1 files changed, 297 insertions, 0 deletions
diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
new file mode 100644
index 0000000..a7c8933
--- /dev/null
+++ b/kexec/kexec-xen.c
@@ -0,0 +1,297 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <elf.h>
+#include "kexec.h"
+#include "kexec-syscall.h"
+#include "crashdump.h"
+
+#include "config.h"
+
+#ifdef HAVE_LIBXENCTRL
+#include "kexec-xen.h"
+
+#include "crashdump.h"
+
+#ifdef CONFIG_LIBXENCTRL_DL
+#include <dlfcn.h>
+
+/* The handle from dlopen(), needed by dlsym(), dlclose() */
+static void *xc_dlhandle;
+xc_hypercall_buffer_t XC__HYPERCALL_BUFFER_NAME(HYPERCALL_BUFFER_NULL);
+
+void *__xc_dlsym(const char *symbol)
+{
+	return dlsym(xc_dlhandle, symbol);
+}
+
+xc_interface *__xc_interface_open(xentoollog_logger *logger,
+				  xentoollog_logger *dombuild_logger,
+				  unsigned open_flags)
+{
+	xc_interface *xch = NULL;
+
+	if (!xc_dlhandle)
+		xc_dlhandle = dlopen("libxenctrl.so", RTLD_NOW | RTLD_NODELETE);
+
+	if (xc_dlhandle) {
+		typedef xc_interface *(*func_t)(xentoollog_logger *logger,
+			xentoollog_logger *dombuild_logger,
+			unsigned open_flags);
+
+		func_t func = (func_t)dlsym(xc_dlhandle, "xc_interface_open");
+		xch = func(logger, dombuild_logger, open_flags);
+	}
+
+	return xch;
+}
+
+int __xc_interface_close(xc_interface *xch)
+{
+	int rc = -1;
+
+	if (xc_dlhandle) {
+		typedef int (*func_t)(xc_interface *xch);
+
+		func_t func = (func_t)dlsym(xc_dlhandle, "xc_interface_close");
+		rc = func(xch);
+		dlclose(xc_dlhandle);
+		xc_dlhandle = NULL;
+	}
+
+	return rc;
+}
+#endif /* CONFIG_LIBXENCTRL_DL */
+
+int xen_get_kexec_range(int range, uint64_t *start, uint64_t *end)
+{
+	uint64_t size;
+	xc_interface *xc;
+	int rc = -1;
+
+	xc = xc_interface_open(NULL, NULL, 0);
+	if (!xc) {
+		fprintf(stderr, "failed to open xen control interface.\n");
+		goto out;
+	}
+
+	rc = xc_kexec_get_range(xc, range, 0, &size, start);
+	if (rc < 0) {
+		fprintf(stderr, "failed to get range=%d from hypervisor.\n", range);
+		goto out_close;
+	}
+
+	*end = *start + size - 1;
+
+out_close:
+	xc_interface_close(xc);
+
+out:
+	return rc;
+}
+
+static uint8_t xen_get_kexec_type(unsigned long kexec_flags)
+{
+	if (kexec_flags & KEXEC_ON_CRASH)
+		return KEXEC_TYPE_CRASH;
+
+	if (kexec_flags & KEXEC_LIVE_UPDATE)
+		return KEXEC_TYPE_LIVE_UPDATE;
+
+	return KEXEC_TYPE_DEFAULT;
+}
+
+#define IDENTMAP_1MiB (1024 * 1024)
+
+int xen_kexec_load(struct kexec_info *info)
+{
+	uint32_t nr_segments = info->nr_segments, nr_low_segments = 0;
+	struct kexec_segment *segments = info->segment;
+	uint64_t low_watermark = 0;
+	xc_interface *xch;
+	xc_hypercall_buffer_array_t *array = NULL;
+	uint8_t type;
+	uint8_t arch;
+	xen_kexec_segment_t *xen_segs, *seg;
+	int s;
+	int ret = -1;
+
+	xch = xc_interface_open(NULL, NULL, 0);
+	if (!xch)
+		return -1;
+
+	/*
+	 * Ensure 0 - 1 MiB is mapped and accessible by the image.
+	 * This allows access to the VGA memory and the region
+	 * purgatory copies in the crash case.
+	 *
+	 * First, count the number of additional segments which will
+	 * need to be added in between the ones in segments[].
+	 *
+	 * The segments are already sorted.
+	 */
+	for (s = 0; s < nr_segments && (uint64_t)segments[s].mem <= IDENTMAP_1MiB; s++) {
+		if ((uint64_t)segments[s].mem > low_watermark)
+			nr_low_segments++;
+
+		low_watermark = (uint64_t)segments[s].mem + segments[s].memsz;
+	}
+	if (low_watermark < IDENTMAP_1MiB)
+		nr_low_segments++;
+
+	low_watermark = 0;
+
+	xen_segs = calloc(nr_segments + nr_low_segments, sizeof(*xen_segs));
+	if (!xen_segs)
+		goto out;
+
+	array = xc_hypercall_buffer_array_create(xch, nr_segments);
+	if (array == NULL)
+		goto out;
+
+	seg = xen_segs;
+	for (s = 0; s < nr_segments; s++) {
+		DECLARE_HYPERCALL_BUFFER(void, seg_buf);
+
+		if (low_watermark < IDENTMAP_1MiB && (uint64_t)segments[s].mem > low_watermark) {
+			set_xen_guest_handle(seg->buf.h, HYPERCALL_BUFFER_NULL);
+			seg->buf_size = 0;
+			seg->dest_maddr = low_watermark;
+			low_watermark = (uint64_t)segments[s].mem;
+			if (low_watermark > IDENTMAP_1MiB)
+				low_watermark = IDENTMAP_1MiB;
+			seg->dest_size = low_watermark - seg->dest_maddr;
+			seg++;
+		}
+
+		seg_buf = xc_hypercall_buffer_array_alloc(xch, array, s,
+							  seg_buf, segments[s].bufsz);
+		if (seg_buf == NULL)
+			goto out;
+		memcpy(seg_buf, segments[s].buf, segments[s].bufsz);
+
+		set_xen_guest_handle(seg->buf.h, seg_buf);
+		seg->buf_size = segments[s].bufsz;
+		seg->dest_maddr = (uint64_t)segments[s].mem;
+		seg->dest_size = segments[s].memsz;
+		seg++;
+
+		low_watermark = (uint64_t)segments[s].mem + segments[s].memsz;
+	}
+
+	if ((uint64_t)low_watermark < IDENTMAP_1MiB) {
+		set_xen_guest_handle(seg->buf.h, HYPERCALL_BUFFER_NULL);
+		seg->buf_size = 0;
+		seg->dest_maddr = low_watermark;
+		seg->dest_size = IDENTMAP_1MiB - low_watermark;
+		seg++;
+	}
+
+	type = xen_get_kexec_type(info->kexec_flags);
+
+	arch = (info->kexec_flags & KEXEC_ARCH_MASK) >> 16;
+#if defined(__i386__) || defined(__x86_64__)
+	if (!arch)
+		arch = EM_386;
+#endif
+
+	ret = xc_kexec_load(xch, type, arch, (uint64_t)info->entry,
+			    nr_segments + nr_low_segments, xen_segs);
+
+out:
+	xc_hypercall_buffer_array_destroy(xch, array);
+	free(xen_segs);
+	xc_interface_close(xch);
+
+	return ret;
+}
+
+int xen_kexec_unload(uint64_t kexec_flags)
+{
+	xc_interface *xch;
+	uint8_t type;
+	int ret;
+
+	xch = xc_interface_open(NULL, NULL, 0);
+	if (!xch)
+		return -1;
+
+	type = xen_get_kexec_type(kexec_flags);
+
+	ret = xc_kexec_unload(xch, type);
+
+	xc_interface_close(xch);
+
+	return ret;
+}
+
+int xen_kexec_status(uint64_t kexec_flags)
+{
+	xc_interface *xch;
+	uint8_t type;
+	int ret = -1;
+
+#ifdef HAVE_KEXEC_CMD_STATUS
+	xch = xc_interface_open(NULL, NULL, 0);
+	if (!xch)
+		return -1;
+
+	type = xen_get_kexec_type(kexec_flags);
+
+	ret = xc_kexec_status(xch, type);
+
+	xc_interface_close(xch);
+#endif
+
+	return ret;
+}
+
+int xen_kexec_exec(uint64_t kexec_flags)
+{
+	xc_interface *xch;
+	uint8_t type = KEXEC_TYPE_DEFAULT;
+	int ret;
+
+	xch = xc_interface_open(NULL, NULL, 0);
+	if (!xch)
+		return -1;
+
+	if (kexec_flags & KEXEC_LIVE_UPDATE)
+		type = KEXEC_TYPE_LIVE_UPDATE;
+
+	ret = xc_kexec_exec(xch, type);
+
+	xc_interface_close(xch);
+
+	return ret;
+}
+
+#else /* ! HAVE_LIBXENCTRL */
+
+int xen_get_kexec_range(int range, uint64_t *start, uint64_t *end)
+{
+	return -1;
+}
+
+int xen_kexec_load(struct kexec_info *UNUSED(info))
+{
+	return -1;
+}
+
+int xen_kexec_unload(uint64_t kexec_flags)
+{
+	return -1;
+}
+
+int xen_kexec_status(uint64_t kexec_flags)
+{
+	return -1;
+}
+
+int xen_kexec_exec(uint64_t kexec_flags)
+{
+	return -1;
+}
+
+#endif