linux-kernel - Re: [PATCH v2 15/25] KVM: VMX: Dump FRED context in dump

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Message-ID: <Zmo1cqTgJwfDL0kW@google.com>
Date: Wed, 12 Jun 2024 16:55:30 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Chao Gao <chao.gao@...el.com>
Cc: Xin Li <xin3.li@...el.com>, 
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "kvm@...r.kernel.org" <kvm@...r.kernel.org>, 
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>, 
	"linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>, 
	"pbonzini@...hat.com" <pbonzini@...hat.com>, "corbet@....net" <corbet@....net>, 
	"tglx@...utronix.de" <tglx@...utronix.de>, "mingo@...hat.com" <mingo@...hat.com>, "bp@...en8.de" <bp@...en8.de>, 
	"dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>, "x86@...nel.org" <x86@...nel.org>, 
	"hpa@...or.com" <hpa@...or.com>, "shuah@...nel.org" <shuah@...nel.org>, 
	"vkuznets@...hat.com" <vkuznets@...hat.com>, "peterz@...radead.org" <peterz@...radead.org>, 
	Ravi V Shankar <ravi.v.shankar@...el.com>, "xin@...or.com" <xin@...or.com>
Subject: Re: [PATCH v2 15/25] KVM: VMX: Dump FRED context in dump_vmcs()

On Tue, Apr 30, 2024, Chao Gao wrote:
> On Thu, Feb 08, 2024 at 01:26:35AM +0800, Xin Li wrote:
> >@@ -6449,6 +6451,19 @@ void dump_vmcs(struct kvm_vcpu *vcpu)
> >        vmx_dump_sel("LDTR:", GUEST_LDTR_SELECTOR);
> >        vmx_dump_dtsel("IDTR:", GUEST_IDTR_LIMIT);
> >        vmx_dump_sel("TR:  ", GUEST_TR_SELECTOR);
> >+#ifdef CONFIG_X86_64
> >+       if (kvm_is_fred_enabled(vcpu)) {
> 
> FRED MSRs are accessible even if CR4.FRED isn't set and #ifdef is ugly, I think
> you can simply do:
> 
> 	if (vmentry_ctrl & VM_ENTRY_LOAD_IA32_FRED)
> 
> just like below handling for EFER/PAT etc.

+1