Subject: [PATCH v4 04/66] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x

From: Marc Zyngier <[email-masked]>
Date: Mon, 10 May 2021 17:58:18 +0100

From: Christoffer Dall <[email-masked]>

We were not allowing userspace to set a more privileged mode for the VCPU
than EL1, but we should allow this when nested virtualization is enabled
for the VCPU.

Signed-off-by: Christoffer Dall <[email-masked]>
Signed-off-by: Marc Zyngier <[email-masked]>
---
 arch/arm64/kvm/guest.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 5cb4a1cd5603..e8388a01f763 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -24,6 +24,7 @@
 #include <asm/fpsimd.h>
 #include <asm/kvm.h>
 #include <asm/kvm_emulate.h>
+#include <asm/kvm_nested.h>
 #include <asm/sigcontext.h>
 
 #include "trace.h"
@@ -242,6 +243,11 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 			if (vcpu_el1_is_32bit(vcpu))
 				return -EINVAL;
 			break;
+		case PSR_MODE_EL2h:
+		case PSR_MODE_EL2t:
+			if (vcpu_el1_is_32bit(vcpu) || !nested_virt_in_use(vcpu))
+				return -EINVAL;
+			break;
 		default:
 			err = -EINVAL;
 			goto out;
-- 
2.29.2

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