x86/kvm: Change print code to use pr_*() format

pr_*() is preferred than printk(KERN_* ...), after change all the print
in arch/x86/kernel/kvm.c will have "kvm-guest: xxx" style.

No functional change.

Signed-off-by: Zhenzhong Duan <[e-mail]>
Reviewed-by: Vitaly Kuznetsov <[e-mail]>
Cc: Paolo Bonzini <[e-mail]>
Cc: Radim Krcmar <[e-mail]>
Cc: Sean Christopherson <[e-mail]>
Cc: Vitaly Kuznetsov <[e-mail]>
Cc: Wanpeng Li <[e-mail]>
Cc: Jim Mattson <[e-mail]>
Cc: Joerg Roedel <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

arch/x86/kernel/kvm.c

···
  *   Authors: Anthony Liguori <[e-mail]>
  */
 
+#define pr_fmt(fmt) "kvm-guest: " fmt
+
 #include <linux/context_tracking.h>
 #include <linux/init.h>
 #include <linux/irq.h>
···
 		return;
 
 	wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED));
-	pr_info("kvm-stealtime: cpu %d, msr %llx\n",
-		cpu, (unsigned long long) slow_virt_to_phys(st));
+	pr_info("stealtime: cpu %d, msr %llx\n", cpu,
+		(unsigned long long) slow_virt_to_phys(st));
 }
 
 static DEFINE_PER_CPU_DECRYPTED(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;
···
 		} else {
 			ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
 				(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
-			WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
+			WARN_ONCE(ret < 0, "kvm-guest: failed to send PV IPI: %ld",
+				  ret);
 			min = max = apic_id;
 			ipi_bitmap = 0;
 		}
···
 	if (ipi_bitmap) {
 		ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
 			(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
-		WARN_ONCE(ret < 0, "KVM: failed to send PV IPI: %ld", ret);
+		WARN_ONCE(ret < 0, "kvm-guest: failed to send PV IPI: %ld",
+			  ret);
 	}
 
 	local_irq_restore(flags);
···
 {
 	apic->send_IPI_mask = kvm_send_ipi_mask;
 	apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
-	pr_info("KVM setup pv IPIs\n");
+	pr_info("setup PV IPIs\n");
 }
 
 static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
···
 	smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
 	if (pv_sched_yield_supported()) {
 		smp_ops.send_call_func_ipi = kvm_smp_send_call_func_ipi;
-		pr_info("KVM setup pv sched yield\n");
+		pr_info("setup PV sched yield\n");
 	}
 	if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/kvm:online",
 				      kvm_cpu_online, kvm_cpu_down_prepare) < 0)
-		pr_err("kvm_guest: Failed to install cpu hotplug callbacks\n");
+		pr_err("failed to install cpu hotplug callbacks\n");
 #else
 	sev_map_percpu_data();
 	kvm_guest_cpu_init();
···
 void arch_haltpoll_enable(unsigned int cpu)
 {
 	if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) {
-		pr_err_once("kvm: host does not support poll control\n");
-		pr_err_once("kvm: host upgrade recommended\n");
+		pr_err_once("host does not support poll control\n");
+		pr_err_once("host upgrade recommended\n");
 		return;
 	}