[PATCH 4.4 040/143] arm64: KVM: Skip MMIO insn after emulation
From: Greg Kroah-Hartman
Date: Mon Feb 18 2019 - 09:27:05 EST
4.4-stable review patch. If anyone has any objections, please let me know.
[ Upstream commit 0d640732dbebed0f10f18526de21652931f0b2f2 ]
When we emulate an MMIO instruction, we advance the CPU state within
decode_hsr(), before emulating the instruction effects.
Having this logic in decode_hsr() is opaque, and advancing the state
before emulation is problematic. It gets in the way of applying
consistent single-step logic, and it prevents us from being able to fail
an MMIO instruction with a synchronous exception.
Clean this up by only advancing the CPU state *after* the effects of the
instruction are emulated.
Cc: Peter Maydell <peter.maydell@xxxxxxxxxx>
Reviewed-by: Alex BennÃe <alex.bennee@xxxxxxxxxx>
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxx>
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
arch/arm/kvm/mmio.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
index 387ee2a11e36..885cd0e0015b 100644
@@ -118,6 +118,12 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
vcpu_set_reg(vcpu, vcpu->arch.mmio_decode.rt, data);
+ * The MMIO instruction is emulated and should not be re-executed
+ * in the guest.
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
@@ -151,11 +157,6 @@ static int decode_hsr(struct kvm_vcpu *vcpu, bool *is_write, int *len)
vcpu->arch.mmio_decode.sign_extend = sign_extend;
vcpu->arch.mmio_decode.rt = rt;
- * The MMIO instruction is emulated and should not be re-executed
- * in the guest.
- kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));