On 8/10/22 14:56, Claudio Imbrenda wrote:
If the appropriate UV feature bit is set, there is no need to perform
an export before import.
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Reviewed-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
---
arch/s390/kernel/uv.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index f9810d2a267c..b455646c8d74 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -255,6 +255,8 @@ 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)
{
The misc feature indicates that the UV will automatically transfer
ownership from one protected VM to another when importing a shared page.
Other than that:
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
+ 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;
