[PATCH v7 10/11] KVM: arm64: BTI: Reset BTYPE when skipping emulated instructions

Mark Brown
2020-02-26T15:57:50Z

Since normal execution of any non-branch instruction resets the
PSTATE BTYPE field to 0, so do the same thing when emulating a
trapped instruction.

Branches don't trap directly, so we should never need to assign a
non-zero value to BTYPE here.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
arch/arm64/include/asm/kvm_emulate.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 688c63412cc2..dee51c1dcb93 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -506,10 +506,12 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,

static inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_instr)
{
- if (vcpu_mode_is_32bit(vcpu))
+ if (vcpu_mode_is_32bit(vcpu)) {
kvm_skip_instr32(vcpu, is_wide_instr);
- else
+ } else {
*vcpu_pc(vcpu) += 4;
+ *vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;
+ }

/* advance the singlestep state machine */
*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
--
2.20.1