On Sat, 25 Nov 2023 at 14:54, WANG Rui <wangrui@xxxxxxxxxxx> wrote:
>
> Currently, kexec loads vmlinux.efi to address 0 instead of the link
> address. This causes kexec to fail to boot the new vmlinux.efi on qemu.
>
> pei_loongarch_load: kernel_segment: 0000000000000000
> pei_loongarch_load: kernel_entry: 00000000013f1000
> pei_loongarch_load: image_size: 0000000001ca0000
> pei_loongarch_load: text_offset: 0000000000200000
> pei_loongarch_load: phys_offset: 0000000000000000
> pei_loongarch_load: PE format: yes
> loongarch_load_other_segments:333: command_line: kexec console=ttyS0,115200
> kexec_load: entry = 0x13f1000 flags = 0x1020000
> nr_segments = 2
> segment[0].buf = 0x7fffeea38010
> segment[0].bufsz = 0x1b55200
> segment[0].mem = (nil)
> segment[0].memsz = 0x1ca0000
> segment[1].buf = 0x5555570940b0
> segment[1].bufsz = 0x200
> segment[1].mem = 0x1ca0000
> segment[1].memsz = 0x4000
>
> This patch constrains the range of the kernel segment by `hole_min`
> and `hole_max` to place vmlinux.efi exactly at the link address.
>
> pei_loongarch_load: kernel_segment: 0000000000200000
> pei_loongarch_load: kernel_entry: 00000000013f1000
> pei_loongarch_load: image_size: 0000000001ca0000
> pei_loongarch_load: text_offset: 0000000000200000
> pei_loongarch_load: phys_offset: 0000000000000000
> pei_loongarch_load: PE format: yes
> loongarch_load_other_segments:339: command_line: kexec console=ttyS0,115200
> kexec_load: entry = 0x13f1000 flags = 0x1020000
> nr_segments = 2
> segment[0].buf = 0x7ffff2028010
> segment[0].bufsz = 0x1b55200
> segment[0].mem = 0x200000
> segment[0].memsz = 0x1ca0000
> segment[1].buf = 0x555557498098
> segment[1].bufsz = 0x200
> segment[1].mem = 0x1ea0000
> segment[1].memsz = 0x4000
>
> Signed-off-by: WANG Rui <wangrui@xxxxxxxxxxx>
> ---
>
> v1->v2:
> * Fix the issue preventing it from working on the physical machine.
>
> kexec/arch/loongarch/kexec-loongarch.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/kexec/arch/loongarch/kexec-loongarch.c b/kexec/arch/loongarch/kexec-loongarch.c
> index 62ff8fd..32a42d2 100644
> --- a/kexec/arch/loongarch/kexec-loongarch.c
> +++ b/kexec/arch/loongarch/kexec-loongarch.c
> @@ -265,9 +265,13 @@ unsigned long loongarch_locate_kernel_segment(struct kexec_info *info)
> hole = ULONG_MAX;
> }
> } else {
> - hole = locate_hole(info,
> - loongarch_mem.text_offset + loongarch_mem.image_size,
> - MiB(1), 0, ULONG_MAX, 1);
> + unsigned long hole_min;
> + unsigned long hole_max;
> +
> + hole_min = loongarch_mem.text_offset;
> + hole_max = hole_min + loongarch_mem.image_size;
> + hole = locate_hole(info, loongarch_mem.image_size,
> + MiB(1), hole_min, hole_max, 1);
>
> if (hole == ULONG_MAX)
> dbgprintf("%s: locate_hole failed\n", __func__);
Hi,
Previously when I played with the zboot kernel on a kvm guest I
noticed this issue, but I found that the 1st 2M memory is memblock
reserved but it is not shown in /proc/iomem as reserved, I suspect the
1st 2M is not usable for some arch specific reason but I was not sure.
Below patch can fix it but due to my rusty knowledge of loongarch I
did not send it out. I suspect even if the locate_hole avoids the
wrong memory, in the 2nd kernel it could still access it. Correct?
Index: linux/arch/loongarch/kernel/mem.c
===================================================================
--- linux.orig/arch/loongarch/kernel/mem.c 2023-06-02
10:24:09.633593320 +0800
+++ linux/arch/loongarch/kernel/mem.c 2023-10-05 15:27:05.609455460 +0800
@@ -52,8 +52,8 @@
memblock_set_current_limit(PFN_PHYS(max_low_pfn));
memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
- /* Reserve the first 2MB */
- memblock_reserve(PHYS_OFFSET, 0x200000);
+ /* Mark the first 2MB as nomap */
+ memblock_mark_nomap(PHYS_OFFSET, 0x200000);
/* Reserve the kernel text/data/bss */
memblock_reserve(__pa_symbol(&_text),
> --
> 2.42.0
>
>
> _______________________________________________
> kexec mailing list
> kexec@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/kexec
>
_______________________________________________
kexec mailing list
kexec@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/kexec
