linux-kernel - [PATCH v4 4/7] KVM: SVM: Always print "AVIC enabled" separately, even when force enabled

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Message-ID: <20250919215934.1590410-5-seanjc@google.com>
Date: Fri, 19 Sep 2025 14:59:31 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, 
	Vitaly Kuznetsov <vkuznets@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Naveen N Rao <naveen@...nel.org>
Subject: [PATCH v4 4/7] KVM: SVM: Always print "AVIC enabled" separately, even
 when force enabled

Print the customary "AVIC enabled" informational message even when AVIC is
force enabled on a system that doesn't advertise supported for AVIC in
CPUID, as not printing the standard message can confuse users and tools.

Opportunistically clean up the scary message when AVIC is force enabled,
but keep it as separate message so that it is printed at level "warn",
versus the standard message only being printed for level "info".

Suggested-by: Naveen N Rao (AMD) <naveen@...nel.org>
Reviewed-by: Naveen N Rao (AMD) <naveen@...nel.org>
Tested-by: Naveen N Rao (AMD) <naveen@...nel.org>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/avic.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index b4577401ce5f..b8b73c4103c6 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -1167,16 +1167,15 @@ bool __init avic_hardware_setup(void)
 		return false;
 	}
 
-	if (boot_cpu_has(X86_FEATURE_AVIC)) {
-		pr_info("AVIC enabled\n");
-	} else if (force_avic) {
-		/*
-		 * Some older systems does not advertise AVIC support.
-		 * See Revision Guide for specific AMD processor for more detail.
-		 */
-		pr_warn("AVIC is not supported in CPUID but force enabled");
-		pr_warn("Your system might crash and burn");
-	}
+	/*
+	 * Print a scary message if AVIC is force enabled to make it abundantly
+	 * clear that ignoring CPUID could have repercussions.  See Revision
+	 * Guide for specific AMD processor for more details.
+	 */
+	if (!boot_cpu_has(X86_FEATURE_AVIC))
+		pr_warn("AVIC unsupported in CPUID but force enabled, your system might crash and burn\n");
+
+	pr_info("AVIC enabled\n");
 
 	/* AVIC is a prerequisite for x2AVIC. */
 	x2avic_enabled = boot_cpu_has(X86_FEATURE_X2AVIC);
-- 
2.51.0.470.ga7dc726c21-goog