On 14.02.20 23:26, Christian Borntraeger wrote:
> From: Janosch Frank <frankja@xxxxxxxxxxxxx>
>
> STHYI data has to go through the bounce buffer.
>
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> [borntraeger@xxxxxxxxxx: patch merging, splitting, fixing]
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/kvm/intercept.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
> index 1e231058e4b3..cfabeecbb777 100644
> --- a/arch/s390/kvm/intercept.c
> +++ b/arch/s390/kvm/intercept.c
> @@ -392,7 +392,7 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
> goto out;
> }
>
> - if (addr & ~PAGE_MASK)
> + if (!kvm_s390_pv_is_protected(vcpu->kvm) && (addr & ~PAGE_MASK))
> return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
>
> sctns = (void *)get_zeroed_page(GFP_KERNEL);
> @@ -403,10 +403,15 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
>
> out:
> if (!cc) {
> - r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
> - if (r) {
> - free_page((unsigned long)sctns);
> - return kvm_s390_inject_prog_cond(vcpu, r);
> + if (kvm_s390_pv_is_protected(vcpu->kvm)) {
I have the feeling that we might have to think about proper locking for
kvm_s390_pv_is_protected(). We have to make sure there cannot be any
races with user space. Smells like a new r/w lock maybe.
--
Thanks,
David / dhildenb
