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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-14 13:23:49 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-14 13:23:49 -0400
commitb8cb48aae1b8c50b37dcb7710363aa69a7a0d9ca (patch)
treec7b04bfc8ece8b0121a9030c7f49e7bf9bf570d1 /arch/x86/xen/enlighten.c
parent0cc6d77e55eca9557bbe41bf2db94b31aa8fcb2a (diff)
parent78c86e5e5691fc84d5fbea0cd4ac7147e87b7490 (diff)
Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: split __phys_addr out into separate file xen: use stronger barrier after unlocking lock xen: only enable interrupts while actually blocking for spinlock xen: make -fstack-protector work under Xen
Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r--arch/x86/xen/enlighten.c131
1 files changed, 112 insertions, 19 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b62ccb840cfb..0dd0c2c6cae0 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -51,6 +51,7 @@
51#include <asm/pgtable.h> 51#include <asm/pgtable.h>
52#include <asm/tlbflush.h> 52#include <asm/tlbflush.h>
53#include <asm/reboot.h> 53#include <asm/reboot.h>
54#include <asm/stackprotector.h>
54 55
55#include "xen-ops.h" 56#include "xen-ops.h"
56#include "mmu.h" 57#include "mmu.h"
@@ -330,18 +331,28 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
330 unsigned long frames[pages]; 331 unsigned long frames[pages];
331 int f; 332 int f;
332 333
333 /* A GDT can be up to 64k in size, which corresponds to 8192 334 /*
334 8-byte entries, or 16 4k pages.. */ 335 * A GDT can be up to 64k in size, which corresponds to 8192
336 * 8-byte entries, or 16 4k pages..
337 */
335 338
336 BUG_ON(size > 65536); 339 BUG_ON(size > 65536);
337 BUG_ON(va & ~PAGE_MASK); 340 BUG_ON(va & ~PAGE_MASK);
338 341
339 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) { 342 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
340 int level; 343 int level;
341 pte_t *ptep = lookup_address(va, &level); 344 pte_t *ptep;
342 unsigned long pfn, mfn; 345 unsigned long pfn, mfn;
343 void *virt; 346 void *virt;
344 347
348 /*
349 * The GDT is per-cpu and is in the percpu data area.
350 * That can be virtually mapped, so we need to do a
351 * page-walk to get the underlying MFN for the
352 * hypercall. The page can also be in the kernel's
353 * linear range, so we need to RO that mapping too.
354 */
355 ptep = lookup_address(va, &level);
345 BUG_ON(ptep == NULL); 356 BUG_ON(ptep == NULL);
346 357
347 pfn = pte_pfn(*ptep); 358 pfn = pte_pfn(*ptep);
@@ -358,6 +369,44 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
358 BUG(); 369 BUG();
359} 370}
360 371
372/*
373 * load_gdt for early boot, when the gdt is only mapped once
374 */
375static __init void xen_load_gdt_boot(const struct desc_ptr *dtr)
376{
377 unsigned long va = dtr->address;
378 unsigned int size = dtr->size + 1;
379 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
380 unsigned long frames[pages];
381 int f;
382
383 /*
384 * A GDT can be up to 64k in size, which corresponds to 8192
385 * 8-byte entries, or 16 4k pages..
386 */
387
388 BUG_ON(size > 65536);
389 BUG_ON(va & ~PAGE_MASK);
390
391 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
392 pte_t pte;
393 unsigned long pfn, mfn;
394
395 pfn = virt_to_pfn(va);
396 mfn = pfn_to_mfn(pfn);
397
398 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
399
400 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
401 BUG();
402
403 frames[f] = mfn;
404 }
405
406 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
407 BUG();
408}
409
361static void load_TLS_descriptor(struct thread_struct *t, 410static void load_TLS_descriptor(struct thread_struct *t,
362 unsigned int cpu, unsigned int i) 411 unsigned int cpu, unsigned int i)
363{ 412{
@@ -581,6 +630,29 @@ static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
581 preempt_enable(); 630 preempt_enable();
582} 631}
583 632
633/*
634 * Version of write_gdt_entry for use at early boot-time needed to
635 * update an entry as simply as possible.
636 */
637static __init void xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
638 const void *desc, int type)
639{
640 switch (type) {
641 case DESC_LDT:
642 case DESC_TSS:
643 /* ignore */
644 break;
645
646 default: {
647 xmaddr_t maddr = virt_to_machine(&dt[entry]);
648
649 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
650 dt[entry] = *(struct desc_struct *)desc;
651 }
652
653 }
654}
655
584static void xen_load_sp0(struct tss_struct *tss, 656static void xen_load_sp0(struct tss_struct *tss,
585 struct thread_struct *thread) 657 struct thread_struct *thread)
586{ 658{
@@ -965,6 +1037,23 @@ static const struct machine_ops __initdata xen_machine_ops = {
965 .emergency_restart = xen_emergency_restart, 1037 .emergency_restart = xen_emergency_restart,
966}; 1038};
967 1039
1040/*
1041 * Set up the GDT and segment registers for -fstack-protector. Until
1042 * we do this, we have to be careful not to call any stack-protected
1043 * function, which is most of the kernel.
1044 */
1045static void __init xen_setup_stackprotector(void)
1046{
1047 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1048 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1049
1050 setup_stack_canary_segment(0);
1051 switch_to_new_gdt(0);
1052
1053 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1054 pv_cpu_ops.load_gdt = xen_load_gdt;
1055}
1056
968/* First C function to be called on Xen boot */ 1057/* First C function to be called on Xen boot */
969asmlinkage void __init xen_start_kernel(void) 1058asmlinkage void __init xen_start_kernel(void)
970{ 1059{
@@ -983,13 +1072,28 @@ asmlinkage void __init xen_start_kernel(void)
983 pv_apic_ops = xen_apic_ops; 1072 pv_apic_ops = xen_apic_ops;
984 pv_mmu_ops = xen_mmu_ops; 1073 pv_mmu_ops = xen_mmu_ops;
985 1074
986#ifdef CONFIG_X86_64
987 /* 1075 /*
988 * Setup percpu state. We only need to do this for 64-bit 1076 * Set up some pagetable state before starting to set any ptes.
989 * because 32-bit already has %fs set properly.
990 */ 1077 */
991 load_percpu_segment(0); 1078
992#endif 1079 /* Prevent unwanted bits from being set in PTEs. */
1080 __supported_pte_mask &= ~_PAGE_GLOBAL;
1081 if (!xen_initial_domain())
1082 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1083
1084 __supported_pte_mask |= _PAGE_IOMAP;
1085
1086 xen_setup_features();
1087
1088 /* Get mfn list */
1089 if (!xen_feature(XENFEAT_auto_translated_physmap))
1090 xen_build_dynamic_phys_to_machine();
1091
1092 /*
1093 * Set up kernel GDT and segment registers, mainly so that
1094 * -fstack-protector code can be executed.
1095 */
1096 xen_setup_stackprotector();
993 1097
994 xen_init_irq_ops(); 1098 xen_init_irq_ops();
995 xen_init_cpuid_mask(); 1099 xen_init_cpuid_mask();
@@ -1001,8 +1105,6 @@ asmlinkage void __init xen_start_kernel(void)
1001 set_xen_basic_apic_ops(); 1105 set_xen_basic_apic_ops();
1002#endif 1106#endif
1003 1107
1004 xen_setup_features();
1005
1006 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) { 1108 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1007 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start; 1109 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1008 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit; 1110 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
@@ -1019,17 +1121,8 @@ asmlinkage void __init xen_start_kernel(void)
1019 1121
1020 xen_smp_init(); 1122 xen_smp_init();
1021 1123
1022 /* Get mfn list */
1023 if (!xen_feature(XENFEAT_auto_translated_physmap))
1024 xen_build_dynamic_phys_to_machine();
1025
1026 pgd = (pgd_t *)xen_start_info->pt_base; 1124 pgd = (pgd_t *)xen_start_info->pt_base;
1027 1125
1028 /* Prevent unwanted bits from being set in PTEs. */
1029 __supported_pte_mask &= ~_PAGE_GLOBAL;
1030 if (!xen_initial_domain())
1031 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1032
1033#ifdef CONFIG_X86_64 1126#ifdef CONFIG_X86_64
1034 /* Work out if we support NX */ 1127 /* Work out if we support NX */
1035 check_efer(); 1128 check_efer();