KVM: arm64: Update page shift if stage 2 block mapping not supported
Commit 196f878a (" 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 1559b758 ("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: 1559b758 ("KVM: arm/arm64: Re-check VMA on detecting a poisoned page") Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Link: https://lore.kernel.org/r/20200901133357.52640-2-alexandru.elisei@arm.com
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