On 09/02/2021 15.38, Claudio Imbrenda wrote:
Add support for 1M and 2G pages.
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
lib/s390x/mmu.h | 73 +++++++++++++-
lib/s390x/mmu.c | 246 +++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 294 insertions(+), 25 deletions(-)
[...]
+/*
+ * Get the pte (page) DAT table entry for the given address and pmd,
+ * allocating it if necessary.
+ * The pmd must not be large.
+ */
+static inline pte_t *get_pte(pmd_t *pmd, uintptr_t vaddr)
+{
pte_t *pte = pte_alloc(pmd, vaddr);
- return &pte_val(*pte);
+ assert(!pmd_large(*pmd));
+ pte = pte_alloc(pmd, vaddr);
Why is this function doing "pte = pte_alloc(pmd, vaddr)" twice now?
+ return pte;
+}
[...]
+ if ((level == 1) && !pgd_none(*(pgd_t *)ptr))
+ idte_pgdp(va, ptr);
+ else if ((level == 2) && !p4d_none(*(p4d_t *)ptr))
+ idte_p4dp(va, ptr);
+ else if ((level == 3) && !pud_none(*(pud_t *)ptr))
+ idte_pudp(va, ptr);
+ else if ((level == 4) && !pmd_none(*(pmd_t *)ptr))
+ idte_pmdp(va, ptr);
+ else if (!pte_none(*(pte_t *)ptr))
+ ipte(va, ptr);
Meta-comment: Being someone who worked quite a bit with the page tables on
s390x, but never really got in touch with the way it is handled in the Linux
kernel, I'm always having a hard time to match all these TLAs to the PoP:
pmd, pud, p4d ...
Can we please have a proper place in the kvm-unit-tests sources somewhere
(maybe at the beginning of mmu.c), where the TLAs are explained and how they
map to the region and segment tables of the Z architecture?
(I personally would prefer to completely switch to the Z arch naming
instead, but I guess that's too much of a change right now)
Thomas
