From 24fe0195bc19306b2769b43b3e22bd35bd6fb061 Mon Sep 17 00:00:00 2001 From: Pierre Morel Date: Thu, 14 Jul 2022 12:18:23 +0200 Subject: KVM: s390: guest support for topology function 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 it uses the PTF with command 2 instruction that the topology changed and that it 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 supports the CPU Topology facility. Signed-off-by: Pierre Morel Reviewed-by: Nico Boehr Reviewed-by: Janis Schoetterl-Glausch Reviewed-by: Janosch Frank Link: https://lore.kernel.org/r/20220714101824.101601-2-pmorel@linux.ibm.com Message-Id: <20220714101824.101601-2-pmorel@linux.ibm.com> Signed-off-by: Janosch Frank --- arch/s390/kvm/priv.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'arch/s390/kvm/priv.c') diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 12c464c7cddf..3335fa09b6f1 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -873,10 +873,18 @@ static int handle_stsi(struct kvm_vcpu *vcpu) if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); - if (fc > 3) { - kvm_s390_set_psw_cc(vcpu, 3); - return 0; - } + /* Bailout forbidden function codes */ + if (fc > 3 && fc != 15) + goto out_no_data; + + /* + * fc 15 is provided only with + * - PTF/CPU topology support through facility 15 + * - KVM_CAP_S390_USER_STSI + */ + if (fc == 15 && (!test_kvm_facility(vcpu->kvm, 11) || + !vcpu->kvm->arch.user_stsi)) + goto out_no_data; if (vcpu->run->s.regs.gprs[0] & 0x0fffff00 || vcpu->run->s.regs.gprs[1] & 0xffff0000) @@ -910,6 +918,10 @@ static int handle_stsi(struct kvm_vcpu *vcpu) goto out_no_data; handle_stsi_3_2_2(vcpu, (void *) mem); break; + case 15: /* fc 15 is fully handled in userspace */ + insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2); + trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2); + return -EREMOTE; } if (kvm_s390_pv_cpu_is_protected(vcpu)) { memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem, -- cgit v1.2.3