Messages in this thread | | | Date | Tue, 19 Jun 2012 10:24:22 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v3 5/6] KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic |
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On 06/18/2012 06:16 PM, Avi Kivity wrote:
> 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. >
Okay.
> Also these are just simple wrappers, why to them at all?
For gfn_to_hva_read(), they will call gfn_to_hva_many(...write = false) in the later patch.
For kvm_read_hva() and kvm_read_hva_atomic(), they are pure wrappers, i think its name is a good hint to let gfn_to_hva_read to pair with kvm_read_hva()/kvm_read_hva_atomic().
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