Messages in this thread | | | Subject | Re: selftests/x86/fsgsbase_64 test problem | From | "H. Peter Anvin" <> | Date | Fri, 26 Jan 2018 14:51:19 -0800 |
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On 01/26/18 11:46, Andy Lutomirski wrote: > > Under QEMU TCG, gs stays equal to 1. On native or KVM, on Skylake, it > changes to 0. > > On KVM or native, I do not observe do_debug getting called with %gs == > 1. On TCG, I do. I don't think that's precisely the problem that's > causing the test to fail, since the test doesn't use TF or ptrace, but > I wouldn't be shocked if it's related. > > hpa, any insight? > > (NB: if you want to play with this as I've described it, you may need > to make invalid_selector() in ptrace.c always return false. The > current implementation is too strict and causes problems.) >
Looking at it. I want to grok this in the general context of fsgsbase as well, of course.
-hpa
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