4 files changed, 24 insertions, 10 deletions

diff --git a/Documentation/ABI/stable/sysfs-bus-xen-backend b/Documentation/ABI/stable/sysfs-bus-xen-backend
index 3d5951c8bf5f..e8b60bd766f7 100644
--- a/Documentation/ABI/stable/sysfs-bus-xen-backend
+++ b/Documentation/ABI/stable/sysfs-bus-xen-backend
@@ -73,3 +73,12 @@ KernelVersion:	3.0
 Contact:        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 Description:
                 Number of sectors written by the frontend.
+
+What:           /sys/bus/xen-backend/devices/*/state
+Date:           August 2018
+KernelVersion:  4.19
+Contact:        Joe Jin <joe.jin@oracle.com>
+Description:
+                The state of the device. One of: 'Unknown',
+                'Initialising', 'Initialised', 'Connected', 'Closing',
+                'Closed', 'Reconfiguring', 'Reconfigured'.
diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
index a564084c6141..f8b1ad2c3828 100644
--- a/arch/x86/include/asm/pgtable-3level.h
+++ b/arch/x86/include/asm/pgtable-3level.h
@@ -2,6 +2,8 @@
 #ifndef _ASM_X86_PGTABLE_3LEVEL_H
 #define _ASM_X86_PGTABLE_3LEVEL_H
 
+#include <asm/atomic64_32.h>
+
 /*
  * Intel Physical Address Extension (PAE) Mode - three-level page
  * tables on PPro+ CPUs.
@@ -150,10 +152,7 @@ static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
 {
         pte_t res;
 
-        /* xchg acts as a barrier before the setting of the high bits */
-        res.pte_low = xchg(&ptep->pte_low, 0);
-        res.pte_high = ptep->pte_high;
-        ptep->pte_high = 0;
+        res.pte = (pteval_t)arch_atomic64_xchg((atomic64_t *)ptep, 0);
 
         return res;
 }
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 45b700ac5fe7..2fe5c9b1816b 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -435,14 +435,13 @@ static void xen_set_pud(pud_t *ptr, pud_t val)
 static void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
 {
         trace_xen_mmu_set_pte_atomic(ptep, pte);
-        set_64bit((u64 *)ptep, native_pte_val(pte));
+        __xen_set_pte(ptep, pte);
 }
 
 static void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
         trace_xen_mmu_pte_clear(mm, addr, ptep);
-        if (!xen_batched_set_pte(ptep, native_make_pte(0)))
-                native_pte_clear(mm, addr, ptep);
+        __xen_set_pte(ptep, native_make_pte(0));
 }
 
 static void xen_pmd_clear(pmd_t *pmdp)
@@ -1570,7 +1569,7 @@ static void __init xen_set_pte_init(pte_t *ptep, pte_t pte)
                 pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
                                pte_val_ma(pte));
 #endif
-        native_set_pte(ptep, pte);
+        __xen_set_pte(ptep, pte);
 }
 
 /* Early in boot, while setting up the initial pagetable, assume
@@ -2061,7 +2060,6 @@ void __init xen_relocate_p2m(void)
         pud_t *pud;
         pgd_t *pgd;
         unsigned long *new_p2m;
-        int save_pud;
 
         size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
         n_pte = roundup(size, PAGE_SIZE) >> PAGE_SHIFT;
@@ -2091,7 +2089,6 @@ void __init xen_relocate_p2m(void)
 
         pgd = __va(read_cr3_pa());
         new_p2m = (unsigned long *)(2 * PGDIR_SIZE);
-        save_pud = n_pud;
         for (idx_pud = 0; idx_pud < n_pud; idx_pud++) {
                 pud = early_memremap(pud_phys, PAGE_SIZE);
                 clear_page(pud);
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index f2088838f690..5b471889d723 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -402,10 +402,19 @@ static ssize_t modalias_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(modalias);
 
+static ssize_t state_show(struct device *dev,
+                            struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%s\n",
+                        xenbus_strstate(to_xenbus_device(dev)->state));
+}
+static DEVICE_ATTR_RO(state);
+
 static struct attribute *xenbus_dev_attrs[] = {
         &dev_attr_nodename.attr,
         &dev_attr_devtype.attr,
         &dev_attr_modalias.attr,
+        &dev_attr_state.attr,
         NULL,
 };