On Mon, 3 Feb 2020 08:19:57 -0500
Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
> From: Janosch Frank <frankja@xxxxxxxxxxxxx>
>
> For protected VMs, the VCPU resets are done by the Ultravisor, as KVM
> has no access to the VCPU registers.
>
> As the Ultravisor will only accept a call for the reset that is
> needed, we need to fence the UV calls when chaining resets.
Stale note, chaining resets is gone?
"Note that the ultravisor will only accept a call for the exact reset
that has been requested." ?
>
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> ---
> arch/s390/kvm/kvm-s390.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 3e4716b3fc02..f7a3f84be064 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -4699,6 +4699,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> void __user *argp = (void __user *)arg;
> int idx;
> long r;
> + u32 ret;
>
> vcpu_load(vcpu);
>
> @@ -4720,14 +4721,33 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> case KVM_S390_CLEAR_RESET:
> r = 0;
> kvm_arch_vcpu_ioctl_clear_reset(vcpu);
> + if (kvm_s390_pv_handle_cpu(vcpu)) {
> + r = uv_cmd_nodata(kvm_s390_pv_handle_cpu(vcpu),
> + UVC_CMD_CPU_RESET_CLEAR, &ret);
> + VCPU_EVENT(vcpu, 3, "PROTVIRT RESET CLEAR VCPU: cpu %d rc %x rrc %x",
> + vcpu->vcpu_id, ret >> 16, ret & 0x0000ffff);
I think VCPU_EVENT() already traces the vcpu_id, doesn't it?
> + }
> break;
> case KVM_S390_INITIAL_RESET:
> r = 0;
> kvm_arch_vcpu_ioctl_initial_reset(vcpu);
> + if (kvm_s390_pv_handle_cpu(vcpu)) {
> + r = uv_cmd_nodata(kvm_s390_pv_handle_cpu(vcpu),
> + UVC_CMD_CPU_RESET_INITIAL,
> + &ret);
> + VCPU_EVENT(vcpu, 3, "PROTVIRT RESET INITIAL VCPU: cpu %d rc %x rrc %x",
> + vcpu->vcpu_id, ret >> 16, ret & 0x0000ffff);
> + }
> break;
> case KVM_S390_NORMAL_RESET:
> r = 0;
> kvm_arch_vcpu_ioctl_normal_reset(vcpu);
> + if (kvm_s390_pv_handle_cpu(vcpu)) {
> + r = uv_cmd_nodata(kvm_s390_pv_handle_cpu(vcpu),
> + UVC_CMD_CPU_RESET, &ret);
> + VCPU_EVENT(vcpu, 3, "PROTVIRT RESET NORMAL VCPU: cpu %d rc %x rrc %x",
> + vcpu->vcpu_id, ret >> 16, ret & 0x0000ffff);
> + }
> break;
> case KVM_SET_ONE_REG:
> case KVM_GET_ONE_REG: {
Otherwise, looks good.
