Re: [PATCH] KVM: MMU: fix huge page adapted on non-PAE host

From: Avi Kivity
Date: Mon May 28 2012 - 06:57:26 EST


On 05/28/2012 09:10 AM, Xiao Guangrong wrote:
> The huge page size is 4M on non-PAE host, but 2M page size is used in
> transparent_hugepage_adjust(), so the page we get after adjust the
> mapping level is not the head page, the BUG_ON() will be triggered
>
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 72102e0..be3cea4 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -2595,8 +2595,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
> *gfnp = gfn;
> kvm_release_pfn_clean(pfn);
> pfn &= ~mask;
> - if (!get_page_unless_zero(pfn_to_page(pfn)))
> - BUG();
> + kvm_get_pfn(pfn);
> *pfnp = pfn;
> }
> }

Shouldn't we adjust mask instead?

--
error compiling committee.c: too many arguments to function
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