linux-kernel - Re: [PATCH v15 01/41] KVM: SEV: Rename kvm_ghcb_get_sw_exit_code() to kvm_get_cached_sw_exit

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Message-ID: <72a65866-fecd-5106-17bc-115ba60e67ae@amd.com>
Date: Mon, 15 Sep 2025 11:15:09 -0500
From: Tom Lendacky <thomas.lendacky@....com>
To: Sean Christopherson <seanjc@...gle.com>,
 Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
 Mathias Krause <minipli@...ecurity.net>, John Allen <john.allen@....com>,
 Rick Edgecombe <rick.p.edgecombe@...el.com>, Chao Gao <chao.gao@...el.com>,
 Maxim Levitsky <mlevitsk@...hat.com>, Xiaoyao Li <xiaoyao.li@...el.com>,
 Zhang Yi Z <yi.z.zhang@...ux.intel.com>
Subject: Re: [PATCH v15 01/41] KVM: SEV: Rename kvm_ghcb_get_sw_exit_code() to
 kvm_get_cached_sw_exit_code()

On 9/12/25 18:22, Sean Christopherson wrote:
> Rename kvm_ghcb_get_sw_exit_code() to kvm_get_cached_sw_exit_code() to make
> it clear that KVM is getting the cached value, not reading directly from
> the guest-controlled GHCB.  More importantly, vacating
> kvm_ghcb_get_sw_exit_code() will allow adding a KVM-specific macro-built
> kvm_ghcb_get_##field() helper to read values from the GHCB.
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@....com>

Makes me wonder if we want to create kvm_get_cached_sw_exit_info_{1,2}
routines rather than referencing control->exit_info_{1,2} directly?

> ---
>  arch/x86/kvm/svm/sev.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 2fdd2e478a97..fe8d148b76c0 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -3216,7 +3216,7 @@ void sev_free_vcpu(struct kvm_vcpu *vcpu)
>  		kvfree(svm->sev_es.ghcb_sa);
>  }
>  
> -static u64 kvm_ghcb_get_sw_exit_code(struct vmcb_control_area *control)
> +static u64 kvm_get_cached_sw_exit_code(struct vmcb_control_area *control)
>  {
>  	return (((u64)control->exit_code_hi) << 32) | control->exit_code;
>  }
> @@ -3242,7 +3242,7 @@ static void dump_ghcb(struct vcpu_svm *svm)
>  	 */
>  	pr_err("GHCB (GPA=%016llx) snapshot:\n", svm->vmcb->control.ghcb_gpa);
>  	pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_code",
> -	       kvm_ghcb_get_sw_exit_code(control), kvm_ghcb_sw_exit_code_is_valid(svm));
> +	       kvm_get_cached_sw_exit_code(control), kvm_ghcb_sw_exit_code_is_valid(svm));
>  	pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_1",
>  	       control->exit_info_1, kvm_ghcb_sw_exit_info_1_is_valid(svm));
>  	pr_err("%-20s%016llx is_valid: %u\n", "sw_exit_info_2",
> @@ -3331,7 +3331,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
>  	 * Retrieve the exit code now even though it may not be marked valid
>  	 * as it could help with debugging.
>  	 */
> -	exit_code = kvm_ghcb_get_sw_exit_code(control);
> +	exit_code = kvm_get_cached_sw_exit_code(control);
>  
>  	/* Only GHCB Usage code 0 is supported */
>  	if (svm->sev_es.ghcb->ghcb_usage) {
> @@ -4336,7 +4336,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
>  
>  	svm_vmgexit_success(svm, 0);
>  
> -	exit_code = kvm_ghcb_get_sw_exit_code(control);
> +	exit_code = kvm_get_cached_sw_exit_code(control);
>  	switch (exit_code) {
>  	case SVM_VMGEXIT_MMIO_READ:
>  		ret = setup_vmgexit_scratch(svm, true, control->exit_info_2);