Il 23/09/2014 13:14, Christoffer Dall ha scritto:
> On Tue, Sep 23, 2014 at 10:36:30AM +0200, Paolo Bonzini wrote:
>> Il 23/09/2014 00:07, Will Deacon ha scritto:
>>>>> {
>>>>> if (!(lr_desc.state & LR_STATE_MASK))
>>>>> - set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
>>>>> + __set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
>>>>> }
>>> Does this work for big-endian arm64 machines? Surely the bug is due to
>>> casting a u32 * to an unsigned long *, and not specifically related to
>>> atomics (which is where it happened to explode)?
>>
> It does look like the whole thing is broken on BE systems, but fixing
> that becomes non-trivial. I don't think this fix is incorrect in
> itself, but we do have a larger issue with BE.
>
> I took a stab at fixing this (untested for BE), which looks something
> like the following, but I'm a bit uneasy about having to test and merge
> this as a fix given the rush before 3.17 is released.
>
> Thoughts?
If big-endian is broken anyway, let's apply this only:
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 35b0c12..c66dc9ed 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -168,8 +168,8 @@ struct vgic_v2_cpu_if {
> u32 vgic_hcr;
> u32 vgic_vmcr;
> u32 vgic_misr; /* Saved only */
> - u32 vgic_eisr[2]; /* Saved only */
> - u32 vgic_elrsr[2]; /* Saved only */
> + u64 vgic_eisr; /* Saved only */
> + u64 vgic_elrsr; /* Saved only */
> u32 vgic_apr;
> u32 vgic_lr[VGIC_V2_MAX_LRS];
> };
> diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
> index 416baed..2935405 100644
> --- a/virt/kvm/arm/vgic-v2.c
> +++ b/virt/kvm/arm/vgic-v2.c
> @@ -71,35 +71,17 @@ static void vgic_v2_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
> struct vgic_lr lr_desc)
> {
> if (!(lr_desc.state & LR_STATE_MASK))
> - __set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
> + vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr |= (1ULL << lr);
> }
>
> static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu)
> {
> - u64 val;
> -
> -#if BITS_PER_LONG == 64
> - val = vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr[1];
> - val <<= 32;
> - val |= vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr[0];
> -#else
> - val = *(u64 *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr;
> -#endif
> - return val;
> + return vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr;
> }
>
> static u64 vgic_v2_get_eisr(const struct kvm_vcpu *vcpu)
> {
> - u64 val;
> -
> -#if BITS_PER_LONG == 64
> - val = vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr[1];
> - val <<= 32;
> - val |= vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr[0];
> -#else
> - val = *(u64 *)vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr;
> -#endif
> - return val;
> + return vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr;
> }
>
> static u32 vgic_v2_get_interrupt_status(const struct kvm_vcpu *vcpu)
which matches what vgic-v3 already does.
BE can be fixed in 3.18.
Paolo
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
