From: Hans-Jörg Höxer <hshoexer@genua.de>
Subject: vmm(4)/amd64: reduce use of extern
To: <tech@openbsd.org>
Cc: <Hans-Joerg_Hoexer@genua.de>
Date: Mon, 28 Apr 2025 12:57:18 +0200

Hi,

this diff reduces the use of "extern" in amd64/vmm_machdep.c and related
files.  There might be some more low hanging fruits in eg. pmap.c.

Take care,
HJ.
---------------------------------------------------------------------
commit 16aef1f12194538826704172daf34311931778d5
Author: Hans-Joerg Hoexer <hshoexer@genua.de>
Date:   Mon Apr 28 11:49:20 2025 +0200

    kern: cleanup vmm(4)/amd64 related use of "extern"

diff --git a/sys/arch/amd64/amd64/identcpu.c b/sys/arch/amd64/amd64/identcpu.c
index 1a9a99e9bbb..78d88b3983b 100644
--- a/sys/arch/amd64/amd64/identcpu.c
+++ b/sys/arch/amd64/amd64/identcpu.c
@@ -147,7 +147,6 @@ intelcore_update_sensor(void *args)
 void
 cpu_hz_update_sensor(void *args)
 {
-	extern uint64_t	 tsc_frequency;
 	struct cpu_info	*ci = args;
 	uint64_t	 mperf, aperf, mdelta, adelta, val;
 	unsigned long	 s;
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index 7f85f92cb88..8b909d0304d 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -483,7 +483,6 @@ bios_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
 	/* NOTREACHED */
 }
 
-extern int tsc_is_invariant;
 extern int amd64_has_xcrypt;
 extern int need_retpoline;
 
@@ -504,7 +503,6 @@ int
 cpu_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
     size_t newlen, struct proc *p)
 {
-	extern uint64_t tsc_frequency;
 	dev_t consdev;
 	dev_t dev;
 
diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c
index bfd667f99bf..278330495bb 100644
--- a/sys/arch/amd64/amd64/pmap.c
+++ b/sys/arch/amd64/amd64/pmap.c
@@ -307,9 +307,6 @@ void pmap_pdp_ctor_intel(pd_entry_t *);
 extern vaddr_t msgbuf_vaddr;
 extern paddr_t msgbuf_paddr;
 
-extern vaddr_t idt_vaddr;			/* we allocate IDT early */
-extern paddr_t idt_paddr;
-
 extern vaddr_t lo32_vaddr;
 extern vaddr_t lo32_paddr;
 
diff --git a/sys/arch/amd64/amd64/vmm_machdep.c b/sys/arch/amd64/amd64/vmm_machdep.c
index 9b5d56da27b..8bd747ef476 100644
--- a/sys/arch/amd64/amd64/vmm_machdep.c
+++ b/sys/arch/amd64/amd64/vmm_machdep.c
@@ -181,9 +181,6 @@ struct vmm_reg_debug_info {
 };
 #endif /* VMM_DEBUG */
 
-extern uint64_t tsc_frequency;
-extern int tsc_is_invariant;
-
 const char *vmm_hv_signature = VMM_HV_SIGNATURE;
 
 const struct kmem_pa_mode vmm_kp_contig = {
@@ -193,9 +190,6 @@ const struct kmem_pa_mode vmm_kp_contig = {
 	.kp_zero = 1,
 };
 
-extern struct cfdriver vmm_cd;
-extern const struct cfattach vmm_ca;
-
 /*
  * Helper struct to easily get the VMCS field IDs needed in vmread/vmwrite
  * to access the individual fields of the guest segment registers. This
@@ -225,16 +219,6 @@ const struct {
 	  VMCS_GUEST_IA32_TR_AR, VMCS_GUEST_IA32_TR_BASE }
 };
 
-/* Pools for VMs and VCPUs */
-extern struct pool vm_pool;
-extern struct pool vcpu_pool;
-
-extern struct vmm_softc *vmm_softc;
-
-/* IDT information used when populating host state area */
-extern vaddr_t idt_vaddr;
-extern struct gate_descriptor *idt;
-
 /* Constants used in "CR access exit" */
 #define CR_WRITE	0
 #define CR_READ		1
diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h
index 77ad7bf0f34..07b3ad1df35 100644
--- a/sys/arch/amd64/include/cpu.h
+++ b/sys/arch/amd64/include/cpu.h
@@ -419,6 +419,10 @@ extern int amd64_pos_cbit;
 extern int amd64_min_noes_asid;
 
 /* machdep.c */
+extern vaddr_t idt_vaddr;
+extern paddr_t idt_paddr;
+extern struct gate_descriptor *idt;
+
 void	dumpconf(void);
 void	cpu_set_vendor(struct cpu_info *, int _level, const char *_vendor);
 void	cpu_reset(void);
@@ -476,6 +480,10 @@ void k1x_setperf(int);
 void est_init(struct cpu_info *);
 void est_setperf(int);
 
+/* tsc.c */
+extern uint64_t tsc_frequency;
+extern int tsc_is_invariant;
+
 #ifdef MULTIPROCESSOR
 /* mp_setperf.c */
 void mp_setperf_init(void);
diff --git a/sys/dev/vmm/vmm.h b/sys/dev/vmm/vmm.h
index 00cf820c9f1..f27433b9e1b 100644
--- a/sys/dev/vmm/vmm.h
+++ b/sys/dev/vmm/vmm.h
@@ -228,6 +228,12 @@ struct vmm_softc {
 	uint8_t			vpids[512];	/* [p] bitmap of VPID/ASIDs */
 };
 
+extern struct vmm_softc *vmm_softc;
+extern struct pool vm_pool;
+extern struct pool vcpu_pool;
+extern struct cfdriver vmm_cd;
+extern const struct cfattach vmm_ca;
+
 int vmm_probe(struct device *, void *, void *);
 int vmm_activate(struct device *, int);
 void vmm_attach(struct device *, struct device *,  void *);