Add basic KVM paravirt support. Avoid vm-exits on IO delays.
Add KVM_GET_PARA_FEATURES ioctl so paravirt features can be reported via
cpuid.
Signed-off-by: Marcelo Tosatti <[EMAIL PROTECTED]>
Index: linux-2.6-x86-kvm/arch/x86/Kconfig
===================================================================
--- linux-2.6-x86-kvm.orig/arch/x86/Kconfig
+++ linux-2.6-x86-kvm/arch/x86/Kconfig
@@ -357,6 +356,14 @@ config VMI
at the moment), by linking the kernel to a GPL-ed ROM module
provided by the hypervisor.
+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"
endif
Index: linux-2.6-x86-kvm/arch/x86/kernel/Makefile
===================================================================
--- linux-2.6-x86-kvm.orig/arch/x86/kernel/Makefile
+++ linux-2.6-x86-kvm/arch/x86/kernel/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_K8_NB) += k8.o
obj-$(CONFIG_MGEODE_LX) += geode_32.o mfgpt_32.o
obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o
+obj-$(CONFIG_KVM_GUEST) += kvm.o
obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o
obj-y += pcspeaker.o
Index: linux-2.6-x86-kvm/arch/x86/kernel/kvm.c
===================================================================
--- /dev/null
+++ linux-2.6-x86-kvm/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: linux-2.6-x86-kvm/arch/x86/kernel/setup_32.c
===================================================================
--- linux-2.6-x86-kvm.orig/arch/x86/kernel/setup_32.c
+++ linux-2.6-x86-kvm/arch/x86/kernel/setup_32.c
@@ -46,6 +46,7 @@
#include <linux/pfn.h>
#include <linux/pci.h>
#include <linux/init_ohci1394_dma.h>
+#include <linux/kvm_para.h>
#include <video/edid.h>
@@ -772,6 +773,7 @@ void __init setup_arch(char **cmdline_p)
*/
vmi_init();
#endif
+ kvm_guest_init();
/*
* NOTE: before this point _nobody_ is allowed to allocate
Index: linux-2.6-x86-kvm/arch/x86/kernel/setup_64.c
===================================================================
--- linux-2.6-x86-kvm.orig/arch/x86/kernel/setup_64.c
+++ linux-2.6-x86-kvm/arch/x86/kernel/setup_64.c
@@ -42,6 +42,7 @@
#include <linux/ctype.h>
#include <linux/uaccess.h>
#include <linux/init_ohci1394_dma.h>
+#include <linux/kvm_para.h>
#include <asm/mtrr.h>
#include <asm/uaccess.h>
@@ -506,6 +507,8 @@ 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: linux-2.6-x86-kvm/arch/x86/kvm/x86.c
===================================================================
--- linux-2.6-x86-kvm.orig/arch/x86/kvm/x86.c
+++ linux-2.6-x86-kvm/arch/x86/kvm/x86.c
@@ -680,6 +680,7 @@ int kvm_dev_ioctl_check_extension(long e
case KVM_CAP_USER_MEMORY:
case KVM_CAP_SET_TSS_ADDR:
case KVM_CAP_EXT_CPUID:
+ case KVM_CAP_PARA_FEATURES:
r = 1;
break;
case KVM_CAP_VAPIC:
@@ -727,6 +728,15 @@ long kvm_arch_dev_ioctl(struct file *fil
r = 0;
break;
}
+ case KVM_GET_PARA_FEATURES: {
+ __u32 para_features = KVM_PARA_FEATURES;
+
+ r = -EFAULT;
+ if (copy_to_user(argp, ¶_features, sizeof para_features))
+ goto out;
+ r = 0;
+ break;
+ }
default:
r = -EINVAL;
}
Index: linux-2.6-x86-kvm/include/asm-x86/kvm_para.h
===================================================================
--- linux-2.6-x86-kvm.orig/include/asm-x86/kvm_para.h
+++ linux-2.6-x86-kvm/include/asm-x86/kvm_para.h
@@ -5,6 +5,7 @@
* should be used to determine that a VM is running under KVM.
*/
#define KVM_CPUID_SIGNATURE 0x40000000
+#define KVM_FEATURE_NOP_IO_DELAY 0
/* This CPUID returns a feature bitmap in eax. Before enabling a particular
* paravirtualization, the appropriate feature bit should be checked.
@@ -14,6 +15,8 @@
#ifdef __KERNEL__
#include <asm/processor.h>
+#define KVM_PARA_FEATURES (1UL << KVM_FEATURE_NOP_IO_DELAY)
+
/* This instruction is vmcall. On non-VT architectures, it will generate a
* trap that we will then rewrite to the appropriate instruction.
*/
Index: linux-2.6-x86-kvm/include/linux/kvm.h
===================================================================
--- linux-2.6-x86-kvm.orig/include/linux/kvm.h
+++ linux-2.6-x86-kvm/include/linux/kvm.h
@@ -221,6 +221,7 @@ struct kvm_vapic_addr {
* Get size for mmap(vcpu_fd)
*/
#define KVM_GET_VCPU_MMAP_SIZE _IO(KVMIO, 0x04) /* in bytes */
+#define KVM_GET_PARA_FEATURES _IOR(KVMIO, 0x05, __u32)
/*
* Extension capability list.
@@ -232,6 +233,7 @@ struct kvm_vapic_addr {
#define KVM_CAP_SET_TSS_ADDR 4
#define KVM_CAP_EXT_CPUID 5
#define KVM_CAP_VAPIC 6
+#define KVM_CAP_PARA_FEATURES 7
/*
* ioctls for VM fds
Index: linux-2.6-x86-kvm/include/linux/kvm_para.h
===================================================================
--- linux-2.6-x86-kvm.orig/include/linux/kvm_para.h
+++ linux-2.6-x86-kvm/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))
--
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