[Xen-devel] [PATCH] miscellaneous cleanup

["Jan Beulich" <JBeulich@xxxxxxxx>]

... noticed while putting together the 16Tb support patches for x86.

Briefly, this (in order of the changes below)
- fixes an inefficiency in x86's context switch code (translations to/
  from struct page are more involved than to/from MFNs)
- drop unnecessary MFM-to-page conversions
- drop a redundant call to destroy_xen_mappings() (an indentical call
  is being made a few lines up)
- simplify a VA-to-MFN translation
- drop dead code (several occurrences)
- add a missing __init annotation

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -1512,12 +1512,12 @@ static void __context_switch(void)
                                   per_cpu(compat_gdt_table, cpu);
     if ( need_full_gdt(n) )
     {
-        struct page_info *page = virt_to_page(gdt);
+        unsigned long mfn = virt_to_mfn(gdt);
         unsigned int i;
         for ( i = 0; i < NR_RESERVED_GDT_PAGES; i++ )
             l1e_write(n->arch.perdomain_ptes +
                       FIRST_RESERVED_GDT_PAGE + i,
-                      l1e_from_page(page + i, __PAGE_HYPERVISOR));
+                      l1e_from_pfn(mfn + i, __PAGE_HYPERVISOR));
     }
 
     if ( need_full_gdt(p) &&
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -422,11 +422,10 @@ void destroy_m2p_mapping(struct mem_hota
  */
 static int setup_compat_m2p_table(struct mem_hotadd_info *info)
 {
-    unsigned long i, va, smap, emap, rwva, epfn = info->epfn;
+    unsigned long i, va, smap, emap, rwva, epfn = info->epfn, mfn;
     unsigned int n;
     l3_pgentry_t *l3_ro_mpt = NULL;
     l2_pgentry_t *l2_ro_mpt = NULL;
-    struct page_info *l1_pg;
     int err = 0;
 
     smap = info->spfn & (~((1UL << (L2_PAGETABLE_SHIFT - 2)) -1));
@@ -475,16 +474,16 @@ static int setup_compat_m2p_table(struct
         if ( n == CNT )
             continue;
 
-        l1_pg = mfn_to_page(alloc_hotadd_mfn(info));
-        err = map_pages_to_xen(rwva, page_to_mfn(l1_pg),
-                               1UL << PAGETABLE_ORDER,
+        mfn = alloc_hotadd_mfn(info);
+        err = map_pages_to_xen(rwva, mfn, 1UL << PAGETABLE_ORDER,
                                PAGE_HYPERVISOR);
         if ( err )
             break;
         /* Fill with INVALID_M2P_ENTRY. */
         memset((void *)rwva, 0xFF, 1UL << L2_PAGETABLE_SHIFT);
         /* NB. Cannot be GLOBAL as the ptes get copied into per-VM space. */
-        l2e_write(&l2_ro_mpt[l2_table_offset(va)], l2e_from_page(l1_pg, 
_PAGE_PSE|_PAGE_PRESENT));
+        l2e_write(&l2_ro_mpt[l2_table_offset(va)],
+                  l2e_from_pfn(mfn, _PAGE_PSE|_PAGE_PRESENT));
     }
 #undef CNT
 #undef MFN
@@ -501,7 +500,7 @@ static int setup_m2p_table(struct mem_ho
     unsigned int n, memflags;
     l2_pgentry_t *l2_ro_mpt = NULL;
     l3_pgentry_t *l3_ro_mpt = NULL;
-    struct page_info *l1_pg, *l2_pg;
+    struct page_info *l2_pg;
     int ret = 0;
 
     ASSERT(l4e_get_flags(idle_pg_table[l4_table_offset(RO_MPT_VIRT_START)])
@@ -544,15 +543,13 @@ static int setup_m2p_table(struct mem_ho
         for ( n = 0; n < CNT; ++n)
             if ( mfn_valid(i + n * PDX_GROUP_COUNT) )
                 break;
-        if ( n == CNT )
-            l1_pg = NULL;
-        else
+        if ( n < CNT )
         {
-            l1_pg = mfn_to_page(alloc_hotadd_mfn(info));
+            unsigned long mfn = alloc_hotadd_mfn(info);
+
             ret = map_pages_to_xen(
                         RDWR_MPT_VIRT_START + i * sizeof(unsigned long),
-                        page_to_mfn(l1_pg),
-                        1UL << PAGETABLE_ORDER,
+                        mfn, 1UL << PAGETABLE_ORDER,
                         PAGE_HYPERVISOR);
             if ( ret )
                 goto error;
@@ -584,7 +581,7 @@ static int setup_m2p_table(struct mem_ho
             }
 
             /* NB. Cannot be GLOBAL as shadow_mode_translate reuses this area. 
*/
-            l2e_write(l2_ro_mpt, l2e_from_page(l1_pg,
+            l2e_write(l2_ro_mpt, l2e_from_pfn(mfn,
                    /*_PAGE_GLOBAL|*/_PAGE_PSE|_PAGE_USER|_PAGE_PRESENT));
         }
         if ( !((unsigned long)l2_ro_mpt & ~PAGE_MASK) )
@@ -1548,8 +1545,6 @@ destroy_frametable:
     NODE_DATA(node)->node_start_pfn = old_node_start;
     NODE_DATA(node)->node_spanned_pages = old_node_span;
 
-    destroy_xen_mappings((unsigned long)mfn_to_virt(spfn),
-                         (unsigned long)mfn_to_virt(epfn));
     return ret;
 }
 
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -156,7 +156,7 @@ void getdomaininfo(struct domain *d, str
     info->max_pages         = d->max_pages;
     info->shr_pages         = atomic_read(&d->shr_pages);
     info->paged_pages       = atomic_read(&d->paged_pages);
-    info->shared_info_frame = mfn_to_gmfn(d, __pa(d->shared_info)>>PAGE_SHIFT);
+    info->shared_info_frame = mfn_to_gmfn(d, virt_to_mfn(d->shared_info));
     BUG_ON(SHARED_M2P(info->shared_info_frame));
 
     info->cpupool = d->cpupool ? d->cpupool->cpupool_id : CPUPOOLID_NONE;
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -121,7 +121,6 @@ extern unsigned long xenheap_virt_end;
 #define page_set_owner(_p,_d) ((_p)->v.inuse.domain = (_d))
 
 #define maddr_get_owner(ma)   (page_get_owner(maddr_to_page((ma))))
-#define vaddr_get_owner(va)   (page_get_owner(virt_to_page((va))))
 
 #define XENSHARE_writable 0
 #define XENSHARE_readonly 1
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -275,12 +275,8 @@ extern unsigned long xen_phys_start;
 /* GDT/LDT shadow mapping area. The first per-domain-mapping sub-area. */
 #define GDT_LDT_VCPU_SHIFT       5
 #define GDT_LDT_VCPU_VA_SHIFT    (GDT_LDT_VCPU_SHIFT + PAGE_SHIFT)
-#ifdef MAX_VIRT_CPUS
-#define GDT_LDT_MBYTES           (MAX_VIRT_CPUS >> (20-GDT_LDT_VCPU_VA_SHIFT))
-#else
 #define GDT_LDT_MBYTES           PERDOMAIN_MBYTES
 #define MAX_VIRT_CPUS            (GDT_LDT_MBYTES << (20-GDT_LDT_VCPU_VA_SHIFT))
-#endif
 #define GDT_LDT_VIRT_START       PERDOMAIN_VIRT_START
 #define GDT_LDT_VIRT_END         (GDT_LDT_VIRT_START + (GDT_LDT_MBYTES << 20))
 
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -265,7 +265,6 @@ struct spage_info
     ((_p)->v.inuse._domain = (_d) ? virt_to_pdx(_d) : 0)
 
 #define maddr_get_owner(ma)   (page_get_owner(maddr_to_page((ma))))
-#define vaddr_get_owner(va)   (page_get_owner(virt_to_page((va))))
 
 #define XENSHARE_writable 0
 #define XENSHARE_readonly 1
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -261,18 +261,6 @@ void copy_page_sse2(void *, const void *
 
 #endif /* !defined(__ASSEMBLY__) */
 
-/* High table entries are reserved by the hypervisor. */
-#define DOMAIN_ENTRIES_PER_L2_PAGETABLE     0
-#define HYPERVISOR_ENTRIES_PER_L2_PAGETABLE 0
-
-#define DOMAIN_ENTRIES_PER_L4_PAGETABLE     \
-    (l4_table_offset(HYPERVISOR_VIRT_START))
-#define GUEST_ENTRIES_PER_L4_PAGETABLE     \
-    (l4_table_offset(HYPERVISOR_VIRT_END))
-#define HYPERVISOR_ENTRIES_PER_L4_PAGETABLE \
-    (L4_PAGETABLE_ENTRIES - GUEST_ENTRIES_PER_L4_PAGETABLE  \
-     + DOMAIN_ENTRIES_PER_L4_PAGETABLE)
-
 /* Where to find each level of the linear mapping */
 #define __linear_l1_table ((l1_pgentry_t *)(LINEAR_PT_VIRT_START))
 #define __linear_l2_table \
--- a/xen/xsm/xsm_policy.c
+++ b/xen/xsm/xsm_policy.c
@@ -25,8 +25,9 @@
 char *__initdata policy_buffer = NULL;
 u32 __initdata policy_size = 0;
 
-int xsm_policy_init(unsigned long *module_map, const multiboot_info_t *mbi,
-                    void *(*bootstrap_map)(const module_t *))
+int __init xsm_policy_init(unsigned long *module_map,
+                           const multiboot_info_t *mbi,
+                           void *(*bootstrap_map)(const module_t *))
 {
     int i;
     module_t *mod = (module_t *)__va(mbi->mods_addr);

Attachment: misc-cleanup.patch
Description: Text document

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