From fbfb98ef79db79ceba764c5c74bececd03eb90bf Mon Sep 17 00:00:00 2001 From: Elliot Berman Date: Tue, 20 Sep 2022 12:06:58 -0700 Subject: [PATCH] UPSTREAM: KVM: arm64: Ignore kvm-arm.mode if !is_hyp_mode_available() Ignore kvm-arm.mode if !is_hyp_mode_available(). Specifically, we want to avoid switching 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. Reasonably though, we should warn if the command line is requesting a KVM mode at all if KVM isn't actually available. Allow "kvm-arm.mode=none" to skip the warning since this would disable KVM anyway. Signed-off-by: Elliot Berman Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220920190658.2880184-1-quic_eberman@quicinc.com (cherry picked from commit b2a4d007c347b4cb4c60f7512733c3f8300a129c) Signed-off-by: Will Deacon Bug: 233587962 Bug: 233588291 Change-Id: I557abb374599ba3f39d21350f8f7f4c7def523c6 --- arch/arm64/kvm/arm.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 5484729a96f9..45e657dfe547 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2275,6 +2275,16 @@ static int __init early_kvm_mode_cfg(char *arg) if (!arg) return -EINVAL; + if (strcmp(arg, "none") == 0) { + kvm_mode = KVM_MODE_NONE; + return 0; + } + + if (!is_hyp_mode_available()) { + pr_warn_once("KVM is not available. Ignoring kvm-arm.mode\n"); + return 0; + } + if (strcmp(arg, "protected") == 0) { if (!is_kernel_in_hyp_mode()) kvm_mode = KVM_MODE_PROTECTED; @@ -2289,11 +2299,6 @@ static int __init early_kvm_mode_cfg(char *arg) return 0; } - if (strcmp(arg, "none") == 0) { - kvm_mode = KVM_MODE_NONE; - return 0; - } - return -EINVAL; } early_param("kvm-arm.mode", early_kvm_mode_cfg);