On Tuesday 07 February 2017 01:12 AM, Eric DeVolder wrote: > Crash kernel region size is available via sysfs on Linux running on > bare metal. However, this does not work when Linux runs as Xen dom0. > In this case Xen crash kernel region size should be established using > __HYPERVISOR_kexec_op hypercall (Linux kernel kexec functionality does > not make a lot of sense in Xen dom0). Sadly hypercalls are not easily > accessible using shell scripts or something like that. Potentially we > can check "xl dmesg" output for crashkernel option but this is not nice. > So, let's add this functionality, for Linux running on bare metal and > as Xen dom0, to kexec-tools. This way kdump scripts may establish crash > kernel region size in one way regardless of platform. All burden of > platform detection lies on kexec-tools. > > Figure (and unit) displayed by this new kexec-tools functionality is > the same as one taken from /sys/kernel/kexec_crash_size. > > This patch just adds print_crashkernel_region_size() function, which > prints crash kernel region size, for x86 arch. Next patches will add > same named function for other archs supported by kexec-tools. Last patch > of this series will export this functionality to the userspace via > separate kexec utility option. IMHO, overall code would have been more cleaner if we introduce get_crash_kernel_load_range() for each arch. Then a single function to get_crash_kernel_size() in kexec/kexec.c. ~Pratyush
