>>> On 06.09.12 at 17:47, Matt Fleming <matt.fleming@xxxxxxxxx> wrote: > On Thu, 2012-09-06 at 15:34 +0100, Jan Beulich wrote: >> >>> On 06.09.12 at 15:15, Matt Fleming <matt@xxxxxxxxxxxxxxxxx> wrote: >> > + >> > + pgd += i; >> > + save[i] = *pgd; >> > + set_pgd(pgd, efi_one_to_one_pgd[i]); >> > + } >> >> Did you, as an alternative, consider switching to a different >> CR3 instead of copying back and forth? > > I did consider it, but I couldn't convince myself whether or not the EFI > pagetable would need to be manually kept in sync with any other > pagetables. But now I look at the code a bit harder, it seems that > should be taken care of automatically. In fact, the tboot code seems to > do something similar. I'll try that approach. Actually, I think the copying approach is even broken - what if multiple threads currently on the same address space want to invoke a runtime call simultaneously? The first one to get here would save the right values, but the second one wouldn't. Jan -- 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
