138 lines
4.5 KiB
C
138 lines
4.5 KiB
C
/******************************************************************************
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* kexec.h - Public portion
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*
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* Xen port written by:
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* - Simon 'Horms' Horman <horms@verge.net.au>
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* - Magnus Damm <magnus@valinux.co.jp>
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*/
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#ifndef _XEN_PUBLIC_KEXEC_H
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#define _XEN_PUBLIC_KEXEC_H
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/* This file describes the Kexec / Kdump hypercall interface for Xen.
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*
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* Kexec under vanilla Linux allows a user to reboot the physical machine
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* into a new user-specified kernel. The Xen port extends this idea
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* to allow rebooting of the machine from dom0. When kexec for dom0
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* is used to reboot, both the hypervisor and the domains get replaced
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* with some other kernel. It is possible to kexec between vanilla
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* Linux and Xen and back again. Xen to Xen works well too.
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*
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* The hypercall interface for kexec can be divided into three main
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* types of hypercall operations:
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*
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* 1) Range information:
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* This is used by the dom0 kernel to ask the hypervisor about various
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* address information. This information is needed to allow kexec-tools
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* to fill in the ELF headers for /proc/vmcore properly.
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*
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* 2) Load and unload of images:
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* There are no big surprises here, the kexec binary from kexec-tools
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* runs in userspace in dom0. The tool loads/unloads data into the
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* dom0 kernel such as new kernel, initramfs and hypervisor. When
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* loaded the dom0 kernel performs a load hypercall operation, and
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* before releasing all page references the dom0 kernel calls unload.
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*
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* 3) Kexec operation:
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* This is used to start a previously loaded kernel.
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*/
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#include "xen.h"
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#if defined(__i386__) || defined(__x86_64__)
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#define KEXEC_XEN_NO_PAGES 17
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#endif
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/*
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* Prototype for this hypercall is:
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* int kexec_op(int cmd, void *args)
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* @cmd == KEXEC_CMD_...
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* KEXEC operation to perform
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* @args == Operation-specific extra arguments (NULL if none).
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*/
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/*
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* Kexec supports two types of operation:
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* - kexec into a regular kernel, very similar to a standard reboot
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* - KEXEC_TYPE_DEFAULT is used to specify this type
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* - kexec into a special "crash kernel", aka kexec-on-panic
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* - KEXEC_TYPE_CRASH is used to specify this type
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* - parts of our system may be broken at kexec-on-panic time
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* - the code should be kept as simple and self-contained as possible
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*/
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#define KEXEC_TYPE_DEFAULT 0
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#define KEXEC_TYPE_CRASH 1
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/* The kexec implementation for Xen allows the user to load two
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* types of kernels, KEXEC_TYPE_DEFAULT and KEXEC_TYPE_CRASH.
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* All data needed for a kexec reboot is kept in one xen_kexec_image_t
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* per "instance". The data mainly consists of machine address lists to pages
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* together with destination addresses. The data in xen_kexec_image_t
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* is passed to the "code page" which is one page of code that performs
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* the final relocations before jumping to the new kernel.
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*/
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typedef struct xen_kexec_image {
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#if defined(__i386__) || defined(__x86_64__)
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unsigned long page_list[KEXEC_XEN_NO_PAGES];
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#endif
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unsigned long indirection_page;
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unsigned long start_address;
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} xen_kexec_image_t;
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/*
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* Perform kexec having previously loaded a kexec or kdump kernel
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* as appropriate.
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* type == KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH [in]
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*/
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#define KEXEC_CMD_kexec 0
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typedef struct xen_kexec_exec {
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int type;
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} xen_kexec_exec_t;
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/*
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* Load/Unload kernel image for kexec or kdump.
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* type == KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH [in]
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* image == relocation information for kexec (ignored for unload) [in]
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*/
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#define KEXEC_CMD_kexec_load 1
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#define KEXEC_CMD_kexec_unload 2
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typedef struct xen_kexec_load {
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int type;
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xen_kexec_image_t image;
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} xen_kexec_load_t;
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#define KEXEC_RANGE_MA_CRASH 0 /* machine address and size of crash area */
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#define KEXEC_RANGE_MA_XEN 1 /* machine address and size of Xen itself */
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#define KEXEC_RANGE_MA_CPU 2 /* machine address and size of a CPU note */
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/*
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* Find the address and size of certain memory areas
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* range == KEXEC_RANGE_... [in]
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* nr == physical CPU number (starting from 0) if KEXEC_RANGE_MA_CPU [in]
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* size == number of bytes reserved in window [out]
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* start == address of the first byte in the window [out]
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*/
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#define KEXEC_CMD_kexec_get_range 3
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typedef struct xen_kexec_range {
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int range;
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int nr;
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unsigned long size;
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unsigned long start;
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} xen_kexec_range_t;
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#endif /* _XEN_PUBLIC_KEXEC_H */
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/*
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* Local variables:
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* mode: C
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* c-set-style: "BSD"
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* c-basic-offset: 4
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* tab-width: 4
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* indent-tabs-mode: nil
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* End:
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*/
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