From 435697f25ea047cec2851d94d52522c1b0a98ac5 Mon Sep 17 00:00:00 2001 From: Alexandru Elisei Date: Tue, 1 Sep 2020 14:33:56 +0100 Subject: [PATCH] KVM: arm64: Update page shift if stage 2 block mapping not supported Commit 1a24237099490 (" KVM: arm/arm64: Signal SIGBUS when stage2 discovers hwpoison memory") modifies user_mem_abort() to send a SIGBUS signal when the fault IPA maps to a hwpoisoned page. Commit 9aa7c2bb36c1 ("KVM: arm/arm64: Re-check VMA on detecting a poisoned page") changed kvm_send_hwpoison_signal() to use the page shift instead of the VMA because at that point the code had already released the mmap lock, which means userspace could have modified the VMA. If userspace uses hugetlbfs for the VM memory, user_mem_abort() tries to map the guest fault IPA using block mappings in stage 2. That is not always possible, if, for example, userspace uses dirty page logging for the VM. Update the page shift appropriately in those cases when we downgrade the stage 2 entry from a block mapping to a page. Fixes: 9aa7c2bb36c1 ("KVM: arm/arm64: Re-check VMA on detecting a poisoned page") Signed-off-by: Alexandru Elisei Signed-off-by: Marc Zyngier Reviewed-by: Gavin Shan Link: https://lore.kernel.org/r/20200901133357.52640-2-alexandru.elisei@arm.com --- arch/arm64/kvm/mmu.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 16b8660ddbccd..f58d657a898df 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1871,6 +1871,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, !fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) { force_pte = true; vma_pagesize = PAGE_SIZE; + vma_shift = PAGE_SHIFT; } /* -- 2.39.5