x86: don't maintain compat M2P when !PV32

It's effectively unused in this case (as well as when "pv=no-32").

While touching their definitions anyway, also adjust section placement
of m2p_compat_vstart and compat_idle_pg_table_l2. Similarly, while
putting init_xen_pae_l2_slots() inside #ifdef, also move it to a PV-only
source file.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 00ef05b4af76263a104030674a604817464e7966..66975d5f2c3cd34cceea8abdec5b94a98bd0b4eb 100644 (file)
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -764,8 +764,10 @@ int arch_domain_create(struct domain *d,
     }
     d->arch.emulation_flags = emflags;
 
+#ifdef CONFIG_PV32
     HYPERVISOR_COMPAT_VIRT_START(d) =
         is_pv_domain(d) ? __HYPERVISOR_COMPAT_VIRT_START : ~0u;
+#endif
 
     if ( (rc = paging_domain_init(d)) != 0 )
         goto fail;

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 638f6bf580d0f2ca3bc6692eda31f5144f021624..35ec0e11f68e99e119aac23b0c662e2bb4eb0054 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -1427,13 +1427,6 @@ static bool pae_xen_mappings_check(const struct domain *d,
     return true;
 }
 
-void init_xen_pae_l2_slots(l2_pgentry_t *l2t, const struct domain *d)
-{
-    memcpy(&l2t[COMPAT_L2_PAGETABLE_FIRST_XEN_SLOT(d)],
-           compat_idle_pg_table_l2,
-           COMPAT_L2_PAGETABLE_XEN_SLOTS(d) * sizeof(*l2t));
-}
-
 static int promote_l2_table(struct page_info *page, unsigned long type)
 {
     struct domain *d = page_get_owner(page);

diff --git a/xen/arch/x86/pv/mm.c b/xen/arch/x86/pv/mm.c
index 5d4cd009410b800f1ca96e6e076010bd179dcaf7..14cb0f2d4ecea92690445f9bfceb6d45d1fc7a6a 100644 (file)
--- a/xen/arch/x86/pv/mm.c
+++ b/xen/arch/x86/pv/mm.c
@@ -128,6 +128,15 @@ bool pv_map_ldt_shadow_page(unsigned int offset)
     return true;
 }
 
+#ifdef CONFIG_PV32
+void init_xen_pae_l2_slots(l2_pgentry_t *l2t, const struct domain *d)
+{
+    memcpy(&l2t[COMPAT_L2_PAGETABLE_FIRST_XEN_SLOT(d)],
+           compat_idle_pg_table_l2,
+           COMPAT_L2_PAGETABLE_XEN_SLOTS(d) * sizeof(*l2t));
+}
+#endif
+
 /*
  * Local variables:
  * mode: C

diff --git a/xen/arch/x86/x86_64/compat/mm.c b/xen/arch/x86/x86_64/compat/mm.c
index d4c6be3032bb43b7b1d379a4e3f509d450426f8a..febdaa1977e4252c01580f5ce1e142aec30dc90c 100644 (file)
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -103,6 +103,9 @@ int compat_arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
             .max_mfn = MACH2PHYS_COMPAT_NR_ENTRIES(d) - 1
         };
 
+        if ( !opt_pv32 )
+            return -EOPNOTSUPP;
+
         if ( copy_to_guest(arg, &mapping, 1) )
             rc = -EFAULT;
 
@@ -115,6 +118,9 @@ int compat_arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         unsigned long limit;
         compat_pfn_t last_mfn;
 
+        if ( !opt_pv32 )
+            return -EOPNOTSUPP;
+
         if ( copy_from_guest(&xmml, arg, 1) )
             return -EFAULT;
 

diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c
index 227eba911e15df8d363f224bf458336831791ce8..29048d34dcd478887b4c16753c3c24e62ebc8618 100644 (file)
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -34,17 +34,30 @@ EMIT_FILE;
 #include <asm/fixmap.h>
 #include <asm/hypercall.h>
 #include <asm/msr.h>
+#include <asm/pv/domain.h>
 #include <asm/setup.h>
 #include <asm/numa.h>
 #include <asm/mem_paging.h>
 #include <asm/mem_sharing.h>
 #include <public/memory.h>
 
+#ifdef CONFIG_PV32
+
 #define compat_machine_to_phys_mapping ((unsigned int *)RDWR_COMPAT_MPT_VIRT_START)
 
-unsigned int __read_mostly m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START;
+unsigned int __initdata m2p_compat_vstart = __HYPERVISOR_COMPAT_VIRT_START;
+
+l2_pgentry_t *__read_mostly compat_idle_pg_table_l2;
+
+#else /* !CONFIG_PV32 */
+
+/*
+ * Declare the symbol such that (dead) code referencing it can be built
+ * without a lot of #ifdef-ary (relying on DCE by the compiler).
+ */
+extern unsigned int compat_machine_to_phys_mapping[];
 
-l2_pgentry_t *compat_idle_pg_table_l2;
+#endif /* CONFIG_PV32 */
 
 void *do_page_walk(struct vcpu *v, unsigned long addr)
 {
@@ -220,7 +233,8 @@ static void destroy_compat_m2p_mapping(struct mem_hotadd_info *info)
 {
     unsigned long i, smap = info->spfn, emap = info->spfn;
 
-    if ( smap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2) )
+    if ( !opt_pv32 ||
+         smap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2) )
         return;
 
     if ( emap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2) )
@@ -328,7 +342,8 @@ static int setup_compat_m2p_table(struct mem_hotadd_info *info)
      * Notice: For hot-added memory, only range below m2p_compat_vstart
      * will be filled up (assuming memory is discontinous when booting).
      */
-    if   ((smap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2)) )
+    if ( !opt_pv32 ||
+         (smap > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2)) )
         return 0;
 
     if ( epfn > ((RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) >> 2) )
@@ -611,17 +626,24 @@ void __init paging_init(void)
 #undef MFN
 
     /* Create user-accessible L2 directory to map the MPT for compat guests. */
-    if ( (l2_ro_mpt = alloc_xen_pagetable()) == NULL )
-        goto nomem;
-    compat_idle_pg_table_l2 = l2_ro_mpt;
-    clear_page(l2_ro_mpt);
-    /* Allocate and map the compatibility mode machine-to-phys table. */
-    mpt_size = (mpt_size >> 1) + (1UL << (L2_PAGETABLE_SHIFT - 1));
-    if ( mpt_size > RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START )
-        mpt_size = RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START;
-    mpt_size &= ~((1UL << L2_PAGETABLE_SHIFT) - 1UL);
-    if ( (m2p_compat_vstart + mpt_size) < MACH2PHYS_COMPAT_VIRT_END )
-        m2p_compat_vstart = MACH2PHYS_COMPAT_VIRT_END - mpt_size;
+    if ( opt_pv32 )
+    {
+        if ( (l2_ro_mpt = alloc_xen_pagetable()) == NULL )
+            goto nomem;
+        compat_idle_pg_table_l2 = l2_ro_mpt;
+        clear_page(l2_ro_mpt);
+
+        /* Allocate and map the compatibility mode machine-to-phys table. */
+        mpt_size = (mpt_size >> 1) + (1UL << (L2_PAGETABLE_SHIFT - 1));
+        if ( mpt_size > RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START )
+            mpt_size = RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START;
+        mpt_size &= ~((1UL << L2_PAGETABLE_SHIFT) - 1UL);
+        if ( (m2p_compat_vstart + mpt_size) < MACH2PHYS_COMPAT_VIRT_END )
+            m2p_compat_vstart = MACH2PHYS_COMPAT_VIRT_END - mpt_size;
+    }
+    else
+        mpt_size = 0;
+
 #define MFN(x) (((x) << L2_PAGETABLE_SHIFT) / sizeof(unsigned int))
 #define CNT ((sizeof(*frame_table) & -sizeof(*frame_table)) / \
              sizeof(*compat_machine_to_phys_mapping))
@@ -847,23 +869,24 @@ void __init subarch_init_memory(void)
                 mfn_to_page(_mfn(m2p_start_mfn + i)), SHARE_ro);
     }
 
-    for ( v  = RDWR_COMPAT_MPT_VIRT_START;
-          v != RDWR_COMPAT_MPT_VIRT_END;
-          v += 1 << L2_PAGETABLE_SHIFT )
-    {
-        l3e = l3e_from_l4e(idle_pg_table[l4_table_offset(v)],
-                           l3_table_offset(v));
-        if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
-            continue;
-        l2e = l2e_from_l3e(l3e, l2_table_offset(v));
-        if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
-            continue;
-        m2p_start_mfn = l2e_get_pfn(l2e);
+    if ( opt_pv32 )
+        for ( v  = RDWR_COMPAT_MPT_VIRT_START;
+              v != RDWR_COMPAT_MPT_VIRT_END;
+              v += 1 << L2_PAGETABLE_SHIFT )
+        {
+            l3e = l3e_from_l4e(idle_pg_table[l4_table_offset(v)],
+                               l3_table_offset(v));
+            if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) )
+                continue;
+            l2e = l2e_from_l3e(l3e, l2_table_offset(v));
+            if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) )
+                continue;
+            m2p_start_mfn = l2e_get_pfn(l2e);
 
-        for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
-            share_xen_page_with_privileged_guests(
-                mfn_to_page(_mfn(m2p_start_mfn + i)), SHARE_ro);
-    }
+            for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
+                share_xen_page_with_privileged_guests(
+                    mfn_to_page(_mfn(m2p_start_mfn + i)), SHARE_ro);
+        }
 
     /* Mark all of direct map NX if hardware supports it. */
     if ( !cpu_has_nx )
@@ -935,6 +958,9 @@ long subarch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
 
     case XENMEM_machphys_compat_mfn_list:
+        if ( !opt_pv32 )
+            return -EOPNOTSUPP;
+
         if ( copy_from_guest(&xmml, arg, 1) )
             return -EFAULT;
 
@@ -1464,7 +1490,8 @@ void set_gpfn_from_mfn(unsigned long mfn, unsigned long pfn)
     if ( unlikely(!machine_to_phys_mapping_valid) )
         return;
 
-    if ( mfn < (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) / 4 )
+    if ( opt_pv32 &&
+         mfn < (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) / 4 )
         compat_machine_to_phys_mapping[mfn] = entry;
 
     machine_to_phys_mapping[mfn] = entry;

diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index 665e9cc31d4476aa275e636812407df7032c7dd7..eb25fc47580eac301fde5e466fa35c804a337a74 100644 (file)
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -142,7 +142,7 @@ extern unsigned char boot_edid_info[128];
  *  0xffff82c000000000 - 0xffff82cfffffffff [64GB,  2^36 bytes, PML4:261]
  *    vmap()/ioremap()/fixmap area.
  *  0xffff82d000000000 - 0xffff82d03fffffff [1GB,   2^30 bytes, PML4:261]
- *    Compatibility machine-to-phys translation table.
+ *    Compatibility machine-to-phys translation table (CONFIG_PV32).
  *  0xffff82d040000000 - 0xffff82d07fffffff [1GB,   2^30 bytes, PML4:261]
  *    Xen text, static data, bss.
 #ifndef CONFIG_BIGMEM
@@ -246,9 +246,18 @@ extern unsigned char boot_edid_info[128];
 
 #ifndef __ASSEMBLY__
 
+#ifdef CONFIG_PV32
+
 /* This is not a fixed value, just a lower limit. */
 #define __HYPERVISOR_COMPAT_VIRT_START 0xF5800000
 #define HYPERVISOR_COMPAT_VIRT_START(d) ((d)->arch.hv_compat_vstart)
+
+#else /* !CONFIG_PV32 */
+
+#define HYPERVISOR_COMPAT_VIRT_START(d) ((void)(d), 0)
+
+#endif /* CONFIG_PV32 */
+
 #define MACH2PHYS_COMPAT_VIRT_START    HYPERVISOR_COMPAT_VIRT_START
 #define MACH2PHYS_COMPAT_VIRT_END      0xFFE00000
 #define MACH2PHYS_COMPAT_NR_ENTRIES(d) \

diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 635335634d5232da6ded63e1ff502a214381e048..5fb347a94ceb9b096abbd62105724470373b8b6f 100644 (file)
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -307,7 +307,9 @@ struct arch_domain
 {
     struct page_info *perdomain_l3_pg;
 
+#ifdef CONFIG_PV32
     unsigned int hv_compat_vstart;
+#endif
 
     /* Maximum physical-address bitwidth supported by this guest. */
     unsigned int physaddr_bitsize;

diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 89a55592c43fc9ac3aac7d2bc4dac9e4974b4c4a..632ece1cee5c14e539a215da70cfc194e97f8e1e 100644 (file)
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -42,8 +42,12 @@
 #define _PGT_validated    PG_shift(6)
 #define PGT_validated     PG_mask(1, 6)
  /* PAE only: is this an L2 page directory containing Xen-private mappings? */
+#ifdef CONFIG_PV32
 #define _PGT_pae_xen_l2   PG_shift(7)
 #define PGT_pae_xen_l2    PG_mask(1, 7)
+#else
+#define PGT_pae_xen_l2    0
+#endif
 /* Has this page been *partially* validated for use as its current type? */
 #define _PGT_partial      PG_shift(8)
 #define PGT_partial       PG_mask(1, 8)