Hi gengdongjiu, On 05/04/17 00:05, gengdongjiu wrote: > thanks for the patch, have you consider to told Qemu or KVM tools > the reason for this bus error(SEA/SEI)?
They should never need to know. We should treat Qemu/kvmtool like any other program. Programs should only need to know about the affect on them, not the underlying reason or mechanism. > when Qemu or KVM tools get this SIGBUS signal, it do not know receive > this SIGBUS due to SEA or SEI. Why would this matter? Firmware signalled Linux that something bad happened. Linux handles the problem and everything keeps running. The interface with firmware has to be architecture specific. When signalling user-space it should be architecture agnostic, otherwise we can't write portable user space code. If Qemu was affected by the error (currently only if some of its memory was hwpoisoned) we send it SIGBUS as we would for any other program. Qemu can choose if and how to signal the guest about this error, it doesn't have to use the same interface as firmware and the host used. With TCG Qemu may be emulating a totally different architecture! Looking at the list of errors in table 250 of UEFI 2.6, cache-errors are the only case I can imagine we would want to report to a guest, these are effectively transient memory errors. SIGBUS is still appropriate here, but we probably need a new si_code value to indicate the error can be cleared. (unlike hwpoison which appears to never re-use the affected page). Thanks, James _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
