On Sat, 14 Sept 2024 at 08:46, Dave Young <dyoung@xxxxxxxxxx> wrote: > > On Fri, 13 Sept 2024 at 18:56, Dave Young <dyoung@xxxxxxxxxx> 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. > > > > I'm still confused after reading the code about why this issue can > still happen with a efi_mem_reserve. > Usama, Breno, could any of you share the exact steps on how to > reproduce this issue with a kvm guest? > The code does not use efi_mem_reserve() only memblock_reserve().
