| Message ID | 0d50d13e5f9bd590ee97ff150f1393c4d99a8fa0.1649219184.git.kai.huang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | TDX host kernel support | expand |
On 4/5/22 21:49, Kai Huang wrote: > Enabling TDX consumes additional memory (used by TDX as metadata) and > additional initialization time. Introduce a kernel command line to > allow to opt-in TDX host kernel support when user truly wants to use > TDX. From the cover letter: "This series doesn't initialize TDX at boot time" Could you please square that circle for me? How does a feature that doesn't get initialized a boot time need a boot-time command line opt-in?
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3f1cc5e317ed..cfa5b36890ea 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5790,6 +5790,12 @@ tdfx= [HW,DRM] + tdx_host= [X86-64, TDX] + Format: {on|off} + on: Enable TDX host kernel support + off: Disable TDX host kernel support + Default is off. + test_suspend= [SUSPEND][,N] Specify "mem" (for Suspend-to-RAM) or "standby" (for standby suspend) or "freeze" (for suspend type freeze) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 031af7b83cea..fee243cd454f 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -116,6 +116,16 @@ static struct tdsysinfo_struct tdx_sysinfo; /* TDX global KeyID to protect TDX metadata */ static u32 tdx_global_keyid; +static bool enable_tdx_host; + +static int __init tdx_host_setup(char *s) +{ + if (!strcmp(s, "on")) + enable_tdx_host = true; + return 1; +} +__setup("tdx_host=", tdx_host_setup); + static bool __seamrr_enabled(void) { return (seamrr_mask & SEAMRR_ENABLED_BITS) == SEAMRR_ENABLED_BITS; @@ -500,6 +510,10 @@ static int detect_p_seamldr(void) static int __tdx_detect(void) { + /* Disabled by kernel command line */ + if (!enable_tdx_host) + goto no_tdx_module; + /* The TDX module is not loaded if SEAMRR is disabled */ if (!seamrr_enabled()) { pr_info("SEAMRR not enabled.\n");
Enabling TDX consumes additional memory (used by TDX as metadata) and additional initialization time. Introduce a kernel command line to allow to opt-in TDX host kernel support when user truly wants to use TDX. Signed-off-by: Kai Huang <kai.huang@intel.com> --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ arch/x86/virt/vmx/tdx/tdx.c | 14 ++++++++++++++ 2 files changed, 20 insertions(+)