d2eea68e7d
One of the nice ideas behind paravirt is that CONFIG_XEN=y can be included in a standard configuration and be no worse for native booting than as a Xen guest. The glibc feature that supports the vDSO "nosegneg" note is designed specifically to make this easy. You just have to flip one bit at boot time. This patch makes Xen flip the bit, so a CONFIG_XEN=y kernel on bare hardware does not make glibc use the less-optimized library builds. Signed-off-by: Roland McGrath <roland@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
/*
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* Machine specific setup for xen
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*
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* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
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*/
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/pm.h>
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#include <asm/elf.h>
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#include <asm/e820.h>
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#include <asm/setup.h>
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#include <asm/xen/hypervisor.h>
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#include <asm/xen/hypercall.h>
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#include <xen/interface/physdev.h>
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#include <xen/features.h>
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#include "xen-ops.h"
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#include "vdso.h"
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/* These are code, but not functions. Defined in entry.S */
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extern const char xen_hypervisor_callback[];
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extern const char xen_failsafe_callback[];
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unsigned long *phys_to_machine_mapping;
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EXPORT_SYMBOL(phys_to_machine_mapping);
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/**
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* machine_specific_memory_setup - Hook for machine specific memory setup.
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**/
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char * __init xen_memory_setup(void)
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{
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unsigned long max_pfn = xen_start_info->nr_pages;
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e820.nr_map = 0;
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add_memory_region(0, PFN_PHYS(max_pfn), E820_RAM);
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return "Xen";
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}
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static void xen_idle(void)
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{
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local_irq_disable();
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if (need_resched())
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local_irq_enable();
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else {
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current_thread_info()->status &= ~TS_POLLING;
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smp_mb__after_clear_bit();
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safe_halt();
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current_thread_info()->status |= TS_POLLING;
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}
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}
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/*
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* Set the bit indicating "nosegneg" library variants should be used.
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*/
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static void fiddle_vdso(void)
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{
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extern u32 VDSO_NOTE_MASK; /* See ../kernel/vsyscall-note.S. */
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extern char vsyscall_int80_start;
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u32 *mask = (u32 *) ((unsigned long) &VDSO_NOTE_MASK - VDSO_PRELINK +
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&vsyscall_int80_start);
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*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
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}
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void __init xen_arch_setup(void)
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{
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struct physdev_set_iopl set_iopl;
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int rc;
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HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
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HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
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if (!xen_feature(XENFEAT_auto_translated_physmap))
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HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
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HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback,
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__KERNEL_CS, (unsigned long)xen_failsafe_callback);
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set_iopl.iopl = 1;
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rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
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if (rc != 0)
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printk(KERN_INFO "physdev_op failed %d\n", rc);
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#ifdef CONFIG_ACPI
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if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
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printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
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disable_acpi();
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}
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#endif
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memcpy(boot_command_line, xen_start_info->cmd_line,
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MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
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COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
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pm_idle = xen_idle;
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#ifdef CONFIG_SMP
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/* fill cpus_possible with all available cpus */
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xen_fill_possible_map();
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#endif
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paravirt_disable_iospace();
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fiddle_vdso();
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}
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