[PATCH 30/38] KVM: Make vcpu_load() and vcpu_put() arch operations

From: Avi Kivity
Date: Mon Nov 27 2006 - 07:40:59 EST


Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>

Index: linux-2.6/drivers/kvm/kvm.h
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm.h
+++ linux-2.6/drivers/kvm/kvm.h
@@ -260,6 +260,9 @@ struct kvm_arch_ops {
int (*hardware_setup)(void); /* __init */
void (*hardware_unsetup)(void); /* __exit */

+ struct kvm_vcpu *(*vcpu_load)(struct kvm_vcpu *vcpu);
+ void (*vcpu_put)(struct kvm_vcpu *vcpu);
+
int (*set_guest_debug)(struct kvm_vcpu *vcpu,
struct kvm_debug_guest *dbg);
int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
@@ -296,6 +299,8 @@ struct kvm_arch_ops {
void (*skip_emulated_instruction)(struct kvm_vcpu *vcpu);
};

+void __vcpu_clear(void *arg); /* temporary hack */
+
extern struct kvm_stat kvm_stat;
extern struct kvm_arch_ops *kvm_arch_ops;

@@ -373,6 +378,8 @@ int kvm_write_guest(struct kvm_vcpu *vcp
void vmcs_writel(unsigned long field, unsigned long value);
unsigned long vmcs_readl(unsigned long field);

+unsigned long segment_base(u16 selector);
+
static inline struct page *_gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
@@ -501,6 +508,18 @@ static inline void get_idt(struct descri
asm ("sidt %0" : "=m"(*table));
}

+static inline void get_gdt(struct descriptor_table *table)
+{
+ asm ("sgdt %0" : "=m"(*table));
+}
+
+static inline unsigned long read_tr_base(void)
+{
+ u16 tr;
+ asm ("str %0" : "=g"(tr));
+ return segment_base(tr);
+}
+
#ifdef __x86_64__
static inline unsigned long read_msr(unsigned long msr)
{
Index: linux-2.6/drivers/kvm/kvm_main.c
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm_main.c
+++ linux-2.6/drivers/kvm/kvm_main.c
@@ -84,11 +84,6 @@ struct vmx_msr_entry *find_msr_entry(str
}
EXPORT_SYMBOL_GPL(find_msr_entry);

-static void get_gdt(struct descriptor_table *table)
-{
- asm ("sgdt %0" : "=m"(*table));
-}
-
struct segment_descriptor {
u16 limit_low;
u16 base_low;
@@ -115,7 +110,7 @@ struct segment_descriptor_64 {

#endif

-static unsigned long segment_base(u16 selector)
+unsigned long segment_base(u16 selector)
{
struct descriptor_table gdt;
struct segment_descriptor *d;
@@ -141,17 +136,12 @@ static unsigned long segment_base(u16 se
#endif
return v;
}
-
-static unsigned long read_tr_base(void)
-{
- u16 tr;
- asm ("str %0" : "=g"(tr));
- return segment_base(tr);
-}
+EXPORT_SYMBOL_GPL(segment_base);

DEFINE_PER_CPU(struct vmcs *, vmxarea);
EXPORT_SYMBOL_GPL(per_cpu__vmxarea); /* temporary hack */
-static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
+DEFINE_PER_CPU(struct vmcs *, current_vmcs);
+EXPORT_SYMBOL_GPL(per_cpu__current_vmcs); /* temporary hack */

struct vmcs_descriptor {
int size;
@@ -242,7 +232,7 @@ static void vmcs_clear(struct vmcs *vmcs
vmcs, phys_addr);
}

-static void __vcpu_clear(void *arg)
+void __vcpu_clear(void *arg)
{
struct kvm_vcpu *vcpu = arg;
int cpu = smp_processor_id();
@@ -252,6 +242,7 @@ static void __vcpu_clear(void *arg)
if (per_cpu(current_vmcs, cpu) == vcpu->vmcs)
per_cpu(current_vmcs, cpu) = 0;
}
+EXPORT_SYMBOL_GPL(__vcpu_clear);

static int vcpu_slot(struct kvm_vcpu *vcpu)
{
@@ -259,53 +250,6 @@ static int vcpu_slot(struct kvm_vcpu *vc
}

/*
- * Switches to specified vcpu, until a matching vcpu_put(), but assumes
- * vcpu mutex is already taken.
- */
-static struct kvm_vcpu *__vcpu_load(struct kvm_vcpu *vcpu)
-{
- u64 phys_addr = __pa(vcpu->vmcs);
- int cpu;
-
- cpu = get_cpu();
-
- if (vcpu->cpu != cpu) {
- smp_call_function(__vcpu_clear, vcpu, 0, 1);
- vcpu->launched = 0;
- }
-
- if (per_cpu(current_vmcs, cpu) != vcpu->vmcs) {
- u8 error;
-
- per_cpu(current_vmcs, cpu) = vcpu->vmcs;
- asm volatile (ASM_VMX_VMPTRLD_RAX "; setna %0"
- : "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
- : "cc");
- if (error)
- printk(KERN_ERR "kvm: vmptrld %p/%llx fail\n",
- vcpu->vmcs, phys_addr);
- }
-
- if (vcpu->cpu != cpu) {
- struct descriptor_table dt;
- unsigned long sysenter_esp;
-
- vcpu->cpu = cpu;
- /*
- * Linux uses per-cpu TSS and GDT, so set these when switching
- * processors.
- */
- vmcs_writel(HOST_TR_BASE, read_tr_base()); /* 22.2.4 */
- get_gdt(&dt);
- vmcs_writel(HOST_GDTR_BASE, dt.base); /* 22.2.4 */
-
- rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
- vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
- }
- return vcpu;
-}
-
-/*
* Switches to specified vcpu, until a matching vcpu_put()
*/
static struct kvm_vcpu *vcpu_load(struct kvm *kvm, int vcpu_slot)
@@ -317,11 +261,12 @@ static struct kvm_vcpu *vcpu_load(struct
mutex_unlock(&vcpu->mutex);
return 0;
}
- return __vcpu_load(vcpu);
+ return kvm_arch_ops->vcpu_load(vcpu);
}

static void vcpu_put(struct kvm_vcpu *vcpu)
{
+ kvm_arch_ops->vcpu_put(vcpu);
put_cpu();
mutex_unlock(&vcpu->mutex);
}
@@ -698,7 +643,7 @@ static int kvm_dev_ioctl_create_vcpu(str
vcpu->vmcs = vmcs;
vcpu->launched = 0;

- __vcpu_load(vcpu);
+ kvm_arch_ops->vcpu_load(vcpu);

r = kvm_arch_ops->vcpu_setup(vcpu);
if (r >= 0)
Index: linux-2.6/drivers/kvm/vmx.c
===================================================================
--- linux-2.6.orig/drivers/kvm/vmx.c
+++ linux-2.6/drivers/kvm/vmx.c
@@ -29,6 +29,7 @@ MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");

DECLARE_PER_CPU(struct vmcs *, vmxarea);
+DECLARE_PER_CPU(struct vmcs *, current_vmcs);

#ifdef __x86_64__
#define HOST_IS_64 1
@@ -76,6 +77,58 @@ static const u32 vmx_msr_index[] = {

struct vmx_msr_entry *find_msr_entry(struct kvm_vcpu *vcpu, u32 msr);

+/*
+ * Switches to specified vcpu, until a matching vcpu_put(), but assumes
+ * vcpu mutex is already taken.
+ */
+static struct kvm_vcpu *vmx_vcpu_load(struct kvm_vcpu *vcpu)
+{
+ u64 phys_addr = __pa(vcpu->vmcs);
+ int cpu;
+
+ cpu = get_cpu();
+
+ if (vcpu->cpu != cpu) {
+ smp_call_function(__vcpu_clear, vcpu, 0, 1);
+ vcpu->launched = 0;
+ }
+
+ if (per_cpu(current_vmcs, cpu) != vcpu->vmcs) {
+ u8 error;
+
+ per_cpu(current_vmcs, cpu) = vcpu->vmcs;
+ asm volatile (ASM_VMX_VMPTRLD_RAX "; setna %0"
+ : "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
+ : "cc");
+ if (error)
+ printk(KERN_ERR "kvm: vmptrld %p/%llx fail\n",
+ vcpu->vmcs, phys_addr);
+ }
+
+ if (vcpu->cpu != cpu) {
+ struct descriptor_table dt;
+ unsigned long sysenter_esp;
+
+ vcpu->cpu = cpu;
+ /*
+ * Linux uses per-cpu TSS and GDT, so set these when switching
+ * processors.
+ */
+ vmcs_writel(HOST_TR_BASE, read_tr_base()); /* 22.2.4 */
+ get_gdt(&dt);
+ vmcs_writel(HOST_GDTR_BASE, dt.base); /* 22.2.4 */
+
+ rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
+ vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
+ }
+ return vcpu;
+}
+
+static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
+{
+ put_cpu();
+}
+
static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
{
return vmcs_readl(GUEST_RFLAGS);
@@ -1745,6 +1798,9 @@ static struct kvm_arch_ops vmx_arch_ops
.hardware_enable = hardware_enable,
.hardware_disable = hardware_disable,

+ .vcpu_load = vmx_vcpu_load,
+ .vcpu_put = vmx_vcpu_put,
+
.set_guest_debug = set_guest_debug,
.get_msr = vmx_get_msr,
.set_msr = vmx_set_msr,
-
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