linux-kernel - Re: [PATCH v2 2/7] KVM: x86: Extract VMXON and EFER.SVME enablement to kernel

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Message-ID: <6a5dd3e0-672c-4be3-a1c7-26fe3db17d00@intel.com>
Date: Fri, 19 Dec 2025 09:30:22 -0800
From: Dave Hansen <dave.hansen@...el.com>
To: Sean Christopherson <seanjc@...gle.com>,
 Xu Yilun <yilun.xu@...ux.intel.com>
Cc: Chao Gao <chao.gao@...el.com>, Thomas Gleixner <tglx@...utronix.de>,
 Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
 Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
 Kiryl Shutsemau <kas@...nel.org>, Paolo Bonzini <pbonzini@...hat.com>,
 linux-kernel@...r.kernel.org, linux-coco@...ts.linux.dev,
 kvm@...r.kernel.org, Dan Williams <dan.j.williams@...el.com>
Subject: Re: [PATCH v2 2/7] KVM: x86: Extract VMXON and EFER.SVME enablement
 to kernel

On 12/19/25 07:40, Sean Christopherson wrote:
> Is there any **need** for tdx_cpu_enable() and try_init_module_global() to run
> with IRQs disabled?  AFAICT, the lockdep_assert_irqs_disabled() checks added by
> commit 6162b310bc21 ("x86/virt/tdx: Add skeleton to enable TDX on demand") were
> purely because, _when the code was written_, KVM enabled virtualization via IPI
> function calls.

Yeah, the intent was to prevent "rmmod kvm_intel" from running while TDX
was being initialized. The way it ended up, though, I think TDX init
would have been called in a KVM path _anyway_, which makes this double
useless.