diff mbox series

[v1,04/11] KVM: s390: pv: handle secure storage exceptions for normal guests

Message ID 20210517200758.22593-5-imbrenda@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series KVM: s390: pv: implement lazy destroy | expand

Commit Message

Claudio Imbrenda May 17, 2021, 8:07 p.m. UTC 
With upcoming patches, normal guests might touch secure pages.

This patch extends the existing exception handler to convert the pages
to non secure also when the exception is triggered by a normal guest.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 arch/s390/mm/fault.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index efdef35bc415..24a39457cd48 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -789,9 +789,20 @@  void do_secure_storage_access(struct pt_regs *regs)
 	struct vm_area_struct *vma;
 	struct mm_struct *mm;
 	struct page *page;
+	struct gmap *gmap;
 	int rc;
 
 	switch (get_fault_type(regs)) {
+	case GMAP_FAULT:
+		gmap = (struct gmap *)S390_lowcore.gmap;
+		/*
+		 * Very unlikely, but if it happens, simply try again.
+		 * The next attempt will trigger a different exception.
+		 */
+		addr = __gmap_translate(gmap, addr);
+		if (addr == -EFAULT)
+			break;
+		fallthrough;
 	case USER_FAULT:
 		mm = current->mm;
 		mmap_read_lock(mm);
@@ -820,7 +831,6 @@  void do_secure_storage_access(struct pt_regs *regs)
 		if (rc)
 			BUG();
 		break;
-	case GMAP_FAULT:
 	default:
 		do_fault_error(regs, VM_READ | VM_WRITE, VM_FAULT_BADMAP);
 		WARN_ON_ONCE(1);