Merge tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 updates from Dave Hansen:
 "The most significant are some changes to ensure that symbols exported
  for KVM are used only by KVM modules themselves, along with some
  related cleanups.

  In true x86/misc fashion, the other patch is completely unrelated and
  just enhances an existing pr_warn() to make it clear to users how they
  have tainted their kernel when something is mucking with MSRs.

  Summary:

   - Make MSR-induced taint easier for users to track down

   - Restrict KVM-specific exports to KVM itself"

* tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible
  x86/mm: Drop unnecessary export of "ptdump_walk_pgd_level_debugfs"
  x86/mtrr: Drop unnecessary export of "mtrr_state"
  x86/bugs: Drop unnecessary export of "x86_spec_ctrl_base"
  x86/msr: Add CPU_OUT_OF_SPEC taint name to "unrecognized" pr_warn(msg)

Author: torvalds

arch/x86/entry/entry.S

@@ -4,6 +4,7 @@
  */
 
 #include <linux/export.h>
+#include <linux/kvm_types.h>
 #include <linux/linkage.h>
 #include <linux/objtool.h>
 #include <asm/msr-index.h>
@@ -29,8 +30,7 @@ SYM_FUNC_START(write_ibpb)
 	FILL_RETURN_BUFFER %rax, RSB_CLEAR_LOOPS, X86_BUG_IBPB_NO_RET
 	RET
 SYM_FUNC_END(write_ibpb)
-/* For KVM */
-EXPORT_SYMBOL_GPL(write_ibpb);
+EXPORT_SYMBOL_FOR_KVM(write_ibpb);
 
 SYM_FUNC_START(__WARN_trap)
 	ANNOTATE_NOENDBR
@@ -56,8 +56,7 @@ SYM_CODE_START_NOALIGN(x86_verw_sel)
 	.word __KERNEL_DS
 .align L1_CACHE_BYTES, 0xcc
 SYM_CODE_END(x86_verw_sel);
-/* For KVM */
-EXPORT_SYMBOL_GPL(x86_verw_sel);
+EXPORT_SYMBOL_FOR_KVM(x86_verw_sel);
 
 .popsection
 

arch/x86/entry/entry_64.S

@@ -19,6 +19,7 @@
  * - idtentry:		Define exception entry points.
  */
 #include <linux/export.h>
+#include <linux/kvm_types.h>
 #include <linux/linkage.h>
 #include <asm/segment.h>
 #include <asm/cache.h>
@@ -1566,5 +1567,5 @@ SYM_FUNC_START(clear_bhb_loop)
 	pop	%rbp
 	RET
 SYM_FUNC_END(clear_bhb_loop)
-EXPORT_SYMBOL_GPL(clear_bhb_loop)
+EXPORT_SYMBOL_FOR_KVM(clear_bhb_loop)
 STACK_FRAME_NON_STANDARD(clear_bhb_loop)

arch/x86/entry/entry_64_fred.S

@@ -4,6 +4,7 @@
  */
 
 #include <linux/export.h>
+#include <linux/kvm_types.h>
 
 #include <asm/asm.h>
 #include <asm/fred.h>
@@ -146,5 +147,5 @@ SYM_FUNC_START(asm_fred_entry_from_kvm)
 	RET
 
 SYM_FUNC_END(asm_fred_entry_from_kvm)
-EXPORT_SYMBOL_GPL(asm_fred_entry_from_kvm);
+EXPORT_SYMBOL_FOR_KVM(asm_fred_entry_from_kvm);
 #endif

arch/x86/events/amd/core.c

@@ -2,6 +2,7 @@
 #include <linux/perf_event.h>
 #include <linux/jump_label.h>
 #include <linux/export.h>
+#include <linux/kvm_types.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -1574,7 +1575,7 @@ void amd_pmu_enable_virt(void)
 	/* Reload all events */
 	amd_pmu_reload_virt();
 }
-EXPORT_SYMBOL_GPL(amd_pmu_enable_virt);
+EXPORT_SYMBOL_FOR_KVM(amd_pmu_enable_virt);
 
 void amd_pmu_disable_virt(void)
 {
@@ -1591,4 +1592,4 @@ void amd_pmu_disable_virt(void)
 	/* Reload all events */
 	amd_pmu_reload_virt();
 }
-EXPORT_SYMBOL_GPL(amd_pmu_disable_virt);
+EXPORT_SYMBOL_FOR_KVM(amd_pmu_disable_virt);

arch/x86/events/core.c

@@ -20,6 +20,7 @@
 #include <linux/export.h>
 #include <linux/init.h>
 #include <linux/kdebug.h>
+#include <linux/kvm_types.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/clock.h>
 #include <linux/uaccess.h>
@@ -723,7 +724,7 @@ struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data)
 {
 	return static_call(x86_pmu_guest_get_msrs)(nr, data);
 }
-EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
+EXPORT_SYMBOL_FOR_KVM(perf_guest_get_msrs);
 
 /*
  * There may be PMI landing after enabled=0. The PMI hitting could be before or
@@ -3078,7 +3079,7 @@ void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
 	cap->events_mask_len	= x86_pmu.events_mask_len;
 	cap->pebs_ept		= x86_pmu.pebs_ept;
 }
-EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);
+EXPORT_SYMBOL_FOR_KVM(perf_get_x86_pmu_capability);
 
 u64 perf_get_hw_event_config(int hw_event)
 {
@@ -3089,4 +3090,4 @@ u64 perf_get_hw_event_config(int hw_event)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(perf_get_hw_event_config);
+EXPORT_SYMBOL_FOR_KVM(perf_get_hw_event_config);

arch/x86/events/intel/lbr.c

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#include <linux/kvm_types.h>
 #include <linux/perf_event.h>
 #include <linux/types.h>
 
@@ -1705,7 +1706,7 @@ void x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
 	lbr->info = x86_pmu.lbr_info;
 	lbr->has_callstack = x86_pmu_has_lbr_callstack();
 }
-EXPORT_SYMBOL_GPL(x86_perf_get_lbr);
+EXPORT_SYMBOL_FOR_KVM(x86_perf_get_lbr);
 
 struct event_constraint vlbr_constraint =
 	__EVENT_CONSTRAINT(INTEL_FIXED_VLBR_EVENT, (1ULL << INTEL_PMC_IDX_FIXED_VLBR),

arch/x86/events/intel/pt.c

@@ -17,6 +17,7 @@
 #include <linux/limits.h>
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <linux/kvm_types.h>
 
 #include <asm/cpuid/api.h>
 #include <asm/perf_event.h>
@@ -82,13 +83,13 @@ u32 intel_pt_validate_cap(u32 *caps, enum pt_capabilities capability)
 
 	return (c & cd->mask) >> shift;
 }
-EXPORT_SYMBOL_GPL(intel_pt_validate_cap);
+EXPORT_SYMBOL_FOR_KVM(intel_pt_validate_cap);
 
 u32 intel_pt_validate_hw_cap(enum pt_capabilities cap)
 {
 	return intel_pt_validate_cap(pt_pmu.caps, cap);
 }
-EXPORT_SYMBOL_GPL(intel_pt_validate_hw_cap);
+EXPORT_SYMBOL_FOR_KVM(intel_pt_validate_hw_cap);
 
 static ssize_t pt_cap_show(struct device *cdev,
 			   struct device_attribute *attr,
@@ -1590,7 +1591,7 @@ void intel_pt_handle_vmx(int on)
 
 	local_irq_restore(flags);
 }
-EXPORT_SYMBOL_GPL(intel_pt_handle_vmx);
+EXPORT_SYMBOL_FOR_KVM(intel_pt_handle_vmx);
 
 /*
  * PMU callbacks

arch/x86/include/asm/kvm_types.h

@@ -10,6 +10,11 @@
 #define KVM_SUB_MODULES kvm-intel
 #else
 #undef KVM_SUB_MODULES
+/*
+ * Don't export symbols for KVM without vendor modules, as kvm.ko is built iff
+ * at least one vendor module is enabled.
+ */
+#define EXPORT_SYMBOL_FOR_KVM(symbol)
 #endif
 
 #define KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE 40

arch/x86/kernel/apic/apic.c

@@ -36,6 +36,7 @@
 #include <linux/dmi.h>
 #include <linux/smp.h>
 #include <linux/mm.h>
+#include <linux/kvm_types.h>
 
 #include <xen/xen.h>
 
@@ -2319,7 +2320,7 @@ u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid)
 		dest |= msg->arch_addr_hi.destid_8_31 << 8;
 	return dest;
 }
-EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
+EXPORT_SYMBOL_FOR_KVM(x86_msi_msg_get_destid);
 
 static void __init apic_bsp_up_setup(void)
 {

arch/x86/kernel/apic/apic_common.c

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: GPL-2.0
  */
 #include <linux/irq.h>
+#include <linux/kvm_types.h>
 #include <asm/apic.h>
 
 #include "local.h"
@@ -25,7 +26,7 @@ u32 default_cpu_present_to_apicid(int mps_cpu)
 	else
 		return BAD_APICID;
 }
-EXPORT_SYMBOL_GPL(default_cpu_present_to_apicid);
+EXPORT_SYMBOL_FOR_KVM(default_cpu_present_to_apicid);
 
 /*
  * Set up the logical destination ID when the APIC operates in logical