Merge tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:

 - Add swap entry for hugetlbfs support

 - Add PTE_MARKER support for hugetlbs mappings; this fixes a regression
   (possible page fault loop) which was introduced when support for
   UFFDIO_POISON for hugetlbfs was added

 - Add ARCH_HAS_PREEMPT_LAZY and PREEMPT_DYNAMIC support

 - Mark IRQ entries in entry code, so that stack tracers can filter out
   the non-IRQ parts of stack traces. This fixes stack depot capacity
   limit warnings, since without filtering the number of unique stack
   traces is huge

 - In PCI code fix leak of struct zpci_dev object, and fix potential
   double remove of hotplug slot

 - Fix pagefault_disable() / pagefault_enable() unbalance in
   arch_stack_user_walk_common()

 - A couple of inline assembly optimizations, more cmpxchg() to
   try_cmpxchg() conversions, and removal of usages of xchg() and
   cmpxchg() on one and two byte memory areas

 - Various other small improvements and cleanups

* tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (27 commits)
  Revert "s390/mm: Allow large pages for KASAN shadow mapping"
  s390/spinlock: Use flag output constraint for arch_cmpxchg_niai8()
  s390/spinlock: Use R constraint for arch_load_niai4()
  s390/spinlock: Generate shorter code for arch_spin_unlock()
  s390/spinlock: Remove condition code clobber from arch_spin_unlock()
  s390/spinlock: Use symbolic names in inline assemblies
  s390: Support PREEMPT_DYNAMIC
  s390/pci: Fix potential double remove of hotplug slot
  s390/pci: Fix leak of struct zpci_dev when zpci_add_device() fails
  s390/mm/hugetlbfs: Add missing includes
  s390/mm: Add PTE_MARKER support for hugetlbfs mappings
  s390/mm: Introduce region-third and segment table swap entries
  s390/mm: Introduce region-third and segment table entry present bits
  s390/mm: Rearrange region-third and segment table entry SW bits
  KVM: s390: Increase size of union sca_utility to four bytes
  KVM: s390: Remove one byte cmpxchg() usage
  KVM: s390: Use try_cmpxchg() instead of cmpxchg() loops
  s390/ap: Replace xchg() with WRITE_ONCE()
  s390/mm: Allow large pages for KASAN shadow mapping
  s390: Add ARCH_HAS_PREEMPT_LAZY support
  ...

2 files changed, 23 insertions, 11 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index e14638936de6..26e1ea1940ec 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -453,7 +453,7 @@ static void ap_tasklet_fn(unsigned long dummy)
 	 * important that no requests on any AP get lost.
 	 */
 	if (ap_irq_flag)
-		xchg(ap_airq.lsi_ptr, 0);
+		WRITE_ONCE(*ap_airq.lsi_ptr, 0);
 
 	spin_lock_bh(&ap_queues_lock);
 	hash_for_each(ap_queues, bkt, aq, hnode) {
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 8c0b40d8eb39..a52c2690933f 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -360,10 +360,26 @@ static int vfio_ap_validate_nib(struct kvm_vcpu *vcpu, dma_addr_t *nib)
 	return 0;
 }
 
-static int ensure_nib_shared(unsigned long addr, struct gmap *gmap)
+/**
+ * ensure_nib_shared() - Ensure the address of the NIB is secure and shared
+ * @addr: the physical (absolute) address of the NIB
+ *
+ * This function checks whether the NIB page, which has been pinned with
+ * vfio_pin_pages(), is a shared page belonging to a secure guest.
+ *
+ * It will call uv_pin_shared() on it; if the page was already pinned shared
+ * (i.e. if the NIB belongs to a secure guest and is shared), then 0
+ * (success) is returned. If the NIB was not shared, vfio_pin_pages() had
+ * exported it and now it does not belong to the secure guest anymore. In
+ * that case, an error is returned.
+ *
+ * Context: the NIB (at physical address @addr) has to be pinned with
+ *	    vfio_pin_pages() before calling this function.
+ *
+ * Return: 0 in case of success, otherwise an error < 0.
+ */
+static int ensure_nib_shared(unsigned long addr)
 {
-	int ret;
-
 	/*
 	 * The nib has to be located in shared storage since guest and
 	 * host access it. vfio_pin_pages() will do a pin shared and
@@ -374,12 +390,7 @@ static int ensure_nib_shared(unsigned long addr, struct gmap *gmap)
 	 *
 	 * If the page is already pinned shared the UV will return a success.
 	 */
-	ret = uv_pin_shared(addr);
-	if (ret) {
-		/* vfio_pin_pages() likely exported the page so let's re-import */
-		gmap_convert_to_secure(gmap, addr);
-	}
-	return ret;
+	return uv_pin_shared(addr);
 }
 
 /**
@@ -425,6 +436,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
 		return status;
 	}
 
+	/* The pin will probably be successful even if the NIB was not shared */
 	ret = vfio_pin_pages(&q->matrix_mdev->vdev, nib, 1,
 			     IOMMU_READ | IOMMU_WRITE, &h_page);
 	switch (ret) {
@@ -447,7 +459,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
 
 	/* NIB in non-shared storage is a rc 6 for PV guests */
 	if (kvm_s390_pv_cpu_is_protected(vcpu) &&
-	    ensure_nib_shared(h_nib & PAGE_MASK, kvm->arch.gmap)) {
+	    ensure_nib_shared(h_nib & PAGE_MASK)) {
 		vfio_unpin_pages(&q->matrix_mdev->vdev, nib, 1);
 		status.response_code = AP_RESPONSE_INVALID_ADDRESS;
 		return status;