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| author | Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> | 2022-04-06 02:29:10 +0300 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-04-07 08:27:50 -0700 |
| commit | 59bd54a84d15e9335de5b8abe7b3b9713a36b99b (patch) | |
| tree | 092fe681be97bfa61b235a9b494114a881180ab0 /arch/x86/coco/tdx/tdx.c | |
| parent | 3123109284176b1532874591f7c81f3837bbdc17 (diff) | |
| download | linux-59bd54a84d15e9335de5b8abe7b3b9713a36b99b.tar.bz2 | |
x86/tdx: Detect running as a TDX guest in early boot
In preparation of extending cc_platform_has() API to support TDX guest,
use CPUID instruction to detect support for TDX guests in the early
boot code (via tdx_early_init()). Since copy_bootdata() is the first
user of cc_platform_has() API, detect the TDX guest status before it.
Define a synthetic feature flag (X86_FEATURE_TDX_GUEST) and set this
bit in a valid TDX guest platform.
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20220405232939.73860-2-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/coco/tdx/tdx.c')
| -rw-r--r-- | arch/x86/coco/tdx/tdx.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c new file mode 100644 index 000000000000..97674471fd1e --- /dev/null +++ b/arch/x86/coco/tdx/tdx.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2021-2022 Intel Corporation */ + +#undef pr_fmt +#define pr_fmt(fmt) "tdx: " fmt + +#include <linux/cpufeature.h> +#include <asm/tdx.h> + +void __init tdx_early_init(void) +{ + u32 eax, sig[3]; + + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2], &sig[1]); + + if (memcmp(TDX_IDENT, sig, sizeof(sig))) + return; + + setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); + + pr_info("Guest detected\n"); +} |