2021-07-22 17:05:10

by Pierre Morel

Subject: [PATCH v2 1/2] s390x: KVM: accept STSI for CPU topology information

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 <[email protected]>
---
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,
--
2.25.1

2021-07-23 08:41:11

by Christian Borntraeger

Subject: Re: [PATCH v2 1/2] s390x: KVM: accept STSI for CPU topology information

On 22.07.21 19:02, 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 <[email protected]>
> ---
> 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))) {

Especially as you use test_kvm_facility here you really want to have the cpu
model in patch 2 (and not CAP).

> 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,
>