On Fri, Jun 02, 2023, Anish Moorthy wrote:
> KVM_HVA_ERR_RO_BAD satisfies kvm_is_error_hva(), so there's no need to
> duplicate the "if (writable)" block. Fix this by bringing all
> kvm_is_error_hva() cases under one conditional.
>
> Signed-off-by: Anish Moorthy <amoorthy@xxxxxxxxxx>
> ---
> virt/kvm/kvm_main.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index b9d2606f9251..05d6e7e3994d 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2711,16 +2711,14 @@ kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn,
> if (hva)
> *hva = addr;
>
> - if (addr == KVM_HVA_ERR_RO_BAD) {
> - if (writable)
> - *writable = false;
> - return KVM_PFN_ERR_RO_FAULT;
> - }
> -
> if (kvm_is_error_hva(addr)) {
> if (writable)
> *writable = false;
> - return KVM_PFN_NOSLOT;
> +
> + if (addr == KVM_HVA_ERR_RO_BAD)
> + return KVM_PFN_ERR_RO_FAULT;
> + else
> + return KVM_PFN_NOSLOT;
Similar to an earlier patch, preferred style for terminal if-statements is
if (addr == KVM_HVA_ERR_RO_BAD)
return KVM_PFN_ERR_RO_FAULT;
return KVM_PFN_NOSLOT;
Again, there are reasons for the style/rule. In this case, it will yield a smaller
diff (obviously not a huge deal, but helpful), and it makes it more obvious that
the taken path of "if (kvm_is_error_hva(addr))" is itself terminal.
Alternatively, a ternary operator is often used for these types of things, though
in this case I much prefer the above, as I find the below hard to read.
return addr == KVM_HVA_ERR_RO_BAD ? KVM_PFN_ERR_RO_FAULT :
KVM_PFN_NOSLOT;
