Messages in this thread | | | From | Keno Fischer <> | Date | Tue, 7 Apr 2020 14:06:11 -0400 | Subject | Re: [RFC PATCH v2] x86/arch_prctl: Add ARCH_SET_XCR0 to set XCR0 per-thread |
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Hi Andi,
> The rationale from that post should have been in this description.
Yes, sorry.
> You can already do what you want using the clearcpuid= boot flags using the > infrastructure in [1], which is in newer kernels.
Yes, that it useful, but doesn't solve the problem where we're trying to jointly replay traces with differing XCR0 values (as mentioned before, this is useful for recordings from multiple nodes of a distributed system). Even for the single trace case, having to reboot the system or boot a virtual machine manually for every bug report I get would be operationally annoying. A potential solution to the operational problem would be using the raw kvm API to get a very lightweight VM with modified XCR0 but that has performance and complexity concerns.
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