Re: [PATCH] x86/sev: Check whether SEV or SME is supported first

From: Joerg Roedel
Date: Mon May 31 2021 - 05:37:25 EST


On Thu, May 27, 2021 at 11:08:32PM +0800, Pu Wen wrote:
> Reading MSR_AMD64_SEV which is not implemented on Hygon Dhyana CPU will cause
> the kernel reboot, and native_read_msr_safe() has no help.

The reason for the reboot is that there is no #GP or #DF handler set up
when this MSR is read, so its propagated to a shutdown event. But there
is an IDT already, so you can set up early and #GP handler to fix the
reboot.

Regards,

Joerg