On 27.03.20 11:23, Christian Borntraeger wrote:
> On 27.03.20 10:23, Christian Borntraeger wrote:
>> If a signal is pending we might return -ENOMEM instead of -EINTR.
>> We should propagate the proper error during KSM unsharing.
>>
>> Fixes: 3ac8e38015d4 ("s390/mm: disable KSM for storage key enabled pages")
>> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>> ---
>> arch/s390/mm/gmap.c | 9 +++++----
>> 1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
>> index 27926a06df32..1ef864c252e6 100644
>> --- a/arch/s390/mm/gmap.c
>> +++ b/arch/s390/mm/gmap.c
>> @@ -2552,12 +2552,13 @@ int gmap_mark_unmergeable(void)
>> {
>> struct mm_struct *mm = current->mm;
>> struct vm_area_struct *vma;
>> + int ret;
>>
>> for (vma = mm->mmap; vma; vma = vma->vm_next) {
>> - if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
>> - MADV_UNMERGEABLE, &vma->vm_flags)) {
>> - return -ENOMEM;
>> - }
>> + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
>> + MADV_UNMERGEABLE, &vma->vm_flags);
>> + if (ret)
>> + return ret;
>> }
>> mm->def_flags &= ~VM_MERGEABLE;
>> return 0;
>
>
> After the qemu patch discussion I would add
>
>
> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index 0e268b3d1591..ba8f9cbe4376 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -4680,6 +4680,12 @@ KVM_PV_ENABLE
> command has succeeded, any CPU added via hotplug will become
> protected during its creation as well.
>
> + Errors:
> +
> + ===== =============================
> + EINTR an unmasked signal is pending
> + ===== =============================
> +
> KVM_PV_DISABLE
>
> Deregister the VM from the Ultravisor and reclaim the memory that
>
>
> and change the patch description to something like
>
>
> s390/gmap: return proper error code on ksm unsharing
>
> If a signal is pending we might return -ENOMEM instead of -EINTR.
> We should propagate the proper error during KSM unsharing.
> unmerge_ksm_pages returns -ERESTARTSYS on signal_pending. This gets
> translated by entry.S to -EINTR. It is important to get this error
> code so that userspace can retry.
>
> Fixes: 3ac8e38015d4 ("s390/mm: disable KSM for storage key enabled pages")
> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
> Reported-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxx>
> Tested-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>
Looks good.
--
Thanks,
David / dhildenb
