Re: [PATCH 19/21] KVM: TDX: Add an ioctl to create initial guest memory

[Edgecombe, Rick P]

On Tue, 2024-09-03 at 20:07 -0700, Rick Edgecombe wrote:
> +static int tdx_gmem_post_populate(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
> +                                 void __user *src, int order, void *_arg)
> +{
> +       u64 error_code = PFERR_GUEST_FINAL_MASK | PFERR_PRIVATE_ACCESS;
> +       struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> +       struct tdx_gmem_post_populate_arg *arg = _arg;
> +       struct kvm_vcpu *vcpu = arg->vcpu;
> +       gpa_t gpa = gfn_to_gpa(gfn);
> +       u8 level = PG_LEVEL_4K;
> +       struct page *page;
> +       int ret, i;
> +       u64 err, entry, level_state;
> +
> +       /*
> +        * Get the source page if it has been faulted in. Return failure if
> the
> +        * source page has been swapped out or unmapped in primary memory.
> +        */
> +       ret = get_user_pages_fast((unsigned long)src, 1, 0, &page);
> +       if (ret < 0)
> +               return ret;
> +       if (ret != 1)
> +               return -ENOMEM;
> +
> +       if (!kvm_mem_is_private(kvm, gfn)) {
> +               ret = -EFAULT;
> +               goto out_put_page;
> +       }

Paulo had said he was going to add this check in gmem code. I thought it was not
added but it actually is. So we can drop this check.