland part of the hypervisor handle it when userland >> support the CPU Topology facility. >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> arch/s390/include/asm/kvm_host.h | 11 ++++++++--- >> arch/s390/kvm/kvm-s390.c | 27 ++++++++++++++++++++++++++- >> arch/s390/kvm/priv.c | 15 +++++++++++---- >> arch/s390/kvm/vsie.c | 3 +++ >> 4 files changed, 48 insertions(+), 8 deletions(-) >> >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index 766028d54a3e..bb54196d4ed6 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -97,15 +97,19 @@ struct bsca_block { >> union ipte_control ipte_control; >> __u64 reserved[5]; >> __u64 mcn; >> - __u64 reserved2; >> +#define SCA_UTILITY_MTCR 0x8000 >> + __u16 utility; >> + __u8 reserved2[6]; >> struct bsca_entry cpu[KVM_S390_BSCA_CPU_SLOTS]; >> }; >> >> struct esca_block { >> union ipte_control ipte_control; >> - __u64 reserved1[7]; >> + __u64 reserved1[6]; >> + __u16 utility; >> + __u8 reserved2[6]; >> __u64 mcn[4]; >> - __u64 reserved2[20]; >> + __u64 reserved3[20]; >> struct esca_entry cpu[KVM_S390_ESCA_CPU_SLOTS]; >> }; >> >> @@ -249,6 +253,7 @@ struct kvm_s390_sie_block { >> #define ECB_SPECI 0x08 >> #define ECB_SRSI 0x04 >> #define ECB_HOSTPROTINT 0x02 >> +#define ECB_PTF 0x01 >> __u8 ecb; /* 0x0061 */ >> #define ECB2_CMMA 0x80 >> #define ECB2_IEP 0x20 >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 8fcb56141689..95b96019ca8e 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -1691,6 +1691,25 @@ static int kvm_s390_get_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr) >> return ret; >> } >> >> +/** >> + * kvm_s390_sca_set_mtcr > > the format for kdoc is: > > function_name - very short description > > please add a very short description. something like: > > kvm_s390_sca_set_mtcr - update mtcr to signal topology change
OK, thanks,
Pierre
-- Pierre Morel IBM Lab Boeblingen
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