From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nadav Amit <nadav.amit@gmail.com>
Subject: Re: [patch 2/5] KVM: MMU: allow pinning spte translations (TDP-only)
Date: Wed, 02 Jul 2014 03:58:58 +0300
Message-ID: <53B35952.4070408@gmail.com>
References: <20140618231203.846608908@amt.cnet> <20140618231521.569025131@amt.cnet>
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Cc: pbonzini@redhat.com, xiaoguangrong@linux.vnet.ibm.com,
	gleb@kernel.org, avi@cloudius-systems.com
To: mtosatti@redhat.com, kvm@vger.kernel.org, ak@linux.intel.com
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I tried to use the patches (regardless of PEBS).
When the host uses huge-pages, I get an a oops.
I did not delve into the patch details, but I think there is some mess 
with the indexes - see below:

On 6/19/14, 2:12 AM, mtosatti@redhat.com wrote:
> +
> +static bool direct_pin_sptes(struct kvm_vcpu *vcpu, gfn_t gfn)
> +{
> +	u64 *sptes[4];
> +	int r, i, level;
> +
> +	r = get_sptep_hierarchy(vcpu, gfn << PAGE_SHIFT, sptes);
> +	if (!r)
> +		return false;
> +
> +	level = 5 - r;
> +	if (!is_last_spte(*sptes[r-1], level))
should be *sptes[level-1]
> +		return false;
> +	if (!is_shadow_present_pte(*sptes[r-1]))
should be *sptes[level-1]
> +		return false;
> +
> +	for (i = 0; i < r; i++) {
> +		u64 *sptep = sptes[i];
should be sptes[3 - i];
> +		struct kvm_mmu_page *sp = page_header(__pa(sptep));
> +
> +		sp->pinned = true;
> +		set_bit(SPTE_PINNED_BIT, (unsigned long *)sptep);
> +	}
> +
> +	return true;
> +}
>

Regards,
Nadav