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From: Kuppuswamy Sathyanarayanan  <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>
Cc: Peter H Anvin <hpa@zytor.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Sean Christopherson <seanjc@google.com>,
	Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
	Kuppuswamy Sathyanarayanan 
	<sathyanarayanan.kuppuswamy@linux.intel.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 04/12] x86/x86: Add early_is_tdx_guest() interface
Date: Sat, 12 Jun 2021 14:04:45 -0700	[thread overview]
Message-ID: <20210612210445.2164948-1-sathyanarayanan.kuppuswamy@linux.intel.com> (raw)
In-Reply-To: <YMJ/IrBZiCsNMtvO@zn.tnic>

Add helper function to detect TDX feature support. It will be used
to protect TDX specific code in decompression code.

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>
---

Changes since v1:
 * Removed is_tdx_guest() interface. We will rely on
   prot_guest_has(PR_GUEST_TDX) for TDX related checks.
 * Renamed is_tdx_guest() to early_is_tdx_guest() as per
   review suggestion.
 * Fixed commit title and log to reflect above changes.
 * Simplified native_cpuid_has_tdx_guest() as per review suggestion.

 arch/x86/boot/compressed/Makefile |  1 +
 arch/x86/boot/compressed/tdx.c    | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 arch/x86/boot/compressed/tdx.c

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 431bf7f846c3..22a2a6cc2ab4 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -98,6 +98,7 @@ ifdef CONFIG_X86_64
 endif
 
 vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
+vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o
 
 vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
 efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c
new file mode 100644
index 000000000000..ddfa4a6d1939
--- /dev/null
+++ b/arch/x86/boot/compressed/tdx.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * tdx.c - Early boot code for TDX
+ */
+
+#include <asm/tdx.h>
+
+static int __ro_after_init tdx_guest = -1;
+
+static inline bool native_cpuid_has_tdx_guest(void)
+{
+	u32 eax = TDX_CPUID_LEAF_ID, sig[3] = {0};
+
+	if (native_cpuid_eax(0) < TDX_CPUID_LEAF_ID)
+		return false;
+
+	native_cpuid(&eax, &sig[0], &sig[1], &sig[2]);
+
+	return !memcmp("IntelTDX    ", sig, 12);
+}
+
+bool early_is_tdx_guest(void)
+{
+	if (tdx_guest < 0)
+		tdx_guest = native_cpuid_has_tdx_guest();
+
+	return !!tdx_guest;
+}
-- 
2.25.1


  reply	other threads:[~2021-06-12 21:05 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-02  2:21 [PATCH v1 00/11] Add TDX Guest Support (Initial support) Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 01/11] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 02/11] x86/tdx: Introduce INTEL_TDX_GUEST config option Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 03/11] x86/cpufeatures: Add TDX Guest CPU feature Kuppuswamy Sathyanarayanan
2021-06-07 14:32   ` Tom Lendacky
2021-06-07 16:59     ` Kuppuswamy, Sathyanarayanan
2021-06-10 12:28   ` Borislav Petkov
2021-06-10 14:28     ` Kuppuswamy, Sathyanarayanan
2021-06-10 14:29     ` Kirill A. Shutemov
2021-06-10 14:35       ` Borislav Petkov
2021-06-10 14:41         ` Kirill A. Shutemov
2021-06-10 15:56           ` Borislav Petkov
2021-06-12 21:02             ` [PATCH v2 03/12] " Kuppuswamy Sathyanarayanan
2021-06-16  9:52               ` Borislav Petkov
2021-06-16 16:57                 ` Kuppuswamy, Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 04/11] x86/x86: Add is_tdx_guest() interface Kuppuswamy Sathyanarayanan
2021-06-10 19:59   ` Borislav Petkov
2021-06-10 21:01     ` Kuppuswamy, Sathyanarayanan
2021-06-10 21:07       ` Borislav Petkov
2021-06-12 21:04         ` Kuppuswamy Sathyanarayanan [this message]
2021-06-17 17:05           ` [PATCH v2 04/12] x86/x86: Add early_is_tdx_guest() interface Borislav Petkov
2021-06-18 19:14             ` Kuppuswamy, Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 05/11] x86/tdx: Add __tdx_module_call() and __tdx_hypercall() helper functions Kuppuswamy Sathyanarayanan
2021-06-14  8:47   ` Borislav Petkov
2021-06-14 19:45     ` Kuppuswamy, Sathyanarayanan
2021-06-14 20:11       ` Borislav Petkov
2021-06-14 21:37         ` Kuppuswamy, Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 06/11] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 07/11] x86/traps: Add #VE support for TDX guest Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 08/11] x86/tdx: Add HLT " Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 09/11] x86/tdx: Wire up KVM hypercalls Kuppuswamy Sathyanarayanan
2021-06-12 21:08   ` [PATCH v2 10/12] " Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 10/11] x86/tdx: Add MSR support for TDX guest Kuppuswamy Sathyanarayanan
2021-06-02  2:21 ` [PATCH v1 11/11] x86/tdx: Handle CPUID via #VE Kuppuswamy Sathyanarayanan

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