| From 5914466764e6ea444117ebdc1eca84850968bd01 Mon Sep 17 00:00:00 2001 |
| From: Mark Rutland <mark.rutland@arm.com> |
| Date: Fri, 9 Nov 2018 15:07:10 +0000 |
| Subject: arm64: KVM: Skip MMIO insn after emulation |
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| |
| [ 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@linaro.org> |
| Reviewed-by: Alex Bennée <alex.bennee@linaro.org> |
| Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> |
| Signed-off-by: Mark Rutland <mark.rutland@arm.com> |
| Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| virt/kvm/arm/mmio.c | 11 ++++++----- |
| 1 file changed, 6 insertions(+), 5 deletions(-) |
| |
| diff --git a/virt/kvm/arm/mmio.c b/virt/kvm/arm/mmio.c |
| index dac7ceb1a677..08443a15e6be 100644 |
| --- a/virt/kvm/arm/mmio.c |
| +++ b/virt/kvm/arm/mmio.c |
| @@ -117,6 +117,12 @@ 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)); |
| + |
| return 0; |
| } |
| |
| @@ -144,11 +150,6 @@ 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)); |
| return 0; |
| } |
| |
| -- |
| 2.19.1 |
| |