[PATCH 07/12] KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes
Marc Zyngier
maz at kernel.org
Fri Oct 30 12:40:12 EDT 2020
From: Gavin Shan <gshan at redhat.com>
Although huge pages can be created out of multiple contiguous PMDs
or PTEs, the corresponding sizes are not supported at Stage-2 yet.
Instead of failing the mapping, fall back to the nearer supported
mapping size (CONT_PMD to PMD and CONT_PTE to PTE respectively).
Suggested-by: Marc Zyngier <maz at kernel.org>
Signed-off-by: Gavin Shan <gshan at redhat.com>
[maz: rewritten commit message]
Signed-off-by: Marc Zyngier <maz at kernel.org>
Link: https://lore.kernel.org/r/20201025230626.18501-1-gshan@redhat.com
---
arch/arm64/kvm/mmu.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index a816cb8e619b..e431d2d8e368 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -787,14 +787,26 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
vma_shift = PAGE_SHIFT;
}
- if (vma_shift == PUD_SHIFT &&
- !fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
- vma_shift = PMD_SHIFT;
-
- if (vma_shift == PMD_SHIFT &&
- !fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) {
- force_pte = true;
+ switch (vma_shift) {
+ case PUD_SHIFT:
+ if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
+ break;
+ fallthrough;
+ case CONT_PMD_SHIFT:
+ vma_shift = PMD_SHIFT;
+ fallthrough;
+ case PMD_SHIFT:
+ if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE))
+ break;
+ fallthrough;
+ case CONT_PTE_SHIFT:
vma_shift = PAGE_SHIFT;
+ force_pte = true;
+ fallthrough;
+ case PAGE_SHIFT:
+ break;
+ default:
+ WARN_ONCE(1, "Unknown vma_shift %d", vma_shift);
}
vma_pagesize = 1UL << vma_shift;
--
2.28.0
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