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/******************************************************************************
* machine_kexec.c
*
* Copyright (C) 2013 Citrix Systems R&D Ltd.
*
* Portions derived from Linux's arch/x86/kernel/machine_kexec_64.c.
*
* Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
*
* Xen port written by:
* - Simon 'Horms' Horman <horms@verge.net.au>
* - Magnus Damm <magnus@valinux.co.jp>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <xen/types.h>
#include <xen/domain_page.h>
#include <xen/elfstructs.h>
#include <xen/kexec.h>
#include <asm/fixmap.h>
#include <asm/hpet.h>
#include <asm/page.h>
#include <asm/machine_kexec.h>
/*
* Add a mapping for a page to the page tables used during kexec.
*/
int machine_kexec_add_page(struct kexec_image *image, unsigned long vaddr,
unsigned long maddr)
{
struct page_info *l4_page;
struct page_info *l3_page;
struct page_info *l2_page;
struct page_info *l1_page;
l4_pgentry_t *l4 = NULL;
l3_pgentry_t *l3 = NULL;
l2_pgentry_t *l2 = NULL;
l1_pgentry_t *l1 = NULL;
int ret = -ENOMEM;
l4_page = image->aux_page;
if ( !l4_page )
{
l4_page = kimage_alloc_control_page(image, 0);
if ( !l4_page )
goto out;
image->aux_page = l4_page;
}
l4 = __map_domain_page(l4_page);
l4 += l4_table_offset(vaddr);
if ( !(l4e_get_flags(*l4) & _PAGE_PRESENT) )
{
l3_page = kimage_alloc_control_page(image, 0);
if ( !l3_page )
goto out;
l4e_write(l4, l4e_from_page(l3_page, __PAGE_HYPERVISOR));
}
else
l3_page = l4e_get_page(*l4);
l3 = __map_domain_page(l3_page);
l3 += l3_table_offset(vaddr);
if ( !(l3e_get_flags(*l3) & _PAGE_PRESENT) )
{
l2_page = kimage_alloc_control_page(image, 0);
if ( !l2_page )
goto out;
l3e_write(l3, l3e_from_page(l2_page, __PAGE_HYPERVISOR));
}
else
l2_page = l3e_get_page(*l3);
l2 = __map_domain_page(l2_page);
l2 += l2_table_offset(vaddr);
if ( !(l2e_get_flags(*l2) & _PAGE_PRESENT) )
{
l1_page = kimage_alloc_control_page(image, 0);
if ( !l1_page )
goto out;
l2e_write(l2, l2e_from_page(l1_page, __PAGE_HYPERVISOR));
}
else
l1_page = l2e_get_page(*l2);
l1 = __map_domain_page(l1_page);
l1 += l1_table_offset(vaddr);
l1e_write(l1, l1e_from_pfn(maddr >> PAGE_SHIFT, __PAGE_HYPERVISOR));
ret = 0;
out:
if ( l1 )
unmap_domain_page(l1);
if ( l2 )
unmap_domain_page(l2);
if ( l3 )
unmap_domain_page(l3);
if ( l4 )
unmap_domain_page(l4);
return ret;
}
int machine_kexec_load(struct kexec_image *image)
{
void *code_page;
int ret;
switch ( image->arch )
{
case EM_386:
case EM_X86_64:
break;
default:
return -EINVAL;
}
code_page = __map_domain_page(image->control_code_page);
memcpy(code_page, kexec_reloc, kexec_reloc_end - (char *)kexec_reloc);
unmap_domain_page(code_page);
/*
* Add a mapping for the control code page to the same virtual
* address as kexec_reloc. This allows us to keep running after
* these page tables are loaded in kexec_reloc.
*/
ret = machine_kexec_add_page(image, (unsigned long)kexec_reloc,
page_to_maddr(image->control_code_page));
if ( ret < 0 )
return ret;
return 0;
}
void machine_kexec_unload(struct kexec_image *image)
{
/* no-op. kimage_free() frees all control pages. */
}
void machine_reboot_kexec(struct kexec_image *image)
{
BUG_ON(smp_processor_id() != 0);
smp_send_stop();
machine_kexec(image);
BUG();
}
void machine_kexec(struct kexec_image *image)
{
int i;
unsigned long reloc_flags = 0;
/* We are about to permenantly jump out of the Xen context into the kexec
* purgatory code. We really dont want to be still servicing interupts.
*/
local_irq_disable();
/* Now regular interrupts are disabled, we need to reduce the impact
* of interrupts not disabled by 'cli'.
*
* The NMI handlers have already been set up nmi_shootdown_cpus(). All
* pcpus other than us have the nmi_crash handler, while we have the nop
* handler.
*
* The MCE handlers touch extensive areas of Xen code and data. At this
* point, there is nothing we can usefully do, so set the nop handler.
*/
for ( i = 0; i < nr_cpu_ids; i++ )
{
if ( idt_tables[i] == NULL )
continue;
_update_gate_addr_lower(&idt_tables[i][X86_EXC_MC], &trap_nop);
}
/* Reset CPUID masking and faulting to the host's default. */
ctxt_switch_levelling(NULL);
/* Disable CET. */
if ( read_cr4() & X86_CR4_CET )
{
wrmsrl(MSR_S_CET, 0);
write_cr4(read_cr4() & ~X86_CR4_CET);
}
/* Explicitly enable NMIs on this CPU. Some crashdump kernels do
* not like running with NMIs disabled. */
enable_nmis();
if ( image->arch == EM_386 )
reloc_flags |= KEXEC_RELOC_FLAG_COMPAT;
kexec_reloc(page_to_maddr(image->control_code_page),
page_to_maddr(image->aux_page),
image->head, image->entry_maddr, reloc_flags);
}
int machine_kexec_get(xen_kexec_range_t *range)
{
if (range->range != KEXEC_RANGE_MA_XEN)
return -EINVAL;
return machine_kexec_get_xen(range);
}
void arch_crash_save_vmcoreinfo(void)
{
VMCOREINFO_SYMBOL(dom_xen);
VMCOREINFO_SYMBOL(dom_io);
VMCOREINFO_SYMBOL_ALIAS(pgd_l4, idle_pg_table);
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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