From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Sat, 26 Aug 2017 11:11:07 +0000 (+0000)
Subject: x86/pv: Simplify access to the LDT/GDT ptes
X-Git-Tag: archive/raspbian/4.11.1-1+rpi1~1^2~66^2~1523^2~1
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=d4c5054907f93f87b805501980bf764db7988ee8;p=xen.git

x86/pv: Simplify access to the LDT/GDT ptes

Rename gdt_ldt_ptes() to pv_gdt_ptes() and drop the domain parameter, as it is
incorrect to use the helper with d != v->domain.

Introduce pv_ldt_ptes() to abstract away the fact that the LDT mapping is 16
slots after the GDT, and adjust the callers accordingly.

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

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 57c44b1c29..dbddc536d3 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1591,7 +1591,7 @@ static void __context_switch(void)
     if ( need_full_gdt(nd) )
     {
         unsigned long mfn = virt_to_mfn(gdt);
-        l1_pgentry_t *pl1e = gdt_ldt_ptes(nd, n);
+        l1_pgentry_t *pl1e = pv_gdt_ptes(n);
         unsigned int i;
 
         for ( i = 0; i < NR_RESERVED_GDT_PAGES; i++ )
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 74637a1243..1f23470cef 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -629,9 +629,9 @@ static void invalidate_shadow_ldt(struct vcpu *v, int flush)
         goto out;
 
     v->arch.pv_vcpu.shadow_ldt_mapcnt = 0;
-    pl1e = gdt_ldt_ptes(v->domain, v);
+    pl1e = pv_ldt_ptes(v);
 
-    for ( i = 16; i < 32; i++ )
+    for ( i = 0; i < 16; i++ )
     {
         if ( !(l1e_get_flags(pl1e[i]) & _PAGE_PRESENT) )
             continue;
@@ -707,7 +707,7 @@ bool map_ldt_shadow_page(unsigned int offset)
         return false;
     }
 
-    pl1e = &gdt_ldt_ptes(d, v)[(offset >> PAGE_SHIFT) + 16];
+    pl1e = &pv_ldt_ptes(v)[offset >> PAGE_SHIFT];
     l1e_add_flags(gl1e, _PAGE_RW);
 
     spin_lock(&v->arch.pv_vcpu.shadow_ldt_lock);
@@ -4399,7 +4399,7 @@ void destroy_gdt(struct vcpu *v)
     unsigned long pfn, zero_pfn = PFN_DOWN(__pa(zero_page));
 
     v->arch.pv_vcpu.gdt_ents = 0;
-    pl1e = gdt_ldt_ptes(v->domain, v);
+    pl1e = pv_gdt_ptes(v);
     for ( i = 0; i < FIRST_RESERVED_GDT_PAGE; i++ )
     {
         pfn = l1e_get_pfn(pl1e[i]);
@@ -4444,7 +4444,7 @@ long set_gdt(struct vcpu *v,
 
     /* Install the new GDT. */
     v->arch.pv_vcpu.gdt_ents = entries;
-    pl1e = gdt_ldt_ptes(d, v);
+    pl1e = pv_gdt_ptes(v);
     for ( i = 0; i < nr_pages; i++ )
     {
         v->arch.pv_vcpu.gdt_frames[i] = frames[i];
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index de0250725a..fb8bf17458 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -433,9 +433,10 @@ struct arch_domain
 
 #define gdt_ldt_pt_idx(v) \
       ((v)->vcpu_id >> (PAGETABLE_ORDER - GDT_LDT_VCPU_SHIFT))
-#define gdt_ldt_ptes(d, v) \
-    ((d)->arch.pv_domain.gdt_ldt_l1tab[gdt_ldt_pt_idx(v)] + \
+#define pv_gdt_ptes(v) \
+    ((v)->domain->arch.pv_domain.gdt_ldt_l1tab[gdt_ldt_pt_idx(v)] + \
      (((v)->vcpu_id << GDT_LDT_VCPU_SHIFT) & (L1_PAGETABLE_ENTRIES - 1)))
+#define pv_ldt_ptes(v) (pv_gdt_ptes(v) + 16)
 
 struct pv_vcpu
 {