Re: [PATCH v4 18/36] KVM: S390: protvirt: Introduce instruction data area bounce buffer

Cornelia Huck
2020-02-25T17:22:21Z

On Tue, 25 Feb 2020 08:50:47 +0100
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> This is the guest breaking event address. So a guest (and QEMU) can read it.
> It is kind of overlaid sida and gbea. Something like this:
>
> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
> index cd81a58349a9..055bf0ec8fbb 100644
> --- a/arch/s390/kvm/pv.c
> +++ b/arch/s390/kvm/pv.c
> @@ -39,6 +39,11 @@ int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
> vcpu->arch.sie_block->pv_handle_config = 0;
> memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv));
> vcpu->arch.sie_block->sdf = 0;
> + /*
> + * the sidad field (for sdf == 2) is now the gbea field (for sdf == 0).

s/the sidad/The sidad/

> + * Use the reset value of gbea to not leak the kernel pointer of the

s/to not leak/to avoid leaking/

> + * just free sida

s/free sida/freed sida./

> + */
> vcpu->arch.sie_block->gbea = 1;
> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
>