From 9a1be9a472468ef0f5f30ab84de390cc0c571ab8 Mon Sep 17 00:00:00 2001 From: Elliot Berman Date: Tue, 20 Sep 2022 12:06:58 -0700 Subject: [PATCH] FROMGIT: 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 Bug: 249052880 (cherry picked from commit b2a4d007c347b4cb4c60f7512733c3f8300a129c https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git next) Change-Id: I196649fc00537e563a1fab0a22bf23c5b7abe00d Signed-off-by: Elliot Berman (cherry picked from commit 8015dd49c00e036b214801b34a727b7c98aa84e3) --- 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 20974e71c9a6..67c20d4d6ade 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2142,6 +2142,16 @@ 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) { kvm_mode = KVM_MODE_PROTECTED; return 0; @@ -2152,11 +2162,6 @@ 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);