On Fri, 13 Sept 2024 at 19:07, Usama Arif <usamaarif642@xxxxxxxxx> wrote: > > > > 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. That piece of code is only used by kexec_load > > 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. Ok, I mean efi_mem_reserve should be able to work if you retest with kexec_file_load. > > Thanks, > Usama > > > kexec [-s] -l will use kexec_file_load syscall > > > > Thanks > > Dave > > >
