[PATCH] KVM: arm64: Update comment of create_hyp_mappings

Marc Zyngier maz at kernel.org
Thu Nov 3 06:07:38 PDT 2022


On Thu, 03 Nov 2022 05:32:28 +0000,
Wei-Lin Chang <r09922117 at csie.ntu.edu.tw> wrote:
> 
> HYP_PAGE_OFFSET is removed since 4.8, and the method for generating Hyp
> VAs has evolved. Update the functional description of
> create_hyp_mappings accordingly.
> 
> Signed-off-by: Wei-Lin Chang <r09922117 at csie.ntu.edu.tw>
> ---
>  arch/arm64/kvm/mmu.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index c9a13e487..a9ae4a3f9 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -424,9 +424,10 @@ void kvm_unshare_hyp(void *from, void *to)
>   * @to:		The virtual kernel end address of the range (exclusive)
>   * @prot:	The protection to be applied to this range
>   *
> - * The same virtual address as the kernel virtual address is also used
> - * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
> - * physical pages.
> + * The Hyp virtual address is generated by masking the kernel VA with
> + * va_mask then inserting tag_val for the higher bits starting from
> + * tag_lsb. See kvm_compute_layout() in va_layout.c for more info.
> + * Both Hyp VA and kernel VA ranges map to the same underlying physical pages.
>   */
>  int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
>  {

What's the difference with the previous instance of this patch?

       M.

-- 
Without deviation from the norm, progress is not possible.



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