Re: [PATCH v3 5/6] KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic

From: Avi Kivity
Date: Mon Jun 18 2012 - 06:16:35 EST


On 06/12/2012 05:48 AM, Xiao Guangrong wrote:
> This set of functions is only used to read data from host space, read is
> a special case in the later patch
>
>
> +/*
> + * The hva returned by this function is only allowed to be read.
> + * It should pair with kvm_read_hva() or kvm_read_hva_atomic().
> + */
> +static unsigned long gfn_to_hva_read(struct kvm *kvm, gfn_t gfn)
> +{
> + return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
> +}
> +
> +static int kvm_read_hva(void *data, void *hva, int len)
> +{
> + return __copy_from_user(data, (void __user *)hva, len);
> +
> +}
> +
> +static int kvm_read_hva_atomic(void *data, void *hva, int len)
> +{
> + return __copy_from_user_inatomic(data, (void __user *)hva, len);
> +
> +}

Why cast to __user? Make it __user in the first place.

Also these are just simple wrappers, why to them at all?



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


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