It can sometimes be useful to dump the .dtb file generated by kvmtool
when debugging a guest. Currently, this is achieved by rebuilding the
tool and changing some #defines, which is fairly clumsy to use.
This patch adds a new command-line option for ARM, allowing the dtb
to be dumped to a named file at runtime.
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
---
tools/kvm/arm/fdt.c | 18 ++++++------------
tools/kvm/arm/include/kvm/kvm-config-arch.h | 8 ++++++++
2 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/tools/kvm/arm/fdt.c b/tools/kvm/arm/fdt.c
index c7f4b52..e52c10c 100644
--- a/tools/kvm/arm/fdt.c
+++ b/tools/kvm/arm/fdt.c
@@ -13,9 +13,6 @@
#include <linux/kernel.h>
#include <linux/sizes.h>
-#define DEBUG 0
-#define DEBUG_FDT_DUMP_FILE "/tmp/kvmtool.dtb"
-
static char kern_cmdline[COMMAND_LINE_SIZE];
bool kvm__load_firmware(struct kvm *kvm, const char *firmware_filename)
@@ -28,25 +25,21 @@ int kvm__arch_setup_firmware(struct kvm *kvm)
return 0;
}
-#if DEBUG
-static void dump_fdt(void *fdt)
+static void dump_fdt(const char *dtb_file, void *fdt)
{
int count, fd;
- fd = open(DEBUG_FDT_DUMP_FILE, O_CREAT | O_TRUNC | O_RDWR, 0666);
+ fd = open(dtb_file, O_CREAT | O_TRUNC | O_RDWR, 0666);
if (fd < 0)
- die("Failed to write dtb to %s", DEBUG_FDT_DUMP_FILE);
+ die("Failed to write dtb to %s", dtb_file);
count = write(fd, fdt, FDT_MAX_SIZE);
if (count < 0)
die_perror("Failed to dump dtb");
- pr_info("Wrote %d bytes to dtb %s\n", count, DEBUG_FDT_DUMP_FILE);
+ pr_info("Wrote %d bytes to dtb %s\n", count, dtb_file);
close(fd);
}
-#else
-static void dump_fdt(void *fdt) { }
-#endif
#define DEVICE_NAME_MAX_LEN 32
static void generate_virtio_mmio_node(void *fdt, struct virtio_mmio *vmmio)
@@ -143,7 +136,8 @@ static int setup_fdt(struct kvm *kvm)
_FDT(fdt_open_into(fdt, fdt_dest, FDT_MAX_SIZE));
_FDT(fdt_pack(fdt_dest));
- dump_fdt(fdt_dest);
+ if (kvm->cfg.arch.dump_dtb_filename)
+ dump_fdt(kvm->cfg.arch.dump_dtb_filename, fdt_dest);
return 0;
}
late_init(setup_fdt);
diff --git a/tools/kvm/arm/include/kvm/kvm-config-arch.h b/tools/kvm/arm/include/kvm/kvm-config-arch.h
index 60f61de..f63f302 100644
--- a/tools/kvm/arm/include/kvm/kvm-config-arch.h
+++ b/tools/kvm/arm/include/kvm/kvm-config-arch.h
@@ -1,7 +1,15 @@
#ifndef KVM__KVM_CONFIG_ARCH_H
#define KVM__KVM_CONFIG_ARCH_H
+#include "kvm/parse-options.h"
+
struct kvm_config_arch {
+ const char *dump_dtb_filename;
};
+#define OPT_ARCH_RUN(pfx, cfg) \
+ pfx, \
+ OPT_STRING('\0', "dump-dtb", &(cfg)->dump_dtb_filename, \
+ ".dtb file", "Dump generated .dtb to specified file"),
+
#endif /* KVM__KVM_CONFIG_ARCH_H */
--
1.8.0
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