From: Marc Zyngier <marc.zyngier@arm.com>
To: Shannon Zhao <zhaoshenglong@huawei.com>,
kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org
Subject: Re: [PATCH 1/3] KVM: ARM64: Fix wrong use of the CPSR MODE mask
Date: Wed, 13 Jan 2016 09:31:53 +0000 [thread overview]
Message-ID: <56961989.9080404@arm.com> (raw)
In-Reply-To: <1452676601-14796-2-git-send-email-zhaoshenglong@huawei.com>
On 13/01/16 09:16, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
>
> The values of CPSR MODE mask are different between aarch32 and aarch64.
> It should use the right one according to the execution state.
>
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> ---
> arch/arm64/include/asm/kvm_emulate.h | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
> index 3066328..779a587 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -127,10 +127,14 @@ static inline unsigned long *vcpu_spsr(const struct kvm_vcpu *vcpu)
>
> static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
> {
> - u32 mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;
> + u32 mode;
>
> - if (vcpu_mode_is_32bit(vcpu))
> + if (vcpu_mode_is_32bit(vcpu)) {
> + mode = *vcpu_cpsr(vcpu) & COMPAT_PSR_MODE_MASK;
> return mode > COMPAT_PSR_MODE_USR;
> + }
> +
> + mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;
>
> return mode != PSR_MODE_EL0t;
> }
>
Nice catch. At the moment, it will only affect perf's is_user_mode()
with a 32bit guest (always reporting the guest as running in kernel
mode), so that's not a big deal with mainline (but it clearly has a much
bigger implication with the PMU support).
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2016-01-13 9:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-13 9:16 [PATCH 0/3] Three fixes for KVM ARM64 Shannon Zhao
2016-01-13 9:16 ` [PATCH 1/3] KVM: ARM64: Fix wrong use of the CPSR MODE mask Shannon Zhao
2016-01-13 9:31 ` Marc Zyngier [this message]
2016-01-14 1:27 ` Shannon Zhao
2016-01-13 9:16 ` [PATCH 2/3] KVM: ARM64: Fix comments of the CP handler Shannon Zhao
2016-01-13 9:32 ` Marc Zyngier
2016-01-13 9:16 ` [PATCH 3/3] KVM: ARM64: Fix guest dead loop when register accessor returns false Shannon Zhao
2016-01-13 11:02 ` Marc Zyngier
2016-01-13 14:20 ` Shannon Zhao
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