Re: [Crash-utility] [PATCH] x86_64: Fix for AMD SME issue
Hi Lianbo,
Applied at my end:
https://github.com/crash-utility/crash/commit/763e221388219b07bd949a9ba48...
(wrapped two lines over 100 chars.)
Thanks,
Kazu
On 2022/08/03 16:33, HAGIO KAZUHITO(萩尾 一仁) wrote:
> On 2022/08/01 15:22, lijiang wrote:
>
>>>> @@ -1938,6 +1946,7 @@ x86_64_pud_offset(ulong pgd_pte, ulong vaddr, int
>>> verbose, int IS_XEN)
>>>> FILL_PUD(pud_paddr, PHYSADDR, PAGESIZE());
>>>> pud = ((ulong *)pud_paddr) + pud_index(vaddr);
>>>> pud_pte = ULONG(machdep->pud + PAGEOFFSET(pud));
>>>> + pud_pte &= ~machdep->machspec->sme_mask;
>>>
>>> Taking this for example, the pud_pte is masked here..
>>>
>>>
>> Good questions. This was based on two considerations:
>> [1] ensure to display the printing information as below:
>> ...
>> P4D: 761c01a70 => 761c02067
>> PUD: 761c02b28 => 16bea5063
>> ^^^^^^^^^^
>> Otherwise, it will display the address of PUD with the C-bit.
>> Or Remove the C-bit when printing information?
>> + fprintf(fp, " PUD: %lx => %lx\n", (ulong)pud, pud_pte &
>> ~machdep->machspec->sme_mask);
>
> I thought it might be good to display the raw pte value, but ok,
> the current way also looks good.
>
>>
>> [2] consider the cases of using hugepage.
>> -On this machine, it supports 1G and 2M hugepage according to the
>> vmcore.
>>
>>
>>> > if (verbose) {
>>>> if (IS_XEN)
>>>> fprintf(fp, " PUD: %lx => %lx
[machine]\n",
>>> (ulong)pud, pud_pte);
>>>> @@ -1960,6 +1969,7 @@ x86_64_pmd_offset(ulong pud_pte, ulong vaddr, int
>>> verbose, int IS_XEN)
>>>> ulong pmd_pte;
>>>>
>>>> pmd_paddr = pud_pte & PHYSICAL_PAGE_MASK;
>>>> + pmd_paddr &= ~machdep->machspec->sme_mask;
>>>
>>> and also here the pud_pte is masked again. Is this needed?
>>>
>>>
>> They are needed, otherwise some crash commands may not work well, for
>> example:
>> ...
>> kmem: seek error: kernel virtual address: ffedfea0c627ec28 type: "page
>> inuse"
>
> ah ok, x86_64_kpgd_offset returns the pointer of a pgd entry, so
> x86_64_p4d_offset and x86_64_pud_offset need to mask the pgd entry
> before using it. Let's go with this.
>
> Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
>
> Thanks,
> Kazu
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