From 39e6fd28a1bf177eb2f7031388ad82c6d6077bfb Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 9 Nov 2018 15:07:10 +0000 Subject: [PATCH] arm64: KVM: Skip MMIO insn after emulation MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ 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 Reviewed-by: Alex Bennée Reviewed-by: Christoffer Dall Signed-off-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Sasha Levin --- 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 4cb5a93182e92..c215bb4423acf 100644 --- a/arch/arm/kvm/mmio.c +++ b/arch/arm/kvm/mmio.c @@ -118,6 +118,12 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) *vcpu_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)); + return 0; } @@ -154,11 +160,6 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, 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)); return 0; } -- 2.47.2