diff --git a/drivers/kvm/Kconfig b/drivers/kvm/Kconfig
index 0a419a0de603a352cb2411cfacbb005f17590d9c..8749fa4ffcee955725e9f8992104c086522828a2 100644
--- a/drivers/kvm/Kconfig
+++ b/drivers/kvm/Kconfig
@@ -17,6 +17,7 @@ if VIRTUALIZATION
config KVM
tristate "Kernel-based Virtual Machine (KVM) support"
depends on X86 && EXPERIMENTAL
+ select PREEMPT_NOTIFIERS
select ANON_INODES
---help---
Support hosting fully virtualized guest machines using hardware
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index e92c84b04c1f382dd02e64a4efc0bb047b746369..0667183ecbed888518b94d36a7d1ea7cad65cf9d 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -13,6 +13,7 @@
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
+#include <linux/preempt.h>
#include <asm/signal.h>
#include <linux/kvm.h>
@@ -301,6 +302,7 @@ void kvm_io_bus_register_dev(struct kvm_io_bus *bus,
struct kvm_vcpu {
struct kvm *kvm;
+ struct preempt_notifier preempt_notifier;
int vcpu_id;
struct mutex mutex;
int cpu;
@@ -429,7 +431,7 @@ struct kvm_arch_ops {
struct kvm_vcpu *(*vcpu_create)(struct kvm *kvm, unsigned id);
void (*vcpu_free)(struct kvm_vcpu *vcpu);
- void (*vcpu_load)(struct kvm_vcpu *vcpu);
+ void (*vcpu_load)(struct kvm_vcpu *vcpu, int cpu);
void (*vcpu_put)(struct kvm_vcpu *vcpu);
void (*vcpu_decache)(struct kvm_vcpu *vcpu);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 20947462f40185dc9aef08b6d48c89e1776d74cf..6035e6d3541722260e43d23afd749618cc65394a 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -54,6 +54,8 @@ static cpumask_t cpus_hardware_enabled;
struct kvm_arch_ops *kvm_arch_ops;
+static __read_mostly struct preempt_ops kvm_preempt_ops;
+
#define STAT_OFFSET(x) offsetof(struct kvm_vcpu, stat.x)
static struct kvm_stats_debugfs_item {
@@ -239,13 +241,21 @@ EXPORT_SYMBOL_GPL(kvm_put_guest_fpu);
*/
static void vcpu_load(struct kvm_vcpu *vcpu)
{
+ int cpu;
+
mutex_lock(&vcpu->mutex);
- kvm_arch_ops->vcpu_load(vcpu);
+ cpu = get_cpu();
+ preempt_notifier_register(&vcpu->preempt_notifier);
+ kvm_arch_ops->vcpu_load(vcpu, cpu);
+ put_cpu();
}
static void vcpu_put(struct kvm_vcpu *vcpu)
{
+ preempt_disable();
kvm_arch_ops->vcpu_put(vcpu);
+ preempt_notifier_unregister(&vcpu->preempt_notifier);
+ preempt_enable();
mutex_unlock(&vcpu->mutex);
}
@@ -1672,9 +1682,7 @@ void kvm_resched(struct kvm_vcpu *vcpu)
{
if (!need_resched())
return;
- vcpu_put(vcpu);
cond_resched();
- vcpu_load(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_resched);
@@ -1722,11 +1730,9 @@ static int pio_copy_data(struct kvm_vcpu *vcpu)
unsigned bytes;
int nr_pages = vcpu->pio.guest_pages[1] ? 2 : 1;
- kvm_arch_ops->vcpu_put(vcpu);
q = vmap(vcpu->pio.guest_pages, nr_pages, VM_READ|VM_WRITE,
PAGE_KERNEL);
if (!q) {
- kvm_arch_ops->vcpu_load(vcpu);
free_pio_guest_pages(vcpu);
return -ENOMEM;
}
@@ -1738,7 +1744,6 @@ static int pio_copy_data(struct kvm_vcpu *vcpu)
memcpy(p, q, bytes);
q -= vcpu->pio.guest_page_offset;
vunmap(q);
- kvm_arch_ops->vcpu_load(vcpu);
free_pio_guest_pages(vcpu);
return 0;
}
@@ -2413,6 +2418,8 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
if (IS_ERR(vcpu))
return PTR_ERR(vcpu);
+ preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
+
vcpu_load(vcpu);
r = kvm_mmu_setup(vcpu);
vcpu_put(vcpu);
@@ -3145,6 +3152,27 @@ static struct sys_device kvm_sysdev = {
hpa_t bad_page_address;
+static inline
+struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
+{
+ return container_of(pn, struct kvm_vcpu, preempt_notifier);
+}
+
+static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
+{
+ struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
+
+ kvm_arch_ops->vcpu_load(vcpu, cpu);
+}
+
+static void kvm_sched_out(struct preempt_notifier *pn,
+ struct task_struct *next)
+{
+ struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
+
+ kvm_arch_ops->vcpu_put(vcpu);
+}
+
int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
{
int r;
@@ -3191,6 +3219,9 @@ int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module)
goto out_free;
}
+ kvm_preempt_ops.sched_in = kvm_sched_in;
+ kvm_preempt_ops.sched_out = kvm_sched_out;
+
return r;
out_free:
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 5437de2aa2d806a16590bf3596c1d032ca0fc681..396c736e546b6926d98ec6c401ef8e7d5c9df55c 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -276,9 +276,7 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
kvm_mmu_free_some_pages(vcpu);
if (r < 0) {
spin_unlock(&vcpu->kvm->lock);
- kvm_arch_ops->vcpu_put(vcpu);
r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
- kvm_arch_ops->vcpu_load(vcpu);
spin_lock(&vcpu->kvm->lock);
kvm_mmu_free_some_pages(vcpu);
}
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 0feec8558599975d927cc641ecef76e7a43504c5..3997bbd78fb76429b18603f7d6f16c61a65c7274 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -625,12 +625,11 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
kfree(svm);
}
-static void svm_vcpu_load(struct kvm_vcpu *vcpu)
+static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- int cpu, i;
+ int i;
- cpu = get_cpu();
if (unlikely(cpu != vcpu->cpu)) {
u64 tsc_this, delta;
@@ -657,7 +656,6 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
rdtscll(vcpu->host_tsc);
- put_cpu();
}
static void svm_vcpu_decache(struct kvm_vcpu *vcpu)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 18f9b0b3fb1f36b7b5981a5d9a0d44d72dd9cd46..8c87d20f8e39135e1560eb47963de74f28fe4b38 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -396,6 +396,7 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
static void vmx_load_host_state(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ unsigned long flags;
if (!vmx->host_state.loaded)
return;
@@ -408,12 +409,12 @@ static void vmx_load_host_state(struct kvm_vcpu *vcpu)
* If we have to reload gs, we must take care to
* preserve our gs base.
*/
- local_irq_disable();
+ local_irq_save(flags);
load_gs(vmx->host_state.gs_sel);
#ifdef CONFIG_X86_64
wrmsrl(MSR_GS_BASE, vmcs_readl(HOST_GS_BASE));
#endif
- local_irq_enable();
+ local_irq_restore(flags);
reload_tss();
}
@@ -427,15 +428,12 @@ static void vmx_load_host_state(struct kvm_vcpu *vcpu)
* Switches to specified vcpu, until a matching vcpu_put(), but assumes
* vcpu mutex is already taken.
*/
-static void vmx_vcpu_load(struct kvm_vcpu *vcpu)
+static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u64 phys_addr = __pa(vmx->vmcs);
- int cpu;
u64 tsc_this, delta;
- cpu = get_cpu();
-
if (vcpu->cpu != cpu)
vcpu_clear(vcpu);
@@ -480,7 +478,6 @@ static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
vmx_load_host_state(vcpu);
kvm_put_guest_fpu(vcpu);
- put_cpu();
}
static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
@@ -2127,6 +2124,8 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (unlikely(r))
goto out;
+ preempt_disable();
+
if (!vcpu->mmio_read_completed)
do_interrupt_requests(vcpu, kvm_run);
@@ -2269,6 +2268,9 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
vcpu->interrupt_window_open = (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0;
asm ("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));
+ vmx->launched = 1;
+
+ preempt_enable();
if (unlikely(fail)) {
kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
@@ -2283,7 +2285,6 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (unlikely(prof_on == KVM_PROFILING))
profile_hit(KVM_PROFILING, (void *)vmcs_readl(GUEST_RIP));
- vmx->launched = 1;
r = kvm_handle_exit(kvm_run, vcpu);
if (r > 0) {
/* Give scheduler a change to reschedule. */
@@ -2372,6 +2373,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
{
int err;
struct vcpu_vmx *vmx = kzalloc(sizeof(*vmx), GFP_KERNEL);
+ int cpu;
if (!vmx)
return ERR_PTR(-ENOMEM);
@@ -2396,9 +2398,11 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
vmcs_clear(vmx->vmcs);
- vmx_vcpu_load(&vmx->vcpu);
+ cpu = get_cpu();
+ vmx_vcpu_load(&vmx->vcpu, cpu);
err = vmx_vcpu_setup(&vmx->vcpu);
vmx_vcpu_put(&vmx->vcpu);
+ put_cpu();
if (err)
goto free_vmcs;