Commit 88ed43d3 authored by Tom Lendacky's avatar Tom Lendacky Committed by Borislav Petkov (AMD)
Browse files

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: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/afda29585c2724b9698003f24cefa77eb35f4ffb.1713974291.git.thomas.lendacky@amd.com
parent 1e525507

arch/x86/boot/compressed/sev.c

+81 −81
Original line number Diff line number Diff line
@@ -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)

{

	/*