Conny reported that a guest Linux currently spits out: "The s390-virtio transport is deprecated. Please switch to a modern host providing virtio-ccw."
This is strange, because we have no legacy virtio transport in QEMU :) Main problem is, that a page is tested for acccess, and the test does not fail. All memory access variants like stb_phys() will never fail. On invalid memory, they simply do nothing. Linux uses lura for this check. Let's introduce a _real MMU that handles prefixing and can later be used for things like low address protection. The other BUG is that a check for invalid memory is wrong. Therefore, Patch 1 alone makes the guest crash when trying to initialize the virtio transport. Crazy stuff. David Hildenbrand (6): s390x/tcg: fix checking for invalid memory check s390x/tcg: add MMU for real addresses s390x/tcg: make lura(g) use the new _real mmu. s390x/tcg: make stora(g) use the new _real mmu s390x/tcg: make testblock use the new _real mmu s390x/tcg: make idte/ipte use the new _real mmu target/s390x/cpu.h | 4 +++- target/s390x/excp_helper.c | 29 +++++++++++++++++++---------- target/s390x/internal.h | 2 ++ target/s390x/mem_helper.c | 36 +++++++++++------------------------- target/s390x/mmu_helper.c | 19 +++++++++++++++++++ target/s390x/translate.c | 4 ---- 6 files changed, 54 insertions(+), 40 deletions(-) -- 2.13.5
