(snip some cc's) On 14 September 2015 at 11:31, Shannon Zhao <zhaoshenglong@xxxxxxxxxx> wrote: > > > On 2015/9/14 17:09, Ard Biesheuvel wrote: >> On 14 September 2015 at 10:42, Shannon Zhao <zhaoshenglong@xxxxxxxxxx> wrote: >> [..] >> >>> >>> It only needs to apply following patch to fix a bug in Linux kernel when >>> mapping EFI_MEMORY_RUNTIME memory. >>> >> >> Could you explain why you think efi_virtmap_init() should fail if >> there are no EFI_MEMORY_RUNTIME regions? >> > > My understanding is that if there are no EFI_MEMORY_RUNTIME regions, it > means we can't use runtime services and should not set the bit > EFI_RUNTIME_SERVICES of efi.flags. But if efi_virtmap_init() return > true, the bit will be set. > As I said, if you don't want the EFI_RUNTIME_SERVICES bit to be set for other reasons, don't rig efi_virtmap_init() to return false when it shouldn't. >> The absence of such regions is allowed by the spec, so >> efi_virtmap_init() is correct imo to return success. >> > Sorry, not well know about the spec. Could you point out where the spec > says this? > Well, I think it doesn't work that way. You are claiming that a memory map without at least one EFI_MEMORY_RUNTIME constitutes an error condition, so the burden is on you to provide a reference to the spec that says you must have at least one such region. -- Ard. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
