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x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'
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commit d048573 upstream.

So we are using the 'ia32_cap' value in a number of places,
which got its name from MSR_IA32_ARCH_CAPABILITIES MSR register.

But there's very little 'IA32' about it - this isn't 32-bit only
code, nor does it originate from there, it's just a historic
quirk that many Intel MSR names are prefixed with IA32_.

This is already clear from the helper method around the MSR:
x86_read_arch_cap_msr(), which doesn't have the IA32 prefix.

So rename 'ia32_cap' to 'x86_arch_cap_msr' to be consistent with
its role and with the naming of the helper function.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@gregkh
Ingo Molnar authored and gregkh committed Apr 17, 2024
1 parent c768db1 commit b4f2718
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Showing 2 changed files with 39 additions and 39 deletions.
30 changes: 15 additions & 15 deletions arch/x86/kernel/cpu/bugs.c
View file
Expand Up @@ -60,7 +60,7 @@ EXPORT_SYMBOL_GPL(x86_spec_ctrl_current);
u64 x86_pred_cmd __ro_after_init = PRED_CMD_IBPB;
EXPORT_SYMBOL_GPL(x86_pred_cmd);

static u64 __ro_after_init ia32_cap;
static u64 __ro_after_init x86_arch_cap_msr;

static DEFINE_MUTEX(spec_ctrl_mutex);

Expand Down Expand Up @@ -145,7 +145,7 @@ void __init cpu_select_mitigations(void)
x86_spec_ctrl_base &= ~SPEC_CTRL_MITIGATIONS_MASK;
}

ia32_cap = x86_read_arch_cap_msr();
x86_arch_cap_msr = x86_read_arch_cap_msr();

/* Select the proper CPU mitigations before patching alternatives: */
spectre_v1_select_mitigation();
Expand Down Expand Up @@ -349,8 +349,8 @@ static void __init taa_select_mitigation(void)
* On MDS_NO=1 CPUs if ARCH_CAP_TSX_CTRL_MSR is not set, microcode
* update is required.
*/
if ( (ia32_cap & ARCH_CAP_MDS_NO) &&
!(ia32_cap & ARCH_CAP_TSX_CTRL_MSR))
if ( (x86_arch_cap_msr & ARCH_CAP_MDS_NO) &&
!(x86_arch_cap_msr & ARCH_CAP_TSX_CTRL_MSR))
taa_mitigation = TAA_MITIGATION_UCODE_NEEDED;

/*
Expand Down Expand Up @@ -440,7 +440,7 @@ static void __init mmio_select_mitigation(void)
* be propagated to uncore buffers, clearing the Fill buffers on idle
* is required irrespective of SMT state.
*/
if (!(ia32_cap & ARCH_CAP_FBSDP_NO))
if (!(x86_arch_cap_msr & ARCH_CAP_FBSDP_NO))
static_branch_enable(&mds_idle_clear);

/*
Expand All @@ -450,10 +450,10 @@ static void __init mmio_select_mitigation(void)
* FB_CLEAR or by the presence of both MD_CLEAR and L1D_FLUSH on MDS
* affected systems.
*/
if ((ia32_cap & ARCH_CAP_FB_CLEAR) ||
if ((x86_arch_cap_msr & ARCH_CAP_FB_CLEAR) ||
(boot_cpu_has(X86_FEATURE_MD_CLEAR) &&
boot_cpu_has(X86_FEATURE_FLUSH_L1D) &&
!(ia32_cap & ARCH_CAP_MDS_NO)))
!(x86_arch_cap_msr & ARCH_CAP_MDS_NO)))
mmio_mitigation = MMIO_MITIGATION_VERW;
else
mmio_mitigation = MMIO_MITIGATION_UCODE_NEEDED;
Expand Down Expand Up @@ -511,7 +511,7 @@ static void __init rfds_select_mitigation(void)
if (rfds_mitigation == RFDS_MITIGATION_OFF)
return;

if (ia32_cap & ARCH_CAP_RFDS_CLEAR)
if (x86_arch_cap_msr & ARCH_CAP_RFDS_CLEAR)
setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
else
rfds_mitigation = RFDS_MITIGATION_UCODE_NEEDED;
Expand Down Expand Up @@ -663,7 +663,7 @@ static void __init srbds_select_mitigation(void)
* are only exposed to SRBDS when TSX is enabled or when CPU is affected
* by Processor MMIO Stale Data vulnerability.
*/
if ((ia32_cap & ARCH_CAP_MDS_NO) && !boot_cpu_has(X86_FEATURE_RTM) &&
if ((x86_arch_cap_msr & ARCH_CAP_MDS_NO) && !boot_cpu_has(X86_FEATURE_RTM) &&
!boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA))
srbds_mitigation = SRBDS_MITIGATION_TSX_OFF;
else if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
Expand Down Expand Up @@ -806,7 +806,7 @@ static void __init gds_select_mitigation(void)
/* Will verify below that mitigation _can_ be disabled */

/* No microcode */
if (!(ia32_cap & ARCH_CAP_GDS_CTRL)) {
if (!(x86_arch_cap_msr & ARCH_CAP_GDS_CTRL)) {
if (gds_mitigation == GDS_MITIGATION_FORCE) {
/*
* This only needs to be done on the boot CPU so do it
Expand Down Expand Up @@ -1518,14 +1518,14 @@ static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void)
/* Disable in-kernel use of non-RSB RET predictors */
static void __init spec_ctrl_disable_kernel_rrsba(void)
{
u64 ia32_cap;
u64 x86_arch_cap_msr;

if (!boot_cpu_has(X86_FEATURE_RRSBA_CTRL))
return;

ia32_cap = x86_read_arch_cap_msr();
x86_arch_cap_msr = x86_read_arch_cap_msr();

if (ia32_cap & ARCH_CAP_RRSBA) {
if (x86_arch_cap_msr & ARCH_CAP_RRSBA) {
x86_spec_ctrl_base |= SPEC_CTRL_RRSBA_DIS_S;
update_spec_ctrl(x86_spec_ctrl_base);
}
Expand Down Expand Up @@ -1892,7 +1892,7 @@ static void update_mds_branch_idle(void)
if (sched_smt_active()) {
static_branch_enable(&mds_idle_clear);
} else if (mmio_mitigation == MMIO_MITIGATION_OFF ||
(ia32_cap & ARCH_CAP_FBSDP_NO)) {
(x86_arch_cap_msr & ARCH_CAP_FBSDP_NO)) {
static_branch_disable(&mds_idle_clear);
}
}
Expand Down Expand Up @@ -2789,7 +2789,7 @@ static const char *spectre_bhi_state(void)
else if (boot_cpu_has(X86_FEATURE_CLEAR_BHB_LOOP))
return "; BHI: SW loop, KVM: SW loop";
else if (boot_cpu_has(X86_FEATURE_RETPOLINE) &&
!(ia32_cap & ARCH_CAP_RRSBA))
!(x86_arch_cap_msr & ARCH_CAP_RRSBA))
return "; BHI: Retpoline";
else if (boot_cpu_has(X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT))
return "; BHI: Syscall hardening, KVM: SW loop";
Expand Down
48 changes: 24 additions & 24 deletions arch/x86/kernel/cpu/common.c
View file
Expand Up @@ -1198,33 +1198,33 @@ static bool __init cpu_matches(const struct x86_cpu_id *table, unsigned long whi

u64 x86_read_arch_cap_msr(void)
{
u64 ia32_cap = 0;
u64 x86_arch_cap_msr = 0;

if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
rdmsrl(MSR_IA32_ARCH_CAPABILITIES, x86_arch_cap_msr);

return ia32_cap;
return x86_arch_cap_msr;
}

static bool arch_cap_mmio_immune(u64 ia32_cap)
static bool arch_cap_mmio_immune(u64 x86_arch_cap_msr)
{
return (ia32_cap & ARCH_CAP_FBSDP_NO &&
ia32_cap & ARCH_CAP_PSDP_NO &&
ia32_cap & ARCH_CAP_SBDR_SSDP_NO);
return (x86_arch_cap_msr & ARCH_CAP_FBSDP_NO &&
x86_arch_cap_msr & ARCH_CAP_PSDP_NO &&
x86_arch_cap_msr & ARCH_CAP_SBDR_SSDP_NO);
}

static bool __init vulnerable_to_rfds(u64 ia32_cap)
static bool __init vulnerable_to_rfds(u64 x86_arch_cap_msr)
{
/* The "immunity" bit trumps everything else: */
if (ia32_cap & ARCH_CAP_RFDS_NO)
if (x86_arch_cap_msr & ARCH_CAP_RFDS_NO)
return false;

/*
* VMMs set ARCH_CAP_RFDS_CLEAR for processors not in the blacklist to
* indicate that mitigation is needed because guest is running on a
* vulnerable hardware or may migrate to such hardware:
*/
if (ia32_cap & ARCH_CAP_RFDS_CLEAR)
if (x86_arch_cap_msr & ARCH_CAP_RFDS_CLEAR)
return true;

/* Only consult the blacklist when there is no enumeration: */
Expand All @@ -1233,11 +1233,11 @@ static bool __init vulnerable_to_rfds(u64 ia32_cap)

static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
{
u64 ia32_cap = x86_read_arch_cap_msr();
u64 x86_arch_cap_msr = x86_read_arch_cap_msr();

/* Set ITLB_MULTIHIT bug if cpu is not in the whitelist and not mitigated */
if (!cpu_matches(cpu_vuln_whitelist, NO_ITLB_MULTIHIT) &&
!(ia32_cap & ARCH_CAP_PSCHANGE_MC_NO))
!(x86_arch_cap_msr & ARCH_CAP_PSCHANGE_MC_NO))
setup_force_cpu_bug(X86_BUG_ITLB_MULTIHIT);

if (cpu_matches(cpu_vuln_whitelist, NO_SPECULATION))
Expand All @@ -1249,23 +1249,23 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
setup_force_cpu_bug(X86_BUG_SPECTRE_V2);

if (!cpu_matches(cpu_vuln_whitelist, NO_SSB) &&
!(ia32_cap & ARCH_CAP_SSB_NO) &&
!(x86_arch_cap_msr & ARCH_CAP_SSB_NO) &&
!cpu_has(c, X86_FEATURE_AMD_SSB_NO))
setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);

/*
* AMD's AutoIBRS is equivalent to Intel's eIBRS - use the Intel feature
* flag and protect from vendor-specific bugs via the whitelist.
*/
if ((ia32_cap & ARCH_CAP_IBRS_ALL) || cpu_has(c, X86_FEATURE_AUTOIBRS)) {
if ((x86_arch_cap_msr & ARCH_CAP_IBRS_ALL) || cpu_has(c, X86_FEATURE_AUTOIBRS)) {
setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED);
if (!cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) &&
!(ia32_cap & ARCH_CAP_PBRSB_NO))
!(x86_arch_cap_msr & ARCH_CAP_PBRSB_NO))
setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
}

if (!cpu_matches(cpu_vuln_whitelist, NO_MDS) &&
!(ia32_cap & ARCH_CAP_MDS_NO)) {
!(x86_arch_cap_msr & ARCH_CAP_MDS_NO)) {
setup_force_cpu_bug(X86_BUG_MDS);
if (cpu_matches(cpu_vuln_whitelist, MSBDS_ONLY))
setup_force_cpu_bug(X86_BUG_MSBDS_ONLY);
Expand All @@ -1284,9 +1284,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
* TSX_CTRL check alone is not sufficient for cases when the microcode
* update is not present or running as guest that don't get TSX_CTRL.
*/
if (!(ia32_cap & ARCH_CAP_TAA_NO) &&
if (!(x86_arch_cap_msr & ARCH_CAP_TAA_NO) &&
(cpu_has(c, X86_FEATURE_RTM) ||
(ia32_cap & ARCH_CAP_TSX_CTRL_MSR)))
(x86_arch_cap_msr & ARCH_CAP_TSX_CTRL_MSR)))
setup_force_cpu_bug(X86_BUG_TAA);

/*
Expand All @@ -1312,15 +1312,15 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
* Set X86_BUG_MMIO_UNKNOWN for CPUs that are neither in the blacklist,
* nor in the whitelist and also don't enumerate MSR ARCH_CAP MMIO bits.
*/
if (!arch_cap_mmio_immune(ia32_cap)) {
if (!arch_cap_mmio_immune(x86_arch_cap_msr)) {
if (cpu_matches(cpu_vuln_blacklist, MMIO))
setup_force_cpu_bug(X86_BUG_MMIO_STALE_DATA);
else if (!cpu_matches(cpu_vuln_whitelist, NO_MMIO))
setup_force_cpu_bug(X86_BUG_MMIO_UNKNOWN);
}

if (!cpu_has(c, X86_FEATURE_BTC_NO)) {
if (cpu_matches(cpu_vuln_blacklist, RETBLEED) || (ia32_cap & ARCH_CAP_RSBA))
if (cpu_matches(cpu_vuln_blacklist, RETBLEED) || (x86_arch_cap_msr & ARCH_CAP_RSBA))
setup_force_cpu_bug(X86_BUG_RETBLEED);
}

Expand All @@ -1333,7 +1333,7 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
* disabling AVX2. The only way to do this in HW is to clear XCR0[2],
* which means that AVX will be disabled.
*/
if (cpu_matches(cpu_vuln_blacklist, GDS) && !(ia32_cap & ARCH_CAP_GDS_NO) &&
if (cpu_matches(cpu_vuln_blacklist, GDS) && !(x86_arch_cap_msr & ARCH_CAP_GDS_NO) &&
boot_cpu_has(X86_FEATURE_AVX))
setup_force_cpu_bug(X86_BUG_GDS);

Expand All @@ -1342,11 +1342,11 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
setup_force_cpu_bug(X86_BUG_SRSO);
}

if (vulnerable_to_rfds(ia32_cap))
if (vulnerable_to_rfds(x86_arch_cap_msr))
setup_force_cpu_bug(X86_BUG_RFDS);

/* When virtualized, eIBRS could be hidden, assume vulnerable */
if (!(ia32_cap & ARCH_CAP_BHI_NO) &&
if (!(x86_arch_cap_msr & ARCH_CAP_BHI_NO) &&
!cpu_matches(cpu_vuln_whitelist, NO_BHI) &&
(boot_cpu_has(X86_FEATURE_IBRS_ENHANCED) ||
boot_cpu_has(X86_FEATURE_HYPERVISOR)))
Expand All @@ -1356,7 +1356,7 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
return;

/* Rogue Data Cache Load? No! */
if (ia32_cap & ARCH_CAP_RDCL_NO)
if (x86_arch_cap_msr & ARCH_CAP_RDCL_NO)
return;

setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
Expand Down

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