| Message ID | 20220414080311.1084834-19-imbrenda@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: pv: implement lazy destroy for reboot | expand |
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;
On Mon, 30 May 2022 12:07:43 +0200 Nico Boehr <nrb@linux.ibm.com> wrote: > 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; fair enough then I'll also fix patch 6 in a similar way, the function is first introduced there
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; }
If the appropriate UV feature bit is set, there is no need to perform an export before import. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> --- arch/s390/kernel/uv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)