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Merge tag 'x86_urgent_for_v6.8_rc7' of git://git.kernel.org/pub/scm/l…
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…inux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Do not reserve SETUP_RNG_SEED setup data in the e820 map as it should
   be used by kexec only

 - Make sure MKTME feature detection happens at an earlier time in the
   boot process so that the physical address size supported by the CPU
   is properly corrected and MTRR masks are programmed properly, leading
   to TDX systems booting without disable_mtrr_cleanup on the cmdline

 - Make sure the different address sizes supported by the CPU are read
   out as early as possible

* tag 'x86_urgent_for_v6.8_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/e820: Don't reserve SETUP_RNG_SEED in e820
  x86/cpu/intel: Detect TME keyid bits before setting MTRR mask registers
  x86/cpu: Allow reducing x86_phys_bits during early_identify_cpu()
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Linus Torvalds committed Mar 3, 2024
2 parents 04b8076 + 7fd817c commit 73d35f8
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Showing 3 changed files with 98 additions and 92 deletions.
4 changes: 2 additions & 2 deletions arch/x86/kernel/cpu/common.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1589,6 +1589,7 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
get_cpu_vendor(c);
get_cpu_cap(c);
setup_force_cpu_cap(X86_FEATURE_CPUID);
get_cpu_address_sizes(c);
cpu_parse_early_param();

if (this_cpu->c_early_init)
Expand All @@ -1601,10 +1602,9 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
this_cpu->c_bsp_init(c);
} else {
setup_clear_cpu_cap(X86_FEATURE_CPUID);
get_cpu_address_sizes(c);
}

get_cpu_address_sizes(c);

setup_force_cpu_cap(X86_FEATURE_ALWAYS);

cpu_set_bug_bits(c);
Expand Down
178 changes: 91 additions & 87 deletions arch/x86/kernel/cpu/intel.c
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Original file line number Diff line number Diff line change
Expand Up @@ -184,6 +184,90 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
return false;
}

#define MSR_IA32_TME_ACTIVATE 0x982

/* Helpers to access TME_ACTIVATE MSR */
#define TME_ACTIVATE_LOCKED(x) (x & 0x1)
#define TME_ACTIVATE_ENABLED(x) (x & 0x2)

#define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */
#define TME_ACTIVATE_POLICY_AES_XTS_128 0

#define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */

#define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */
#define TME_ACTIVATE_CRYPTO_AES_XTS_128 1

/* Values for mktme_status (SW only construct) */
#define MKTME_ENABLED 0
#define MKTME_DISABLED 1
#define MKTME_UNINITIALIZED 2
static int mktme_status = MKTME_UNINITIALIZED;

static void detect_tme_early(struct cpuinfo_x86 *c)
{
u64 tme_activate, tme_policy, tme_crypto_algs;
int keyid_bits = 0, nr_keyids = 0;
static u64 tme_activate_cpu0 = 0;

rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);

if (mktme_status != MKTME_UNINITIALIZED) {
if (tme_activate != tme_activate_cpu0) {
/* Broken BIOS? */
pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
pr_err_once("x86/tme: MKTME is not usable\n");
mktme_status = MKTME_DISABLED;

/* Proceed. We may need to exclude bits from x86_phys_bits. */
}
} else {
tme_activate_cpu0 = tme_activate;
}

if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
pr_info_once("x86/tme: not enabled by BIOS\n");
mktme_status = MKTME_DISABLED;
return;
}

if (mktme_status != MKTME_UNINITIALIZED)
goto detect_keyid_bits;

pr_info("x86/tme: enabled by BIOS\n");

tme_policy = TME_ACTIVATE_POLICY(tme_activate);
if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);

tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
tme_crypto_algs);
mktme_status = MKTME_DISABLED;
}
detect_keyid_bits:
keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
nr_keyids = (1UL << keyid_bits) - 1;
if (nr_keyids) {
pr_info_once("x86/mktme: enabled by BIOS\n");
pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
} else {
pr_info_once("x86/mktme: disabled by BIOS\n");
}

if (mktme_status == MKTME_UNINITIALIZED) {
/* MKTME is usable */
mktme_status = MKTME_ENABLED;
}

/*
* KeyID bits effectively lower the number of physical address
* bits. Update cpuinfo_x86::x86_phys_bits accordingly.
*/
c->x86_phys_bits -= keyid_bits;
}

static void early_init_intel(struct cpuinfo_x86 *c)
{
u64 misc_enable;
Expand Down Expand Up @@ -322,6 +406,13 @@ static void early_init_intel(struct cpuinfo_x86 *c)
*/
if (detect_extended_topology_early(c) < 0)
detect_ht_early(c);

/*
* Adjust the number of physical bits early because it affects the
* valid bits of the MTRR mask registers.
*/
if (cpu_has(c, X86_FEATURE_TME))
detect_tme_early(c);
}

static void bsp_init_intel(struct cpuinfo_x86 *c)
Expand Down Expand Up @@ -482,90 +573,6 @@ static void srat_detect_node(struct cpuinfo_x86 *c)
#endif
}

#define MSR_IA32_TME_ACTIVATE 0x982

/* Helpers to access TME_ACTIVATE MSR */
#define TME_ACTIVATE_LOCKED(x) (x & 0x1)
#define TME_ACTIVATE_ENABLED(x) (x & 0x2)

#define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */
#define TME_ACTIVATE_POLICY_AES_XTS_128 0

#define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */

#define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */
#define TME_ACTIVATE_CRYPTO_AES_XTS_128 1

/* Values for mktme_status (SW only construct) */
#define MKTME_ENABLED 0
#define MKTME_DISABLED 1
#define MKTME_UNINITIALIZED 2
static int mktme_status = MKTME_UNINITIALIZED;

static void detect_tme(struct cpuinfo_x86 *c)
{
u64 tme_activate, tme_policy, tme_crypto_algs;
int keyid_bits = 0, nr_keyids = 0;
static u64 tme_activate_cpu0 = 0;

rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);

if (mktme_status != MKTME_UNINITIALIZED) {
if (tme_activate != tme_activate_cpu0) {
/* Broken BIOS? */
pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
pr_err_once("x86/tme: MKTME is not usable\n");
mktme_status = MKTME_DISABLED;

/* Proceed. We may need to exclude bits from x86_phys_bits. */
}
} else {
tme_activate_cpu0 = tme_activate;
}

if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
pr_info_once("x86/tme: not enabled by BIOS\n");
mktme_status = MKTME_DISABLED;
return;
}

if (mktme_status != MKTME_UNINITIALIZED)
goto detect_keyid_bits;

pr_info("x86/tme: enabled by BIOS\n");

tme_policy = TME_ACTIVATE_POLICY(tme_activate);
if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);

tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
tme_crypto_algs);
mktme_status = MKTME_DISABLED;
}
detect_keyid_bits:
keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
nr_keyids = (1UL << keyid_bits) - 1;
if (nr_keyids) {
pr_info_once("x86/mktme: enabled by BIOS\n");
pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
} else {
pr_info_once("x86/mktme: disabled by BIOS\n");
}

if (mktme_status == MKTME_UNINITIALIZED) {
/* MKTME is usable */
mktme_status = MKTME_ENABLED;
}

/*
* KeyID bits effectively lower the number of physical address
* bits. Update cpuinfo_x86::x86_phys_bits accordingly.
*/
c->x86_phys_bits -= keyid_bits;
}

static void init_cpuid_fault(struct cpuinfo_x86 *c)
{
u64 msr;
Expand Down Expand Up @@ -702,9 +709,6 @@ static void init_intel(struct cpuinfo_x86 *c)

init_ia32_feat_ctl(c);

if (cpu_has(c, X86_FEATURE_TME))
detect_tme(c);

init_intel_misc_features(c);

split_lock_init();
Expand Down
8 changes: 5 additions & 3 deletions arch/x86/kernel/e820.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1017,10 +1017,12 @@ void __init e820__reserve_setup_data(void)
e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);

/*
* SETUP_EFI and SETUP_IMA are supplied by kexec and do not need
* to be reserved.
* SETUP_EFI, SETUP_IMA and SETUP_RNG_SEED are supplied by
* kexec and do not need to be reserved.
*/
if (data->type != SETUP_EFI && data->type != SETUP_IMA)
if (data->type != SETUP_EFI &&
data->type != SETUP_IMA &&
data->type != SETUP_RNG_SEED)
e820__range_update_kexec(pa_data,
sizeof(*data) + data->len,
E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
Expand Down

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