Messages in this thread | | | Date | Fri, 14 Apr 2023 17:50:16 +0000 | Subject | Re: [PATCH v2] KVM: x86: Fix poll command | From | Sean Christopherson <> |
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On Thu, Apr 13, 2023, alexjlzheng@gmail.com wrote: > From: Jinliang Zheng <alexjlzheng@tencent.com> > > According to the hardware manual, when the Poll command is issued, the
Please add "8259", i.e. "According to the 8259 hardware manual".
> byte returned by the I/O read is 1 in Bit 7 when there is an interrupt, > and the highest priority binary code in Bits 2:0. The current pic > simulation code is not implemented strictly according to the above > expression. > > Fix the implementation of pic_poll_read(): > 1. Set Bit 7 when there is an interrupt > 2. Return 0 when there is no interrupt
I don't think #2 is justified. The spec says:
The interrupt requests are ordered in priority from 0 through 7 (0 highest).
I.e. the current code enumerates the _lowest_ priority when there is no interrupt, which seems more correct than reporting the highest priority possible.
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