Re: [PATCH v4 51/75] x86/sev-es: Handle MMIO events

From: Mike Stunes
Date: Wed Jul 22 2020 - 18:53:08 EST




> On Jul 22, 2020, at 1:05 AM, Joerg Roedel <jroedel@xxxxxxx> wrote:
>
> Hmm, I have a theory ...
>
> On Tue, Jul 21, 2020 at 09:01:44PM +0000, Mike Stunes wrote:
>> If I remove the call to probe_roms from setup_arch, or remove the calls to romchecksum from probe_roms, this kernel boots normally.
>>
>> Please let me know of other tests I should run or data that I can collect. Thanks!
>
> ... can you please try the attached diff?
>
> diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
> index 251d0aabc55a..e1fea7a38019 100644
> --- a/arch/x86/kernel/sev-es.c
> +++ b/arch/x86/kernel/sev-es.c
> @@ -389,7 +389,8 @@ static bool vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
> pgd_t *pgd;
> pte_t *pte;
>
> - pgd = pgd_offset(current->active_mm, va);
> + pgd = __va(read_cr3_pa());
> + pgd = &pgd[pgd_index(va)];
> pte = lookup_address_in_pgd(pgd, va, &level);
> if (!pte) {
> ctxt->fi.vector = X86_TRAP_PF;

Thanks Joerg! With that change in place, this kernel boots normally. What was the problem?