3 files changed, 37 insertions, 8 deletions

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 8b901e8d782d..a61c7d5811be 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -879,7 +879,6 @@ int m2p_add_override(unsigned long mfn, struct page *page,
         unsigned long uninitialized_var(address);
         unsigned level;
         pte_t *ptep = NULL;
-        int ret = 0;
 
         pfn = page_to_pfn(page);
         if (!PageHighMem(page)) {
@@ -926,8 +925,8 @@ int m2p_add_override(unsigned long mfn, struct page *page,
          * frontend pages while they are being shared with the backend,
          * because mfn_to_pfn (that ends up being called by GUPF) will
          * return the backend pfn rather than the frontend pfn. */
-        ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
-        if (ret == 0 && get_phys_to_machine(pfn) == mfn)
+        pfn = mfn_to_pfn_no_overrides(mfn);
+        if (get_phys_to_machine(pfn) == mfn)
                 set_phys_to_machine(pfn, FOREIGN_FRAME(mfn));
 
         return 0;
@@ -942,7 +941,6 @@ int m2p_remove_override(struct page *page,
         unsigned long uninitialized_var(address);
         unsigned level;
         pte_t *ptep = NULL;
-        int ret = 0;
 
         pfn = page_to_pfn(page);
         mfn = get_phys_to_machine(pfn);
@@ -1029,8 +1027,8 @@ int m2p_remove_override(struct page *page,
          * the original pfn causes mfn_to_pfn(mfn) to return the frontend
          * pfn again. */
         mfn &= ~FOREIGN_FRAME_BIT;
-        ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
-        if (ret == 0 && get_phys_to_machine(pfn) == FOREIGN_FRAME(mfn) &&
+        pfn = mfn_to_pfn_no_overrides(mfn);
+        if (get_phys_to_machine(pfn) == FOREIGN_FRAME(mfn) &&
                         m2p_find_override(mfn) == NULL)
                 set_phys_to_machine(pfn, mfn);
 
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index d1e4777b4e75..31d04758b76f 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -278,6 +278,15 @@ static void __init xen_smp_prepare_boot_cpu(void)
                    old memory can be recycled */
                 make_lowmem_page_readwrite(xen_initial_gdt);
 
+#ifdef CONFIG_X86_32
+                /*
+                 * Xen starts us with XEN_FLAT_RING1_DS, but linux code
+                 * expects __USER_DS
+                 */
+                loadsegment(ds, __USER_DS);
+                loadsegment(es, __USER_DS);
+#endif
+
                 xen_filter_cpu_maps();
                 xen_setup_vcpu_info_placement();
         }
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 253f63fceea1..be6b86078957 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -259,6 +259,14 @@ void xen_uninit_lock_cpu(int cpu)
 }
 
 
+/*
+ * Our init of PV spinlocks is split in two init functions due to us
+ * using paravirt patching and jump labels patching and having to do
+ * all of this before SMP code is invoked.
+ *
+ * The paravirt patching needs to be done _before_ the alternative asm code
+ * is started, otherwise we would not patch the core kernel code.
+ */
 void __init xen_init_spinlocks(void)
 {
 
@@ -267,12 +275,26 @@ void __init xen_init_spinlocks(void)
                 return;
         }
 
-        static_key_slow_inc(&paravirt_ticketlocks_enabled);
-
         pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(xen_lock_spinning);
         pv_lock_ops.unlock_kick = xen_unlock_kick;
 }
 
+/*
+ * While the jump_label init code needs to happend _after_ the jump labels are
+ * enabled and before SMP is started. Hence we use pre-SMP initcall level
+ * init. We cannot do it in xen_init_spinlocks as that is done before
+ * jump labels are activated.
+ */
+static __init int xen_init_spinlocks_jump(void)
+{
+        if (!xen_pvspin)
+                return 0;
+
+        static_key_slow_inc(&paravirt_ticketlocks_enabled);
+        return 0;
+}
+early_initcall(xen_init_spinlocks_jump);
+
 static __init int xen_parse_nopvspin(char *arg)
 {
         xen_pvspin = false;