Commit 6068754a authored by Nikunj A Dadhania's avatar Nikunj A Dadhania Committed by Borislav Petkov (AMD)
Browse files

x86/sev: Cache the secrets page address 



Instead of calling get_secrets_page(), which parses the CC blob every time
to get the secrets page physical address (secrets_pa), save the secrets
page physical address during snp_init() from the CC blob. Since
get_secrets_page() is no longer used, remove the function.

Signed-off-by: default avatarNikunj A Dadhania <nikunj@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20241009092850.197575-4-nikunj@amd.com
parent f75ff17f

arch/x86/coco/sev/core.c

+11 −40
Original line number Diff line number Diff line
@@ -92,6 +92,9 @@ static struct ghcb *boot_ghcb __section(".data"); 
/* Bitmap of SEV features supported by the hypervisor */

static u64 sev_hv_features __ro_after_init;



/* Secrets page physical address from the CC blob */

static u64 secrets_pa __ro_after_init;



/* #VC handler runtime per-CPU data */

struct sev_es_runtime_data {

	struct ghcb ghcb_page;
@@ -695,45 +698,13 @@ void noinstr __sev_es_nmi_complete(void) 
	__sev_put_ghcb(&state);

}



static u64 __init get_secrets_page(void)

{

	u64 pa_data = boot_params.cc_blob_address;

	struct cc_blob_sev_info info;

	void *map;



	/*

	 * The CC blob contains the address of the secrets page, check if the

	 * blob is present.

	 */

	if (!pa_data)

		return 0;



	map = early_memremap(pa_data, sizeof(info));

	if (!map) {

		pr_err("Unable to locate SNP secrets page: failed to map the Confidential Computing blob.\n");

		return 0;

	}

	memcpy(&info, map, sizeof(info));

	early_memunmap(map, sizeof(info));



	/* smoke-test the secrets page passed */

	if (!info.secrets_phys || info.secrets_len != PAGE_SIZE)

		return 0;



	return info.secrets_phys;

}



static u64 __init get_snp_jump_table_addr(void)

{

	struct snp_secrets_page *secrets;

	void __iomem *mem;

	u64 pa, addr;



	pa = get_secrets_page();

	if (!pa)

		return 0;

	u64 addr;



	mem = ioremap_encrypted(pa, PAGE_SIZE);

	mem = ioremap_encrypted(secrets_pa, PAGE_SIZE);

	if (!mem) {

		pr_err("Unable to locate AP jump table address: failed to map the SNP secrets page.\n");

		return 0;
@@ -2273,6 +2244,11 @@ bool __head snp_init(struct boot_params *bp) 
	if (!cc_info)

		return false;



	if (cc_info->secrets_phys && cc_info->secrets_len == PAGE_SIZE)

		secrets_pa = cc_info->secrets_phys;

	else

		return false;



	setup_cpuid_table(cc_info);



	svsm_setup(cc_info);
@@ -2469,16 +2445,11 @@ static struct platform_device sev_guest_device = { 
static int __init snp_init_platform_device(void)

{

	struct sev_guest_platform_data data;

	u64 gpa;



	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))

		return -ENODEV;



	gpa = get_secrets_page();

	if (!gpa)

		return -ENODEV;



	data.secrets_gpa = gpa;

	data.secrets_gpa = secrets_pa;

	if (platform_device_add_data(&sev_guest_device, &data, sizeof(data)))

		return -ENODEV;