linux-kernel - [PATCH v2] KVM: arm64: Only set KVM_MODE_PROTECTED if is_hyp_mode

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Date:   Fri, 9 Sep 2022 07:45:52 -0700
From:   Elliot Berman <quic_eberman@...cinc.com>
To:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, Marc Zyngier <maz@...nel.org>,
        James Morse <james.morse@....com>,
        "Alexandru Elisei" <alexandru.elisei@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>
CC:     Elliot Berman <quic_eberman@...cinc.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <kvmarm@...ts.cs.columbia.edu>
Subject: [PATCH v2] KVM: arm64: Only set KVM_MODE_PROTECTED if is_hyp_mode_available()

Do not switch kvm_mode to KVM_MODE_PROTECTED if hypervisor mode is not
available. This prevents "Protected KVM" cpu capability being reported
when Linux is booting in EL1 and would not have KVM enabled.

Signed-off-by: Elliot Berman <quic_eberman@...cinc.com>
---
 arch/arm64/kvm/arm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8fe73ee5fa84..861f4b388879 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2272,7 +2272,9 @@ static int __init early_kvm_mode_cfg(char *arg)
 		return -EINVAL;
 
 	if (strcmp(arg, "protected") == 0) {
-		if (!is_kernel_in_hyp_mode())
+		if (!is_hyp_mode_available())
+			kvm_mode = KVM_MODE_DEFAULT;
+		else if (!is_kernel_in_hyp_mode())
 			kvm_mode = KVM_MODE_PROTECTED;
 		else
 			pr_warn_once("Protected KVM not available with VHE\n");

base-commit: 0982c8d859f8f7022b9fd44d421c7ec721bb41f9
-- 
2.25.1