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Commit 0cf1bfd2 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Avi Kivity
Browse files

x86: KVM guest: add basic paravirt support 



Add basic KVM paravirt support. Avoid vm-exits on IO delays.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent a28e4f5a

arch/x86/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -384,6 +384,14 @@ config KVM_CLOCK 
	  provides the guest with timing infrastructure such as time of day, and

	  system time



config KVM_GUEST

	bool "KVM Guest support"

	select PARAVIRT

	depends on !(X86_VISWS || X86_VOYAGER)

	help

	 This option enables various optimizations for running under the KVM

	 hypervisor.



source "arch/x86/lguest/Kconfig"



config PARAVIRT

arch/x86/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ obj-$(CONFIG_DEBUG_RODATA_TEST) += test_rodata.o 
obj-$(CONFIG_DEBUG_NX_TEST)	+= test_nx.o



obj-$(CONFIG_VMI)		+= vmi_32.o vmiclock_32.o

obj-$(CONFIG_KVM_GUEST)		+= kvm.o

obj-$(CONFIG_KVM_CLOCK)		+= kvmclock.o

obj-$(CONFIG_PARAVIRT)		+= paravirt.o paravirt_patch_$(BITS).o

arch/x86/kernel/kvm.c

0 → 100644
+52 −0
Original line number Diff line number Diff line 
/*

 * KVM paravirt_ops implementation

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 *

 * Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com>

 * Copyright IBM Corporation, 2007

 *   Authors: Anthony Liguori <aliguori@us.ibm.com>

 */



#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/kvm_para.h>

#include <linux/cpu.h>

#include <linux/mm.h>



/*

 * No need for any "IO delay" on KVM

 */

static void kvm_io_delay(void)

{

}



static void paravirt_ops_setup(void)

{

	pv_info.name = "KVM";

	pv_info.paravirt_enabled = 1;



	if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))

		pv_cpu_ops.io_delay = kvm_io_delay;



}



void __init kvm_guest_init(void)

{

	if (!kvm_para_available())

		return;



	paravirt_ops_setup();

}

arch/x86/kernel/setup_32.c

+1 −0
Original line number Diff line number Diff line
@@ -832,6 +832,7 @@ void __init setup_arch(char **cmdline_p) 
	 */

	vmi_init();

#endif

	kvm_guest_init();



	/*

	 * NOTE: before this point _nobody_ is allowed to allocate

arch/x86/kernel/setup_64.c

+2 −0
Original line number Diff line number Diff line
@@ -493,6 +493,8 @@ void __init setup_arch(char **cmdline_p) 
	init_apic_mappings();

	ioapic_init_mappings();



	kvm_guest_init();



	/*

	 * We trust e820 completely. No explicit ROM probing in memory.

	 */