Messages in this thread | | | Date | Mon, 25 Mar 2019 15:27:10 +0800 | From | Baoquan He <> | Subject | Re: [PATCH] x86/boot: Use EFI setup data if provided |
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On 03/22/19 at 04:23pm, Borislav Petkov wrote: > On Fri, Mar 22, 2019 at 11:03:43AM +0000, Junichi Nomura wrote: > > Commit 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in > > boot_params") broke kexec boot on EFI systems. efi_get_rsdp_addr() > > in the early parsing code tries to search RSDP from EFI table but > > whose address is virtual. > > > > Since kexec(1) provides physical address of config_table via boot_params, > > efi_get_rsdp_addr() should look for setup_data in the same way as > > efi_systab_init() in arch/x86/platform/efi/efi.c does. > > If the kexec kernel should continue to use efi_systab_init() then you > should make efi_get_rsdp_addr() exit early in the kexec-ed kernel.
Kexec kernel also need to get rsdp to get SRAT tables so that KASLR can avoid those hotpluggable regions in boot compression stage.
The kexec_file_load has filled in acpi_rsdp_addr of kexec kernel in below code. It will return direclty in get_rsdp_addr() since acpi_rsdp_addr is got from boot_params->acpi_rsdp_addr.
arch/x86/kernel/kexec-bzimage64.c <<setup_boot_parameters>> params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr;
The other interface, kexec_load, its boot_params filling is done in user space kexec_tools. And we haven't made the acpi_rsdp_addr filling yet. And the old kexec_tools utility can also cause the new kexec kernel to search efi rspd pointer even thought it's fixed.
Thanks Baoquan
> > -- > Regards/Gruss, > Boris. > > Good mailing practices for 400: avoid top-posting and trim the reply.
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