From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Wed, 23 Aug 2017 16:47:42 +0000 (+0000)
Subject: x86/pv: Minor improvements to guest_get_eff_{,kern}_l1e()
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~1564
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=cb7a030a22e8a1c3f71543694d5a2ab9e59e1a87;p=xen.git

x86/pv: Minor improvements to guest_get_eff_{,kern}_l1e()

 * These functions work in terms of linear addresses, not virtual addresses.
   Update the comments and parameter names.
 * Drop unnecessary inlines.
 * Drop vcpu parameter from guest_get_eff_kern_l1e().  Its sole caller passes
   current, and its callee strictly operates on current.
 * Switch guest_get_eff_kern_l1e()'s parameter from void * to l1_pgentry_t *.
   Both its caller and callee already use the correct type already.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 1f60d6bd39..d5b8a3c548 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -567,15 +567,15 @@ static inline void guest_unmap_l1e(void *p)
     unmap_domain_page(p);
 }
 
-/* Read a PV guest's l1e that maps this virtual address. */
-static inline void guest_get_eff_l1e(unsigned long addr, l1_pgentry_t *eff_l1e)
+/* Read a PV guest's l1e that maps this linear address. */
+static void guest_get_eff_l1e(unsigned long linear, l1_pgentry_t *eff_l1e)
 {
     ASSERT(!paging_mode_translate(current->domain));
     ASSERT(!paging_mode_external(current->domain));
 
-    if ( unlikely(!__addr_ok(addr)) ||
+    if ( unlikely(!__addr_ok(linear)) ||
          __copy_from_user(eff_l1e,
-                          &__linear_l1_table[l1_linear_offset(addr)],
+                          &__linear_l1_table[l1_linear_offset(linear)],
                           sizeof(l1_pgentry_t)) )
         *eff_l1e = l1e_empty();
 }
@@ -584,18 +584,18 @@ static inline void guest_get_eff_l1e(unsigned long addr, l1_pgentry_t *eff_l1e)
  * Read the guest's l1e that maps this address, from the kernel-mode
  * page tables.
  */
-static inline void guest_get_eff_kern_l1e(struct vcpu *v, unsigned long addr,
-                                          void *eff_l1e)
+static void guest_get_eff_kern_l1e(unsigned long linear, l1_pgentry_t *eff_l1e)
 {
-    const bool user_mode = !(v->arch.flags & TF_kernel_mode);
+    struct vcpu *curr = current;
+    const bool user_mode = !(curr->arch.flags & TF_kernel_mode);
 
     if ( user_mode )
-        toggle_guest_mode(v);
+        toggle_guest_mode(curr);
 
-    guest_get_eff_l1e(addr, eff_l1e);
+    guest_get_eff_l1e(linear, eff_l1e);
 
     if ( user_mode )
-        toggle_guest_mode(v);
+        toggle_guest_mode(curr);
 }
 
 static inline void page_set_tlbflush_timestamp(struct page_info *page)
@@ -682,7 +682,7 @@ int map_ldt_shadow_page(unsigned int off)
 
     if ( is_pv_32bit_domain(d) )
         gva = (u32)gva;
-    guest_get_eff_kern_l1e(v, gva, &l1e);
+    guest_get_eff_kern_l1e(gva, &l1e);
     if ( unlikely(!(l1e_get_flags(l1e) & _PAGE_PRESENT)) )
         return 0;