[PATCH v2 15/19] KVM: arm64: Warn when PENDING_EXCEPTION and INCREMENT_PC are set together

Marc Zyngier
2022-06-10T09:35:43Z

We really don't want PENDING_EXCEPTION and INCREMENT_PC to ever be
set at the same time, as they are mutually exclusive. Add checks
that will generate a warning should this ever happen.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_emulate.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 6ec58080ece8..9bdba47f7e14 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -473,11 +473,13 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,

static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
{
+ WARN_ON(vcpu_get_flag(vcpu, PENDING_EXCEPTION));
vcpu_set_flag(vcpu, INCREMENT_PC);
}

#define kvm_pend_exception(v, e) \
do { \
+ WARN_ON(vcpu_get_flag((v), INCREMENT_PC)); \
vcpu_set_flag((v), PENDING_EXCEPTION); \
vcpu_set_flag((v), e); \
} while (0)
--
2.34.1