From 2f40c46021bbb3ecd5c5f05764ecccbc276bc690 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Mon, 26 Oct 2020 10:06:26 +1100 Subject: [PATCH] KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes 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 Signed-off-by: Gavin Shan [maz: rewritten commit message] Signed-off-by: Marc Zyngier 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;