On 13/09/2024 11:56, Dave Young wrote: > On Thu, 12 Sept 2024 at 22:15, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: >> >> (cc Dave) > > Thanks for ccing me. > >> >> Full thread here: >> https://lore.kernel.org/all/CAMj1kXG1hbiafKRyC5qM1Vj5X7x-dmLndqqo2AYnHMRxDz-80w@xxxxxxxxxxxxxx/T/#u >> >> On Thu, 12 Sept 2024 at 16:05, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: >>> >>> On Thu, 12 Sept 2024 at 15:55, Usama Arif <usamaarif642@xxxxxxxxx> wrote: >>>> >>>> >>>> >>>> On 12/09/2024 14:10, Ard Biesheuvel wrote: >>>>> Does the below help at all? >>>>> >>>>> --- a/drivers/firmware/efi/tpm.c >>>>> +++ b/drivers/firmware/efi/tpm.c >>>>> @@ -60,7 +60,7 @@ int __init efi_tpm_eventlog_init(void) >>>>> } >>>>> >>>>> tbl_size = sizeof(*log_tbl) + log_tbl->size; >>>>> - memblock_reserve(efi.tpm_log, tbl_size); >>>>> + efi_mem_reserve(efi.tpm_log, tbl_size); >>>>> >>>>> if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) { >>>>> pr_info("TPM Final Events table not present\n"); >>>> >>>> Unfortunately not. efi_mem_reserve updates e820_table, while kexec looks at /sys/firmware/memmap >>>> which is e820_table_firmware. >>>> >>>> arch_update_firmware_area introduced in the RFC patch does the same thing as efi_mem_reserve does at >>>> its end, just with e820_table_firmware instead of e820_table. >>>> i.e. efi_mem_reserve does: >>>> e820__range_update(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED); >>>> e820__update_table(e820_table); >>>> >>>> while arch_update_firmware_area does: >>>> e820__range_update_firmware(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED); >>>> e820__update_table(e820_table_firmware); >>>> >>> >>> Shame. >>> >>> Using efi_mem_reserve() is appropriate here in any case, but I guess >>> kexec on x86 needs to be fixed to juggle the EFI memory map, memblock >>> table, and 3 (!) versions of the E820 table in the correct way >>> (e820_table, e820_table_kexec and e820_table_firmware) >>> >>> Perhaps we can put this additional logic in x86's implementation of >>> efi_arch_mem_reserve()? AFAICT, all callers of efi_mem_reserve() deal >>> with configuration tables produced by the firmware that may not be >>> reserved correctly if kexec looks at e820_table_firmware[] only. >> > > I have not read all the conversations, let me have a look and response later. > > The first glance about the patch is that I think the kexec_file_load > syscall (default of latest kexec-tools) will not use > e820_table_firmware AFAIK. it will only use e820_table_kexec. I initially thought that as well. But it looks like kexec just reads /sys/firmware/memmap https://github.com/horms/kexec-tools/blob/main/kexec/firmware_memmap.h#L29 which is e820_table_firmware. The patch that Ard sent in https://lore.kernel.org/all/20240912155159.1951792-2-ardb+git@xxxxxxxxxx/ is the right approach to it I believe, and I dont see the issue anymore after applying that patch. > > Usama, can you confirm how you tested this? > kexec -c -l will use kexec_load syscall I am currently testing in my VM setup with kexec_load. But production is running kexec_file_load and has the same issue. Thanks, Usama > kexec [-s] -l will use kexec_file_load syscall > > Thanks > Dave >
