device: 0.886
graphic: 0.829
permissions: 0.723
network: 0.720
other: 0.534
debug: 0.512
vnc: 0.511
performance: 0.428
socket: 0.422
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boot: 0.329
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PID: 0.302
KVM: 0.059

cputlb: uninitialized local variable in tlb_set_page_with_attrs cause SIGSEGV when a CPU access an unmapped IOMMU page
Description of problem:
When a TCG cpu accesses an unmapped page within an IOMMU region that causes a translation fault, QEMU SIGSEGVs in `io_readx`.
The reason was that in `address_space_translate_for_iotlb`, `xlat` is not set on a permission fault.
As a result, `xlat` in `tlb_set_page_with_attr` is uninitialized. This in turn causes various mis-calculation and eventually crashes in `io_readx`.