Re: [PATCH v10 18/19] KVM: s390: pv: avoid export before import if possible
From: Nico Boehr
Date: Mon May 30 2022 - 06:07:57 EST
On Thu, 2022-04-14 at 10:03 +0200, Claudio Imbrenda wrote:
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index e358b8bd864b..43393568f844 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -236,7 +236,8 @@ static int make_secure_pte(pte_t *ptep, unsigned
> long addr,
>
> static bool should_export_before_import(struct uv_cb_header *uvcb,
> struct mm_struct *mm)
> {
> - return uvcb->cmd != UVC_CMD_UNPIN_PAGE_SHARED &&
> + return !test_bit_inv(BIT_UV_FEAT_MISC,
> &uv_info.uv_feature_indications) &&
> + uvcb->cmd != UVC_CMD_UNPIN_PAGE_SHARED &&
> atomic_read(&mm->context.protected_count) > 1;
This might be nicer to read like this:
if (test_bit_inv(BIT_UV_FEAT_MISC, &uv_info.uv_feature_indications))
return false;
if (uvcb->cmd == UVC_CMD_UNPIN_PAGE_SHARED)
return false;
return atomic_read(&mm->context.protected_count) > 1;