Hi,
On Mon, Sep 18, 2017 at 09:49:25PM +0800, gengdongjiu wrote:
> To KVM mailing List about below question, thanks.
>
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I don't think there's a problem here, because the ESR values are defined
as
#define ESR_ELx_EC_IABT_LOW▸ (0x20)
#define ESR_ELx_EC_IABT_CUR▸ (0x21)
...
#define ESR_ELx_EC_DABT_LOW▸ (0x24)
#define ESR_ELx_EC_DABT_CUR▸ (0x25)
and we just or on the differating bit for a data abort:
if (!is_iabt)
esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;
So you'll see that ESR_ELx_EC_IABT_LOW and ESR_ELx_EC_IABT_CUR become
ESR_ELx_EC_DABT_LOW and ESR_ELx_EC_DABT_CUR, respectively.
Thanks,
-Christoffer
>
>
> On 2017/9/18 21:17, Matt Evans wrote:
> > Hi Gengdongjiu,
> >
> >
> >> On 18 Sep 2017, at 07:39, gengdongjiu <gengdong...@huawei.com> wrote:
> >>
> >> Hi Matt,
> >> sorry to disturb you, I want to consult you a question about the
> >> function inject_abt64();
> >> For this function, the abort EC can be ESR_ELx_EC_DABT_LOW or
> >> ESR_ELx_EC_DABT_CUR according to *vcpu_cpsr(vcpu);
> >> why it always ESR_ELx_EC_DABT_LOW? thanks!
> >>
> >> As you can see the Iabort, when injecting the Iabort, it will check the
> >> cpsr to decide to inject the ESR_ELx_EC_IABT_LOW or ESR_ELx_EC_IABT_CUR.
> >> but I do not know why the Dabort will always be ESR_ELx_EC_DABT_LOW when
> >> injecting.
> >>
> >> /*
> >> * Here, the guest runs in AArch64 mode when in EL1. If we get
> >> * an AArch32 fault, it means we managed to trap an EL0 fault.
> >> */
> >> if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)
> >> esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
> >> else
> >> esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
> >
> > I think you're right. When I fixed that line I had noticed the lack of
> > left-shift but didn't think about the actual ESR value.
> >
> > The injected vector is calculated correctly (between current-EL or lower-EL
> > vectors) by get_except_vector() but the EC should also correspond to
> > current-EL or lower-EL.
> >
> > It is worth following this up on the ARM KVM mailing list! (To be fair,
> > your question should have been sent there too :) )
> >
> > Thanks,
> >
> >
> > Matt
> >
> >
> >
> >>
> >>
> >>
> >> commit e4fe9e7dc3828bf6a5714eb3c55aef6260d823a2
> >> Author: Matt Evans <matt.ev...@arm.com>
> >> Date: Mon May 16 13:54:56 2016 +0100
> >>
> >> kvm: arm64: Fix EC field in inject_abt64
> >>
> >> The EC field of the constructed ESR is conditionally modified by ORing
> >> in
> >> ESR_ELx_EC_DABT_LOW for a data abort. However, ESR_ELx_EC_SHIFT is
> >> missing
> >> from this condition.
> >>
> >> Signed-off-by: Matt Evans <matt.ev...@arm.com>
> >> Acked-by: Marc Zyngier <marc.zyng...@arm.com>
> >> Cc: <sta...@vger.kernel.org>
> >> Signed-off-by: Christoffer Dall <christoffer.d...@linaro.org>
> >>
> >> diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
> >> index 4d1ac81870d2..e9e0e6db73f6 100644
> >> --- a/arch/arm64/kvm/inject_fault.c
> >> +++ b/arch/arm64/kvm/inject_fault.c
> >> @@ -162,7 +162,7 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool
> >> is_iabt, unsigned long addr
> >> esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
> >>
> >> if (!is_iabt)
> >> - esr |= ESR_ELx_EC_DABT_LOW;
> >> + esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;
> >>
> >> vcpu_sys_reg(vcpu, ESR_EL1) = esr | ESR_ELx_FSC_EXTABT;
> >> }
> >>
> >
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>
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