diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index cdc43242da92ed3e272982216f5d01ef23b89b22..318a4f9b7ececcaec148e77089234f16bee309c5 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -273,6 +273,7 @@ struct smp_alt_module {
 };
 static LIST_HEAD(smp_alt_modules);
 static DEFINE_SPINLOCK(smp_alt);
+static int smp_mode = 1;	/* protected by smp_alt */
 
 void alternatives_smp_module_add(struct module *mod, char *name,
 				 void *locks, void *locks_end,
@@ -354,7 +355,14 @@ void alternatives_smp_switch(int smp)
 	BUG_ON(!smp && (num_online_cpus() > 1));
 
 	spin_lock_irqsave(&smp_alt, flags);
-	if (smp) {
+
+	/*
+	 * Avoid unnecessary switches because it forces JIT based VMs to
+	 * throw away all cached translations, which can be quite costly.
+	 */
+	if (smp == smp_mode) {
+		/* nothing */
+	} else if (smp) {
 		printk(KERN_INFO "SMP alternatives: switching to SMP code\n");
 		clear_cpu_cap(&boot_cpu_data, X86_FEATURE_UP);
 		clear_cpu_cap(&cpu_data(0), X86_FEATURE_UP);
@@ -369,6 +377,7 @@ void alternatives_smp_switch(int smp)
 			alternatives_smp_unlock(mod->locks, mod->locks_end,
 						mod->text, mod->text_end);
 	}
+	smp_mode = smp;
 	spin_unlock_irqrestore(&smp_alt, flags);
 }
 
@@ -441,7 +450,10 @@ void __init alternative_instructions(void)
 		alternatives_smp_module_add(NULL, "core kernel",
 					    __smp_locks, __smp_locks_end,
 					    _text, _etext);
-		alternatives_smp_switch(0);
+
+		/* Only switch to UP mode if we don't immediately boot others */
+		if (num_possible_cpus() == 1 || setup_max_cpus <= 1)
+			alternatives_smp_switch(0);
 	}
 #endif
  	apply_paravirt(__parainstructions, __parainstructions_end);
diff --git a/include/linux/smp.h b/include/linux/smp.h
index c25e66bcecf335cfead012f4fd8feeff8834e5aa..55232ccf9cfdbb020765e89f99b22c7fc9a35af2 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -78,6 +78,8 @@ int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait);
  */
 void smp_prepare_boot_cpu(void);
 
+extern unsigned int setup_max_cpus;
+
 #else /* !SMP */
 
 /*
diff --git a/init/main.c b/init/main.c
index 3f8aba291ed31d098a8a5ae73904125bb5828be5..5843fe9967034050f59c0fcc3888e78b66f2374b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -128,7 +128,7 @@ static char *ramdisk_execute_command;
 
 #ifdef CONFIG_SMP
 /* Setup configured maximum number of CPUs to activate */
-static unsigned int __initdata max_cpus = NR_CPUS;
+unsigned int __initdata setup_max_cpus = NR_CPUS;
 
 /*
  * Setup routine for controlling SMP activation
@@ -146,7 +146,7 @@ static inline void disable_ioapic_setup(void) {};
 
 static int __init nosmp(char *str)
 {
-	max_cpus = 0;
+	setup_max_cpus = 0;
 	disable_ioapic_setup();
 	return 0;
 }
@@ -155,8 +155,8 @@ early_param("nosmp", nosmp);
 
 static int __init maxcpus(char *str)
 {
-	get_option(&str, &max_cpus);
-	if (max_cpus == 0)
+	get_option(&str, &setup_max_cpus);
+	if (setup_max_cpus == 0)
 		disable_ioapic_setup();
 
 	return 0;
@@ -164,7 +164,7 @@ static int __init maxcpus(char *str)
 
 early_param("maxcpus", maxcpus);
 #else
-#define max_cpus NR_CPUS
+#define setup_max_cpus NR_CPUS
 #endif
 
 /*
@@ -393,7 +393,7 @@ static void __init smp_init(void)
 
 	/* FIXME: This should be done in userspace --RR */
 	for_each_present_cpu(cpu) {
-		if (num_online_cpus() >= max_cpus)
+		if (num_online_cpus() >= setup_max_cpus)
 			break;
 		if (!cpu_online(cpu))
 			cpu_up(cpu);
@@ -401,7 +401,7 @@ static void __init smp_init(void)
 
 	/* Any cleanup work */
 	printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
-	smp_cpus_done(max_cpus);
+	smp_cpus_done(setup_max_cpus);
 }
 
 #endif
@@ -824,7 +824,7 @@ static int __init kernel_init(void * unused)
 	__set_special_pids(1, 1);
 	cad_pid = task_pid(current);
 
-	smp_prepare_cpus(max_cpus);
+	smp_prepare_cpus(setup_max_cpus);
 
 	do_pre_smp_initcalls();