[PATCH 7/7] xen: Fix Xen kdump support
Daniel Kiper
daniel.kiper at oracle.com
Mon Sep 10 07:57:51 EDT 2012
get_crash_memory_ranges() is unreliable under Xen. Proper machine
memory map could be obtained under Xen by calling __HYPERVISOR_memory_op
hypercall with XENMEM_machine_memory_map argument. get_crash_memory_ranges_xen()
does that. It is implemented using ioctl() or libxenctrl interface.
This solution is compatible with 3.x and 4.x Xen versions.
Signed-off-by: Daniel Kiper <daniel.kiper at oracle.com>
---
kexec/arch/i386/crashdump-x86.c | 203 ++++++++++++++++++++++++++++++++++++---
1 files changed, 191 insertions(+), 12 deletions(-)
diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index c6b9354..09c3fd4 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -18,21 +18,41 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+
+#define _XOPEN_SOURCE 600
+#define _BSD_SOURCE
+
+#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>
#include <elf.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "../../kexec.h"
#include "../../kexec-elf.h"
#include "../../kexec-syscall.h"
+#include "../../firmware_memmap.h"
#include "../../crashdump.h"
#include "kexec-x86.h"
#include "crashdump-x86.h"
+
+#ifdef HAVE_LIBXENCTRL
+#ifdef HAVE_XC_GET_MACHINE_MEMORY_MAP
+#include <xenctrl.h>
+#else
+#define __XEN_TOOLS__ 1
+#include <xen/xen.h>
+#include <xen/memory.h>
+#include <xen/sys/privcmd.h>
+#endif /* HAVE_XC_GET_MACHINE_MEMORY_MAP */
+#endif /* HAVE_LIBXENCTRL */
+
#include <x86/x86-linux.h>
extern struct arch_options_t arch_options;
@@ -273,6 +293,162 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
return 0;
}
+#ifdef HAVE_LIBXENCTRL
+#ifdef HAVE_XC_GET_MACHINE_MEMORY_MAP
+static int get_crash_memory_ranges_xen(struct memory_range **range,
+ int *ranges, unsigned long lowmem_limit)
+{
+ int j, rc, ret = -1;
+ struct e820entry e820entries[CRASH_MAX_MEMORY_RANGES];
+ unsigned int i;
+#ifdef XENCTRL_HAS_XC_INTERFACE
+ xc_interface *xc;
+#else
+ int xc;
+#endif
+
+#ifdef XENCTRL_HAS_XC_INTERFACE
+ xc = xc_interface_open(NULL, NULL, 0);
+
+ if (!xc) {
+ fprintf(stderr, "%s: Failed to open Xen control interface\n", __func__);
+ goto err;
+ }
+#else
+ xc = xc_interface_open();
+
+ if (xc == -1) {
+ fprintf(stderr, "%s: Failed to open Xen control interface\n", __func__);
+ goto err;
+ }
+#endif
+
+ rc = xc_get_machine_memory_map(xc, e820entries, CRASH_MAX_MEMORY_RANGES);
+
+ if (rc < 0) {
+ fprintf(stderr, "%s: xc_get_machine_memory_map: %s\n", __func__, strerror(-rc));
+ goto err;
+ }
+
+ for (i = 0, j = 0; i < rc && j < CRASH_MAX_MEMORY_RANGES; ++i, ++j) {
+ crash_memory_range[j].start = e820entries[i].addr;
+ crash_memory_range[j].end = e820entries[i].addr + e820entries[i].size - 1;
+ crash_memory_range[j].type = xen_e820_to_kexec_type(e820entries[i].type);
+ segregate_lowmem_region(&j, lowmem_limit);
+ }
+
+ *range = crash_memory_range;
+ *ranges = j;
+
+ qsort(*range, *ranges, sizeof(struct memory_range), compare_ranges);
+
+ if (exclude_region(ranges, crash_reserved_mem.start,
+ crash_reserved_mem.end) < 0)
+ goto err;
+
+ ret = 0;
+
+err:
+ xc_interface_close(xc);
+
+ return ret;
+}
+#else
+static int get_crash_memory_ranges_xen(struct memory_range **range,
+ int *ranges, unsigned long lowmem_limit)
+{
+ int fd, j, rc, ret = -1;
+ privcmd_hypercall_t hypercall;
+ struct e820entry *e820entries = NULL;
+ struct xen_memory_map *xen_memory_map = NULL;
+ unsigned int i;
+
+ fd = open("/proc/xen/privcmd", O_RDWR);
+
+ if (fd == -1) {
+ fprintf(stderr, "%s: open(/proc/xen/privcmd): %m\n", __func__);
+ goto err;
+ }
+
+ rc = posix_memalign((void **)&e820entries, getpagesize(),
+ sizeof(struct e820entry) * CRASH_MAX_MEMORY_RANGES);
+
+ if (rc) {
+ fprintf(stderr, "%s: posix_memalign(e820entries): %s\n", __func__, strerror(rc));
+ e820entries = NULL;
+ goto err;
+ }
+
+ rc = posix_memalign((void **)&xen_memory_map, getpagesize(),
+ sizeof(struct xen_memory_map));
+
+ if (rc) {
+ fprintf(stderr, "%s: posix_memalign(xen_memory_map): %s\n", __func__, strerror(rc));
+ xen_memory_map = NULL;
+ goto err;
+ }
+
+ if (mlock(e820entries, sizeof(struct e820entry) * CRASH_MAX_MEMORY_RANGES) == -1) {
+ fprintf(stderr, "%s: mlock(e820entries): %m\n", __func__);
+ goto err;
+ }
+
+ if (mlock(xen_memory_map, sizeof(struct xen_memory_map)) == -1) {
+ fprintf(stderr, "%s: mlock(xen_memory_map): %m\n", __func__);
+ goto err;
+ }
+
+ xen_memory_map->nr_entries = CRASH_MAX_MEMORY_RANGES;
+ set_xen_guest_handle(xen_memory_map->buffer, e820entries);
+
+ hypercall.op = __HYPERVISOR_memory_op;
+ hypercall.arg[0] = XENMEM_machine_memory_map;
+ hypercall.arg[1] = (__u64)xen_memory_map;
+
+ rc = ioctl(fd, IOCTL_PRIVCMD_HYPERCALL, &hypercall);
+
+ if (rc == -1) {
+ fprintf(stderr, "%s: ioctl(IOCTL_PRIVCMD_HYPERCALL): %m\n", __func__);
+ goto err;
+ }
+
+ for (i = 0, j = 0; i < xen_memory_map->nr_entries &&
+ j < CRASH_MAX_MEMORY_RANGES; ++i, ++j) {
+ crash_memory_range[j].start = e820entries[i].addr;
+ crash_memory_range[j].end = e820entries[i].addr + e820entries[i].size - 1;
+ crash_memory_range[j].type = xen_e820_to_kexec_type(e820entries[i].type);
+ segregate_lowmem_region(&j, lowmem_limit);
+ }
+
+ *range = crash_memory_range;
+ *ranges = j;
+
+ qsort(*range, *ranges, sizeof(struct memory_range), compare_ranges);
+
+ if (exclude_region(ranges, crash_reserved_mem.start,
+ crash_reserved_mem.end) < 0)
+ goto err;
+
+ ret = 0;
+
+err:
+ munlock(xen_memory_map, sizeof(struct xen_memory_map));
+ munlock(e820entries, sizeof(struct e820entry) * CRASH_MAX_MEMORY_RANGES);
+ free(xen_memory_map);
+ free(e820entries);
+ close(fd);
+
+ return ret;
+}
+#endif /* HAVE_XC_GET_MACHINE_MEMORY_MAP */
+#else
+static int get_crash_memory_ranges_xen(struct memory_range **range,
+ int *ranges, unsigned long lowmem_limit)
+{
+ return 0;
+}
+#endif /* HAVE_LIBXENCTRL */
+
static void segregate_lowmem_region(int *nr_ranges, unsigned long lowmem_limit)
{
unsigned long long end, start;
@@ -724,10 +900,15 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
return -1;
}
- if (get_crash_memory_ranges(&mem_range, &nr_ranges,
- info->kexec_flags,
- elf_info.lowmem_limit) < 0)
- return -1;
+ if (xen_present()) {
+ if (get_crash_memory_ranges_xen(&mem_range, &nr_ranges,
+ elf_info.lowmem_limit) < 0)
+ return -1;
+ } else
+ if (get_crash_memory_ranges(&mem_range, &nr_ranges,
+ info->kexec_flags,
+ elf_info.lowmem_limit) < 0)
+ return -1;
get_backup_area(info, mem_range, nr_ranges);
@@ -784,17 +965,15 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
/* Create elf header segment and store crash image data. */
if (arch_options.core_header_type == CORE_TYPE_ELF64) {
- if (crash_create_elf64_headers(info, &elf_info,
- crash_memory_range, nr_ranges,
- &tmp, &bufsz,
- ELF_CORE_HEADER_ALIGN) < 0)
+ if (crash_create_elf64_headers(info, &elf_info, mem_range,
+ nr_ranges, &tmp, &bufsz,
+ ELF_CORE_HEADER_ALIGN) < 0)
return EFAILED;
}
else {
- if (crash_create_elf32_headers(info, &elf_info,
- crash_memory_range, nr_ranges,
- &tmp, &bufsz,
- ELF_CORE_HEADER_ALIGN) < 0)
+ if (crash_create_elf32_headers(info, &elf_info, mem_range,
+ nr_ranges, &tmp, &bufsz,
+ ELF_CORE_HEADER_ALIGN) < 0)
return EFAILED;
}
/* the size of the elf headers allocated is returned in 'bufsz' */
--
1.5.6.5
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