On 07/10/2012 01:36 PM, Gleb Natapov wrote: > On Mon, Jul 09, 2012 at 04:34:50PM +0300, Avi Kivity wrote: > > On 07/09/2012 04:23 PM, Xiao Guangrong wrote: > > > On 07/09/2012 08:49 PM, Avi Kivity wrote: > > >> On 07/09/2012 02:23 PM, Gleb Natapov wrote: > > >>> > > >>>> kvm-unit-tests.git has a test for xchg to mmio. Does it still work? > > >>>> > > >>>> I agree this code has to go, but it needs to be replaced by something. > > >>>> Maybe a .valid flag in struct operand. > > >>>> > > >>> Valid will not enough for that. > > >> > > >> If we make everything go through operands, any reason why not? > > >> > > > > > > I noticed some instructions need to read ESP for many times (e.g, iret_real), > > > maybe .valid flag is not enough for this case if the stack is in MMIO, yes? > > > > Good catch. We either have to fix it or to restrict stack operations to > > regular memory (->read_std). > > > > > IIUC, I also noticed ESP is not reset back if it is emulated fail (mmio is needed). > > > If the stack located in mmio region, this kind of instruct will be broken, i know no > > > guest will use mmio as stack but SDM does not limit it, is it valid? > > > > Stack in mmio (or task switch in mmio) is architecturally valid. We > > don't have to support it if no guests do it. > > > But the code is already here, why drop it? The read cache is not effective for multiple disjunct reads. The splitting into 8-byte groups is unneeded. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
