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| author | Mark Rutland <mark.rutland@arm.com> | 2018-11-09 15:07:10 +0000 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-12-18 14:10:36 +0000 |
| commit | 0d640732dbebed0f10f18526de21652931f0b2f2 (patch) | |
| tree | aa9c116f560d604190b904d0a0b966cdae8e6519 /virt | |
| parent | 2e6e902d185027f8e3cb8b7305238f7e35d6a436 (diff) | |
| download | lwn-0d640732dbebed0f10f18526de21652931f0b2f2.tar.gz lwn-0d640732dbebed0f10f18526de21652931f0b2f2.zip | |
arm64: KVM: Skip MMIO insn after emulation
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>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/mmio.c | 11 |
1 files 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; } |