On 02/03/2017 16:18, Brijesh Singh wrote:
> +static int __sev_dbg_decrypt_page(struct kvm *kvm, unsigned long src,
> + void *dst, int *error)
> +{
> + inpages = sev_pin_memory(src, PAGE_SIZE, &npages);
> + if (!inpages) {
> + ret = -ENOMEM;
> + goto err_1;
> + }
> +
> + data->handle = sev_get_handle(kvm);
> + data->dst_addr = __psp_pa(dst);
> + data->src_addr = __sev_page_pa(inpages[0]);
> + data->length = PAGE_SIZE;
> +
> + ret = sev_issue_cmd(kvm, SEV_CMD_DBG_DECRYPT, data, error);
> + if (ret)
> + printk(KERN_ERR "SEV: DEBUG_DECRYPT %d (%#010x)\n",
> + ret, *error);
> + sev_unpin_memory(inpages, npages);
> +err_1:
> + kfree(data);
> + return ret;
> +}
> +
> +static int sev_dbg_decrypt(struct kvm *kvm, struct kvm_sev_cmd *argp)
> +{
> + void *data;
> + int ret, offset, len;
> + struct kvm_sev_dbg debug;
> +
> + if (!sev_guest(kvm))
> + return -ENOTTY;
> +
> + if (copy_from_user(&debug, (void *)argp->data,
> + sizeof(struct kvm_sev_dbg)))
> + return -EFAULT;
> + /*
> + * TODO: add support for decrypting length which crosses the
> + * page boundary.
> + */
> + offset = debug.src_addr & (PAGE_SIZE - 1);
> + if (offset + debug.length > PAGE_SIZE)
> + return -EINVAL;
> +
Please do add it, it doesn't seem very different from what you're doing
in LAUNCH_UPDATE_DATA. There's no need for a separate
__sev_dbg_decrypt_page function, you can just pin/unpin here and do a
per-page loop as in LAUNCH_UPDATE_DATA.
Paolo
