x86/msr: Replace wrmsr(msr, low, 0) with wrmsrq(msr, low)

The third argument in wrmsr(msr, low, 0) is unnecessary.  Instead, use
wrmsrq(msr, low), which automatically sets the higher 32 bits of the
MSR value to 0.

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250427092027.1598740-15-xin@zytor.com

9 files changed, 16 insertions, 16 deletions

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index a079a1427091..bfde0a3498b9 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -76,10 +76,10 @@ static void hv_apic_write(u32 reg, u32 val)
 {
 	switch (reg) {
 	case APIC_EOI:
-		wrmsr(HV_X64_MSR_EOI, val, 0);
+		wrmsrq(HV_X64_MSR_EOI, val);
 		break;
 	case APIC_TASKPRI:
-		wrmsr(HV_X64_MSR_TPR, val, 0);
+		wrmsrq(HV_X64_MSR_TPR, val);
 		break;
 	default:
 		native_apic_mem_write(reg, val);
@@ -93,7 +93,7 @@ static void hv_apic_eoi_write(void)
 	if (hvp && (xchg(&hvp->apic_assist, 0) & 0x1))
 		return;
 
-	wrmsr(HV_X64_MSR_EOI, APIC_EOI_ACK, 0);
+	wrmsrq(HV_X64_MSR_EOI, APIC_EOI_ACK);
 }
 
 static bool cpu_is_self(int cpu)
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 0174dd548327..68e10e30fe9b 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -209,7 +209,7 @@ static inline void native_apic_msr_write(u32 reg, u32 v)
 	    reg == APIC_LVR)
 		return;
 
-	wrmsr(APIC_BASE_MSR + (reg >> 4), v, 0);
+	wrmsrq(APIC_BASE_MSR + (reg >> 4), v);
 }
 
 static inline void native_apic_msr_eoi(void)
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index 4f21df7af715..499b1c15cc8b 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -61,7 +61,7 @@ static inline void refresh_sysenter_cs(struct thread_struct *thread)
 		return;
 
 	this_cpu_write(cpu_tss_rw.x86_tss.ss1, thread->sysenter_cs);
-	wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
+	wrmsrq(MSR_IA32_SYSENTER_CS, thread->sysenter_cs);
 }
 #endif
 
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index e153cd1d36fe..d8365c4d9057 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1207,7 +1207,7 @@ void amd_set_dr_addr_mask(unsigned long mask, unsigned int dr)
 	if (per_cpu(amd_dr_addr_mask, cpu)[dr] == mask)
 		return;
 
-	wrmsr(amd_msr_dr_addr_masks[dr], mask, 0);
+	wrmsrq(amd_msr_dr_addr_masks[dr], mask);
 	per_cpu(amd_dr_addr_mask, cpu)[dr] = mask;
 }
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index cefc99990bde..ef9751d577c3 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1982,9 +1982,9 @@ void enable_sep_cpu(void)
 	 */
 
 	tss->x86_tss.ss1 = __KERNEL_CS;
-	wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
-	wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0);
-	wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
+	wrmsrq(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1);
+	wrmsrq(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1));
+	wrmsrq(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32);
 
 	put_cpu();
 }
@@ -2198,7 +2198,7 @@ static inline void setup_getcpu(int cpu)
 	struct desc_struct d = { };
 
 	if (boot_cpu_has(X86_FEATURE_RDTSCP) || boot_cpu_has(X86_FEATURE_RDPID))
-		wrmsr(MSR_TSC_AUX, cpudata, 0);
+		wrmsrq(MSR_TSC_AUX, cpudata);
 
 	/* Store CPU and node number in limit. */
 	d.limit0 = cpudata;
diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
index 324bd4919300..1190c48a16b2 100644
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
@@ -905,7 +905,7 @@ int resctrl_arch_measure_cycles_lat_fn(void *_plr)
 	 * Disable hardware prefetchers.
 	 */
 	rdmsr(MSR_MISC_FEATURE_CONTROL, saved_low, saved_high);
-	wrmsr(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits, 0x0);
+	wrmsrq(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits);
 	mem_r = READ_ONCE(plr->kmem);
 	/*
 	 * Dummy execute of the time measurement to load the needed
@@ -1001,7 +1001,7 @@ static int measure_residency_fn(struct perf_event_attr *miss_attr,
 	 * Disable hardware prefetchers.
 	 */
 	rdmsr(MSR_MISC_FEATURE_CONTROL, saved_low, saved_high);
-	wrmsr(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits, 0x0);
+	wrmsrq(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits);
 
 	/* Initialize rest of local variables */
 	/*
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index f724b8f6a6a4..c85ace29ea3a 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1708,7 +1708,7 @@ void resctrl_arch_mon_event_config_write(void *_config_info)
 		pr_warn_once("Invalid event id %d\n", config_info->evtid);
 		return;
 	}
-	wrmsr(MSR_IA32_EVT_CFG_BASE + index, config_info->mon_config, 0);
+	wrmsrq(MSR_IA32_EVT_CFG_BASE + index, config_info->mon_config);
 }
 
 static void mbm_config_write_domain(struct rdt_resource *r,
diff --git a/arch/x86/kernel/cpu/umwait.c b/arch/x86/kernel/cpu/umwait.c
index 0050eae153bb..933fcd7ff250 100644
--- a/arch/x86/kernel/cpu/umwait.c
+++ b/arch/x86/kernel/cpu/umwait.c
@@ -33,7 +33,7 @@ static DEFINE_MUTEX(umwait_lock);
 static void umwait_update_control_msr(void * unused)
 {
 	lockdep_assert_irqs_disabled();
-	wrmsr(MSR_IA32_UMWAIT_CONTROL, READ_ONCE(umwait_control_cached), 0);
+	wrmsrq(MSR_IA32_UMWAIT_CONTROL, READ_ONCE(umwait_control_cached));
 }
 
 /*
@@ -71,7 +71,7 @@ static int umwait_cpu_offline(unsigned int cpu)
 	 * the original control MSR value in umwait_init(). So there
 	 * is no race condition here.
 	 */
-	wrmsr(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached, 0);
+	wrmsrq(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached);
 
 	return 0;
 }
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 27f7192e1c61..f3642226e0a5 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -400,7 +400,7 @@ static void kvm_disable_steal_time(void)
 	if (!has_steal_clock)
 		return;
 
-	wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
+	wrmsrq(MSR_KVM_STEAL_TIME, 0);
 }
 
 static u64 kvm_steal_clock(int cpu)