[PATCH 2/4] kexec/xen: use libxc to get location of crash notes

David Vrabel
2013-11-06T14:56:00Z

From: David Vrabel <david.vrabel@citrix.com>

Use xc_kexec_get_range(KEXEC_RANGE_MA_CPU) instead of parsing
/proc/iomem (which is only populated by non-upstream ("classic") Xen
kernels).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
kexec/crashdump-xen.c | 67 +++++++++++++++++++++++++++++-------------------
1 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/kexec/crashdump-xen.c b/kexec/crashdump-xen.c
index ff4706c..8185423 100644
--- a/kexec/crashdump-xen.c
+++ b/kexec/crashdump-xen.c
@@ -163,42 +163,55 @@ unsigned long xen_architecture(struct crash_elf_info *elf_info)
return machine;
}

-static int xen_crash_note_callback(void *UNUSED(data), int nr,
- char *UNUSED(str),
- unsigned long base,
- unsigned long length)
-{
- struct crash_note_info *note = xen_phys_notes + nr;
-
- note->base = base;
- note->length = length;
-
- return 0;
-}
-
+#ifdef HAVE_LIBXENCTRL
int xen_get_nr_phys_cpus(void)
{
- char *match = "Crash note\n";
- int cpus, n;
+ xc_interface *xc;
+ int max_cpus;
+ int cpu = -1;

if (xen_phys_cpus)
return xen_phys_cpus;

- if ((cpus = kexec_iomem_for_each_line(match, NULL, NULL))) {
- n = sizeof(struct crash_note_info) * cpus;
- xen_phys_notes = malloc(n);
- if (!xen_phys_notes) {
- fprintf(stderr, "failed to allocate xen_phys_notes.\n");
- return -1;
- }
- memset(xen_phys_notes, 0, n);
- kexec_iomem_for_each_line(match,
- xen_crash_note_callback, NULL);
- xen_phys_cpus = cpus;
+ xc = xc_interface_open(NULL, NULL, 0);
+ if (!xc) {
+ fprintf(stderr, "failed to open xen control interface.\n");
+ return -1;
}

- return cpus;
+ max_cpus = xc_get_max_cpus(xc);
+ if (max_cpus <= 0)
+ goto out;
+
+ xen_phys_notes = calloc(max_cpus, sizeof(*xen_phys_notes));
+ if (xen_phys_notes == NULL)
+ goto out;
+
+ for (cpu = 0; cpu < max_cpus; cpu++) {
+ uint64_t size, start;
+ int ret;
+
+ ret = xc_kexec_get_range(xc, KEXEC_RANGE_MA_CPU, cpu, &size, &start);
+ if (ret < 0)
+ break;
+
+ xen_phys_notes[cpu].base = start;
+ xen_phys_notes[cpu].length = size;
+ }
+
+ xen_phys_cpus = cpu;
+
+out:
+ xc_interface_close(xc);
+ return cpu;
}
+#else
+int xen_get_nr_phys_cpus(void)
+{
+ return -1;
+}
+#endif
+

int xen_get_note(int cpu, uint64_t *addr, uint64_t *len)
{
--
1.7.2.5