From 0cf1bfd2737f41e59f974a61eab11af206d2042a Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Fri, 22 Feb 2008 12:21:36 -0500 Subject: [PATCH] x86: KVM guest: add basic paravirt support Add basic KVM paravirt support. Avoid vm-exits on IO delays. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/Kconfig | 8 ++++++ arch/x86/kernel/Makefile | 1 + arch/x86/kernel/kvm.c | 52 ++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/setup_32.c | 1 + arch/x86/kernel/setup_64.c | 2 ++ include/linux/kvm_para.h | 6 +++++ 6 files changed, 70 insertions(+) create mode 100644 arch/x86/kernel/kvm.c diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 40cedc255ed..e5790fe9e33 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -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 diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 483047a3302..fa19c381954 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -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 diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c new file mode 100644 index 00000000000..a8e36da6012 --- /dev/null +++ b/arch/x86/kernel/kvm.c @@ -0,0 +1,52 @@ +/* + * 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 + * Copyright IBM Corporation, 2007 + * Authors: Anthony Liguori + */ + +#include +#include +#include +#include +#include + +/* + * 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(); +} diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c index 5a849ddd09e..2283422af79 100644 --- a/arch/x86/kernel/setup_32.c +++ b/arch/x86/kernel/setup_32.c @@ -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 diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index 8a9213c023e..a94fb959a87 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -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. */ diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h index 5497aac0d2f..9c462c91a6b 100644 --- a/include/linux/kvm_para.h +++ b/include/linux/kvm_para.h @@ -20,6 +20,12 @@ #include #ifdef __KERNEL__ +#ifdef CONFIG_KVM_GUEST +void __init kvm_guest_init(void); +#else +#define kvm_guest_init() do { } while (0) +#endif + static inline int kvm_para_has_feature(unsigned int feature) { if (kvm_arch_para_features() & (1UL << feature)) -- 2.41.1