On Tue, Jun 27, 2023 at 02:12:46AM +1200, Kai Huang wrote:
> After the global KeyID has been configured on all packages, initialize
> all TDMRs to make all TDX-usable memory regions that are passed to the
> TDX module become usable.
>
> This is the last step of initializing the TDX module.
>
> Initializing TDMRs can be time consuming on large memory systems as it
> involves initializing all metadata entries for all pages that can be
> used by TDX guests. Initializing different TDMRs can be parallelized.
> For now to keep it simple, just initialize all TDMRs one by one. It can
> be enhanced in the future.
Reviewed-by: Yuan Yao <yuan.yao@xxxxxxxxx>
>
> Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
> Reviewed-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> ---
>
> v11 -> v12:
> - Added Kirill's tag
>
> v10 -> v11:
> - No update
>
> v9 -> v10:
> - Code change due to change static 'tdx_tdmr_list' to local 'tdmr_list'.
>
> v8 -> v9:
> - Improved changlog to explain why initializing TDMRs can take long
> time (Dave).
> - Improved comments around 'next-to-initialize' address (Dave).
>
> v7 -> v8: (Dave)
> - Changelog:
> - explicitly call out this is the last step of TDX module initialization.
> - Trimed down changelog by removing SEAMCALL name and details.
> - Removed/trimmed down unnecessary comments.
> - Other changes due to 'struct tdmr_info_list'.
>
> v6 -> v7:
> - Removed need_resched() check. -- Andi.
>
>
> ---
> arch/x86/virt/vmx/tdx/tdx.c | 60 ++++++++++++++++++++++++++++++++-----
> arch/x86/virt/vmx/tdx/tdx.h | 1 +
> 2 files changed, 53 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index f5d4dbc11aee..52b7267ea226 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -994,6 +994,56 @@ static int config_global_keyid(void)
> return ret;
> }
>
> +static int init_tdmr(struct tdmr_info *tdmr)
> +{
> + u64 next;
> +
> + /*
> + * Initializing a TDMR can be time consuming. To avoid long
> + * SEAMCALLs, the TDX module may only initialize a part of the
> + * TDMR in each call.
> + */
> + do {
> + struct tdx_module_output out;
> + int ret;
> +
> + /* All 0's are unused parameters, they mean nothing. */
> + ret = seamcall(TDH_SYS_TDMR_INIT, tdmr->base, 0, 0, 0, NULL,
> + &out);
> + if (ret)
> + return ret;
> + /*
> + * RDX contains 'next-to-initialize' address if
> + * TDH.SYS.TDMR.INIT did not fully complete and
> + * should be retried.
> + */
> + next = out.rdx;
> + cond_resched();
> + /* Keep making SEAMCALLs until the TDMR is done */
> + } while (next < tdmr->base + tdmr->size);
> +
> + return 0;
> +}
> +
> +static int init_tdmrs(struct tdmr_info_list *tdmr_list)
> +{
> + int i;
> +
> + /*
> + * This operation is costly. It can be parallelized,
> + * but keep it simple for now.
> + */
> + for (i = 0; i < tdmr_list->nr_consumed_tdmrs; i++) {
> + int ret;
> +
> + ret = init_tdmr(tdmr_entry(tdmr_list, i));
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int init_tdx_module(void)
> {
> struct tdsysinfo_struct *sysinfo;
> @@ -1067,14 +1117,8 @@ static int init_tdx_module(void)
> if (ret)
> goto out_reset_pamts;
>
> - /*
> - * TODO:
> - *
> - * - Initialize all TDMRs.
> - *
> - * Return error before all steps are done.
> - */
> - ret = -EINVAL;
> + /* Initialize TDMRs to complete the TDX module initialization */
> + ret = init_tdmrs(&tdmr_list);
> out_reset_pamts:
> if (ret) {
> /*
> diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
> index a0438513bec0..f6b4e153890d 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.h
> +++ b/arch/x86/virt/vmx/tdx/tdx.h
> @@ -25,6 +25,7 @@
> #define TDH_SYS_INFO 32
> #define TDH_SYS_INIT 33
> #define TDH_SYS_LP_INIT 35
> +#define TDH_SYS_TDMR_INIT 36
> #define TDH_SYS_CONFIG 45
>
> struct cmr_info {
> --
> 2.40.1
>
