On 01/03/17 02:31, Xiongfeng Wang wrote:

[lot of things]

If an SEA is injected into guest OS, the guest OS will jump to the SEA
exception entry when the context switched to guest OS. And the CPSR and
FAR_EL1 are recovered according to the content of vcpu. Then the guest
OS can signal a process or panic. If another guest process read the
error data, another SEA will be generated and it will be single too.

Without QEMU involved, the drawback is that no APEI table can be mocked
up in guest OS, and no memory_failure() will be called. So the memory of
error data will be released into buddy system and assigned to another
process. If the error was caused by instantaneous radiation or
electromagnetic, the memory is usable again if it is written with a
correct data. If the memory has wore out and a correct data is written,
the ECC error may occurs again with high possibility. Before a 2-bit ECC
error is reported, much more 1-bit errors will be reported. This is
report to host os, the host os can determine the memory node has worn
out and hot-plug out the memory node, and guest os may be terminated if
its memory data can't be migrated.

Of course, it is better to get QEMU involved, so the memory_failure can
be executed in guest OS. But before that implemented, can we add SEA
injection in kvm_handle_guest_abort()?

No. I will strongly object to that. This is a platform decision to
forward SEAs, not an architectural one. The core KVM code is only
concerned about implementing the ARM architecture, and not something
that is firmware dependent.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...