On 1/27/19 11:46 PM, Lianbo Jiang wrote:
> For AMD machine with SME feature, if SME is enabled in the first
> kernel, the crashed kernel's page table(pgd/pud/pmd/pte) contains
> the memory encryption mask, so makedumpfile needs to remove the
> memory encryption mask to obtain the true physical address.
>
> Signed-off-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
> ---
> Changes since v1:
> 1. Merge them into a patch.
> 2. The sme_mask is not an enum number, remove it.
> 3. Sanity check whether the sme_mask is in vmcoreinfo.
> 4. Deal with the huge pages case.
> 5. Cover the 5-level path.
>
> arch/x86_64.c | 30 +++++++++++++++++-------------
> makedumpfile.c | 4 ++++
> makedumpfile.h | 1 +
> 3 files changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86_64.c b/arch/x86_64.c
> index 537fb78..7b3ed10 100644
> --- a/arch/x86_64.c
> +++ b/arch/x86_64.c
> @@ -291,6 +291,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
> unsigned long page_dir, pgd, pud_paddr, pud_pte, pmd_paddr, pmd_pte;
> unsigned long pte_paddr, pte;
> unsigned long p4d_paddr, p4d_pte;
> + unsigned long sme_me_mask = ~0UL;
>
> /*
> * Get PGD.
> @@ -302,6 +303,9 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
> return NOT_PADDR;
> }
>
> + if (NUMBER(sme_mask) != NOT_FOUND_NUMBER)
> + sme_me_mask = ~(NUMBER(sme_mask));
This is a bit confusing since this isn't the sme_me_mask any more, but the
complement. Might want to somehow rename this so that it doesn't cause any
confusion.
> +
> if (check_5level_paging()) {
> page_dir += pgd5_index(vaddr) * sizeof(unsigned long);
> if (!readmem(PADDR, page_dir, &pgd, sizeof pgd)) {
> @@ -309,7 +313,7 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
> return NOT_PADDR;
> }
> if (info->vaddr_for_vtop == vaddr)
> - MSG(" PGD : %16lx => %16lx\n", page_dir, pgd);
> + MSG(" PGD : %16lx => %16lx\n", page_dir, (pgd & sme_me_mask));
No need to remove the mask here. You're just printing out the value of
the entry. It might be nice to know whether the encryption bit is set or
not - after all, ENTRY_MASK is still part of this value.
>
> if (!(pgd & _PAGE_PRESENT)) {
> ERRMSG("Can't get a valid pgd.\n");
> @@ -318,20 +322,20 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
> /*
> * Get P4D.
> */
> - p4d_paddr = pgd & ENTRY_MASK;
> + p4d_paddr = pgd & ENTRY_MASK & sme_me_mask;
This goes back to my original comment that you should just make a local
variable that is "ENTRY_MASK & ~(NUMBER(sme_mask))" since you are
performing this ANDing everywhere ENTRY_MASK is used - except then you
miss the one at the very end of this routine on the return statement.
> p4d_paddr += p4d_index(vaddr) * sizeof(unsigned long);
> if (!readmem(PADDR, p4d_paddr, &p4d_pte, sizeof p4d_pte)) {
> ERRMSG("Can't get p4d_pte (p4d_paddr:%lx).\n", p4d_paddr);
> return NOT_PADDR;
> }
> if (info->vaddr_for_vtop == vaddr)
> - MSG(" P4D : %16lx => %16lx\n", p4d_paddr, p4d_pte);
> + MSG(" P4D : %16lx => %16lx\n", p4d_paddr, (p4d_pte & sme_me_mask));
>
> if (!(p4d_pte & _PAGE_PRESENT)) {
> ERRMSG("Can't get a valid p4d_pte.\n");
> return NOT_PADDR;
> }
> - pud_paddr = p4d_pte & ENTRY_MASK;
> + pud_paddr = p4d_pte & ENTRY_MASK & sme_me_mask;
> }else {
> page_dir += pgd_index(vaddr) * sizeof(unsigned long);
> if (!readmem(PADDR, page_dir, &pgd, sizeof pgd)) {
> @@ -339,13 +343,13 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
> return NOT_PADDR;
> }
> if (info->vaddr_for_vtop == vaddr)
> - MSG(" PGD : %16lx => %16lx\n", page_dir, pgd);
> + MSG(" PGD : %16lx => %16lx\n", page_dir, (pgd & sme_me_mask));
>
> if (!(pgd & _PAGE_PRESENT)) {
> ERRMSG("Can't get a valid pgd.\n");
> return NOT_PADDR;
> }
> - pud_paddr = pgd & ENTRY_MASK;
> + pud_paddr = pgd & ENTRY_MASK & sme_me_mask;
> }
>
> /*
> @@ -357,47 +361,47 @@ __vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
> return NOT_PADDR;
> }
> if (info->vaddr_for_vtop == vaddr)
> - MSG(" PUD : %16lx => %16lx\n", pud_paddr, pud_pte);
> + MSG(" PUD : %16lx => %16lx\n", pud_paddr, (pud_pte & sme_me_mask));
>
> if (!(pud_pte & _PAGE_PRESENT)) {
> ERRMSG("Can't get a valid pud_pte.\n");
> return NOT_PADDR;
> }
> if (pud_pte & _PAGE_PSE) /* 1GB pages */
> - return (pud_pte & ENTRY_MASK & PUD_MASK) +
> + return (pud_pte & ENTRY_MASK & PUD_MASK & sme_me_mask) +
> (vaddr & ~PUD_MASK);
>
> /*
> * Get PMD.
> */
> - pmd_paddr = pud_pte & ENTRY_MASK;
> + pmd_paddr = pud_pte & ENTRY_MASK & sme_me_mask;
> pmd_paddr += pmd_index(vaddr) * sizeof(unsigned long);
> if (!readmem(PADDR, pmd_paddr, &pmd_pte, sizeof pmd_pte)) {
> ERRMSG("Can't get pmd_pte (pmd_paddr:%lx).\n", pmd_paddr);
> return NOT_PADDR;
> }
> if (info->vaddr_for_vtop == vaddr)
> - MSG(" PMD : %16lx => %16lx\n", pmd_paddr, pmd_pte);
> + MSG(" PMD : %16lx => %16lx\n", pmd_paddr, (pmd_pte & sme_me_mask));
>
> if (!(pmd_pte & _PAGE_PRESENT)) {
> ERRMSG("Can't get a valid pmd_pte.\n");
> return NOT_PADDR;
> }
> if (pmd_pte & _PAGE_PSE) /* 2MB pages */
> - return (pmd_pte & ENTRY_MASK & PMD_MASK) +
> + return (pmd_pte & ENTRY_MASK & PMD_MASK & sme_me_mask) +
> (vaddr & ~PMD_MASK);
>
> /*
> * Get PTE.
> */
> - pte_paddr = pmd_pte & ENTRY_MASK;
> + pte_paddr = pmd_pte & ENTRY_MASK & sme_me_mask;
> pte_paddr += pte_index(vaddr) * sizeof(unsigned long);
> if (!readmem(PADDR, pte_paddr, &pte, sizeof pte)) {
> ERRMSG("Can't get pte (pte_paddr:%lx).\n", pte_paddr);
> return NOT_PADDR;
> }
> if (info->vaddr_for_vtop == vaddr)
> - MSG(" PTE : %16lx => %16lx\n", pte_paddr, pte);
> + MSG(" PTE : %16lx => %16lx\n", pte_paddr, (pte & sme_me_mask));
>
> if (!(pte & _PAGE_PRESENT)) {
> ERRMSG("Can't get a valid pte.\n");
Just after here is where I think an "& sme_me_mask" is missing...
Thanks,
Tom
> diff --git a/makedumpfile.c b/makedumpfile.c
> index 8923538..2237eb8 100644
> --- a/makedumpfile.c
> +++ b/makedumpfile.c
> @@ -977,6 +977,8 @@ next_page:
> read_size = MIN(info->page_size - PAGEOFFSET(paddr), size);
>
> pgaddr = PAGEBASE(paddr);
> + if (NUMBER(sme_mask) != NOT_FOUND_NUMBER)
> + pgaddr = pgaddr & ~(NUMBER(sme_mask));
> pgbuf = cache_search(pgaddr, read_size);
> if (!pgbuf) {
> ++cache_miss;
> @@ -2276,6 +2278,7 @@ write_vmcoreinfo_data(void)
> WRITE_NUMBER("NR_FREE_PAGES", NR_FREE_PAGES);
> WRITE_NUMBER("N_ONLINE", N_ONLINE);
> WRITE_NUMBER("pgtable_l5_enabled", pgtable_l5_enabled);
> + WRITE_NUMBER("sme_mask", sme_mask);
>
> WRITE_NUMBER("PG_lru", PG_lru);
> WRITE_NUMBER("PG_private", PG_private);
> @@ -2672,6 +2675,7 @@ read_vmcoreinfo(void)
> READ_NUMBER("NR_FREE_PAGES", NR_FREE_PAGES);
> READ_NUMBER("N_ONLINE", N_ONLINE);
> READ_NUMBER("pgtable_l5_enabled", pgtable_l5_enabled);
> + READ_NUMBER("sme_mask", sme_mask);
>
> READ_NUMBER("PG_lru", PG_lru);
> READ_NUMBER("PG_private", PG_private);
> diff --git a/makedumpfile.h b/makedumpfile.h
> index 73813ed..e97b2e7 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -1912,6 +1912,7 @@ struct number_table {
> long NR_FREE_PAGES;
> long N_ONLINE;
> long pgtable_l5_enabled;
> + long sme_mask;
>
> /*
> * Page flags
>
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