x86/timers: Move simple_udelay_calibration() past kvmclock_init()

simple_udelay_calibration() relies on x86_platform's calibration ops.
For KVM these ops are set late in setup_arch() and so
simple_udelay_calibration() ends up using native version.

Besides being possibly incorrect, this significantly increases kernel
boot time. For example, on my laptop executing start_kernel() by a guest
takes ~10 times more than when KVM's ops are used.

Since early_xdbc_setup_hardware() relies on calibration having been
performed move it too.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: baolu.lu@linux.intel.com
Link: https://lkml.kernel.org/r/20170911185111.20636-1-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 4 insertions, 5 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c63d2b4dd5c8..b40311027c15 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1029,8 +1029,6 @@ void __init setup_arch(char **cmdline_p)
          */
         init_hypervisor_platform();
 
-        tsc_early_delay_calibrate();
-
         x86_init.resources.probe_roms();
 
         /* after parse_early_param, so could debug it */
@@ -1115,9 +1113,6 @@ void __init setup_arch(char **cmdline_p)
         memblock_set_current_limit(ISA_END_ADDRESS);
         e820__memblock_setup();
 
-        if (!early_xdbc_setup_hardware())
-                early_xdbc_register_console();
-
         reserve_bios_regions();
 
         if (efi_enabled(EFI_MEMMAP)) {
@@ -1223,6 +1218,10 @@ void __init setup_arch(char **cmdline_p)
         kvmclock_init();
 #endif
 
+        tsc_early_delay_calibrate();
+        if (!early_xdbc_setup_hardware())
+                early_xdbc_register_console();
+
         x86_init.paging.pagetable_init();
 
         kasan_init();