Re: [PATCH v9 08/19] x86: Secure Launch kernel early boot stub

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On Fri May 31, 2024 at 4:03 AM EEST, Ross Philipson wrote:
> The Secure Launch (SL) stub provides the entry point for Intel TXT (and
> later AMD SKINIT) to vector to during the late launch. The symbol
> sl_stub_entry is that entry point and its offset into the kernel is
> conveyed to the launching code using the MLE (Measured Launch
> Environment) header in the structure named mle_header. The offset of the
> MLE header is set in the kernel_info. The routine sl_stub contains the
> very early late launch setup code responsible for setting up the basic
> environment to allow the normal kernel startup_32 code to proceed. It is
> also responsible for properly waking and handling the APs on Intel
> platforms. The routine sl_main which runs after entering 64b mode is
> responsible for measuring configuration and module information before
> it is used like the boot params, the kernel command line, the TXT heap,
> an external initramfs, etc.
>
> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
> ---
>  Documentation/arch/x86/boot.rst        |  21 +
>  arch/x86/boot/compressed/Makefile      |   3 +-
>  arch/x86/boot/compressed/head_64.S     |  30 +
>  arch/x86/boot/compressed/kernel_info.S |  34 ++
>  arch/x86/boot/compressed/sl_main.c     | 577 ++++++++++++++++++++
>  arch/x86/boot/compressed/sl_stub.S     | 725 +++++++++++++++++++++++++
>  arch/x86/include/asm/msr-index.h       |   5 +
>  arch/x86/include/uapi/asm/bootparam.h  |   1 +
>  arch/x86/kernel/asm-offsets.c          |  20 +
>  9 files changed, 1415 insertions(+), 1 deletion(-)
>  create mode 100644 arch/x86/boot/compressed/sl_main.c
>  create mode 100644 arch/x86/boot/compressed/sl_stub.S
>
> diff --git a/Documentation/arch/x86/boot.rst b/Documentation/arch/x86/boot.rst
> index 4fd492cb4970..295cdf9bcbdb 100644
> --- a/Documentation/arch/x86/boot.rst
> +++ b/Documentation/arch/x86/boot.rst
> @@ -482,6 +482,14 @@ Protocol:	2.00+
>  	    - If 1, KASLR enabled.
>  	    - If 0, KASLR disabled.
>  
> +  Bit 2 (kernel internal): SLAUNCH_FLAG
> +
> +	- Used internally by the setup kernel to communicate
> +	  Secure Launch status to kernel proper.
> +
> +	    - If 1, Secure Launch enabled.
> +	    - If 0, Secure Launch disabled.
> +
>    Bit 5 (write): QUIET_FLAG
>  
>  	- If 0, print early messages.
> @@ -1028,6 +1036,19 @@ Offset/size:	0x000c/4
>  
>    This field contains maximal allowed type for setup_data and setup_indirect structs.
>  
> +============	=================
> +Field name:	mle_header_offset
> +Offset/size:	0x0010/4
> +============	=================
> +
> +  This field contains the offset to the Secure Launch Measured Launch Environment
> +  (MLE) header. This offset is used to locate information needed during a secure
> +  late launch using Intel TXT. If the offset is zero, the kernel does not have
> +  Secure Launch capabilities. The MLE entry point is called from TXT on the BSP
> +  following a success measured launch. The specific state of the processors is
> +  outlined in the TXT Software Development Guide, the latest can be found here:
> +  https://www.intel.com/content/dam/www/public/us/en/documents/guides/intel-txt-software-development-guide.pdf
> +
>  
>  The Image Checksum
>  ==================
> diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> index 9189a0e28686..9076a248d4b4 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -118,7 +118,8 @@ vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o
>  vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_mixed.o
>  vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
>  
> -vmlinux-objs-$(CONFIG_SECURE_LAUNCH) += $(obj)/early_sha1.o $(obj)/early_sha256.o
> +vmlinux-objs-$(CONFIG_SECURE_LAUNCH) += $(obj)/early_sha1.o $(obj)/early_sha256.o \
> +	$(obj)/sl_main.o $(obj)/sl_stub.o
>  
>  $(obj)/vmlinux: $(vmlinux-objs-y) FORCE
>  	$(call if_changed,ld)
> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index 1dcb794c5479..803c9e2e6d85 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -420,6 +420,13 @@ SYM_CODE_START(startup_64)
>  	pushq	$0
>  	popfq
>  
> +#ifdef CONFIG_SECURE_LAUNCH
> +	/* Ensure the relocation region is coverd by a PMR */
> +	movq	%rbx, %rdi
> +	movl	$(_bss - startup_32), %esi
> +	callq	sl_check_region
> +#endif
> +
>  /*
>   * Copy the compressed kernel to the end of our buffer
>   * where decompression in place becomes safe.
> @@ -462,6 +469,29 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
>  	shrq	$3, %rcx
>  	rep	stosq
>  
> +#ifdef CONFIG_SECURE_LAUNCH
> +	/*
> +	 * Have to do the final early sl stub work in 64b area.
> +	 *
> +	 * *********** NOTE ***********
> +	 *
> +	 * Several boot params get used before we get a chance to measure
> +	 * them in this call. This is a known issue and we currently don't
> +	 * have a solution. The scratch field doesn't matter. There is no
> +	 * obvious way to do anything about the use of kernel_alignment or
> +	 * init_size though these seem low risk with all the PMR and overlap
> +	 * checks in place.
> +	 */
> +	movq	%r15, %rdi
> +	callq	sl_main
> +
> +	/* Ensure the decompression location is covered by a PMR */
> +	movq	%rbp, %rdi
> +	movq	output_len(%rip), %rsi
> +	callq	sl_check_region
> +#endif
> +
> +	pushq	%rsi
>  	call	load_stage2_idt
>  
>  	/* Pass boot_params to initialize_identity_maps() */
> diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S
> index c18f07181dd5..e199b87764e9 100644
> --- a/arch/x86/boot/compressed/kernel_info.S
> +++ b/arch/x86/boot/compressed/kernel_info.S
> @@ -28,6 +28,40 @@ SYM_DATA_START(kernel_info)
>  	/* Maximal allowed type for setup_data and setup_indirect structs. */
>  	.long	SETUP_TYPE_MAX
>  
> +	/* Offset to the MLE header structure */
> +#if IS_ENABLED(CONFIG_SECURE_LAUNCH)
> +	.long	rva(mle_header)
> +#else
> +	.long	0
> +#endif
> +
>  kernel_info_var_len_data:
>  	/* Empty for time being... */
>  SYM_DATA_END_LABEL(kernel_info, SYM_L_LOCAL, kernel_info_end)
> +
> +#if IS_ENABLED(CONFIG_SECURE_LAUNCH)
> +	/*
> +	 * The MLE Header per the TXT Specification, section 2.1
> +	 * MLE capabilities, see table 4. Capabilities set:
> +	 * bit 0: Support for GETSEC[WAKEUP] for RLP wakeup
> +	 * bit 1: Support for RLP wakeup using MONITOR address
> +	 * bit 2: The ECX register will contain the pointer to the MLE page table
> +	 * bit 5: TPM 1.2 family: Details/authorities PCR usage support
> +	 * bit 9: Supported format of TPM 2.0 event log - TCG compliant
> +	 */
> +SYM_DATA_START(mle_header)
> +	.long	0x9082ac5a  /* UUID0 */
> +	.long	0x74a7476f  /* UUID1 */
> +	.long	0xa2555c0f  /* UUID2 */
> +	.long	0x42b651cb  /* UUID3 */
> +	.long	0x00000034  /* MLE header size */
> +	.long	0x00020002  /* MLE version 2.2 */
> +	.long	rva(sl_stub_entry) /* Linear entry point of MLE (virt. address) */
> +	.long	0x00000000  /* First valid page of MLE */
> +	.long	0x00000000  /* Offset within binary of first byte of MLE */
> +	.long	rva(_edata) /* Offset within binary of last byte + 1 of MLE */
> +	.long	0x00000227  /* Bit vector of MLE-supported capabilities */
> +	.long	0x00000000  /* Starting linear address of command line (unused) */
> +	.long	0x00000000  /* Ending linear address of command line (unused) */
> +SYM_DATA_END(mle_header)
> +#endif
> diff --git a/arch/x86/boot/compressed/sl_main.c b/arch/x86/boot/compressed/sl_main.c
> new file mode 100644
> index 000000000000..61e9baf410fd
> --- /dev/null
> +++ b/arch/x86/boot/compressed/sl_main.c
> @@ -0,0 +1,577 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Secure Launch early measurement and validation routines.
> + *
> + * Copyright (c) 2024, Oracle and/or its affiliates.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/string.h>
> +#include <linux/linkage.h>
> +#include <asm/segment.h>
> +#include <asm/boot.h>
> +#include <asm/msr.h>
> +#include <asm/mtrr.h>
> +#include <asm/processor-flags.h>
> +#include <asm/asm-offsets.h>
> +#include <asm/bootparam.h>
> +#include <asm/bootparam_utils.h>
> +#include <linux/slr_table.h>
> +#include <linux/slaunch.h>
> +#include <crypto/sha1.h>
> +#include <crypto/sha2.h>
> +
> +#define CAPS_VARIABLE_MTRR_COUNT_MASK	0xff
> +
> +#define SL_TPM12_LOG		1
> +#define SL_TPM20_LOG		2
> +
> +#define SL_TPM20_MAX_ALGS	2
> +
> +#define SL_MAX_EVENT_DATA	64
> +#define SL_TPM12_LOG_SIZE	(sizeof(struct tcg_pcr_event) + \
> +				SL_MAX_EVENT_DATA)
> +#define SL_TPM20_LOG_SIZE	(sizeof(struct tcg_pcr_event2_head) + \
> +				SHA1_DIGEST_SIZE + SHA256_DIGEST_SIZE + \
> +				sizeof(struct tcg_event_field) + \
> +				SL_MAX_EVENT_DATA)
> +
> +static void *evtlog_base;
> +static u32 evtlog_size;
> +static struct txt_heap_event_log_pointer2_1_element *log20_elem;
> +static u32 tpm_log_ver = SL_TPM12_LOG;
> +static struct tcg_efi_specid_event_algs tpm_algs[SL_TPM20_MAX_ALGS] = {0};
> +
> +extern u32 sl_cpu_type;
> +extern u32 sl_mle_start;
> +
> +static u64 sl_txt_read(u32 reg)
> +{
> +	return readq((void *)(u64)(TXT_PRIV_CONFIG_REGS_BASE + reg));
> +}
> +
> +static void sl_txt_write(u32 reg, u64 val)
> +{
> +	writeq(val, (void *)(u64)(TXT_PRIV_CONFIG_REGS_BASE + reg));
> +}
> +
> +static void __noreturn sl_txt_reset(u64 error)
> +{
> +	/* Reading the E2STS register acts as a barrier for TXT registers */
> +	sl_txt_write(TXT_CR_ERRORCODE, error);
> +	sl_txt_read(TXT_CR_E2STS);
> +	sl_txt_write(TXT_CR_CMD_UNLOCK_MEM_CONFIG, 1);
> +	sl_txt_read(TXT_CR_E2STS);
> +	sl_txt_write(TXT_CR_CMD_RESET, 1);
> +
> +	for ( ; ; )
> +		asm volatile ("hlt");
> +
> +	unreachable();
> +}
> +
> +static u64 sl_rdmsr(u32 reg)
> +{
> +	u64 lo, hi;
> +
> +	asm volatile ("rdmsr" : "=a" (lo), "=d" (hi) : "c" (reg));
> +
> +	return (hi << 32) | lo;
> +}
> +
> +static struct slr_table *sl_locate_and_validate_slrt(void)
> +{
> +	struct txt_os_mle_data *os_mle_data;
> +	struct slr_table *slrt;
> +	void *txt_heap;
> +
> +	txt_heap = (void *)sl_txt_read(TXT_CR_HEAP_BASE);
> +	os_mle_data = txt_os_mle_data_start(txt_heap);
> +
> +	if (!os_mle_data->slrt)
> +		sl_txt_reset(SL_ERROR_INVALID_SLRT);
> +
> +	slrt = (struct slr_table *)os_mle_data->slrt;
> +
> +	if (slrt->magic != SLR_TABLE_MAGIC)
> +		sl_txt_reset(SL_ERROR_INVALID_SLRT);
> +
> +	if (slrt->architecture != SLR_INTEL_TXT)
> +		sl_txt_reset(SL_ERROR_INVALID_SLRT);
> +
> +	return slrt;
> +}
> +
> +static void sl_check_pmr_coverage(void *base, u32 size, bool allow_hi)
> +{
> +	struct txt_os_sinit_data *os_sinit_data;
> +	void *end = base + size;
> +	void *txt_heap;
> +
> +	if (!(sl_cpu_type & SL_CPU_INTEL))
> +		return;
> +
> +	txt_heap = (void *)sl_txt_read(TXT_CR_HEAP_BASE);
> +	os_sinit_data = txt_os_sinit_data_start(txt_heap);
> +
> +	if ((end >= (void *)0x100000000ULL) && (base < (void *)0x100000000ULL))
> +		sl_txt_reset(SL_ERROR_REGION_STRADDLE_4GB);
> +
> +	/*
> +	 * Note that the late stub code validates that the hi PMR covers
> +	 * all memory above 4G. At this point the code can only check that
> +	 * regions are within the hi PMR but that is sufficient.
> +	 */
> +	if ((end > (void *)0x100000000ULL) && (base >= (void *)0x100000000ULL)) {
> +		if (allow_hi) {
> +			if (end >= (void *)(os_sinit_data->vtd_pmr_hi_base +
> +					   os_sinit_data->vtd_pmr_hi_size))
> +				sl_txt_reset(SL_ERROR_BUFFER_BEYOND_PMR);
> +		} else {
> +			sl_txt_reset(SL_ERROR_REGION_ABOVE_4GB);
> +		}
> +	}
> +
> +	if (end >= (void *)os_sinit_data->vtd_pmr_lo_size)
> +		sl_txt_reset(SL_ERROR_BUFFER_BEYOND_PMR);
> +}
> +
> +/*
> + * Some MSRs are modified by the pre-launch code including the MTRRs.
> + * The early MLE code has to restore these values. This code validates
> + * the values after they are measured.
> + */
> +static void sl_txt_validate_msrs(struct txt_os_mle_data *os_mle_data)
> +{
> +	struct slr_txt_mtrr_state *saved_bsp_mtrrs;
> +	u64 mtrr_caps, mtrr_def_type, mtrr_var;
> +	struct slr_entry_intel_info *txt_info;
> +	u64 misc_en_msr;
> +	u32 vcnt, i;
> +
> +	txt_info = (struct slr_entry_intel_info *)os_mle_data->txt_info;
> +	saved_bsp_mtrrs = &txt_info->saved_bsp_mtrrs;
> +
> +	mtrr_caps = sl_rdmsr(MSR_MTRRcap);
> +	vcnt = (u32)(mtrr_caps & CAPS_VARIABLE_MTRR_COUNT_MASK);
> +
> +	if (saved_bsp_mtrrs->mtrr_vcnt > vcnt)
> +		sl_txt_reset(SL_ERROR_MTRR_INV_VCNT);
> +	if (saved_bsp_mtrrs->mtrr_vcnt > TXT_OS_MLE_MAX_VARIABLE_MTRRS)
> +		sl_txt_reset(SL_ERROR_MTRR_INV_VCNT);
> +
> +	mtrr_def_type = sl_rdmsr(MSR_MTRRdefType);
> +	if (saved_bsp_mtrrs->default_mem_type != mtrr_def_type)
> +		sl_txt_reset(SL_ERROR_MTRR_INV_DEF_TYPE);
> +
> +	for (i = 0; i < saved_bsp_mtrrs->mtrr_vcnt; i++) {
> +		mtrr_var = sl_rdmsr(MTRRphysBase_MSR(i));
> +		if (saved_bsp_mtrrs->mtrr_pair[i].mtrr_physbase != mtrr_var)
> +			sl_txt_reset(SL_ERROR_MTRR_INV_BASE);
> +		mtrr_var = sl_rdmsr(MTRRphysMask_MSR(i));
> +		if (saved_bsp_mtrrs->mtrr_pair[i].mtrr_physmask != mtrr_var)
> +			sl_txt_reset(SL_ERROR_MTRR_INV_MASK);
> +	}
> +
> +	misc_en_msr = sl_rdmsr(MSR_IA32_MISC_ENABLE);
> +	if (txt_info->saved_misc_enable_msr != misc_en_msr)
> +		sl_txt_reset(SL_ERROR_MSR_INV_MISC_EN);
> +}
> +
> +static void sl_find_drtm_event_log(struct slr_table *slrt)
> +{
> +	struct txt_os_sinit_data *os_sinit_data;
> +	struct slr_entry_log_info *log_info;
> +	void *txt_heap;
> +
> +	log_info = slr_next_entry_by_tag(slrt, NULL, SLR_ENTRY_LOG_INFO);
> +	if (!log_info)
> +		sl_txt_reset(SL_ERROR_SLRT_MISSING_ENTRY);
> +
> +	evtlog_base = (void *)log_info->addr;
> +	evtlog_size = log_info->size;
> +
> +	txt_heap = (void *)sl_txt_read(TXT_CR_HEAP_BASE);
> +
> +	/*
> +	 * For TPM 2.0, the event log 2.1 extended data structure has to also
> +	 * be located and fixed up.
> +	 */
> +	os_sinit_data = txt_os_sinit_data_start(txt_heap);
> +
> +	/*
> +	 * Only support version 6 and later that properly handle the
> +	 * list of ExtDataElements in the OS-SINIT structure.
> +	 */
> +	if (os_sinit_data->version < 6)
> +		sl_txt_reset(SL_ERROR_OS_SINIT_BAD_VERSION);
> +
> +	/* Find the TPM2.0 logging extended heap element */
> +	log20_elem = tpm20_find_log2_1_element(os_sinit_data);

s/tpm20/tpm2/

> +
> +	/* If found, this implies TPM20 log and family */
> +	if (log20_elem)
> +		tpm_log_ver = SL_TPM20_LOG;
> +}
> +
> +static void sl_validate_event_log_buffer(void)
> +{
> +	struct txt_os_sinit_data *os_sinit_data;
> +	void *txt_heap, *txt_end;
> +	void *mle_base, *mle_end;
> +	void *evtlog_end;
> +
> +	if ((u64)evtlog_size > (LLONG_MAX - (u64)evtlog_base))
> +		sl_txt_reset(SL_ERROR_INTEGER_OVERFLOW);
> +	evtlog_end = evtlog_base + evtlog_size;
> +
> +	txt_heap = (void *)sl_txt_read(TXT_CR_HEAP_BASE);
> +	txt_end = txt_heap + sl_txt_read(TXT_CR_HEAP_SIZE);
> +	os_sinit_data = txt_os_sinit_data_start(txt_heap);
> +
> +	mle_base = (void *)(u64)sl_mle_start;
> +	mle_end = mle_base + os_sinit_data->mle_size;
> +
> +	/*
> +	 * This check is to ensure the event log buffer does not overlap with
> +	 * the MLE image.
> +	 */
> +	if (evtlog_base >= mle_end && evtlog_end > mle_end)
> +		goto pmr_check; /* above */
> +
> +	if (evtlog_end <= mle_base && evtlog_base < mle_base)
> +		goto pmr_check; /* below */
> +
> +	sl_txt_reset(SL_ERROR_MLE_BUFFER_OVERLAP);
> +
> +pmr_check:
> +	/*
> +	 * The TXT heap is protected by the DPR. If the TPM event log is
> +	 * inside the TXT heap, there is no need for a PMR check.
> +	 */
> +	if (evtlog_base > txt_heap && evtlog_end < txt_end)
> +		return;
> +
> +	sl_check_pmr_coverage(evtlog_base, evtlog_size, true);
> +}
> +
> +static void sl_find_event_log_algorithms(void)
> +{
> +	struct tcg_efi_specid_event_head *efi_head =
> +		(struct tcg_efi_specid_event_head *)(evtlog_base +
> +					log20_elem->first_record_offset +
> +					sizeof(struct tcg_pcr_event));
> +
> +	if (efi_head->num_algs == 0 || efi_head->num_algs > 2)
> +		sl_txt_reset(SL_ERROR_TPM_NUMBER_ALGS);
> +
> +	memcpy(&tpm_algs[0], &efi_head->digest_sizes[0],
> +	       sizeof(struct tcg_efi_specid_event_algs) * efi_head->num_algs);
> +}
> +
> +static void sl_tpm12_log_event(u32 pcr, u32 event_type,
> +			       const u8 *data, u32 length,
> +			       const u8 *event_data, u32 event_size)
> +{
> +	u8 sha1_hash[SHA1_DIGEST_SIZE] = {0};
> +	u8 log_buf[SL_TPM12_LOG_SIZE] = {0};
> +	struct tcg_pcr_event *pcr_event;
> +	u32 total_size;
> +
> +	pcr_event = (struct tcg_pcr_event *)log_buf;
> +	pcr_event->pcr_idx = pcr;
> +	pcr_event->event_type = event_type;
> +	if (length > 0) {
> +		sha1(data, length, &sha1_hash[0]);
> +		memcpy(&pcr_event->digest[0], &sha1_hash[0], SHA1_DIGEST_SIZE);
> +	}
> +	pcr_event->event_size = event_size;
> +	if (event_size > 0)
> +		memcpy((u8 *)pcr_event + sizeof(struct tcg_pcr_event),
> +		       event_data, event_size);
> +
> +	total_size = sizeof(struct tcg_pcr_event) + event_size;
> +
> +	if (tpm12_log_event(evtlog_base, evtlog_size, total_size, pcr_event))
> +		sl_txt_reset(SL_ERROR_TPM_LOGGING_FAILED);
> +}
> +
> +static void sl_tpm20_log_event(u32 pcr, u32 event_type,
> +			       const u8 *data, u32 length,
> +			       const u8 *event_data, u32 event_size)
> +{
> +	u8 sha256_hash[SHA256_DIGEST_SIZE] = {0};
> +	u8 sha1_hash[SHA1_DIGEST_SIZE] = {0};
> +	u8 log_buf[SL_TPM20_LOG_SIZE] = {0};
> +	struct sha256_state sctx256 = {0};
> +	struct tcg_pcr_event2_head *head;
> +	struct tcg_event_field *event;
> +	u32 total_size;
> +	u16 *alg_ptr;
> +	u8 *dgst_ptr;
> +
> +	head = (struct tcg_pcr_event2_head *)log_buf;
> +	head->pcr_idx = pcr;
> +	head->event_type = event_type;
> +	total_size = sizeof(struct tcg_pcr_event2_head);
> +	alg_ptr = (u16 *)(log_buf + sizeof(struct tcg_pcr_event2_head));
> +
> +	for ( ; head->count < 2; head->count++) {
> +		if (!tpm_algs[head->count].alg_id)
> +			break;
> +
> +		*alg_ptr = tpm_algs[head->count].alg_id;
> +		dgst_ptr = (u8 *)alg_ptr + sizeof(u16);
> +
> +		if (tpm_algs[head->count].alg_id == TPM_ALG_SHA256 &&
> +		    length) {
> +			sha256_init(&sctx256);
> +			sha256_update(&sctx256, data, length);
> +			sha256_final(&sctx256, &sha256_hash[0]);
> +		} else if (tpm_algs[head->count].alg_id == TPM_ALG_SHA1 &&
> +			   length) {
> +			sha1(data, length, &sha1_hash[0]);
> +		}
> +
> +		if (tpm_algs[head->count].alg_id == TPM_ALG_SHA256) {
> +			memcpy(dgst_ptr, &sha256_hash[0], SHA256_DIGEST_SIZE);
> +			total_size += SHA256_DIGEST_SIZE + sizeof(u16);
> +			alg_ptr = (u16 *)((u8 *)alg_ptr + SHA256_DIGEST_SIZE + sizeof(u16));
> +		} else if (tpm_algs[head->count].alg_id == TPM_ALG_SHA1) {
> +			memcpy(dgst_ptr, &sha1_hash[0], SHA1_DIGEST_SIZE);
> +			total_size += SHA1_DIGEST_SIZE + sizeof(u16);
> +			alg_ptr = (u16 *)((u8 *)alg_ptr + SHA1_DIGEST_SIZE + sizeof(u16));
> +		} else {
> +			sl_txt_reset(SL_ERROR_TPM_UNKNOWN_DIGEST);
> +		}
> +	}
> +
> +	event = (struct tcg_event_field *)(log_buf + total_size);
> +	event->event_size = event_size;
> +	if (event_size > 0)
> +		memcpy((u8 *)event + sizeof(struct tcg_event_field), event_data, event_size);
> +	total_size += sizeof(struct tcg_event_field) + event_size;
> +
> +	if (tpm20_log_event(log20_elem, evtlog_base, evtlog_size, total_size, &log_buf[0]))
> +		sl_txt_reset(SL_ERROR_TPM_LOGGING_FAILED);
> +}
> +
> +static void sl_tpm_extend_evtlog(u32 pcr, u32 type,
> +				 const u8 *data, u32 length, const char *desc)
> +{
> +	if (tpm_log_ver == SL_TPM20_LOG)
> +		sl_tpm20_log_event(pcr, type, data, length,
> +				   (const u8 *)desc, strlen(desc));
> +	else
> +		sl_tpm12_log_event(pcr, type, data, length,
> +				   (const u8 *)desc, strlen(desc));
> +}
> +
> +static struct setup_data *sl_handle_setup_data(struct setup_data *curr,
> +					       struct slr_policy_entry *entry)
> +{
> +	struct setup_indirect *ind;
> +	struct setup_data *next;
> +
> +	if (!curr)
> +		return NULL;
> +
> +	next = (struct setup_data *)(unsigned long)curr->next;
> +
> +	/* SETUP_INDIRECT instances have to be handled differently */
> +	if (curr->type == SETUP_INDIRECT) {
> +		ind = (struct setup_indirect *)((u8 *)curr + offsetof(struct setup_data, data));
> +
> +		sl_check_pmr_coverage((void *)ind->addr, ind->len, true);
> +
> +		sl_tpm_extend_evtlog(entry->pcr, TXT_EVTYPE_SLAUNCH,
> +				     (void *)ind->addr, ind->len,
> +				     entry->evt_info);
> +
> +		return next;
> +	}
> +
> +	sl_check_pmr_coverage(((u8 *)curr) + sizeof(struct setup_data),
> +			      curr->len, true);
> +
> +	sl_tpm_extend_evtlog(entry->pcr, TXT_EVTYPE_SLAUNCH,
> +			     ((u8 *)curr) + sizeof(struct setup_data),
> +			     curr->len,
> +			     entry->evt_info);
> +
> +	return next;
> +}
> +
> +static void sl_extend_setup_data(struct slr_policy_entry *entry)
> +{
> +	struct setup_data *data;
> +
> +	/*
> +	 * Measuring the boot params measured the fixed e820 memory map.
> +	 * Measure any setup_data entries including e820 extended entries.
> +	 */
> +	data = (struct setup_data *)(unsigned long)entry->entity;
> +	while (data)
> +		data = sl_handle_setup_data(data, entry);
> +}
> +
> +static void sl_extend_slrt(struct slr_policy_entry *entry)
> +{
> +	struct slr_table *slrt = (struct slr_table *)entry->entity;
> +	struct slr_entry_intel_info *intel_info;
> +
> +	/*
> +	 * In revision one of the SLRT, the only table that needs to be
> +	 * measured is the Intel info table. Everything else is meta-data,
> +	 * addresses and sizes. Note the size of what to measure is not set.
> +	 * The flag SLR_POLICY_IMPLICIT_SIZE leaves it to the measuring code
> +	 * to sort out.
> +	 */
> +	if (slrt->revision == 1) {
> +		intel_info = slr_next_entry_by_tag(slrt, NULL, SLR_ENTRY_INTEL_INFO);
> +		if (!intel_info)
> +			sl_txt_reset(SL_ERROR_SLRT_MISSING_ENTRY);
> +
> +		sl_tpm_extend_evtlog(entry->pcr, TXT_EVTYPE_SLAUNCH,
> +				     (void *)entry->entity, sizeof(struct slr_entry_intel_info),
> +				     entry->evt_info);
> +	}
> +}
> +
> +static void sl_extend_txt_os2mle(struct slr_policy_entry *entry)
> +{
> +	struct txt_os_mle_data *os_mle_data;
> +	void *txt_heap;
> +
> +	txt_heap = (void *)sl_txt_read(TXT_CR_HEAP_BASE);
> +	os_mle_data = txt_os_mle_data_start(txt_heap);
> +
> +	/*
> +	 * Version 1 of the OS-MLE heap structure has no fields to measure. It just
> +	 * has addresses and sizes and a scratch buffer.
> +	 */
> +	if (os_mle_data->version == 1)
> +		return;
> +}
> +
> +static void sl_process_extend_policy(struct slr_table *slrt)
> +{
> +	struct slr_entry_policy *policy;
> +	u16 i;
> +
> +	policy = slr_next_entry_by_tag(slrt, NULL, SLR_ENTRY_ENTRY_POLICY);
> +	if (!policy)
> +		sl_txt_reset(SL_ERROR_SLRT_MISSING_ENTRY);
> +
> +	for (i = 0; i < policy->nr_entries; i++) {
> +		switch (policy->policy_entries[i].entity_type) {
> +		case SLR_ET_SETUP_DATA:
> +			sl_extend_setup_data(&policy->policy_entries[i]);
> +			break;
> +		case SLR_ET_SLRT:
> +			sl_extend_slrt(&policy->policy_entries[i]);
> +			break;
> +		case SLR_ET_TXT_OS2MLE:
> +			sl_extend_txt_os2mle(&policy->policy_entries[i]);
> +			break;
> +		case SLR_ET_UNUSED:
> +			continue;
> +		default:
> +			sl_tpm_extend_evtlog(policy->policy_entries[i].pcr, TXT_EVTYPE_SLAUNCH,
> +					     (void *)policy->policy_entries[i].entity,
> +					     policy->policy_entries[i].size,
> +					     policy->policy_entries[i].evt_info);
> +		}
> +	}
> +}
> +
> +static void sl_process_extend_uefi_config(struct slr_table *slrt)
> +{
> +	struct slr_entry_uefi_config *uefi_config;
> +	u16 i;
> +
> +	uefi_config = slr_next_entry_by_tag(slrt, NULL, SLR_ENTRY_UEFI_CONFIG);
> +
> +	/* Optionally here depending on how SL kernel was booted */
> +	if (!uefi_config)
> +		return;
> +
> +	for (i = 0; i < uefi_config->nr_entries; i++) {
> +		sl_tpm_extend_evtlog(uefi_config->uefi_cfg_entries[i].pcr, TXT_EVTYPE_SLAUNCH,
> +				     (void *)uefi_config->uefi_cfg_entries[i].cfg,
> +				     uefi_config->uefi_cfg_entries[i].size,
> +				     uefi_config->uefi_cfg_entries[i].evt_info);
> +	}
> +}
> +
> +asmlinkage __visible void sl_check_region(void *base, u32 size)
> +{
> +	sl_check_pmr_coverage(base, size, false);
> +}
> +
> +asmlinkage __visible void sl_main(void *bootparams)
> +{
> +	struct boot_params *bp  = (struct boot_params *)bootparams;
> +	struct txt_os_mle_data *os_mle_data;
> +	struct slr_table *slrt;
> +	void *txt_heap;
> +
> +	/*
> +	 * Ensure loadflags do not indicate a secure launch was done
> +	 * unless it really was.
> +	 */
> +	bp->hdr.loadflags &= ~SLAUNCH_FLAG;
> +
> +	/*
> +	 * Currently only Intel TXT is supported for Secure Launch. Testing
> +	 * this value also indicates that the kernel was booted successfully
> +	 * through the Secure Launch entry point and is in SMX mode.
> +	 */
> +	if (!(sl_cpu_type & SL_CPU_INTEL))
> +		return;
> +
> +	slrt = sl_locate_and_validate_slrt();
> +
> +	/* Locate the TPM event log. */
> +	sl_find_drtm_event_log(slrt);
> +
> +	/* Validate the location of the event log buffer before using it */
> +	sl_validate_event_log_buffer();
> +
> +	/*
> +	 * Find the TPM hash algorithms used by the ACM and recorded in the
> +	 * event log.
> +	 */
> +	if (tpm_log_ver == SL_TPM20_LOG)
> +		sl_find_event_log_algorithms();
> +
> +	/*
> +	 * Sanitize them before measuring. Set the SLAUNCH_FLAG early since if
> +	 * anything fails, the system will reset anyway.
> +	 */
> +	sanitize_boot_params(bp);
> +	bp->hdr.loadflags |= SLAUNCH_FLAG;
> +
> +	sl_check_pmr_coverage(bootparams, PAGE_SIZE, false);
> +
> +	/* Place event log SL specific tags before and after measurements */
> +	sl_tpm_extend_evtlog(17, TXT_EVTYPE_SLAUNCH_START, NULL, 0, "");
> +
> +	/* Process all policy entries and extend the measurements to the evtlog */

These comments obfuscate code here but would make a lot more sense
in the beginning of each corresponding function.

/*
 * Process all policy entries and extend the measurements to the evtlog 
 */
static void sl_process_extend_policy(struct slr_table *slrt)
{
	/* ... */
}

BTW what good that "process" does here? Why not just sl_extend_policy()?


> +	sl_process_extend_policy(slrt);
> +
> +	/* Process all EFI config entries and extend the measurements to the evtlog */
> +	sl_process_extend_uefi_config(slrt);

Ditto.

> +
> +	sl_tpm_extend_evtlog(17, TXT_EVTYPE_SLAUNCH_END, NULL, 0, "");
> +
> +	/* No PMR check is needed, the TXT heap is covered by the DPR */
> +	txt_heap = (void *)sl_txt_read(TXT_CR_HEAP_BASE);
> +	os_mle_data = txt_os_mle_data_start(txt_heap);
> +
> +	/*
> +	 * Now that the OS-MLE data is measured, ensure the MTRR and
> +	 * misc enable MSRs are what we expect.
> +	 */
> +	sl_txt_validate_msrs(os_mle_data);
> +}
> diff --git a/arch/x86/boot/compressed/sl_stub.S b/arch/x86/boot/compressed/sl_stub.S
> new file mode 100644
> index 000000000000..24b8f23d5dcc
> --- /dev/null
> +++ b/arch/x86/boot/compressed/sl_stub.S
> @@ -0,0 +1,725 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +/*
> + * Secure Launch protected mode entry point.
> + *
> + * Copyright (c) 2024, Oracle and/or its affiliates.
> + */
> +	.code32
> +	.text
> +#include <linux/linkage.h>
> +#include <asm/segment.h>
> +#include <asm/msr.h>
> +#include <asm/apicdef.h>
> +#include <asm/trapnr.h>
> +#include <asm/processor-flags.h>
> +#include <asm/asm-offsets.h>
> +#include <asm/bootparam.h>
> +#include <asm/page_types.h>
> +#include <asm/irq_vectors.h>
> +#include <linux/slr_table.h>
> +#include <linux/slaunch.h>
> +
> +/* CPUID: leaf 1, ECX, SMX feature bit */
> +#define X86_FEATURE_BIT_SMX	(1 << 6)
> +
> +#define IDT_VECTOR_LO_BITS	0
> +#define IDT_VECTOR_HI_BITS	6
> +
> +/*
> + * See the comment in head_64.S for detailed information on what this macro
> + * and others like it are used for. The comment appears right at the top of
> + * the file.
> + */
> +#define rva(X) ((X) - sl_stub_entry)
> +
> +/*
> + * The GETSEC op code is open coded because older versions of
> + * GCC do not support the getsec mnemonic.
> + */
> +.macro GETSEC leaf
> +	pushl	%ebx
> +	xorl	%ebx, %ebx	/* Must be zero for SMCTRL */
> +	movl	\leaf, %eax	/* Leaf function */
> +	.byte 	0x0f, 0x37	/* GETSEC opcode */
> +	popl	%ebx
> +.endm
> +
> +.macro TXT_RESET error
> +	/*
> +	 * Set a sticky error value and reset. Note the movs to %eax act as
> +	 * TXT register barriers.
> +	 */
> +	movl	\error, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_ERRORCODE)
> +	movl	(TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_E2STS), %eax
> +	movl	$1, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_CMD_NO_SECRETS)
> +	movl	(TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_E2STS), %eax
> +	movl	$1, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_CMD_UNLOCK_MEM_CONFIG)
> +	movl	(TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_E2STS), %eax
> +	movl	$1, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_CMD_RESET)
> +1:
> +	hlt
> +	jmp	1b
> +.endm
> +
> +	.code32
> +SYM_FUNC_START(sl_stub_entry)
> +	cli
> +	cld
> +
> +	/*
> +	 * On entry, %ebx has the entry abs offset to sl_stub_entry. This
> +	 * will be correctly scaled using the rva macro and avoid causing
> +	 * relocations. Only %cs and %ds segments are known good.
> +	 */
> +
> +	/* Load GDT, set segment regs and lret to __SL32_CS */
> +	leal	rva(sl_gdt_desc)(%ebx), %eax
> +	addl	%eax, 2(%eax)
> +	lgdt	(%eax)
> +
> +	movl	$(__SL32_DS), %eax
> +	movw	%ax, %ds
> +	movw	%ax, %es
> +	movw	%ax, %fs
> +	movw	%ax, %gs
> +	movw	%ax, %ss
> +
> +	/*
> +	 * Now that %ss is known good, take the first stack for the BSP. The
> +	 * AP stacks are only used on Intel.
> +	 */
> +	leal	rva(sl_stacks_end)(%ebx), %esp
> +
> +	leal	rva(.Lsl_cs)(%ebx), %eax
> +	pushl	$(__SL32_CS)
> +	pushl	%eax
> +	lret
> +
> +.Lsl_cs:
> +	/* Save our base pointer reg and page table for MLE */
> +	pushl	%ebx
> +	pushl	%ecx
> +
> +	/* See if SMX feature is supported. */
> +	movl	$1, %eax
> +	cpuid
> +	testl	$(X86_FEATURE_BIT_SMX), %ecx
> +	jz	.Ldo_unknown_cpu
> +
> +	popl	%ecx
> +	popl	%ebx
> +
> +	/* Know it is Intel */
> +	movl	$(SL_CPU_INTEL), rva(sl_cpu_type)(%ebx)
> +
> +	/* Locate the base of the MLE using the page tables in %ecx */
> +	call	sl_find_mle_base
> +
> +	/* Increment CPU count for BSP */
> +	incl	rva(sl_txt_cpu_count)(%ebx)
> +
> +	/*
> +	 * Enable SMI with GETSEC[SMCTRL] which were disabled by SENTER.
> +	 * NMIs were also disabled by SENTER. Since there is no IDT for the BSP,
> +	 * allow the mainline kernel re-enable them in the normal course of
> +	 * booting.
> +	 */
> +	GETSEC	$(SMX_X86_GETSEC_SMCTRL)
> +
> +	/* Clear the TXT error registers for a clean start of day */
> +	movl	$0, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_ERRORCODE)
> +	movl	$0xffffffff, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_ESTS)
> +
> +	/* On Intel, the zero page address is passed in the TXT heap */
> +	/* Read physical base of heap into EAX */
> +	movl	(TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_HEAP_BASE), %eax
> +	/* Read the size of the BIOS data into ECX (first 8 bytes) */
> +	movl	(%eax), %ecx
> +	/* Skip over BIOS data and size of OS to MLE data section */
> +	leal	8(%eax, %ecx), %eax
> +
> +	/* Need to verify the values in the OS-MLE struct passed in */
> +	call	sl_txt_verify_os_mle_struct
> +
> +	/*
> +	 * Get the boot params address from the heap. Note %esi and %ebx MUST
> +	 * be preserved across calls and operations.
> +	 */
> +	movl	SL_boot_params_addr(%eax), %esi
> +
> +	/* Save %ebx so the APs can find their way home */
> +	movl	%ebx, (SL_mle_scratch + SL_SCRATCH_AP_EBX)(%eax)
> +
> +	/* Fetch the AP wake code block address from the heap */
> +	movl	SL_ap_wake_block(%eax), %edi
> +	movl	%edi, rva(sl_txt_ap_wake_block)(%ebx)
> +
> +	/* Store the offset in the AP wake block to the jmp address */
> +	movl	$(sl_ap_jmp_offset - sl_txt_ap_wake_begin), \
> +		(SL_mle_scratch + SL_SCRATCH_AP_JMP_OFFSET)(%eax)
> +
> +	/* Store the offset in the AP wake block to the AP stacks block */
> +	movl	$(sl_stacks - sl_txt_ap_wake_begin), \
> +		(SL_mle_scratch + SL_SCRATCH_AP_STACKS_OFFSET)(%eax)
> +
> +	/* %eax still is the base of the OS-MLE block, save it */
> +	pushl	%eax
> +
> +	/* Relocate the AP wake code to the safe block */
> +	call	sl_txt_reloc_ap_wake
> +
> +	/*
> +	 * Wake up all APs that are blocked in the ACM and wait for them to
> +	 * halt. This should be done before restoring the MTRRs so the ACM is
> +	 * still properly in WB memory.
> +	 */
> +	call	sl_txt_wake_aps
> +
> +	/* Restore OS-MLE in %eax */
> +	popl	%eax
> +
> +	/*
> +	 * %edi is used by this routine to find the MTRRs which are in the SLRT
> +	 * in the Intel info.
> +	 */
> +	movl	SL_txt_info(%eax), %edi
> +	call	sl_txt_load_regs
> +
> +	jmp	.Lcpu_setup_done
> +
> +.Ldo_unknown_cpu:
> +	/* Non-Intel CPUs are not yet supported */
> +	ud2
> +
> +.Lcpu_setup_done:
> +	/*
> +	 * Don't enable MCE at this point. The kernel will enable
> +	 * it on the BSP later when it is ready.
> +	 */
> +
> +	/* Done, jump to normal 32b pm entry */
> +	jmp	startup_32
> +SYM_FUNC_END(sl_stub_entry)
> +
> +SYM_FUNC_START(sl_find_mle_base)
> +	/* %ecx has PDPT, get first PD */
> +	movl	(%ecx), %eax
> +	andl	$(PAGE_MASK), %eax
> +	/* Get first PT from first PDE */
> +	movl	(%eax), %eax
> +	andl	$(PAGE_MASK), %eax
> +	/* Get MLE base from first PTE */
> +	movl	(%eax), %eax
> +	andl	$(PAGE_MASK), %eax
> +
> +	movl	%eax, rva(sl_mle_start)(%ebx)
> +	ret
> +SYM_FUNC_END(sl_find_mle_base)
> +
> +SYM_FUNC_START(sl_check_buffer_mle_overlap)
> +	/* %ecx: buffer begin %edx: buffer end */
> +	/* %ebx: MLE begin %edi: MLE end */
> +	/* %eax: region may be inside MLE */
> +
> +	cmpl	%edi, %ecx
> +	jb	.Lnext_check
> +	cmpl	%edi, %edx
> +	jbe	.Lnext_check
> +	jmp	.Lvalid /* Buffer above MLE */
> +
> +.Lnext_check:
> +	cmpl	%ebx, %edx
> +	ja	.Linside_check
> +	cmpl	%ebx, %ecx
> +	jae	.Linside_check
> +	jmp	.Lvalid /* Buffer below MLE */
> +
> +.Linside_check:
> +	cmpl	$0, %eax
> +	jz	.Linvalid
> +	cmpl	%ebx, %ecx
> +	jb	.Linvalid
> +	cmpl	%edi, %edx
> +	ja	.Linvalid
> +	jmp	.Lvalid /* Buffer in MLE */
> +
> +.Linvalid:
> +	TXT_RESET $(SL_ERROR_MLE_BUFFER_OVERLAP)
> +
> +.Lvalid:
> +	ret
> +SYM_FUNC_END(sl_check_buffer_mle_overlap)
> +
> +SYM_FUNC_START(sl_txt_verify_os_mle_struct)
> +	pushl	%ebx
> +	/*
> +	 * %eax points to the base of the OS-MLE struct. Need to also
> +	 * read some values from the OS-SINIT struct too.
> +	 */
> +	movl	-8(%eax), %ecx
> +	/* Skip over OS to MLE data section and size of OS-SINIT structure */
> +	leal	(%eax, %ecx), %edx
> +
> +	/* Load MLE image base absolute offset */
> +	movl	rva(sl_mle_start)(%ebx), %ebx
> +
> +	/* Verify the value of the low PMR base. It should always be 0. */
> +	movl	SL_vtd_pmr_lo_base(%edx), %esi
> +	cmpl	$0, %esi
> +	jz	.Lvalid_pmr_base
> +	TXT_RESET $(SL_ERROR_LO_PMR_BASE)
> +
> +.Lvalid_pmr_base:
> +	/* Grab some values from OS-SINIT structure */
> +	movl	SL_mle_size(%edx), %edi
> +	addl	%ebx, %edi
> +	jc	.Loverflow_detected
> +	movl	SL_vtd_pmr_lo_size(%edx), %esi
> +
> +	/* Check the AP wake block */
> +	movl	SL_ap_wake_block(%eax), %ecx
> +	movl	SL_ap_wake_block_size(%eax), %edx
> +	addl	%ecx, %edx
> +	jc	.Loverflow_detected
> +	pushl	%eax
> +	xorl	%eax, %eax
> +	call	sl_check_buffer_mle_overlap
> +	popl	%eax
> +	cmpl	%esi, %edx
> +	ja	.Lbuffer_beyond_pmr
> +
> +	/*
> +	 * Check the boot params. Note during a UEFI boot, the boot
> +	 * params will be inside the MLE image. Test for this case
> +	 * in the overlap case.
> +	 */
> +	movl	SL_boot_params_addr(%eax), %ecx
> +	movl	$(PAGE_SIZE), %edx
> +	addl	%ecx, %edx
> +	jc	.Loverflow_detected
> +	pushl	%eax
> +	movl	$1, %eax
> +	call	sl_check_buffer_mle_overlap
> +	popl	%eax
> +	cmpl	%esi, %edx
> +	ja	.Lbuffer_beyond_pmr
> +
> +	/* Check that the AP wake block is big enough */
> +	cmpl	$(sl_txt_ap_wake_end - sl_txt_ap_wake_begin), \
> +		SL_ap_wake_block_size(%eax)
> +	jae	.Lwake_block_ok
> +	TXT_RESET $(SL_ERROR_WAKE_BLOCK_TOO_SMALL)
> +
> +.Lwake_block_ok:
> +	popl	%ebx
> +	ret
> +
> +.Loverflow_detected:
> +	TXT_RESET $(SL_ERROR_INTEGER_OVERFLOW)
> +
> +.Lbuffer_beyond_pmr:
> +	TXT_RESET $(SL_ERROR_BUFFER_BEYOND_PMR)
> +SYM_FUNC_END(sl_txt_verify_os_mle_struct)
> +
> +SYM_FUNC_START(sl_txt_ap_entry)
> +	cli
> +	cld
> +	/*
> +	 * The %cs and %ds segments are known good after waking the AP.
> +	 * First order of business is to find where we are and
> +	 * save it in %ebx.
> +	 */
> +
> +	/* Read physical base of heap into EAX */
> +	movl	(TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_HEAP_BASE), %eax
> +	/* Read the size of the BIOS data into ECX (first 8 bytes) */
> +	movl	(%eax), %ecx
> +	/* Skip over BIOS data and size of OS to MLE data section */
> +	leal	8(%eax, %ecx), %eax
> +
> +	/* Saved %ebx from the BSP and stash OS-MLE pointer */
> +	movl	(SL_mle_scratch + SL_SCRATCH_AP_EBX)(%eax), %ebx
> +
> +	/* Save TXT info ptr in %edi for call to sl_txt_load_regs */
> +	movl	SL_txt_info(%eax), %edi
> +
> +	/* Lock and get our stack index */
> +	movl	$1, %ecx
> +.Lspin:
> +	xorl	%eax, %eax
> +	lock cmpxchgl	%ecx, rva(sl_txt_spin_lock)(%ebx)
> +	pause
> +	jnz	.Lspin
> +
> +	/* Increment the stack index and use the next value inside lock */
> +	incl	rva(sl_txt_stack_index)(%ebx)
> +	movl	rva(sl_txt_stack_index)(%ebx), %eax
> +
> +	/* Unlock */
> +	movl	$0, rva(sl_txt_spin_lock)(%ebx)
> +
> +	/* Location of the relocated AP wake block */
> +	movl	rva(sl_txt_ap_wake_block)(%ebx), %ecx
> +
> +	/* Load reloc GDT, set segment regs and lret to __SL32_CS */
> +	lgdt	(sl_ap_gdt_desc - sl_txt_ap_wake_begin)(%ecx)
> +
> +	movl	$(__SL32_DS), %edx
> +	movw	%dx, %ds
> +	movw	%dx, %es
> +	movw	%dx, %fs
> +	movw	%dx, %gs
> +	movw	%dx, %ss
> +
> +	/* Load our reloc AP stack */
> +	movl	$(TXT_BOOT_STACK_SIZE), %edx
> +	mull	%edx
> +	leal	(sl_stacks_end - sl_txt_ap_wake_begin)(%ecx), %esp
> +	subl	%eax, %esp
> +
> +	/* Switch to AP code segment */
> +	leal	rva(.Lsl_ap_cs)(%ebx), %eax
> +	pushl	$(__SL32_CS)
> +	pushl	%eax
> +	lret
> +
> +.Lsl_ap_cs:
> +	/* Load the relocated AP IDT */
> +	lidt	(sl_ap_idt_desc - sl_txt_ap_wake_begin)(%ecx)
> +
> +	/* Fixup MTRRs and misc enable MSR on APs too */
> +	call	sl_txt_load_regs
> +
> +	/* Enable SMI with GETSEC[SMCTRL] */
> +	GETSEC $(SMX_X86_GETSEC_SMCTRL)
> +
> +	/* IRET-to-self can be used to enable NMIs which SENTER disabled */
> +	leal	rva(.Lnmi_enabled_ap)(%ebx), %eax
> +	pushfl
> +	pushl	$(__SL32_CS)
> +	pushl	%eax
> +	iret
> +
> +.Lnmi_enabled_ap:
> +	/* Put APs in X2APIC mode like the BSP */
> +	movl	$(MSR_IA32_APICBASE), %ecx
> +	rdmsr
> +	orl	$(XAPIC_ENABLE | X2APIC_ENABLE), %eax
> +	wrmsr
> +
> +	/*
> +	 * Basically done, increment the CPU count and jump off to the AP
> +	 * wake block to wait.
> +	 */
> +	lock incl	rva(sl_txt_cpu_count)(%ebx)
> +
> +	movl	rva(sl_txt_ap_wake_block)(%ebx), %eax
> +	jmp	*%eax
> +SYM_FUNC_END(sl_txt_ap_entry)
> +
> +SYM_FUNC_START(sl_txt_reloc_ap_wake)
> +	/* Save boot params register */
> +	pushl	%esi
> +
> +	movl	rva(sl_txt_ap_wake_block)(%ebx), %edi
> +
> +	/* Fixup AP IDT and GDT descriptor before relocating */
> +	leal	rva(sl_ap_idt_desc)(%ebx), %eax
> +	addl	%edi, 2(%eax)
> +	leal	rva(sl_ap_gdt_desc)(%ebx), %eax
> +	addl	%edi, 2(%eax)
> +
> +	/*
> +	 * Copy the AP wake code and AP GDT/IDT to the protected wake block
> +	 * provided by the loader. Destination already in %edi.
> +	 */
> +	movl	$(sl_txt_ap_wake_end - sl_txt_ap_wake_begin), %ecx
> +	leal	rva(sl_txt_ap_wake_begin)(%ebx), %esi
> +	rep movsb
> +
> +	/* Setup the IDT for the APs to use in the relocation block */
> +	movl	rva(sl_txt_ap_wake_block)(%ebx), %ecx
> +	addl	$(sl_ap_idt - sl_txt_ap_wake_begin), %ecx
> +	xorl	%edx, %edx
> +
> +	/* Form the default reset vector relocation address */
> +	movl	rva(sl_txt_ap_wake_block)(%ebx), %esi
> +	addl	$(sl_txt_int_reset - sl_txt_ap_wake_begin), %esi
> +
> +1:
> +	cmpw	$(NR_VECTORS), %dx
> +	jz	.Lap_idt_done
> +
> +	cmpw	$(X86_TRAP_NMI), %dx
> +	jz	2f
> +
> +	/* Load all other fixed vectors with reset handler */
> +	movl	%esi, %eax
> +	movw	%ax, (IDT_VECTOR_LO_BITS)(%ecx)
> +	shrl	$16, %eax
> +	movw	%ax, (IDT_VECTOR_HI_BITS)(%ecx)
> +	jmp	3f
> +
> +2:
> +	/* Load single wake NMI IPI vector at the relocation address */
> +	movl	rva(sl_txt_ap_wake_block)(%ebx), %eax
> +	addl	$(sl_txt_int_nmi - sl_txt_ap_wake_begin), %eax
> +	movw	%ax, (IDT_VECTOR_LO_BITS)(%ecx)
> +	shrl	$16, %eax
> +	movw	%ax, (IDT_VECTOR_HI_BITS)(%ecx)
> +
> +3:
> +	incw	%dx
> +	addl	$8, %ecx
> +	jmp	1b
> +
> +.Lap_idt_done:
> +	popl	%esi
> +	ret
> +SYM_FUNC_END(sl_txt_reloc_ap_wake)
> +
> +SYM_FUNC_START(sl_txt_load_regs)
> +	/* Save base pointer register */
> +	pushl	%ebx
> +
> +	/*
> +	 * On Intel, the original variable MTRRs and Misc Enable MSR are
> +	 * restored on the BSP at early boot. Each AP will also restore
> +	 * its MTRRs and Misc Enable MSR.
> +	 */
> +	pushl	%edi
> +	addl	$(SL_saved_bsp_mtrrs), %edi
> +	movl	(%edi), %ebx
> +	pushl	%ebx /* default_mem_type lo */
> +	addl	$4, %edi
> +	movl	(%edi), %ebx
> +	pushl	%ebx /* default_mem_type hi */
> +	addl	$4, %edi
> +	movl	(%edi), %ebx /* mtrr_vcnt lo, don't care about hi part */
> +	addl	$8, %edi /* now at MTRR pair array */
> +	/* Write the variable MTRRs */
> +	movl	$(MSR_MTRRphysBase0), %ecx
> +1:
> +	cmpl	$0, %ebx
> +	jz	2f
> +
> +	movl	(%edi), %eax /* MTRRphysBaseX lo */
> +	addl	$4, %edi
> +	movl	(%edi), %edx /* MTRRphysBaseX hi */
> +	wrmsr
> +	addl	$4, %edi
> +	incl	%ecx
> +	movl	(%edi), %eax /* MTRRphysMaskX lo */
> +	addl	$4, %edi
> +	movl	(%edi), %edx /* MTRRphysMaskX hi */
> +	wrmsr
> +	addl	$4, %edi
> +	incl	%ecx
> +
> +	decl	%ebx
> +	jmp	1b
> +2:
> +	/* Write the default MTRR register */
> +	popl	%edx
> +	popl	%eax
> +	movl	$(MSR_MTRRdefType), %ecx
> +	wrmsr
> +
> +	/* Return to beginning and write the misc enable msr */
> +	popl	%edi
> +	addl	$(SL_saved_misc_enable_msr), %edi
> +	movl	(%edi), %eax /* saved_misc_enable_msr lo */
> +	addl	$4, %edi
> +	movl	(%edi), %edx /* saved_misc_enable_msr hi */
> +	movl	$(MSR_IA32_MISC_ENABLE), %ecx
> +	wrmsr
> +
> +	popl	%ebx
> +	ret
> +SYM_FUNC_END(sl_txt_load_regs)
> +
> +SYM_FUNC_START(sl_txt_wake_aps)
> +	/* Save boot params register */
> +	pushl	%esi
> +
> +	/* First setup the MLE join structure and load it into TXT reg */
> +	leal	rva(sl_gdt)(%ebx), %eax
> +	leal	rva(sl_txt_ap_entry)(%ebx), %ecx
> +	leal	rva(sl_smx_rlp_mle_join)(%ebx), %edx
> +	movl	%eax, SL_rlp_gdt_base(%edx)
> +	movl	%ecx, SL_rlp_entry_point(%edx)
> +	movl	%edx, (TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_MLE_JOIN)
> +
> +	/* Another TXT heap walk to find various values needed to wake APs */
> +	movl	(TXT_PRIV_CONFIG_REGS_BASE + TXT_CR_HEAP_BASE), %eax
> +	/* At BIOS data size, find the number of logical processors */
> +	movl	(SL_num_logical_procs + 8)(%eax), %edx
> +	/* Skip over BIOS data */
> +	movl	(%eax), %ecx
> +	addl	%ecx, %eax
> +	/* Skip over OS to MLE */
> +	movl	(%eax), %ecx
> +	addl	%ecx, %eax
> +	/* At OS-SNIT size, get capabilities to know how to wake up the APs */
> +	movl	(SL_capabilities + 8)(%eax), %esi
> +	/* Skip over OS to SNIT */
> +	movl	(%eax), %ecx
> +	addl	%ecx, %eax
> +	/* At SINIT-MLE size, get the AP wake MONITOR address */
> +	movl	(SL_rlp_wakeup_addr + 8)(%eax), %edi
> +
> +	/* Determine how to wake up the APs */
> +	testl	$(1 << TXT_SINIT_MLE_CAP_WAKE_MONITOR), %esi
> +	jz	.Lwake_getsec
> +
> +	/* Wake using MWAIT MONITOR */
> +	movl	$1, (%edi)
> +	jmp	.Laps_awake
> +
> +.Lwake_getsec:
> +	/* Wake using GETSEC(WAKEUP) */
> +	GETSEC	$(SMX_X86_GETSEC_WAKEUP)
> +
> +.Laps_awake:
> +	/*
> +	 * All of the APs are woken up and rendesvous in the relocated wake
> +	 * block starting at sl_txt_ap_wake_begin. Wait for all of them to
> +	 * halt.
> +	 */
> +	pause
> +	cmpl	rva(sl_txt_cpu_count)(%ebx), %edx
> +	jne	.Laps_awake
> +
> +	popl	%esi
> +	ret
> +SYM_FUNC_END(sl_txt_wake_aps)
> +
> +/* This is the beginning of the relocated AP wake code block */
> +	.global sl_txt_ap_wake_begin
> +sl_txt_ap_wake_begin:
> +
> +	/* Get the LAPIC ID for each AP and stash it on the stack */
> +	movl	$(MSR_IA32_X2APIC_APICID), %ecx
> +	rdmsr
> +	pushl	%eax
> +
> +	/*
> +	 * Get a pointer to the monitor location on this APs stack to test below
> +	 * after mwait returns. Currently %esp points to just past the pushed APIC
> +	 * ID value.
> +	 */
> +	movl	%esp, %eax
> +	subl	$(TXT_BOOT_STACK_SIZE - 4), %eax
> +	movl	$0, (%eax)
> +
> +	/* Clear ecx/edx so no invalid extensions or hints are passed to monitor */
> +	xorl	%ecx, %ecx
> +	xorl	%edx, %edx
> +
> +	/*
> +	 * Arm the monitor and wait for it to be poked by he SMP bringup code. The mwait
> +	 * instruction can return for a number of reasons. Test to see if it returned
> +	 * because the monitor was written to.
> +	 */
> +	monitor
> +
> +1:
> +	mfence
> +	mwait
> +	movl	(%eax), %edx
> +	testl	%edx, %edx
> +	jz	1b
> +
> +	/*
> +	 * This is the long absolute jump to the 32b Secure Launch protected mode stub
> +	 * code in sl_trampoline_start32() in the rmpiggy. The jump address will be
> +	 * fixed in the SMP boot code when the first AP is brought up. This whole area
> +	 * is provided and protected in the memory map by the prelaunch code.
> +	 */
> +	.byte	0xea
> +sl_ap_jmp_offset:
> +	.long	0x00000000
> +	.word	__SL32_CS
> +
> +SYM_FUNC_START(sl_txt_int_nmi)
> +	/* NMI context, just IRET */
> +	iret
> +SYM_FUNC_END(sl_txt_int_nmi)
> +
> +SYM_FUNC_START(sl_txt_int_reset)
> +	TXT_RESET $(SL_ERROR_INV_AP_INTERRUPT)
> +SYM_FUNC_END(sl_txt_int_reset)
> +
> +	.balign 8
> +SYM_DATA_START_LOCAL(sl_ap_idt_desc)
> +	.word	sl_ap_idt_end - sl_ap_idt - 1		/* Limit */
> +	.long	sl_ap_idt - sl_txt_ap_wake_begin	/* Base */
> +SYM_DATA_END_LABEL(sl_ap_idt_desc, SYM_L_LOCAL, sl_ap_idt_desc_end)
> +
> +	.balign 8
> +SYM_DATA_START_LOCAL(sl_ap_idt)
> +	.rept	NR_VECTORS
> +	.word	0x0000		/* Offset 15 to 0 */
> +	.word	__SL32_CS	/* Segment selector */
> +	.word	0x8e00		/* Present, DPL=0, 32b Vector, Interrupt */
> +	.word	0x0000		/* Offset 31 to 16 */
> +	.endr
> +SYM_DATA_END_LABEL(sl_ap_idt, SYM_L_LOCAL, sl_ap_idt_end)
> +
> +	.balign 8
> +SYM_DATA_START_LOCAL(sl_ap_gdt_desc)
> +	.word	sl_ap_gdt_end - sl_ap_gdt - 1
> +	.long	sl_ap_gdt - sl_txt_ap_wake_begin
> +SYM_DATA_END_LABEL(sl_ap_gdt_desc, SYM_L_LOCAL, sl_ap_gdt_desc_end)
> +
> +	.balign	8
> +SYM_DATA_START_LOCAL(sl_ap_gdt)
> +	.quad	0x0000000000000000	/* NULL */
> +	.quad	0x00cf9a000000ffff	/* __SL32_CS */
> +	.quad	0x00cf92000000ffff	/* __SL32_DS */
> +SYM_DATA_END_LABEL(sl_ap_gdt, SYM_L_LOCAL, sl_ap_gdt_end)
> +
> +	/* Small stacks for BSP and APs to work with */
> +	.balign 64
> +SYM_DATA_START_LOCAL(sl_stacks)
> +	.fill (TXT_MAX_CPUS * TXT_BOOT_STACK_SIZE), 1, 0
> +SYM_DATA_END_LABEL(sl_stacks, SYM_L_LOCAL, sl_stacks_end)
> +
> +/* This is the end of the relocated AP wake code block */
> +	.global sl_txt_ap_wake_end
> +sl_txt_ap_wake_end:
> +
> +	.data
> +	.balign 8
> +SYM_DATA_START_LOCAL(sl_gdt_desc)
> +	.word	sl_gdt_end - sl_gdt - 1
> +	.long	sl_gdt - sl_gdt_desc
> +SYM_DATA_END_LABEL(sl_gdt_desc, SYM_L_LOCAL, sl_gdt_desc_end)
> +
> +	.balign	8
> +SYM_DATA_START_LOCAL(sl_gdt)
> +	.quad	0x0000000000000000	/* NULL */
> +	.quad	0x00cf9a000000ffff	/* __SL32_CS */
> +	.quad	0x00cf92000000ffff	/* __SL32_DS */
> +SYM_DATA_END_LABEL(sl_gdt, SYM_L_LOCAL, sl_gdt_end)
> +
> +	.balign 8
> +SYM_DATA_START_LOCAL(sl_smx_rlp_mle_join)
> +	.long	sl_gdt_end - sl_gdt - 1	/* GDT limit */
> +	.long	0x00000000		/* GDT base */
> +	.long	__SL32_CS	/* Seg Sel - CS (DS, ES, SS = seg_sel+8) */
> +	.long	0x00000000	/* Entry point physical address */
> +SYM_DATA_END(sl_smx_rlp_mle_join)
> +
> +SYM_DATA(sl_cpu_type, .long 0x00000000)
> +
> +SYM_DATA(sl_mle_start, .long 0x00000000)
> +
> +SYM_DATA_LOCAL(sl_txt_spin_lock, .long 0x00000000)
> +
> +SYM_DATA_LOCAL(sl_txt_stack_index, .long 0x00000000)
> +
> +SYM_DATA_LOCAL(sl_txt_cpu_count, .long 0x00000000)
> +
> +SYM_DATA_LOCAL(sl_txt_ap_wake_block, .long 0x00000000)
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
> index e022e6eb766c..37f6167f28ba 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -348,6 +348,9 @@
>  #define MSR_IA32_RTIT_OUTPUT_BASE	0x00000560
>  #define MSR_IA32_RTIT_OUTPUT_MASK	0x00000561
>  
> +#define MSR_MTRRphysBase0		0x00000200
> +#define MSR_MTRRphysMask0		0x00000201
> +
>  #define MSR_MTRRfix64K_00000		0x00000250
>  #define MSR_MTRRfix16K_80000		0x00000258
>  #define MSR_MTRRfix16K_A0000		0x00000259
> @@ -849,6 +852,8 @@
>  #define MSR_IA32_APICBASE_ENABLE	(1<<11)
>  #define MSR_IA32_APICBASE_BASE		(0xfffff<<12)
>  
> +#define MSR_IA32_X2APIC_APICID		0x00000802
> +
>  #define MSR_IA32_UCODE_WRITE		0x00000079
>  #define MSR_IA32_UCODE_REV		0x0000008b
>  

MSR updates are better to be split to their own patch.

> diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
> index 9b82eebd7add..7ce283a22d6b 100644
> --- a/arch/x86/include/uapi/asm/bootparam.h
> +++ b/arch/x86/include/uapi/asm/bootparam.h
> @@ -12,6 +12,7 @@
>  /* loadflags */
>  #define LOADED_HIGH	(1<<0)
>  #define KASLR_FLAG	(1<<1)
> +#define SLAUNCH_FLAG	(1<<2)
>  #define QUIET_FLAG	(1<<5)
>  #define KEEP_SEGMENTS	(1<<6)
>  #define CAN_USE_HEAP	(1<<7)
> diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
> index a98020bf31bb..925adce6e2c7 100644
> --- a/arch/x86/kernel/asm-offsets.c
> +++ b/arch/x86/kernel/asm-offsets.c
> @@ -13,6 +13,8 @@
>  #include <linux/hardirq.h>
>  #include <linux/suspend.h>
>  #include <linux/kbuild.h>
> +#include <linux/slr_table.h>
> +#include <linux/slaunch.h>
>  #include <asm/processor.h>
>  #include <asm/thread_info.h>
>  #include <asm/sigframe.h>
> @@ -120,4 +122,22 @@ static void __used common(void)
>  	OFFSET(ARIA_CTX_rounds, aria_ctx, rounds);
>  #endif
>  
> +#ifdef CONFIG_SECURE_LAUNCH
> +	BLANK();
> +	OFFSET(SL_txt_info, txt_os_mle_data, txt_info);
> +	OFFSET(SL_mle_scratch, txt_os_mle_data, mle_scratch);
> +	OFFSET(SL_boot_params_addr, txt_os_mle_data, boot_params_addr);
> +	OFFSET(SL_ap_wake_block, txt_os_mle_data, ap_wake_block);
> +	OFFSET(SL_ap_wake_block_size, txt_os_mle_data, ap_wake_block_size);
> +	OFFSET(SL_saved_misc_enable_msr, slr_entry_intel_info, saved_misc_enable_msr);
> +	OFFSET(SL_saved_bsp_mtrrs, slr_entry_intel_info, saved_bsp_mtrrs);
> +	OFFSET(SL_num_logical_procs, txt_bios_data, num_logical_procs);
> +	OFFSET(SL_capabilities, txt_os_sinit_data, capabilities);
> +	OFFSET(SL_mle_size, txt_os_sinit_data, mle_size);
> +	OFFSET(SL_vtd_pmr_lo_base, txt_os_sinit_data, vtd_pmr_lo_base);
> +	OFFSET(SL_vtd_pmr_lo_size, txt_os_sinit_data, vtd_pmr_lo_size);
> +	OFFSET(SL_rlp_wakeup_addr, txt_sinit_mle_data, rlp_wakeup_addr);
> +	OFFSET(SL_rlp_gdt_base, smx_rlp_mle_join, rlp_gdt_base);
> +	OFFSET(SL_rlp_entry_point, smx_rlp_mle_join, rlp_entry_point);
> +#endif
>  }

BR, Jarkko





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