Re: [PATCH 3/5] Nested VMX patch 3 implements vmptrld and vmptrst

[Gleb Natapov <gleb@redhat.com>]

On Thu, Oct 15, 2009 at 04:41:44PM +0200, oritw@il.ibm.com wrote:
> +static struct page *nested_get_page(struct kvm_vcpu *vcpu,
> +				    u64 vmcs_addr)
> +{
> +	struct page *vmcs_page = NULL;
> +
> +	down_read(&current->mm->mmap_sem);
> +	vmcs_page = gfn_to_page(vcpu->kvm, vmcs_addr >> PAGE_SHIFT);
> +	up_read(&current->mm->mmap_sem);
Why are you taking mmap_sem here? gup_fast() takes it if required.

> +
> +	if (is_error_page(vmcs_page)) {
> +		printk(KERN_ERR "%s error allocating page \n", __func__);
> +		kvm_release_page_clean(vmcs_page);
> +		return NULL;
> +	}
> +
> +	return vmcs_page;
> +
> +}
> +

--
			Gleb.