Add basic KVM paravirt support. Avoid vm-exits on IO delays.
v1->v2:
- replace KVM_CAP_CLOCKSOURCE with KVM_CAP_PARA_FEATURES
- cover FEATURE_CLOCKSOURCE
v2->v3:
- switch to one ioctl per paravirt feature
Signed-off-by: Marcelo Tosatti <[EMAIL PROTECTED]>
Index: kvm.paravirt3/arch/x86/Kconfig
===================================================================
--- kvm.paravirt3.orig/arch/x86/Kconfig
+++ kvm.paravirt3/arch/x86/Kconfig
@@ -382,6 +382,14 @@ 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
Index: kvm.paravirt3/arch/x86/kernel/Makefile
===================================================================
--- kvm.paravirt3.orig/arch/x86/kernel/Makefile
+++ kvm.paravirt3/arch/x86/kernel/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_DEBUG_RODATA_TEST) += test_
obj-$(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
Index: kvm.paravirt3/arch/x86/kernel/kvm.c
===================================================================
--- /dev/null
+++ kvm.paravirt3/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 <[EMAIL PROTECTED]>
+ * Copyright IBM Corporation, 2007
+ * Authors: Anthony Liguori <[EMAIL PROTECTED]>
+ */
+
+#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();
+}
Index: kvm.paravirt3/arch/x86/kernel/setup_32.c
===================================================================
--- kvm.paravirt3.orig/arch/x86/kernel/setup_32.c
+++ kvm.paravirt3/arch/x86/kernel/setup_32.c
@@ -783,6 +783,7 @@ void __init setup_arch(char **cmdline_p)
*/
vmi_init();
#endif
+ kvm_guest_init();
/*
* NOTE: before this point _nobody_ is allowed to allocate
Index: kvm.paravirt3/arch/x86/kernel/setup_64.c
===================================================================
--- kvm.paravirt3.orig/arch/x86/kernel/setup_64.c
+++ kvm.paravirt3/arch/x86/kernel/setup_64.c
@@ -452,6 +452,8 @@ 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.
*/
Index: kvm.paravirt3/include/linux/kvm_para.h
===================================================================
--- kvm.paravirt3.orig/include/linux/kvm_para.h
+++ kvm.paravirt3/include/linux/kvm_para.h
@@ -20,6 +20,12 @@
#include <asm/kvm_para.h>
#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))
Index: kvm.paravirt3/arch/x86/kvm/x86.c
===================================================================
--- kvm.paravirt3.orig/arch/x86/kvm/x86.c
+++ kvm.paravirt3/arch/x86/kvm/x86.c
@@ -797,6 +797,7 @@ int kvm_dev_ioctl_check_extension(long e
case KVM_CAP_SET_TSS_ADDR:
case KVM_CAP_EXT_CPUID:
case KVM_CAP_CLOCKSOURCE:
+ case KVM_CAP_NOP_IO_DELAY:
r = 1;
break;
case KVM_CAP_VAPIC:
Index: kvm.paravirt3/include/asm-x86/kvm_para.h
===================================================================
--- kvm.paravirt3.orig/include/asm-x86/kvm_para.h
+++ kvm.paravirt3/include/asm-x86/kvm_para.h
@@ -10,7 +10,8 @@
* paravirtualization, the appropriate feature bit should be checked.
*/
#define KVM_CPUID_FEATURES 0x40000001
-#define KVM_FEATURE_CLOCKSOURCE 0
+#define KVM_FEATURE_CLOCKSOURCE 0
+#define KVM_FEATURE_NOP_IO_DELAY 1
#define MSR_KVM_WALL_CLOCK 0x11
#define MSR_KVM_SYSTEM_TIME 0x12
Index: kvm.paravirt3/include/linux/kvm.h
===================================================================
--- kvm.paravirt3.orig/include/linux/kvm.h
+++ kvm.paravirt3/include/linux/kvm.h
@@ -236,6 +236,7 @@ struct kvm_vapic_addr {
#define KVM_CAP_CLOCKSOURCE 8
#define KVM_CAP_NR_VCPUS 9 /* returns max vcpus per vm */
#define KVM_CAP_NR_MEMSLOTS 10 /* returns max memory slots per vm */
+#define KVM_CAP_NOP_IO_DELAY 11
/*
* ioctls for VM fds
--
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