[PATCH 2/2] arm64: cpufeatures: Only check for NV1 if NV is present

From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: [PATCH 2/2] arm64: cpufeatures: Only check for NV1 if NV is present
Date: Mon, 12 Feb 2024 14:47:36 +0000	[thread overview]
Message-ID: <20240212144736.1933112-3-maz@kernel.org> (raw)
In-Reply-To: <20240212144736.1933112-1-maz@kernel.org>

We handle ID_AA64MMFR4_EL1.E2H0 being 0 as NV1 being present.
However, this is only true if FEAT_NV is implemented.

Add the required check to has_nv1(), avoiding spuriously advertising
NV1 on HW that doesn't have NV at all.

Fixes: da9af5071b25 ("arm64: cpufeature: Detect HCR_EL2.NV1 being RES0")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kernel/cpufeature.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2f8958f27e9e..3421b684d340 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1812,8 +1812,9 @@ static bool has_nv1(const struct arm64_cpu_capabilities *entry, int scope)
 		{}
 	};
 
-	return !(has_cpuid_feature(entry, scope) ||
-		 is_midr_in_range_list(read_cpuid_id(), nv1_ni_list));
+	return (this_cpu_has_cap(ARM64_HAS_NESTED_VIRT) &&
+		!(has_cpuid_feature(entry, scope) ||
+		  is_midr_in_range_list(read_cpuid_id(), nv1_ni_list)));
 }
 
 #if defined(ID_AA64MMFR0_EL1_TGRAN_LPA2) && defined(ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_LPA2)
-- 
2.39.2


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