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From:   "Kirill A. Shutemov" <kirill@shutemov.name>
To:     bp@alien8.de
Cc:     aarcange@redhat.com, ak@linux.intel.com, dan.j.williams@intel.com,
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Subject: [PATCHv3.1 2/32] x86/coco: Explicitly declare type of confidential computing platform
Date:   Sat, 19 Feb 2022 03:13:04 +0300
Message-Id: <20220219001305.22883-1-kirill.shutemov@linux.intel.com>
In-Reply-To: <YhAWcPbzgUGcJZjI@zn.tnic>
References: <YhAWcPbzgUGcJZjI@zn.tnic>
MIME-Version: 1.0
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Kernel derives type of confidential computing platform from sme_me_mask
value and hv_is_isolation_supported(). This detection process will be
more complicated as more platforms get added.

Declare confidential computing vendor explicitly via cc_init().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/include/asm/coco.h        | 16 ++++++++++++++++
 arch/x86/kernel/cc_platform.c      | 29 +++++++++++++++++------------
 arch/x86/kernel/cpu/mshyperv.c     |  3 +++
 arch/x86/mm/mem_encrypt_identity.c |  8 +++++---
 4 files changed, 41 insertions(+), 15 deletions(-)
 create mode 100644 arch/x86/include/asm/coco.h

diff --git a/arch/x86/include/asm/coco.h b/arch/x86/include/asm/coco.h
new file mode 100644
index 000000000000..6e770e0dd683
--- /dev/null
+++ b/arch/x86/include/asm/coco.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_COCO_H
+#define _ASM_X86_COCO_H
+
+#include <asm/pgtable_types.h>
+
+enum cc_vendor {
+	CC_VENDOR_NONE,
+	CC_VENDOR_AMD,
+	CC_VENDOR_HYPERV,
+	CC_VENDOR_INTEL,
+};
+
+void cc_init(enum cc_vendor);
+
+#endif /* _ASM_X86_COCO_H */
diff --git a/arch/x86/kernel/cc_platform.c b/arch/x86/kernel/cc_platform.c
index 6a6ffcd978f6..891d3074a16e 100644
--- a/arch/x86/kernel/cc_platform.c
+++ b/arch/x86/kernel/cc_platform.c
@@ -9,18 +9,15 @@
 
 #include <linux/export.h>
 #include <linux/cc_platform.h>
-#include <linux/mem_encrypt.h>
 
-#include <asm/mshyperv.h>
+#include <asm/coco.h>
 #include <asm/processor.h>
 
-static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr)
+static enum cc_vendor cc_vendor;
+
+static bool intel_cc_platform_has(enum cc_attr attr)
 {
-#ifdef CONFIG_INTEL_TDX_GUEST
-	return false;
-#else
 	return false;
-#endif
 }
 
 /*
@@ -74,12 +71,20 @@ static bool hyperv_cc_platform_has(enum cc_attr attr)
 
 bool cc_platform_has(enum cc_attr attr)
 {
-	if (sme_me_mask)
+	switch (cc_vendor) {
+	case CC_VENDOR_AMD:
 		return amd_cc_platform_has(attr);
-
-	if (hv_is_isolation_supported())
+	case CC_VENDOR_INTEL:
+		return intel_cc_platform_has(attr);
+	case CC_VENDOR_HYPERV:
 		return hyperv_cc_platform_has(attr);
-
-	return false;
+	default:
+		return false;
+	}
 }
 EXPORT_SYMBOL_GPL(cc_platform_has);
+
+__init void cc_init(enum cc_vendor vendor)
+{
+	cc_vendor = vendor;
+}
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 5a99f993e639..d77cf3a31f07 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -33,6 +33,7 @@
 #include <asm/nmi.h>
 #include <clocksource/hyperv_timer.h>
 #include <asm/numa.h>
+#include <asm/coco.h>
 
 /* Is Linux running as the root partition? */
 bool hv_root_partition;
@@ -344,6 +345,8 @@ static void __init ms_hyperv_init_platform(void)
 		 */
 		swiotlb_force = SWIOTLB_FORCE;
 #endif
+		if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE)
+			cc_init(CC_VENDOR_HYPERV);
 	}
 
 	if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 3f0abb403340..eb7fbd85b77e 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -44,6 +44,7 @@
 #include <asm/setup.h>
 #include <asm/sections.h>
 #include <asm/cmdline.h>
+#include <asm/coco.h>
 
 #include "mm_internal.h"
 
@@ -565,8 +566,7 @@ void __init sme_enable(struct boot_params *bp)
 	} else {
 		/* SEV state cannot be controlled by a command line option */
 		sme_me_mask = me_mask;
-		physical_mask &= ~sme_me_mask;
-		return;
+		goto out;
 	}
 
 	/*
@@ -600,6 +600,8 @@ void __init sme_enable(struct boot_params *bp)
 		sme_me_mask = 0;
 	else
 		sme_me_mask = active_by_default ? me_mask : 0;
-
+out:
 	physical_mask &= ~sme_me_mask;
+	if (sme_me_mask)
+		cc_init(CC_VENDOR_AMD);
 }
-- 
2.34.1