Mailing List Archive

The following commit has been merged into the x86/sev branch of tip:

Commit-ID: 88ed43d32beb1ef3c06164c52b1c6ced47b5988b
Gitweb: https://git.kernel.org/tip/88ed43d32beb1ef3c06164c52b1c6ced47b5988b
Author: Tom Lendacky <thomas.lendacky@amd.com>
AuthorDate: Wed, 24 Apr 2024 10:57:58 -05:00
Committer: Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Thu, 25 Apr 2024 16:14:25 +02:00

x86/sev: Rename snp_init() in boot/compressed/sev.c

The snp_init() function in boot/compressed/sev.c is local to that file, is
not called from outside of the file and is independent of the snp_init()
function in kernel/sev.c. Change the name to better differentiate when
each function is used.

Move the renamed snp_init() and related functions up in the file to avoid
having to add a forward declaration and make the function static.

No functional change.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/afda29585c2724b9698003f24cefa77eb35f4ffb.1713974291.git.thomas.lendacky@amd.com
---
arch/x86/boot/compressed/sev.c | 162 ++++++++++++++++----------------
1 file changed, 81 insertions(+), 81 deletions(-)

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index ec71846..5ad0ff4 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -413,6 +413,85 @@ void snp_check_features(void)
}
}

+/* Search for Confidential Computing blob in the EFI config table. */
+static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp)
+{
+ unsigned long cfg_table_pa;
+ unsigned int cfg_table_len;
+ int ret;
+
+ ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len);
+ if (ret)
+ return NULL;
+
+ return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa,
+ cfg_table_len,
+ EFI_CC_BLOB_GUID);
+}
+
+/*
+ * Initial set up of SNP relies on information provided by the
+ * Confidential Computing blob, which can be passed to the boot kernel
+ * by firmware/bootloader in the following ways:
+ *
+ * - via an entry in the EFI config table
+ * - via a setup_data structure, as defined by the Linux Boot Protocol
+ *
+ * Scan for the blob in that order.
+ */
+static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+{
+ struct cc_blob_sev_info *cc_info;
+
+ cc_info = find_cc_blob_efi(bp);
+ if (cc_info)
+ goto found_cc_info;
+
+ cc_info = find_cc_blob_setup_data(bp);
+ if (!cc_info)
+ return NULL;
+
+found_cc_info:
+ if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+ return cc_info;
+}
+
+/*
+ * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks
+ * will verify the SNP CPUID/MSR bits.
+ */
+static bool early_snp_init(struct boot_params *bp)
+{
+ struct cc_blob_sev_info *cc_info;
+
+ if (!bp)
+ return false;
+
+ cc_info = find_cc_blob(bp);
+ if (!cc_info)
+ return false;
+
+ /*
+ * If a SNP-specific Confidential Computing blob is present, then
+ * firmware/bootloader have indicated SNP support. Verifying this
+ * involves CPUID checks which will be more reliable if the SNP
+ * CPUID table is used. See comments over snp_setup_cpuid_table() for
+ * more details.
+ */
+ setup_cpuid_table(cc_info);
+
+ /*
+ * Pass run-time kernel a pointer to CC info via boot_params so EFI
+ * config table doesn't need to be searched again during early startup
+ * phase.
+ */
+ bp->cc_blob_address = (u32)(unsigned long)cc_info;
+
+ return true;
+}
+
/*
* sev_check_cpu_support - Check for SEV support in the CPU capabilities
*
@@ -463,7 +542,7 @@ void sev_enable(struct boot_params *bp)
bp->cc_blob_address = 0;

/*
- * Do an initial SEV capability check before snp_init() which
+ * Do an initial SEV capability check before early_snp_init() which
* loads the CPUID page and the same checks afterwards are done
* without the hypervisor and are trustworthy.
*
@@ -478,7 +557,7 @@ void sev_enable(struct boot_params *bp)
* Setup/preliminary detection of SNP. This will be sanity-checked
* against CPUID/MSR values later.
*/
- snp = snp_init(bp);
+ snp = early_snp_init(bp);

/* Now repeat the checks with the SNP CPUID table. */

@@ -535,85 +614,6 @@ u64 sev_get_status(void)
return m.q;
}

-/* Search for Confidential Computing blob in the EFI config table. */
-static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp)
-{
- unsigned long cfg_table_pa;
- unsigned int cfg_table_len;
- int ret;
-
- ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len);
- if (ret)
- return NULL;
-
- return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa,
- cfg_table_len,
- EFI_CC_BLOB_GUID);
-}
-
-/*
- * Initial set up of SNP relies on information provided by the
- * Confidential Computing blob, which can be passed to the boot kernel
- * by firmware/bootloader in the following ways:
- *
- * - via an entry in the EFI config table
- * - via a setup_data structure, as defined by the Linux Boot Protocol
- *
- * Scan for the blob in that order.
- */
-static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
-{
- struct cc_blob_sev_info *cc_info;
-
- cc_info = find_cc_blob_efi(bp);
- if (cc_info)
- goto found_cc_info;
-
- cc_info = find_cc_blob_setup_data(bp);
- if (!cc_info)
- return NULL;
-
-found_cc_info:
- if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
- sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
-
- return cc_info;
-}
-
-/*
- * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks
- * will verify the SNP CPUID/MSR bits.
- */
-bool snp_init(struct boot_params *bp)
-{
- struct cc_blob_sev_info *cc_info;
-
- if (!bp)
- return false;
-
- cc_info = find_cc_blob(bp);
- if (!cc_info)
- return false;
-
- /*
- * If a SNP-specific Confidential Computing blob is present, then
- * firmware/bootloader have indicated SNP support. Verifying this
- * involves CPUID checks which will be more reliable if the SNP
- * CPUID table is used. See comments over snp_setup_cpuid_table() for
- * more details.
- */
- setup_cpuid_table(cc_info);
-
- /*
- * Pass run-time kernel a pointer to CC info via boot_params so EFI
- * config table doesn't need to be searched again during early startup
- * phase.
- */
- bp->cc_blob_address = (u32)(unsigned long)cc_info;
-
- return true;
-}
-
void sev_prep_identity_maps(unsigned long top_level_pgt)
{
/*