Commit 428080c9 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Borislav Petkov (AMD)
Browse files

x86/sev: Move early startup code into .head.text section 



In preparation for implementing rigorous build time checks to enforce
that only code that can support it will be called from the early 1:1
mapping of memory, move SEV init code that is called in this manner to
the .head.text section.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Tested-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240227151907.387873-19-ardb+git@google.com
parent 48204aba

arch/x86/boot/compressed/sev.c

+3 −0
Original line number Diff line number Diff line
@@ -116,6 +116,9 @@ static bool fault_in_kernel_space(unsigned long address) 
#undef __init

#define __init



#undef __head

#define __head



#define __BOOT_COMPRESSED



/* Basic instruction decoding support needed */

arch/x86/include/asm/sev.h

+5 −5
Original line number Diff line number Diff line
@@ -213,16 +213,16 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) 
struct snp_guest_request_ioctl;



void setup_ghcb(void);

void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,

void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,

				  unsigned long npages);

void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,

void early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,

				 unsigned long npages);

void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);

void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);

void snp_set_memory_private(unsigned long vaddr, unsigned long npages);

void snp_set_wakeup_secondary_cpu(void);

bool snp_init(struct boot_params *bp);

void __init __noreturn snp_abort(void);

void __noreturn snp_abort(void);

int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);

void snp_accept_memory(phys_addr_t start, phys_addr_t end);

u64 snp_get_unsupported_features(u64 status);

arch/x86/kernel/sev-shared.c

+10 −13
Original line number Diff line number Diff line
@@ -93,7 +93,8 @@ static bool __init sev_es_check_cpu_features(void) 
	return true;

}



static void __noreturn sev_es_terminate(unsigned int set, unsigned int reason)

static void __head __noreturn

sev_es_terminate(unsigned int set, unsigned int reason)

{

	u64 val = GHCB_MSR_TERM_REQ;
@@ -330,13 +331,7 @@ static int sev_cpuid_hv(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid 
 */

static const struct snp_cpuid_table *snp_cpuid_get_table(void)

{

	void *ptr;



	asm ("lea cpuid_table_copy(%%rip), %0"

	     : "=r" (ptr)

	     : "p" (&cpuid_table_copy));



	return ptr;

	return &RIP_REL_REF(cpuid_table_copy);

}



/*
@@ -395,7 +390,7 @@ static u32 snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted) 
	return xsave_size;

}



static bool

static bool __head

snp_cpuid_get_validated_func(struct cpuid_leaf *leaf)

{

	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
@@ -532,7 +527,8 @@ static int snp_cpuid_postprocess(struct ghcb *ghcb, struct es_em_ctxt *ctxt, 
 * Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value

 * should be treated as fatal by caller.

 */

static int snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)

static int __head

snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)

{

	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
@@ -574,7 +570,7 @@ static int snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_le 
 * page yet, so it only supports the MSR based communication with the

 * hypervisor and only the CPUID exit-code.

 */

void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)

void __head do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)

{

	unsigned int subfn = lower_bits(regs->cx, 32);

	unsigned int fn = lower_bits(regs->ax, 32);
@@ -1025,7 +1021,8 @@ struct cc_setup_data { 
 * Search for a Confidential Computing blob passed in as a setup_data entry

 * via the Linux Boot Protocol.

 */

static struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)

static __head

struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp)

{

	struct cc_setup_data *sd = NULL;

	struct setup_data *hdr;
@@ -1052,7 +1049,7 @@ static struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp) 
 * mapping needs to be updated in sync with all the changes to virtual memory

 * layout and related mapping facilities throughout the boot process.

 */

static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info)

static void __head setup_cpuid_table(const struct cc_blob_sev_info *cc_info)

{

	const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table;

	int i;

arch/x86/kernel/sev.c

+8 −6
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/psp-sev.h>

#include <uapi/linux/sev-guest.h>



#include <asm/init.h>

#include <asm/cpu_entry_area.h>

#include <asm/stacktrace.h>

#include <asm/sev.h>
@@ -682,7 +683,8 @@ static u64 __init get_jump_table_addr(void) 
	return ret;

}



static void early_set_pages_state(unsigned long vaddr, unsigned long paddr,

static void __head

early_set_pages_state(unsigned long vaddr, unsigned long paddr,

		      unsigned long npages, enum psc_op op)

{

	unsigned long paddr_end;
@@ -739,7 +741,7 @@ static void early_set_pages_state(unsigned long vaddr, unsigned long paddr, 
	sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);

}



void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,

void __head early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,

					 unsigned long npages)

{

	/*
@@ -2062,7 +2064,7 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs) 
 *

 * Scan for the blob in that order.

 */

static __init struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)

static __head struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)

{

	struct cc_blob_sev_info *cc_info;
@@ -2088,7 +2090,7 @@ static __init struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp) 
	return cc_info;

}



bool __init snp_init(struct boot_params *bp)

bool __head snp_init(struct boot_params *bp)

{

	struct cc_blob_sev_info *cc_info;
@@ -2110,7 +2112,7 @@ bool __init snp_init(struct boot_params *bp) 
	return true;

}



void __init __noreturn snp_abort(void)

void __head __noreturn snp_abort(void)

{

	sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);

}