From 523b3999e5f620cb5ccce6a7ca2780a4cab579a2 Mon Sep 17 00:00:00 2001 From: Alexandru Elisei Date: Thu, 10 Sep 2020 14:33:51 +0100 Subject: [PATCH] KVM: arm64: Try PMD block mappings if PUD mappings are not supported When userspace uses hugetlbfs for the VM memory, user_mem_abort() tries to use the same block size to map the faulting IPA in stage 2. If stage 2 cannot the same block mapping because the block size doesn't fit in the memslot or the memslot is not properly aligned, user_mem_abort() will fall back to a page mapping, regardless of the block size. We can do better for PUD backed hugetlbfs by checking if a PMD block mapping is supported before deciding to use a page. vma_pagesize is an unsigned long, use 1UL instead of 1ULL when assigning its value. Signed-off-by: Alexandru Elisei Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200910133351.118191-1-alexandru.elisei@arm.com --- arch/arm64/kvm/mmu.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 21b70abf65a7..852497bd6d1e 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -779,16 +779,25 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, else vma_shift = PAGE_SHIFT; - vma_pagesize = 1ULL << vma_shift; if (logging_active || - (vma->vm_flags & VM_PFNMAP) || - !fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) { + (vma->vm_flags & VM_PFNMAP)) { force_pte = true; - vma_pagesize = PAGE_SIZE; + 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; + vma_shift = PAGE_SHIFT; } + vma_pagesize = 1UL << vma_shift; if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE) - fault_ipa &= huge_page_mask(hstate_vma(vma)); + fault_ipa &= ~(vma_pagesize - 1); gfn = fault_ipa >> PAGE_SHIFT; mmap_read_unlock(current->mm); -- 2.11.0