From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Dexuan Cui <decui@microsoft.com>,
Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Subject: [PATCHv2] x86/mm: Fix memory encryption features advertisement
Date: Thu, 11 Jan 2024 14:12:24 +0300 [thread overview]
Message-ID: <20240111111224.25289-1-kirill.shutemov@linux.intel.com> (raw)
When memory encryption is enabled, the kernel prints the encryption
flavor that the system supports.
The check assumes that everything is AMD SME/SEV if it doesn't have
the TDX CPU feature set.
Hyper-V vTOM sets cc_vendor to CC_VENDOR_INTEL when it runs as L2 guest
on top of TDX, but not X86_FEATURE_TDX_GUEST. Hyper-V only needs memory
encryption enabled for I/O without the rest of CoCo enabling.
To avoid confusion, check the cc_vendor directly.
Possible alternative is to completely removing the print statement.
For a regular TDX guest, the kernel already prints a message indicating
that it is booting on TDX. Similarly, AMD and Hyper-V can also display
a message during their enumeration process.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
---
arch/x86/mm/mem_encrypt.c | 56 +++++++++++++++++++++------------------
1 file changed, 30 insertions(+), 26 deletions(-)
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index c290c55b632b..d035bce3a2b0 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -42,38 +42,42 @@ bool force_dma_unencrypted(struct device *dev)
static void print_mem_encrypt_feature_info(void)
{
- pr_info("Memory Encryption Features active:");
+ pr_info("Memory Encryption Features active: ");
- if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) {
- pr_cont(" Intel TDX\n");
- return;
- }
+ switch (cc_vendor) {
+ case CC_VENDOR_INTEL:
+ pr_cont("Intel TDX\n");
+ break;
+ case CC_VENDOR_AMD:
+ pr_cont("AMD");
- pr_cont(" AMD");
-
- /* Secure Memory Encryption */
- if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
+ /* Secure Memory Encryption */
+ if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
/*
* SME is mutually exclusive with any of the SEV
* features below.
- */
- pr_cont(" SME\n");
- return;
+ */
+ pr_cont(" SME\n");
+ return;
+ }
+
+ /* Secure Encrypted Virtualization */
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+ pr_cont(" SEV");
+
+ /* Encrypted Register State */
+ if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
+ pr_cont(" SEV-ES");
+
+ /* Secure Nested Paging */
+ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ pr_cont(" SEV-SNP");
+
+ pr_cont("\n");
+ break;
+ default:
+ pr_cont("Unknown\n");
}
-
- /* Secure Encrypted Virtualization */
- if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
- pr_cont(" SEV");
-
- /* Encrypted Register State */
- if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
- pr_cont(" SEV-ES");
-
- /* Secure Nested Paging */
- if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
- pr_cont(" SEV-SNP");
-
- pr_cont("\n");
}
/* Architecture __weak replacement functions */
--
2.41.0
next reply other threads:[~2024-01-11 11:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-11 11:12 Kirill A. Shutemov [this message]
2024-01-11 14:19 ` [PATCHv2] x86/mm: Fix memory encryption features advertisement Kuppuswamy Sathyanarayanan
2024-01-11 15:14 ` Jeremi Piotrowski
2024-01-11 20:46 ` Kuppuswamy Sathyanarayanan
2024-01-11 20:41 ` Tom Lendacky
2024-01-16 10:36 ` Huang, Kai
2024-01-16 10:58 ` kirill.shutemov
2024-01-16 21:16 ` Huang, Kai
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