[PATCH 00/10] arm64 kexec kernel patches V5

[Arun Chandran]

Hi dave,

On Mon, Nov 10, 2014 at 12:47 PM, Dave Young <dyoung at redhat.com> wrote:
> On 11/06/14 at 09:43pm, Arun Chandran wrote:
>> On Thu, Nov 6, 2014 at 8:58 PM, Mark Rutland <mark.rutland at arm.com> wrote:
>> > On Thu, Nov 06, 2014 at 12:16:12PM +0000, Arun Chandran wrote:
>> >> Hi Geoff,
>> >>
>> >> I am trying this on my hardware (apm-mustang.dtb)
>> >>
>> >> On Fri, Oct 24, 2014 at 4:40 AM, Geoff Levand <geoff at infradead.org> wrote:
>> >> > Hi All,
>> >> >
>> >> > This series adds the core support for kexec re-boots on arm64.  I have tested
>> >> > with the ARM VE fast model, the ARM Base model and the ARM Foundation
>> >> > model with various kernel config options for both the first and second stage
>> >> > kernels.
>> >> >
>> >> > To load a second stage kernel and execute a kexec re-boot on arm64 my patches to
>> >> > kexec-tools [2], which have not yet been merged upstream, are needed.
>> >> >
>> >> > Patches 1-4 rework the arm64 hcall mechanism to give the arm64 soft_restart()
>> >> > routine the ability to switch exception levels from EL1 to EL2 for kernels that
>> >> > were entered in EL2.
>> >> >
>> >> > Patches 5 and 6 convert the use of device tree /memreserve/ to device tree
>> >> > reserved-memory nodes.
>> >> >
>> >> > Patch 7 moves proc-macros.S from arm64/mm to arm64/include/asm so that the
>> >> > dcache_line_size macro it defines can be uesd by kexec's relocate kernel
>> >> > routine.
>> >> >
>> >> > Patches 8-10 add the actual kexec support.
>> >> >
>> >> > Please consider all patches for inclusion.  Any comments or suggestions on how
>> >> > to improve are welcome.
>> >> >
>> >> > [1]  https://git.linaro.org/people/geoff.levand/linux-kexec.git
>> >> > [2]  https://git.linaro.org/people/geoff.levand/kexec-tools.git
>> >> >
>> >> > Several things are known to have problems on kexec re-boot:
>> >> >
>> >> > spin-table
>> >> > ----------
>> >> >
>> >> > PROBLEM: The spin-table enable method does not implement all the methods needed
>> >> > for CPU hot-plug, so the first stage kernel cannot be shutdown properly.
>> >> >
>> >> > WORK-AROUND: Upgrade to system firmware that provides PSCI enable method
>> >> > support, OR build the first stage kernel with CONFIG_SMP=n, OR pass 'maxcpus=1'
>> >> > on the first stage kernel command line.
>> >>
>> >> I have CONFIG_SMP=n
>> >>
>> >> >
>> >> > FIX: Upgrade system firmware to provide PSCI enable method support.
>> >> >
>> >> > KVM
>> >> > ---
>> >> >
>> >> > PROBLEM: KVM acquires hypervisor resources on startup, but does not free those
>> >> > resources on shutdown, so the first stage kernel cannot be shutdown properly.
>> >> >
>> >> > WORK-AROUND:  Build the first stage kernel with CONFIG_KVM=n.
>> >>
>> >> KVM also disabled.
>> >>
>> >> /root at genericarmv8:~# usr/local/sbin/kexec --lite -l vmlinux
>> >> --dtb=apm-mustang.dtb --command-line=
>> >> "root=/dev/nfs rw
>> >> nfsroot=10.162.103.145:/nfs_root/linaro-image-lamp-genericarmv8,nfsvers=3
>> >>  ip=:::::eth0:dhcp panic=1 console=ttyS0,115200
>> >> earlyprintk=uart8250-32bit,0x1c020000"
>> >>
>> >> kexec version: 14.10.21.16.36-ga38e0a6
>> >> arch_process_options:85: command_line: root=/dev/nfs rw
>> >> nfsroot=10.162.103.145:/nfs_root/linaro-image-lamp-genericarmv8,nfsvers=3
>> >> ip=:::::eth0:dhcp panic=1 console=ttyS0,115200
>> >> earlyprintk=uart8250-32bit,0x1
>> >> c020000
>> >> arch_process_options:87: initrd: (null)
>> >> arch_process_options:88: dtb: apm-mustang.dtb
>> >> arch_process_options:89: lite: 1
>> >> kernel: 0x7f756e7010 kernel_size: 0x488a308
>> >> Modified cmdline: root=/dev/nfs
>> >> Unable to find /proc/device-tree//chosen/linux,stdout-path, printing
>> >> from purgatory is diabled
>> >> get_memory_ranges_dt:638: node_1516 memory
>> >> get_memory_ranges_dt:664:  RAM: 0000004000000000 - 0000004400000000
>> >> get_memory_ranges_dt:659: SKIP: 0000000000000000 - 0000000000000000
>> >> get_memory_ranges_dt:659: SKIP: 0000000000000000 - 0000000000000000
>> >> get_memory_ranges_dt:659: SKIP: 0000000000000000 - 0000000000000000
>> >> get_memory_ranges_dt:678: Success
>> >> elf_arm64_load: PE format: yes
>> >> p_vaddr: ffffffc000080000
>> >> virt_to_phys: ffffffc000080000 -> 0000004000080000
>> >> add_segment_phys_virt: 0000007f756f7010 - 0000007f75d3cf70 (00645f60)
>> >> -> 0000004000080000 - 00000040006fb000 (0067b000)
>> >> elf_arm64_load: text_offset: 0000000000080000
>> >> elf_arm64_load: image_size:  000000000067f000
>> >> elf_arm64_load: page_offset: ffffffc000000000
>> >> elf_arm64_load: memstart:    0000004000000000
>> >> virt_to_phys: ffffffc000080000 -> 0000004000080000
>> >> elf_arm64_load: e_entry:     ffffffc000080000 -> 0000004000080000
>> >> virt_to_phys: ffffffc000080000 -> 0000004000080000
>> >> Modified cmdline:root=/dev/nfs rw
>> >> nfsroot=10.162.103.145:/nfs_root/linaro-image-lamp-genericarmv8,nfsvers=3
>> >> ip=:::::eth0:dhcp panic=1 console=ttyS0,115200
>> >> earlyprintk=uart8250-32bit,0x1c020000
>> >> Unable to find /proc/device-tree//chosen/linux,stdout-path, printing
>> >> from purgatory is diabled
>> >> read_cpu_info: dtb_1 cpu-0 (/cpus/cpu at 000): hwid-0, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-1 (/cpus/cpu at 001): hwid-1, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-2 (/cpus/cpu at 100): hwid-100, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-3 (/cpus/cpu at 101): hwid-101, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-4 (/cpus/cpu at 200): hwid-200, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-5 (/cpus/cpu at 201): hwid-201, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-6 (/cpus/cpu at 300): hwid-300, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_1 cpu-7 (/cpus/cpu at 301): hwid-301, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-0 (/cpus/cpu at 000): hwid-0, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-1 (/cpus/cpu at 001): hwid-1, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-2 (/cpus/cpu at 100): hwid-100, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-3 (/cpus/cpu at 101): hwid-101, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-4 (/cpus/cpu at 200): hwid-200, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-5 (/cpus/cpu at 201): hwid-201, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-6 (/cpus/cpu at 300): hwid-300, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> read_cpu_info: dtb_2 cpu-7 (/cpus/cpu at 301): hwid-301, 'spin-table',
>> >> cpu-release-addr 400000fff8
>> >> check_cpu_properties: hwid-0: OK
>> >> check_cpu_properties: hwid-1: OK
>> >> check_cpu_properties: hwid-100: OK
>> >> check_cpu_properties: hwid-101: OK
>> >> check_cpu_properties: hwid-200: OK
>> >> check_cpu_properties: hwid-201: OK
>> >> check_cpu_properties: hwid-300: OK
>> >> check_cpu_properties: hwid-301: OK
>> >> dtb:    base 4000700000, size 221ch (8732)
>> >> add_segment_phys_virt: 0000000024c14c90 - 0000000024c16eac (0000221c)
>> >> -> 0000004000700000 - 0000004000703000 (00003000)
>> >> kexec_load: entry = 0x4000080000 flags = 0xb70000
>> >> nr_segments = 2
>> >> segment[0].buf   = 0x7f756f7010
>> >> segment[0].bufsz = 0x645f60
>> >> segment[0].mem   = 0x4000080000
>> >> segment[0].memsz = 0x67b000
>> >> segment[1].buf   = 0x24c14c90
>> >> segment[1].bufsz = 0x221c
>> >> segment[1].mem   = 0x4000700000
>> >> segment[1].memsz = 0x3000
>> >>
>> >> root at genericarmv8:~# /usr/local/sbin/kexec --lite -e
>> >> kexec version: 14.10.21.16.36-ga38e0a6
>> >> arch_process_options:85: command_line: (null)
>> >> arch_process_options:87: initrd: (null)
>> >> arch_process_options:88: dtb: (null)
>> >> arch_process_options:89: lite: 1
>> >> sd 0:0:0:0: [sda] Synchronizing SCSI cache
>> >> kexec: Starting new kernel
>> >> Bye!
>> >>
>> >> It fails to come up.  In debugger I can see
>> >>
>> >>     Core number       : 0
>> >>     Core state        : debug (AArch64 EL1)
>> >>     Debug entry cause : External Debug Request
>> >>     Current PC        : 0xffffffc000083200
>> >
>> > That's a kernel virtual address, and it looks to be somewhere early in
>> > the boot path, given it's close to PAGE_OFFSET + TEXT_OFFSET.
>> >
>> Yes. My earlyconsole setting was wrong that is why I did not see
>> anything in console for the kexec rebooting.
>>
>> With correct earlycon setting I can see
>
> Arun, could you share how did you get the working earlycon? We might have
> same problem..

I invoked kexec like this

 root at genericarmv8:~# ./usr/local/sbin/kexec --lite -l vmlinux --command-line=
"root=/dev/nfs rw
nfsroot=10.162.103.145:/nfs_root/linaro-image-lamp-genericarmv8,nfsvers=3
ip=:::::eth0:dhcp panic=1 console=ttyS0,115200
earlycon=uart8250,mmio32,0x1c020000"


Earlier my command line parameters for earlycon was wrong hence I was
not getting
earlyconsole.

Also have a look at
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/300584.html

If your board has an L3 cache; you may have to apply the modification in the
above link.

--Arun