Messages in this thread Patch in this message | | | From | Kuppuswamy Sathyanarayanan <> | Subject | [PATCH v1 06/11] x86/tdx: Get TD execution environment information via TDINFO | Date | Tue, 1 Jun 2021 19:21:31 -0700 |
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From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Per Guest-Host-Communication Interface (GHCI) for Intel Trust Domain Extensions (Intel TDX) specification, sec 2.4.2, TDCALL[TDINFO] provides basic TD execution environment information, not provided by CPUID.
Call TDINFO during early boot to be used for following system initialization.
The call provides info on which bit in pfn is used to indicate that the page is shared with the host and attributes of the TD, such as debug.
Information about the number of CPUs need not be saved because there are no users so far for it.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> --- arch/x86/kernel/tdx.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c index 97b54317f799..e4383b416ef3 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -4,6 +4,17 @@ #define pr_fmt(fmt) "TDX: " fmt #include <asm/tdx.h> +#include <asm/vmx.h> + +#include <linux/cpu.h> + +/* TDX Module call Leaf IDs */ +#define TDINFO 1 + +static struct { + unsigned int gpa_width; + unsigned long attributes; +} td_info __ro_after_init; /* * Wrapper for simple hypercalls that only return a success/error code. @@ -63,6 +74,19 @@ bool is_tdx_guest(void) } EXPORT_SYMBOL_GPL(is_tdx_guest); +static void tdg_get_info(void) +{ + u64 ret; + struct tdx_module_output out = {0}; + + ret = __tdx_module_call(TDINFO, 0, 0, 0, 0, &out); + + BUG_ON(ret); + + td_info.gpa_width = out.rcx & GENMASK(5, 0); + td_info.attributes = out.rdx; +} + void __init tdx_early_init(void) { if (!cpuid_has_tdx_guest()) @@ -70,5 +94,7 @@ void __init tdx_early_init(void) setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); + tdg_get_info(); + pr_info("TDX guest is initialized\n"); } -- 2.25.1
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