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/* SPDX-License-Identifier: GPL-2.0-only */
#include <console/console.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/mtrr.h>
#include <cpu/intel/microcode.h>
#include <cpu/intel/common/common.h>
#include <intelblocks/cpulib.h>
#include <intelblocks/msr.h>
#include <intelblocks/sgx.h>
#include <intelblocks/systemagent.h>
#include <soc/cpu.h>
#include <soc/pci_devs.h>
int is_sgx_supported(void)
{
struct cpuid_result cpuid_regs;
msr_t msr;
cpuid_regs = cpuid_ext(0x7, 0x0); /* EBX[2] is feature capability */
msr = rdmsr(MTRR_CAP_MSR); /* Bit 12 is PRMRR enablement */
return ((cpuid_regs.ebx & SGX_SUPPORTED) && (msr.lo & MTRR_CAP_PRMRR));
}
void prmrr_core_configure(void)
{
union {
uint64_t data64;
struct {
uint32_t lo;
uint32_t hi;
} data32;
} prmrr_base, prmrr_mask;
msr_t msr;
/*
* Software Developer's Manual Volume 4:
* Order Number: 335592-068US
* Chapter 2.16.1
* MSR_PRMRR_PHYS_MASK is in scope "Core"
* MSR_PRMRR_PHYS_BASE is in scope "Core"
* Return if Hyper-Threading is enabled and not thread 0
*/
if (!is_sgx_supported() || intel_ht_sibling())
return;
/* PRMRR_PHYS_MASK is in scope "Core" */
msr = rdmsr(MSR_PRMRR_PHYS_MASK);
/* If it is locked don't attempt to write PRMRR MSRs. */
if (msr.lo & PRMRR_PHYS_MASK_LOCK)
return;
/* PRMRR base and mask are read from the UNCORE PRMRR MSRs
* that are already set in FSP-M. */
if (soc_get_uncore_prmmr_base_and_mask(&prmrr_base.data64,
&prmrr_mask.data64) < 0) {
printk(BIOS_ERR, "SGX: Failed to get PRMRR base and mask\n");
return;
}
if (!prmrr_base.data32.lo) {
printk(BIOS_ERR, "SGX Error: Uncore PRMRR is not set!\n");
return;
}
printk(BIOS_INFO, "SGX: prmrr_base = 0x%llx\n", prmrr_base.data64);
printk(BIOS_INFO, "SGX: prmrr_mask = 0x%llx\n", prmrr_mask.data64);
/* Program core PRMRR MSRs.
* - Set cache writeback mem attrib in PRMRR base MSR
* - Clear the valid bit in PRMRR mask MSR
* - Lock PRMRR MASK MSR */
prmrr_base.data32.lo |= MTRR_TYPE_WRBACK;
wrmsr(MSR_PRMRR_PHYS_BASE, (msr_t) {.lo = prmrr_base.data32.lo,
.hi = prmrr_base.data32.hi});
prmrr_mask.data32.lo &= ~PRMRR_PHYS_MASK_VALID;
prmrr_mask.data32.lo |= PRMRR_PHYS_MASK_LOCK;
wrmsr(MSR_PRMRR_PHYS_MASK, (msr_t) {.lo = prmrr_mask.data32.lo,
.hi = prmrr_mask.data32.hi});
}
static int is_prmrr_set(void)
{
msr_t prmrr_base, prmrr_mask;
prmrr_base = rdmsr(MSR_PRMRR_PHYS_BASE);
prmrr_mask = rdmsr(MSR_PRMRR_PHYS_MASK);
/* If PRMRR base is zero and PRMRR mask is locked
* then PRMRR is not set */
if ((prmrr_base.hi == 0) && (prmrr_base.lo == 0)
&& (prmrr_mask.lo & PRMRR_PHYS_MASK_LOCK))
return 0;
return 1;
}
static void enable_sgx(void)
{
msr_t msr;
/*
* Intel 64 and IA-32 ArchitecturesSoftware Developer's ManualVolume 3C
* Order Number: 326019-060US
* Chapter 35.10.2 "Additional MSRs Supported by Intel"
* IA32_FEATURE_CONTROL is in scope "Thread"
*/
msr = rdmsr(IA32_FEATURE_CONTROL);
/* Only enable it when it is not locked */
if ((msr.lo & FEATURE_CONTROL_LOCK_BIT) == 0) {
msr.lo |= SGX_GLOBAL_ENABLE; /* Enable it */
wrmsr(IA32_FEATURE_CONTROL, msr);
}
}
static void lock_sgx(void)
{
msr_t msr;
/*
* Intel 64 and IA-32 ArchitecturesSoftware Developer's ManualVolume 3C
* Order Number: 326019-060US
* Chapter 35.10.2 "Additional MSRs Supported by Intel"
* IA32_FEATURE_CONTROL is in scope "Thread"
*/
msr = rdmsr(IA32_FEATURE_CONTROL);
/* If it is locked don't attempt to lock it again. */
if ((msr.lo & 1) == 0) {
msr.lo |= 1; /* Lock it */
wrmsr(IA32_FEATURE_CONTROL, msr);
}
}
static int owner_epoch_update(void)
{
/* TODO - the Owner Epoch update mechanism is not determined yet,
* for PoC just write '0's to the MSRs. */
msr_t msr = {0, 0};
/* SGX_OWNEREPOCH is in scope "Package" */
wrmsr(MSR_SGX_OWNEREPOCH0, msr);
wrmsr(MSR_SGX_OWNEREPOCH1, msr);
return 0;
}
static void activate_sgx(void)
{
msr_t msr;
/* Activate SGX feature by writing 1b to MSR 0x7A on all threads.
* BIOS must ensure bit 0 is set prior to writing to it, then read it
* back and verify the bit is cleared to confirm SGX activation. */
msr = rdmsr(MSR_BIOS_UPGD_TRIG);
if (msr.lo & SGX_ACTIVATE_BIT) {
wrmsr(MSR_BIOS_UPGD_TRIG,
(msr_t) {.lo = SGX_ACTIVATE_BIT, .hi = 0});
/* Read back to verify it is activated */
msr = rdmsr(MSR_BIOS_UPGD_TRIG);
if (msr.lo & SGX_ACTIVATE_BIT)
printk(BIOS_ERR, "SGX activation failed.\n");
else
printk(BIOS_INFO, "SGX activation was successful.\n");
} else {
printk(BIOS_ERR, "SGX feature is deactivated.\n");
}
}
static int is_prmrr_approved(void)
{
msr_t msr;
msr = rdmsr(MSR_PRMRR_PHYS_MASK);
if (msr.lo & PRMRR_PHYS_MASK_VALID) {
printk(BIOS_INFO, "SGX: MCHECK approved SGX PRMRR\n");
return 1;
}
printk(BIOS_INFO, "SGX: MCHECK did not approve SGX PRMRR\n");
return 0;
}
/*
* Configures SGX according to "Intel Software Guard Extensions Technology"
* Document Number: 565432
*/
void sgx_configure(void *unused)
{
if (!is_sgx_supported() || !is_prmrr_set()) {
printk(BIOS_ERR, "SGX: not supported or pre-conditions not met\n");
return;
}
/* Enable the SGX feature on all threads. */
enable_sgx();
/* Update the owner epoch value */
if (owner_epoch_update() < 0)
return;
/* Ensure to lock memory before reloading microcode patch */
if (CONFIG(SOC_INTEL_COMMON_BLOCK_SGX_LOCK_MEMORY))
cpu_lt_lock_memory();
/*
* Update just on the first CPU in the core. Other siblings
* get the update automatically according to Document: 253668-060US
* Intel SDM Chapter 9.11.6.3
* "Update in a System Supporting Intel Hyper-Threading Technology"
* Intel Hyper-Threading Technology has implications on the loading of the
* microcode update. The update must be loaded for each core in a physical
* processor. Thus, for a processor supporting Intel Hyper-Threading
* Technology, only one logical processor per core is required to load the
* microcode update. Each individual logical processor can independently
* load the update. However, MP initialization must provide some mechanism
* (e.g. a software semaphore) to force serialization of microcode update
* loads and to prevent simultaneous load attempts to the same core.
*/
if (!intel_ht_sibling()) {
const void *microcode_patch = intel_microcode_find();
intel_microcode_load_unlocked(microcode_patch);
}
/* Lock the SGX feature on all threads. */
lock_sgx();
/* Activate the SGX feature, if PRMRR config was approved by MCHECK */
if (is_prmrr_approved())
activate_sgx();
}
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