Re: [PATCH v3 1/3] s390x: KVM: accept STSI for CPU topology information

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 03.08.21 10:26, Pierre Morel wrote:
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@xxxxxxxxxxxxx>
---
  arch/s390/kvm/priv.c | 7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 9928f785c677..8581b6881212 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -856,7 +856,8 @@ 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) {
+	if ((fc > 3 && fc != 15) ||
+	    (fc == 15 && !test_kvm_facility(vcpu->kvm, 11))) {
  		kvm_s390_set_psw_cc(vcpu, 3);
  		return 0;
  	}
@@ -893,6 +894,10 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
  			goto out_no_data;
  		handle_stsi_3_2_2(vcpu, (void *) mem);
  		break;
+	case 15:
+		trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
+		insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);
+		return -EREMOTE;
  	}
  	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
  		memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem,


Sorry, I'm a bit rusty on s390x kvm facility handling.


For test_kvm_facility() to succeed, the facility has to be in both:

a) fac_mask: actually available on the HW and supported by KVM (kvm_s390_fac_base via FACILITIES_KVM, kvm_s390_fac_ext via FACILITIES_KVM_CPUMODEL)

b) fac_list: enabled for a VM

AFAIU, facility 11 is neither in FACILITIES_KVM nor FACILITIES_KVM_CPUMODEL, and I remember it's a hypervisor-managed bit.

So unless we unlock facility 11 in FACILITIES_KVM_CPUMODEL, will test_kvm_facility(vcpu->kvm, 11) ever successfully trigger here?


I'm pretty sure I am messing something up :)

--
Thanks,

David / dhildenb




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux