linux-kernel - Re: [PATCH v19 101/130] KVM: TDX: handle ept violation/misconfig exit

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Message-ID: <ZjjnvfSxBtS2psgh@google.com>
Date: Mon, 6 May 2024 07:22:53 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: isaku.yamahata@...el.com
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	isaku.yamahata@...il.com, Paolo Bonzini <pbonzini@...hat.com>, erdemaktas@...gle.com, 
	Sagi Shahar <sagis@...gle.com>, Kai Huang <kai.huang@...el.com>, chen.bo@...el.com, 
	hang.yuan@...el.com, tina.zhang@...el.com
Subject: Re: [PATCH v19 101/130] KVM: TDX: handle ept violation/misconfig exit

On Mon, Feb 26, 2024, isaku.yamahata@...el.com wrote:
> +static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu)
> +{
> +	unsigned long exit_qual;
> +
> +	if (kvm_is_private_gpa(vcpu->kvm, tdexit_gpa(vcpu))) {
> +		/*
> +		 * Always treat SEPT violations as write faults.  Ignore the
> +		 * EXIT_QUALIFICATION reported by TDX-SEAM for SEPT violations.
> +		 * TD private pages are always RWX in the SEPT tables,
> +		 * i.e. they're always mapped writable.  Just as importantly,
> +		 * treating SEPT violations as write faults is necessary to
> +		 * avoid COW allocations, which will cause TDAUGPAGE failures
> +		 * due to aliasing a single HPA to multiple GPAs.
> +		 */
> +#define TDX_SEPT_VIOLATION_EXIT_QUAL	EPT_VIOLATION_ACC_WRITE

This does not needd a #define.  It's use in literally one place, one line below.