On 22.06.2013, at 09:15, Paul Mackerras wrote:
> At present, if the guest creates a valid SLB (segment lookaside buffer)
> entry with the slbmte instruction, then invalidates it with the slbie
> instruction, then reads the entry with the slbmfee/slbmfev instructions,
> the result of the slbmfee will have the valid bit set, even though the
> entry is not actually considered valid by the host. This is confusing,
> if not worse. This fixes it by zeroing out the orige and origv fields
> of the SLB entry structure when the entry is invalidated.
>
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>
Could you please change this to only remove the V bit from orige? I've found it very useful for debugging to see old, invalidated entries in the SLB when dumping it. The spec declares anything but the toggle of the V bit as undefined.
Alex
> ---
> arch/powerpc/kvm/book3s_64_mmu.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
> index 2e93bb5..7519124 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu.c
> @@ -376,6 +376,8 @@ static void kvmppc_mmu_book3s_64_slbie(struct kvm_vcpu *vcpu, u64 ea)
> dprintk("KVM MMU: slbie(0x%llx, 0x%llx)\n", ea, slbe->esid);
>
> slbe->valid = false;
> + slbe->orige = 0;
> + slbe->origv = 0;
>
> kvmppc_mmu_map_segment(vcpu, ea);
> }
> @@ -386,8 +388,11 @@ static void kvmppc_mmu_book3s_64_slbia(struct kvm_vcpu *vcpu)
>
> dprintk("KVM MMU: slbia()\n");
>
> - for (i = 1; i < vcpu->arch.slb_nr; i++)
> + for (i = 1; i < vcpu->arch.slb_nr; i++) {
> vcpu->arch.slb[i].valid = false;
> + vcpu->arch.slb[i].orige = 0;
> + vcpu->arch.slb[i].origv = 0;
> + }
>
> if (vcpu->arch.shared->msr & MSR_IR) {
> kvmppc_mmu_flush_segments(vcpu);
> --
> 1.8.3.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
