Add new XENMEM_machphys_mapping to get info about location and

sizeof of the mach2phys table default mapping. Use this in Linux to
dynamically adapt the mfn_to_pfn() routine to undelrying hypervisor.
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/x86_64/kernel/head64-xen.c b/linux-2.6-xen-sparse/arch/x86_64/kernel/head64-xen.c
index 77176d0a321af269d55e842f02ba0980e0f4881e..de53871f36cff74973166fd49b101def9e42200a 100644 (file)
--- a/linux-2.6-xen-sparse/arch/x86_64/kernel/head64-xen.c
+++ b/linux-2.6-xen-sparse/arch/x86_64/kernel/head64-xen.c
@@ -15,6 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/percpu.h>
+#include <linux/module.h>
 
 #include <asm/processor.h>
 #include <asm/proto.h>
@@ -92,8 +93,16 @@ static void __init setup_boot_cpu_data(void)
        boot_cpu_data.x86_mask = eax & 0xf;
 }
 
+#include <xen/interface/memory.h>
+unsigned long *machine_to_phys_mapping;
+EXPORT_SYMBOL(machine_to_phys_mapping);
+unsigned int machine_to_phys_order;
+EXPORT_SYMBOL(machine_to_phys_order);
+
 void __init x86_64_start_kernel(char * real_mode_data)
 {
+       struct xen_machphys_mapping mapping;
+       unsigned long machine_to_phys_nr_ents;
        char *s;
        int i;
 
@@ -105,6 +114,16 @@ void __init x86_64_start_kernel(char * real_mode_data)
                        xen_start_info->nr_pt_frames;
        }
 
+
+       machine_to_phys_mapping = (unsigned long *)MACH2PHYS_VIRT_START;
+       machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES;
+       if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) {
+               machine_to_phys_mapping = (unsigned long *)mapping.v_start;
+               machine_to_phys_nr_ents = mapping.max_mfn + 1;
+       }
+       while ((1UL << machine_to_phys_order) < machine_to_phys_nr_ents )
+               machine_to_phys_order++;
+
 #if 0
        for (i = 0; i < 256; i++)
                set_intr_gate(i, early_idt_handler);

diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/page.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/page.h
index a31f62f84996558c1e6d50229b5de2551de23a35..9a4c6f95a4e586097be144748b2b72676ae6555d 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/page.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/page.h
@@ -67,6 +67,10 @@
 
 extern unsigned long *phys_to_machine_mapping;
 
+#undef machine_to_phys_mapping
+extern unsigned long *machine_to_phys_mapping;
+extern unsigned int   machine_to_phys_order;
+
 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 {
        if (xen_feature(XENFEAT_auto_translated_physmap))
@@ -90,7 +94,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
        if (xen_feature(XENFEAT_auto_translated_physmap))
                return mfn;
 
-       if (mfn >= MACH2PHYS_NR_ENTRIES)
+       if (unlikely((mfn >> machine_to_phys_order) != 0))
                return max_mapnr;
 
        /* The array access can fail (e.g., device space beyond end of RAM). */
@@ -106,7 +110,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
                "       .long 1b,3b\n"
                ".previous"
                : "=r" (pfn)
-               : "m" (machine_to_phys_mapping[mfn]), "ir" (max_mapnr) );
+               : "m" (machine_to_phys_mapping[mfn]), "m" (max_mapnr) );
 
        return pfn;
 }

diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/setup_arch_post.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/setup_arch_post.h
index 1b678d12f68b7b1d1cbf8c3ba611dab74dc60f37..0f1caa06040f83492b94b29424c6c5df8023eb6f 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/setup_arch_post.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/setup_arch_post.h
@@ -7,6 +7,7 @@
  **/
 
 #include <xen/interface/callback.h>
+#include <xen/interface/memory.h>
 
 static char * __init machine_specific_memory_setup(void)
 {
@@ -44,9 +45,16 @@ extern void hypervisor_callback(void);
 extern void failsafe_callback(void);
 extern void nmi(void);
 
+unsigned long *machine_to_phys_mapping;
+EXPORT_SYMBOL(machine_to_phys_mapping);
+unsigned int machine_to_phys_order;
+EXPORT_SYMBOL(machine_to_phys_order);
+
 static void __init machine_specific_arch_setup(void)
 {
        int ret;
+       struct xen_machphys_mapping mapping;
+       unsigned long machine_to_phys_nr_ents;
        struct xen_platform_parameters pp;
        struct callback_register event = {
                .type = CALLBACKTYPE_event,
@@ -81,4 +89,13 @@ static void __init machine_specific_arch_setup(void)
        if (HYPERVISOR_xen_version(XENVER_platform_parameters,
                                   &pp) == 0)
                set_fixaddr_top(pp.virt_start - PAGE_SIZE);
+
+       machine_to_phys_mapping = (unsigned long *)MACH2PHYS_VIRT_START;
+       machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES;
+       if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) {
+               machine_to_phys_mapping = (unsigned long *)mapping.v_start;
+               machine_to_phys_nr_ents = mapping.max_mfn + 1;
+       }
+       while ((1UL << machine_to_phys_order) < machine_to_phys_nr_ents )
+               machine_to_phys_order++;
 }

diff --git a/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/page.h b/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/page.h
index 92fdee2fab6018ab3062a08b4ee01a3e4a97fd3f..8cffad59f5b39004599f182218e8980fbddbcea8 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/page.h
+++ b/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/page.h
@@ -85,6 +85,10 @@ void copy_page(void *, void *);
 
 extern unsigned long *phys_to_machine_mapping;
 
+#undef machine_to_phys_mapping
+extern unsigned long *machine_to_phys_mapping;
+extern unsigned int   machine_to_phys_order;
+
 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 {
        if (xen_feature(XENFEAT_auto_translated_physmap))
@@ -107,7 +111,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
        if (xen_feature(XENFEAT_auto_translated_physmap))
                return mfn;
 
-       if (mfn >= MACH2PHYS_NR_ENTRIES)
+       if (unlikely((mfn >> machine_to_phys_order) != 0))
                return end_pfn;
 
        /* The array access can fail (e.g., device space beyond end of RAM). */
@@ -123,7 +127,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
                "       .quad 1b,3b\n"
                ".previous"
                : "=r" (pfn)
-               : "m" (machine_to_phys_mapping[mfn]), "ir" (end_pfn) );
+               : "m" (machine_to_phys_mapping[mfn]), "m" (end_pfn) );
 
        return pfn;
 }

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 1d5ffdb44b5af12ce1cbdac3967bad34d6d4c626..573726fd3a54700de2be0e7c95af80d939f5e56e 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3051,6 +3051,20 @@ long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
         return 0;
     }
 
+    case XENMEM_machphys_mapping:
+    {
+        struct xen_machphys_mapping mapping = {
+            .v_start = MACH2PHYS_VIRT_START,
+            .v_end   = MACH2PHYS_VIRT_END,
+            .max_mfn = MACH2PHYS_NR_ENTRIES - 1
+        };
+
+        if ( copy_to_guest(arg, &mapping, 1) )
+            return -EFAULT;
+
+        return 0;
+    }
+
     default:
         return subarch_memory_op(op, arg);
     }

diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index a467ae503897c45275dfb2e7ddc6f3acef6d9258..9791437ca0e5b0e22178e4f513d9a0d344732800 100644 (file)
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -140,6 +140,20 @@ struct xen_machphys_mfn_list {
 typedef struct xen_machphys_mfn_list xen_machphys_mfn_list_t;
 DEFINE_XEN_GUEST_HANDLE(xen_machphys_mfn_list_t);
 
+/*
+ * Returns the location in virtual address space of the machine_to_phys
+ * mapping table. Architectures which do not have a m2p table, or which do not
+ * map it by default into guest address space, do not implement this command.
+ * arg == addr of xen_machphys_mapping_t.
+ */
+#define XENMEM_machphys_mapping     12
+struct xen_machphys_mapping {
+    unsigned long v_start, v_end; /* Start and end virtual addresses.   */
+    unsigned long max_mfn;        /* Maximum MFN that can be looked up. */
+};
+typedef struct xen_machphys_mapping xen_machphys_mapping_t;
+DEFINE_XEN_GUEST_HANDLE(xen_machphys_mapping_t);
+
 /*
  * Sets the GPFN at which a particular page appears in the specified guest's
  * pseudophysical address space.