Messages in this thread | | | Date | Tue, 30 May 2017 15:37:32 +0200 | From | Gioh Kim <> | Subject | Re: [RFC] KVM: SVM: ignore type when setting segment registers |
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On Tue, May 30, 2017 at 02:54:21PM +0200, Radim Krčmář wrote: > 2017-05-29 15:24+0200, Gioh Kim: > > Current code sets unusable as 1 if present is 1 and type is 0. > > In Long mode, type value in segment descriptor is ignored. > > So I think type should be ignored when setting the segment registers, > > if type means the descriptor type in the segment descriptor. > > > > Is the type field of struct kvm_segment the descriptor type? > > Yes. > > > If so, why type is checked when setting segment registers? > > No idea. 19bca6ab75d8 ("KVM: SVM: Fix cross vendor migration issue with > unusable bit") also moved the assigment up to initialize it before use > and I think that is enough. > > > If the type field is not the descriptor type, > > is it ok to set unusable when present is 1? > > Looks like a bug. type = 0 can be a usable read-only data segment. > > > I'm copying a code as following to show what code I'm asking. > > Please send it as a patch,
Hi Radim,
Thank you for reply. I sent a patch: https://lkml.org/lkml/2017/5/30/459 I'd appreciate if if you could review it.
-- Best regards, Gi-Oh Kim TEL: 0176 2697 8962
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