xen: add elfnote.h to avoid using numbers instead of constants

Various features and parameters of a pv-kernel are specified via
elf notes in the kernel image. Those notes are part of the interface
between the Xen hypervisor and the kernel.

Instead of using num,bers in the code when interpreting the elf notes
make use of the header supplied by Xen for that purpose.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

diff --git a/grub-core/loader/i386/xen_fileXX.c b/grub-core/loader/i386/xen_fileXX.c
index 36b40e4b079488423f30628ed631d9b33e3dbb28..03215cab2c14eccdda6e2ed7da4128d998d14e3b 100644 (file)
--- a/grub-core/loader/i386/xen_fileXX.c
+++ b/grub-core/loader/i386/xen_fileXX.c
@@ -18,6 +18,7 @@
 
 #include <grub/xen_file.h>
 #include <grub/misc.h>
+#include <xen/elfnote.h>
 
 static grub_err_t
 parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
@@ -203,35 +204,35 @@ parse_note (grub_elf_t elf, struct grub_xen_file_info *xi,
       xi->has_note = 1;
       switch (nh->n_type)
        {
-       case 1:
+       case XEN_ELFNOTE_ENTRY:
          xi->entry_point = grub_le_to_cpu_addr (*(Elf_Addr *) desc);
          break;
-       case 2:
+       case XEN_ELFNOTE_HYPERCALL_PAGE:
          xi->hypercall_page = grub_le_to_cpu_addr (*(Elf_Addr *) desc);
          xi->has_hypercall_page = 1;
          break;
-       case 3:
+       case XEN_ELFNOTE_VIRT_BASE:
          xi->virt_base = grub_le_to_cpu_addr (*(Elf_Addr *) desc);
          break;
-       case 4:
+       case XEN_ELFNOTE_PADDR_OFFSET:
          xi->paddr_offset = grub_le_to_cpu_addr (*(Elf_Addr *) desc);
          break;
-       case 5:
+       case XEN_ELFNOTE_XEN_VERSION:
          grub_dprintf ("xen", "xenversion = `%s'\n", (char *) desc);
          break;
-       case 6:
+       case XEN_ELFNOTE_GUEST_OS:
          grub_dprintf ("xen", "name = `%s'\n", (char *) desc);
          break;
-       case 7:
+       case XEN_ELFNOTE_GUEST_VERSION:
          grub_dprintf ("xen", "version = `%s'\n", (char *) desc);
          break;
-       case 8:
+       case XEN_ELFNOTE_LOADER:
          if (descsz < 7
              || grub_memcmp (desc, "generic", descsz == 7 ? 7 : 8) != 0)
            return grub_error (GRUB_ERR_BAD_OS, "invalid loader");
          break;
          /* PAE */
-       case 9:
+       case XEN_ELFNOTE_PAE_MODE:
          grub_dprintf ("xen", "pae = `%s', %d, %d\n", (char *) desc,
                        xi->arch, descsz);
          if (xi->arch != GRUB_XEN_FILE_I386

diff --git a/include/xen/elfnote.h b/include/xen/elfnote.h
new file mode 100644 (file)
index 0000000..71cd4ec
--- /dev/null
+++ b/include/xen/elfnote.h
@@ -0,0 +1,281 @@
+/******************************************************************************
+ * elfnote.h
+ *
+ * Definitions used for the Xen ELF notes.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Copyright (c) 2006, Ian Campbell, XenSource Ltd.
+ */
+
+#ifndef __XEN_PUBLIC_ELFNOTE_H__
+#define __XEN_PUBLIC_ELFNOTE_H__
+
+/*
+ * `incontents 200 elfnotes ELF notes
+ *
+ * The notes should live in a PT_NOTE segment and have "Xen" in the
+ * name field.
+ *
+ * Numeric types are either 4 or 8 bytes depending on the content of
+ * the desc field.
+ *
+ * LEGACY indicated the fields in the legacy __xen_guest string which
+ * this a note type replaces.
+ *
+ * String values (for non-legacy) are NULL terminated ASCII, also known
+ * as ASCIZ type.
+ */
+
+/*
+ * NAME=VALUE pair (string).
+ */
+#define XEN_ELFNOTE_INFO           0
+
+/*
+ * The virtual address of the entry point (numeric).
+ *
+ * LEGACY: VIRT_ENTRY
+ */
+#define XEN_ELFNOTE_ENTRY          1
+
+/* The virtual address of the hypercall transfer page (numeric).
+ *
+ * LEGACY: HYPERCALL_PAGE. (n.b. legacy value is a physical page
+ * number not a virtual address)
+ */
+#define XEN_ELFNOTE_HYPERCALL_PAGE 2
+
+/* The virtual address where the kernel image should be mapped (numeric).
+ *
+ * Defaults to 0.
+ *
+ * LEGACY: VIRT_BASE
+ */
+#define XEN_ELFNOTE_VIRT_BASE      3
+
+/*
+ * The offset of the ELF paddr field from the actual required
+ * pseudo-physical address (numeric).
+ *
+ * This is used to maintain backwards compatibility with older kernels
+ * which wrote __PAGE_OFFSET into that field. This field defaults to 0
+ * if not present.
+ *
+ * LEGACY: ELF_PADDR_OFFSET. (n.b. legacy default is VIRT_BASE)
+ */
+#define XEN_ELFNOTE_PADDR_OFFSET   4
+
+/*
+ * The version of Xen that we work with (string).
+ *
+ * LEGACY: XEN_VER
+ */
+#define XEN_ELFNOTE_XEN_VERSION    5
+
+/*
+ * The name of the guest operating system (string).
+ *
+ * LEGACY: GUEST_OS
+ */
+#define XEN_ELFNOTE_GUEST_OS       6
+
+/*
+ * The version of the guest operating system (string).
+ *
+ * LEGACY: GUEST_VER
+ */
+#define XEN_ELFNOTE_GUEST_VERSION  7
+
+/*
+ * The loader type (string).
+ *
+ * LEGACY: LOADER
+ */
+#define XEN_ELFNOTE_LOADER         8
+
+/*
+ * The kernel supports PAE (x86/32 only, string = "yes", "no" or
+ * "bimodal").
+ *
+ * For compatibility with Xen 3.0.3 and earlier the "bimodal" setting
+ * may be given as "yes,bimodal" which will cause older Xen to treat
+ * this kernel as PAE.
+ *
+ * LEGACY: PAE (n.b. The legacy interface included a provision to
+ * indicate 'extended-cr3' support allowing L3 page tables to be
+ * placed above 4G. It is assumed that any kernel new enough to use
+ * these ELF notes will include this and therefore "yes" here is
+ * equivalent to "yes[entended-cr3]" in the __xen_guest interface.
+ */
+#define XEN_ELFNOTE_PAE_MODE       9
+
+/*
+ * The features supported/required by this kernel (string).
+ *
+ * The string must consist of a list of feature names (as given in
+ * features.h, without the "XENFEAT_" prefix) separated by '|'
+ * characters. If a feature is required for the kernel to function
+ * then the feature name must be preceded by a '!' character.
+ *
+ * LEGACY: FEATURES
+ */
+#define XEN_ELFNOTE_FEATURES      10
+
+/*
+ * The kernel requires the symbol table to be loaded (string = "yes" or "no")
+ * LEGACY: BSD_SYMTAB (n.b. The legacy treated the presence or absence
+ * of this string as a boolean flag rather than requiring "yes" or
+ * "no".
+ */
+#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
+
+/*
+ * List of maddr_t-sized mask/value pairs describing how to recognize
+ * (non-present) L1 page table entries carrying valid MFNs (numeric).
+ */
+#define XEN_ELFNOTE_L1_MFN_VALID  13
+
+/*
+ * Whether or not the guest supports cooperative suspend cancellation.
+ * This is a numeric value.
+ *
+ * Default is 0
+ */
+#define XEN_ELFNOTE_SUSPEND_CANCEL 14
+
+/*
+ * The (non-default) location the initial phys-to-machine map should be
+ * placed at by the hypervisor (Dom0) or the tools (DomU).
+ * The kernel must be prepared for this mapping to be established using
+ * large pages, despite such otherwise not being available to guests.
+ * The kernel must also be able to handle the page table pages used for
+ * this mapping not being accessible through the initial mapping.
+ * (Only x86-64 supports this at present.)
+ */
+#define XEN_ELFNOTE_INIT_P2M      15
+
+/*
+ * Whether or not the guest can deal with being passed an initrd not
+ * mapped through its initial page tables.
+ */
+#define XEN_ELFNOTE_MOD_START_PFN 16
+
+/*
+ * The features supported by this kernel (numeric).
+ *
+ * Other than XEN_ELFNOTE_FEATURES on pre-4.2 Xen, this note allows a
+ * kernel to specify support for features that older hypervisors don't
+ * know about. The set of features 4.2 and newer hypervisors will
+ * consider supported by the kernel is the combination of the sets
+ * specified through this and the string note.
+ *
+ * LEGACY: FEATURES
+ */
+#define XEN_ELFNOTE_SUPPORTED_FEATURES 17
+
+/*
+ * Physical entry point into the kernel.
+ *
+ * 32bit entry point into the kernel. When requested to launch the
+ * guest kernel in a HVM container, Xen will use this entry point to
+ * launch the guest in 32bit protected mode with paging disabled.
+ * Ignored otherwise.
+ */
+#define XEN_ELFNOTE_PHYS32_ENTRY 18
+
+/*
+ * The number of the highest elfnote defined.
+ */
+#define XEN_ELFNOTE_MAX XEN_ELFNOTE_PHYS32_ENTRY
+
+/*
+ * System information exported through crash notes.
+ *
+ * The kexec / kdump code will create one XEN_ELFNOTE_CRASH_INFO
+ * note in case of a system crash. This note will contain various
+ * information about the system, see xen/include/xen/elfcore.h.
+ */
+#define XEN_ELFNOTE_CRASH_INFO 0x1000001
+
+/*
+ * System registers exported through crash notes.
+ *
+ * The kexec / kdump code will create one XEN_ELFNOTE_CRASH_REGS
+ * note per cpu in case of a system crash. This note is architecture
+ * specific and will contain registers not saved in the "CORE" note.
+ * See xen/include/xen/elfcore.h for more information.
+ */
+#define XEN_ELFNOTE_CRASH_REGS 0x1000002
+
+
+/*
+ * xen dump-core none note.
+ * xm dump-core code will create one XEN_ELFNOTE_DUMPCORE_NONE
+ * in its dump file to indicate that the file is xen dump-core
+ * file. This note doesn't have any other information.
+ * See tools/libxc/xc_core.h for more information.
+ */
+#define XEN_ELFNOTE_DUMPCORE_NONE               0x2000000
+
+/*
+ * xen dump-core header note.
+ * xm dump-core code will create one XEN_ELFNOTE_DUMPCORE_HEADER
+ * in its dump file.
+ * See tools/libxc/xc_core.h for more information.
+ */
+#define XEN_ELFNOTE_DUMPCORE_HEADER             0x2000001
+
+/*
+ * xen dump-core xen version note.
+ * xm dump-core code will create one XEN_ELFNOTE_DUMPCORE_XEN_VERSION
+ * in its dump file. It contains the xen version obtained via the
+ * XENVER hypercall.
+ * See tools/libxc/xc_core.h for more information.
+ */
+#define XEN_ELFNOTE_DUMPCORE_XEN_VERSION        0x2000002
+
+/*
+ * xen dump-core format version note.
+ * xm dump-core code will create one XEN_ELFNOTE_DUMPCORE_FORMAT_VERSION
+ * in its dump file. It contains a format version identifier.
+ * See tools/libxc/xc_core.h for more information.
+ */
+#define XEN_ELFNOTE_DUMPCORE_FORMAT_VERSION     0x2000003
+
+#endif /* __XEN_PUBLIC_ELFNOTE_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */