linux-kernel - Re: [RFC PATCH v1 5/5] KVM: Remove kvm

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Message-ID: <aMmk0lUJ8gs7OBw-@google.com>
Date: Tue, 16 Sep 2025 10:56:34 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: "Xin Li (Intel)" <xin@...or.com>
Cc: linux-kernel@...r.kernel.org, kvm@...r.kernel.org, 
	linux-pm@...r.kernel.org, pbonzini@...hat.com, tglx@...utronix.de, 
	mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com, x86@...nel.org, 
	hpa@...or.com, rafael@...nel.org, pavel@...nel.org, brgerst@...il.com, 
	david.kaplan@....com, peterz@...radead.org, andrew.cooper3@...rix.com, 
	kprateek.nayak@....com, arjan@...ux.intel.com, chao.gao@...el.com, 
	rick.p.edgecombe@...el.com, dan.j.williams@...el.com
Subject: Re: [RFC PATCH v1 5/5] KVM: Remove kvm_rebooting and its references

On Tue, Sep 09, 2025, Xin Li (Intel) wrote:
> Drop kvm_rebooting and all related uses.  Virtualization is now disabled
> immediately before a CPU shuts down, eliminating any chance of executing
> virtualization instructions during reboot.

Wrong.  KVM clears EFER.SVME in reponse to kvm_shutdown(), and thus can trip
#UDs on e.g. VMRUN.