Merge tag 'kvmarm-fixes-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.12, take #1

- Fix pKVM error path on init, making sure we do not change critical
  system registers as we're about to fail

- Make sure that the host's vector length is at capped by a value
  common to all CPUs

- Fix kvm_has_feat*() handling of "negative" features, as the current
  code is pretty broken

- Promote Joey to the status of official reviewer, while James steps
  down -- hopefully only temporarly

1 files changed, 10 insertions, 6 deletions

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 8e149ef5e89b..ad8b0d6b77ea 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -34,6 +34,7 @@
 #include <linux/uaccess.h>
 #include <linux/hugetlb.h>
 #include <linux/kfence.h>
+#include <linux/pagewalk.h>
 #include <asm/asm-extable.h>
 #include <asm/asm-offsets.h>
 #include <asm/ptrace.h>
@@ -492,9 +493,9 @@ void do_secure_storage_access(struct pt_regs *regs)
 	union teid teid = { .val = regs->int_parm_long };
 	unsigned long addr = get_fault_address(regs);
 	struct vm_area_struct *vma;
+	struct folio_walk fw;
 	struct mm_struct *mm;
 	struct folio *folio;
-	struct page *page;
 	struct gmap *gmap;
 	int rc;
 
@@ -536,15 +537,18 @@ void do_secure_storage_access(struct pt_regs *regs)
 		vma = find_vma(mm, addr);
 		if (!vma)
 			return handle_fault_error(regs, SEGV_MAPERR);
-		page = follow_page(vma, addr, FOLL_WRITE | FOLL_GET);
-		if (IS_ERR_OR_NULL(page)) {
+		folio = folio_walk_start(&fw, vma, addr, 0);
+		if (!folio) {
 			mmap_read_unlock(mm);
 			break;
 		}
-		folio = page_folio(page);
-		if (arch_make_folio_accessible(folio))
-			send_sig(SIGSEGV, current, 0);
+		/* arch_make_folio_accessible() needs a raised refcount. */
+		folio_get(folio);
+		rc = arch_make_folio_accessible(folio);
 		folio_put(folio);
+		folio_walk_end(&fw, vma);
+		if (rc)
+			send_sig(SIGSEGV, current, 0);
 		mmap_read_unlock(mm);
 		break;
 	case KERNEL_FAULT: