[LINUX] Support variable hypervisor_virt_start.

Introduce a new elfnote that specifies the lower boundary the kernel
wants to tolerate for the hypervisor hole.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff --git a/linux-2.6-xen-sparse/arch/i386/kernel/head-xen.S b/linux-2.6-xen-sparse/arch/i386/kernel/head-xen.S
index dcef669792bd362998382e4868adc849895ade24..1d0278c69bdf9a194a05fa6d23cd726f844794d2 100644 (file)
--- a/linux-2.6-xen-sparse/arch/i386/kernel/head-xen.S
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/head-xen.S
@@ -9,7 +9,7 @@
 #include <asm/page.h>
 #include <asm/thread_info.h>
 #include <asm/asm-offsets.h>
-#include <xen/interface/arch-x86_32.h>
+#include <xen/interface/xen.h>
 #include <xen/interface/elfnote.h>
 
 /*
@@ -192,6 +192,7 @@ ENTRY(cpu_gdt_table)
 #endif /* !CONFIG_XEN_COMPAT_030002 */
        ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          .long,  startup_32)
        ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, .long,  hypercall_page)
+       ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   .long,  HYPERVISOR_VIRT_START)
        ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .asciz, "writable_page_tables|writable_descriptor_tables|auto_translated_physmap|pae_pgdir_above_4gb|supervisor_mode_kernel")
 #ifdef CONFIG_X86_PAE
        ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz, "yes")

diff --git a/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c b/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c
index 16a0155ecbc0ad79932e2299ef2ce37032ad0fe8..4939ab106e0fb7b10e0b79d7c43c129cebb0f1d2 100644 (file)
--- a/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c
+++ b/linux-2.6-xen-sparse/arch/i386/mm/fault-xen.c
@@ -282,12 +282,6 @@ static int spurious_fault(struct pt_regs *regs,
        pmd_t *pmd;
        pte_t *pte;
 
-#ifdef CONFIG_XEN
-       /* Faults in hypervisor area are never spurious. */
-       if (address >= HYPERVISOR_VIRT_START)
-               return 0;
-#endif
-
        /* Reserved-bit violation or user access to kernel space? */
        if (error_code & 0x0c)
                return 0;
@@ -372,7 +366,7 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs,
        if (unlikely(address >= TASK_SIZE)) { 
 #ifdef CONFIG_XEN
                /* Faults in hypervisor area can never be patched up. */
-               if (address >= HYPERVISOR_VIRT_START)
+               if (address >= hypervisor_virt_start)
                        goto bad_area_nosemaphore;
 #endif
                if (!(error_code & 5))

diff --git a/linux-2.6-xen-sparse/arch/i386/mm/init-xen.c b/linux-2.6-xen-sparse/arch/i386/mm/init-xen.c
index 4f0175462a16ad806ee8b82ebb5595b93ff7d4ce..4d2b33068fd33bffeaba6e0f7a6b403957201dde 100644 (file)
--- a/linux-2.6-xen-sparse/arch/i386/mm/init-xen.c
+++ b/linux-2.6-xen-sparse/arch/i386/mm/init-xen.c
@@ -130,7 +130,7 @@ static void __init page_table_range_init (unsigned long start, unsigned long end
                pud = pud_offset(pgd, vaddr);
                pmd = pmd_offset(pud, vaddr);
                for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); pmd++, pmd_idx++) {
-                       if (vaddr < HYPERVISOR_VIRT_START && pmd_none(*pmd)) 
+                       if (vaddr < hypervisor_virt_start && pmd_none(*pmd))
                                one_page_table_init(pmd);
 
                        vaddr += PMD_SIZE;
@@ -187,7 +187,7 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
                pmd += pmd_idx;
                for (; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, pmd_idx++) {
                        unsigned int address = pfn * PAGE_SIZE + PAGE_OFFSET;
-                       if (address >= HYPERVISOR_VIRT_START)
+                       if (address >= hypervisor_virt_start)
                                continue;
 
                        /* Map with big pages if possible, otherwise create normal page tables. */
@@ -410,7 +410,7 @@ static void __init pagetable_init (void)
         * created - mappings will be set by set_fixmap():
         */
        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-       page_table_range_init(vaddr, 0, pgd_base);
+       page_table_range_init(vaddr, hypervisor_virt_start, pgd_base);
 
        permanent_kmaps_init(pgd_base);
 }

diff --git a/linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c b/linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c
index 843c9d0fd3a461b66e0f1d78b03a0703ebd3b1c5..d8435389177fc8df842a9b61a1fcaadb0d1c5458 100644 (file)
--- a/linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c
+++ b/linux-2.6-xen-sparse/arch/i386/mm/pgtable-xen.c
@@ -186,9 +186,16 @@ void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
 }
 
 static int nr_fixmaps = 0;
+unsigned long hypervisor_virt_start = HYPERVISOR_VIRT_START;
 unsigned long __FIXADDR_TOP = (HYPERVISOR_VIRT_START - 2 * PAGE_SIZE);
 EXPORT_SYMBOL(__FIXADDR_TOP);
 
+void __init set_fixaddr_top()
+{
+       BUG_ON(nr_fixmaps > 0);
+       __FIXADDR_TOP = hypervisor_virt_start - 2 * PAGE_SIZE;
+}
+
 void __set_fixmap (enum fixed_addresses idx, maddr_t phys, pgprot_t flags)
 {
        unsigned long address = __fix_to_virt(idx);
@@ -211,12 +218,6 @@ void __set_fixmap (enum fixed_addresses idx, maddr_t phys, pgprot_t flags)
        nr_fixmaps++;
 }
 
-void set_fixaddr_top(unsigned long top)
-{
-       BUG_ON(nr_fixmaps > 0);
-       __FIXADDR_TOP = top - PAGE_SIZE;
-}
-
 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
        pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);

diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/fixmap.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/fixmap.h
index 992a7c13ed56bd7b7b0ab3405f57eb6e401335a8..a9c3cc28fd8989b1d402c12d019b85b2e6f050b5 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/fixmap.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/fixmap.h
@@ -98,7 +98,7 @@ enum fixed_addresses {
 extern void __set_fixmap(enum fixed_addresses idx,
                                        maddr_t phys, pgprot_t flags);
 
-extern void set_fixaddr_top(unsigned long top);
+extern void set_fixaddr_top(void);
 
 #define set_fixmap(idx, phys) \
                __set_fixmap(idx, phys, PAGE_KERNEL)

diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/hypervisor.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/hypervisor.h
index a037eb24e461299bccb12e7495482f801a71b095..ef82d357283c5f4549bbf37300356bf4193e223d 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/hypervisor.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/hypervisor.h
@@ -56,6 +56,10 @@
 
 extern shared_info_t *HYPERVISOR_shared_info;
 
+#ifdef CONFIG_X86_32
+extern unsigned long hypervisor_virt_start;
+#endif
+
 /* arch/xen/i386/kernel/setup.c */
 extern start_info_t *xen_start_info;
 #ifdef CONFIG_XEN_PRIVILEGED_GUEST

diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-2level-defs.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-2level-defs.h
index 3791d2de3964f5529be3e0ba37379243b8dccba4..bd6346f41050d67b642b5ced758cb0c8b987c379 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-2level-defs.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-2level-defs.h
@@ -9,7 +9,6 @@
 
 #define PGDIR_SHIFT    22
 #define PTRS_PER_PGD   1024
-#define PTRS_PER_PGD_NO_HV     (HYPERVISOR_VIRT_START >> PGDIR_SHIFT)
 
 /*
  * the i386 is two-level, so we don't really have any

diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level-defs.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level-defs.h
index 10445c142c408d90d0430d3f03070b3c21d45094..148c8d9e78e96e21c5b53a14006696de3deea00c 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level-defs.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level-defs.h
@@ -8,7 +8,6 @@
  */
 #define PGDIR_SHIFT    30
 #define PTRS_PER_PGD   4
-#define PTRS_PER_PGD_NO_HV 4
 
 /*
  * PMD_SHIFT determines the size of the area a middle-level

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 7314dedbdeea0e5f5ef5424ad2788e3ec3a30f16..bed1e1d21136159736737d6076167b188baebb78 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
@@ -92,8 +92,10 @@ static void __init machine_specific_arch_setup(void)
 #endif
 
        if (HYPERVISOR_xen_version(XENVER_platform_parameters,
-                                  &pp) == 0)
-               set_fixaddr_top(pp.virt_start - PAGE_SIZE);
+                                  &pp) == 0) {
+               hypervisor_virt_start = pp.virt_start;
+               set_fixaddr_top();
+       }
 
        machine_to_phys_mapping = (unsigned long *)MACH2PHYS_VIRT_START;
        machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES;

diff --git a/xen/include/public/elfnote.h b/xen/include/public/elfnote.h
index 8f03504b1ed38cf38a056e785f178a07051a3306..ccf959d6e10882f18febbfd24d43bea0d828e3e4 100644 (file)
--- a/xen/include/public/elfnote.h
+++ b/xen/include/public/elfnote.h
@@ -138,6 +138,15 @@
  */
 #define XEN_ELFNOTE_BSD_SYMTAB    11
 
+/*
+ * The lowest address the hypervisor hole can begin at (numeric).
+ *
+ * This must not be set higher than HYPERVISOR_VIRT_START. Its presence
+ * also indicates to the hypervisor that the kernel can deal with the
+ * hole starting at a higher address.
+ */
+#define XEN_ELFNOTE_HV_START_LOW  12
+
 #endif /* __XEN_PUBLIC_ELFNOTE_H__ */
 
 /*