From 2cebb9aed9930b8859f2c0f2f6a33cc5dc9e0d91 Mon Sep 17 00:00:00 2001
From: Chenyi Qiang <chenyi.qiang@intel.com>
Date: Tue, 14 Sep 2021 17:50:41 +0800
Subject: [PATCH] KVM: nVMX: Fix nested bus lock VM exit
Git-commit: 24a996ade34d00deef5dee2c33aacd8fda91ec31
Patch-mainline: v5.15-rc4
References: stable-5.14.10
commit 24a996ade34d00deef5dee2c33aacd8fda91ec31 upstream.
Nested bus lock VM exits are not supported yet. If L2 triggers bus lock
VM exit, it will be directed to L1 VMM, which would cause unexpected
behavior. Therefore, handle L2's bus lock VM exits in L0 directly.
Fixes: fe6b6bc802b4 ("KVM: VMX: Enable bus lock VM exit")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-id: <20210914095041.29764-1-chenyi.qiang@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/x86/kvm/vmx/nested.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index ac1803dac435..ce30503f5438 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5898,6 +5898,12 @@ static bool nested_vmx_l0_wants_exit(struct kvm_vcpu *vcpu,
case EXIT_REASON_VMFUNC:
/* VM functions are emulated through L2->L0 vmexits. */
return true;
+ case EXIT_REASON_BUS_LOCK:
+ /*
+ * At present, bus lock VM exit is never exposed to L1.
+ * Handle L2's bus locks in L0 directly.
+ */
+ return true;
default:
break;
}
--
2.26.2