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-rw-r--r--drivers/kvm/kvm.h4
-rw-r--r--drivers/kvm/kvm_main.c11
-rw-r--r--drivers/kvm/svm.c94
-rw-r--r--drivers/kvm/vmx.c88
-rw-r--r--include/linux/kvm.h11
5 files changed, 180 insertions, 28 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 100df6f38d9..32023d1ac24 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -173,6 +173,7 @@ struct kvm_vcpu {
struct mutex mutex;
int cpu;
int launched;
+ int interrupt_window_open;
unsigned long irq_summary; /* bit vector: 1 per word in irq_pending */
#define NR_IRQ_WORDS KVM_IRQ_BITMAP_SIZE(unsigned long)
unsigned long irq_pending[NR_IRQ_WORDS];
@@ -247,6 +248,9 @@ struct kvm_stat {
u32 io_exits;
u32 mmio_exits;
u32 signal_exits;
+ u32 irq_window_exits;
+ u32 halt_exits;
+ u32 request_irq_exits;
u32 irq_exits;
};
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index b54caf0ceeb..aca14139a68 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -58,6 +58,9 @@ static struct kvm_stats_debugfs_item {
{ "io_exits", &kvm_stat.io_exits },
{ "mmio_exits", &kvm_stat.mmio_exits },
{ "signal_exits", &kvm_stat.signal_exits },
+ { "irq_window", &kvm_stat.irq_window_exits },
+ { "halt_exits", &kvm_stat.halt_exits },
+ { "request_irq", &kvm_stat.request_irq_exits },
{ "irq_exits", &kvm_stat.irq_exits },
{ 0, 0 }
};
@@ -1693,12 +1696,12 @@ static long kvm_dev_ioctl(struct file *filp,
if (copy_from_user(&kvm_run, (void *)arg, sizeof kvm_run))
goto out;
r = kvm_dev_ioctl_run(kvm, &kvm_run);
- if (r < 0)
+ if (r < 0 && r != -EINTR)
goto out;
- r = -EFAULT;
- if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run))
+ if (copy_to_user((void *)arg, &kvm_run, sizeof kvm_run)) {
+ r = -EFAULT;
goto out;
- r = 0;
+ }
break;
}
case KVM_GET_REGS: {
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index fa042873571..855207a9b39 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -235,6 +235,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
vcpu->rip = vcpu->svm->vmcb->save.rip = vcpu->svm->next_rip;
vcpu->svm->vmcb->control.int_state &= ~SVM_INTERRUPT_SHADOW_MASK;
+
+ vcpu->interrupt_window_open = 1;
}
static int has_svm(void)
@@ -1031,10 +1033,11 @@ static int halt_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
vcpu->svm->next_rip = vcpu->svm->vmcb->save.rip + 1;
skip_emulated_instruction(vcpu);
- if (vcpu->irq_summary && (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF))
+ if (vcpu->irq_summary)
return 1;
kvm_run->exit_reason = KVM_EXIT_HLT;
+ ++kvm_stat.halt_exits;
return 0;
}
@@ -1186,6 +1189,24 @@ static int msr_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
return rdmsr_interception(vcpu, kvm_run);
}
+static int interrupt_window_interception(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ /*
+ * If the user space waits to inject interrupts, exit as soon as
+ * possible
+ */
+ if (kvm_run->request_interrupt_window &&
+ !vcpu->irq_summary &&
+ (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF)) {
+ ++kvm_stat.irq_window_exits;
+ kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
+ return 0;
+ }
+
+ return 1;
+}
+
static int (*svm_exit_handlers[])(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run) = {
[SVM_EXIT_READ_CR0] = emulate_on_interception,
@@ -1210,6 +1231,7 @@ static int (*svm_exit_handlers[])(struct kvm_vcpu *vcpu,
[SVM_EXIT_NMI] = nop_on_interception,
[SVM_EXIT_SMI] = nop_on_interception,
[SVM_EXIT_INIT] = nop_on_interception,
+ [SVM_EXIT_VINTR] = interrupt_window_interception,
/* [SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception, */
[SVM_EXIT_CPUID] = cpuid_interception,
[SVM_EXIT_HLT] = halt_interception,
@@ -1278,15 +1300,11 @@ static void pre_svm_run(struct kvm_vcpu *vcpu)
}
-static inline void kvm_try_inject_irq(struct kvm_vcpu *vcpu)
+static inline void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
{
struct vmcb_control_area *control;
- if (!vcpu->irq_summary)
- return;
-
control = &vcpu->svm->vmcb->control;
-
control->int_vector = pop_irq(vcpu);
control->int_ctl &= ~V_INTR_PRIO_MASK;
control->int_ctl |= V_IRQ_MASK |
@@ -1301,6 +1319,59 @@ static void kvm_reput_irq(struct kvm_vcpu *vcpu)
control->int_ctl &= ~V_IRQ_MASK;
push_irq(vcpu, control->int_vector);
}
+
+ vcpu->interrupt_window_open =
+ !(control->int_state & SVM_INTERRUPT_SHADOW_MASK);
+}
+
+static void do_interrupt_requests(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ struct vmcb_control_area *control = &vcpu->svm->vmcb->control;
+
+ vcpu->interrupt_window_open =
+ (!(control->int_state & SVM_INTERRUPT_SHADOW_MASK) &&
+ (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF));
+
+ if (vcpu->interrupt_window_open && vcpu->irq_summary)
+ /*
+ * If interrupts enabled, and not blocked by sti or mov ss. Good.
+ */
+ kvm_do_inject_irq(vcpu);
+
+ /*
+ * Interrupts blocked. Wait for unblock.
+ */
+ if (!vcpu->interrupt_window_open &&
+ (vcpu->irq_summary || kvm_run->request_interrupt_window)) {
+ control->intercept |= 1ULL << INTERCEPT_VINTR;
+ } else
+ control->intercept &= ~(1ULL << INTERCEPT_VINTR);
+}
+
+static void post_kvm_run_save(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ kvm_run->ready_for_interrupt_injection = (vcpu->interrupt_window_open &&
+ vcpu->irq_summary == 0);
+ kvm_run->if_flag = (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF) != 0;
+ kvm_run->cr8 = vcpu->cr8;
+ kvm_run->apic_base = vcpu->apic_base;
+}
+
+/*
+ * Check if userspace requested an interrupt window, and that the
+ * interrupt window is open.
+ *
+ * No need to exit to userspace if we already have an interrupt queued.
+ */
+static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ return (!vcpu->irq_summary &&
+ kvm_run->request_interrupt_window &&
+ vcpu->interrupt_window_open &&
+ (vcpu->svm->vmcb->save.rflags & X86_EFLAGS_IF));
}
static void save_db_regs(unsigned long *db_regs)
@@ -1326,7 +1397,7 @@ static int svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
u16 ldt_selector;
again:
- kvm_try_inject_irq(vcpu);
+ do_interrupt_requests(vcpu, kvm_run);
clgi();
@@ -1487,17 +1558,26 @@ again:
if (vcpu->svm->vmcb->control.exit_code == SVM_EXIT_ERR) {
kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY;
kvm_run->exit_reason = vcpu->svm->vmcb->control.exit_code;
+ post_kvm_run_save(vcpu, kvm_run);
return 0;
}
if (handle_exit(vcpu, kvm_run)) {
if (signal_pending(current)) {
++kvm_stat.signal_exits;
+ post_kvm_run_save(vcpu, kvm_run);
+ return -EINTR;
+ }
+
+ if (dm_request_for_irq_injection(vcpu, kvm_run)) {
+ ++kvm_stat.request_irq_exits;
+ post_kvm_run_save(vcpu, kvm_run);
return -EINTR;
}
kvm_resched(vcpu);
goto again;
}
+ post_kvm_run_save(vcpu, kvm_run);
return 0;
}
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 2d204fd4597..c55635ddf42 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -263,6 +263,7 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
if (interruptibility & 3)
vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
interruptibility & ~3);
+ vcpu->interrupt_window_open = 1;
}
static void vmx_inject_gp(struct kvm_vcpu *vcpu, unsigned error_code)
@@ -1214,21 +1215,34 @@ static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
irq | INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK);
}
-static void kvm_try_inject_irq(struct kvm_vcpu *vcpu)
+
+static void do_interrupt_requests(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
{
- if ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF)
- && (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0)
+ u32 cpu_based_vm_exec_control;
+
+ vcpu->interrupt_window_open =
+ ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) &&
+ (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0);
+
+ if (vcpu->interrupt_window_open &&
+ vcpu->irq_summary &&
+ !(vmcs_read32(VM_ENTRY_INTR_INFO_FIELD) & INTR_INFO_VALID_MASK))
/*
- * Interrupts enabled, and not blocked by sti or mov ss. Good.
+ * If interrupts enabled, and not blocked by sti or mov ss. Good.
*/
kvm_do_inject_irq(vcpu);
- else
+
+ cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
+ if (!vcpu->interrupt_window_open &&
+ (vcpu->irq_summary || kvm_run->request_interrupt_window))
/*
* Interrupts blocked. Wait for unblock.
*/
- vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,
- vmcs_read32(CPU_BASED_VM_EXEC_CONTROL)
- | CPU_BASED_VIRTUAL_INTR_PENDING);
+ cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
+ else
+ cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
+ vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}
static void kvm_guest_debug_pre(struct kvm_vcpu *vcpu)
@@ -1565,23 +1579,41 @@ static int handle_wrmsr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
return 1;
}
+static void post_kvm_run_save(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ kvm_run->if_flag = (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) != 0;
+ kvm_run->cr8 = vcpu->cr8;
+ kvm_run->apic_base = vcpu->apic_base;
+ kvm_run->ready_for_interrupt_injection = (vcpu->interrupt_window_open &&
+ vcpu->irq_summary == 0);
+}
+
static int handle_interrupt_window(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run)
{
- /* Turn off interrupt window reporting. */
- vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,
- vmcs_read32(CPU_BASED_VM_EXEC_CONTROL)
- & ~CPU_BASED_VIRTUAL_INTR_PENDING);
+ /*
+ * If the user space waits to inject interrupts, exit as soon as
+ * possible
+ */
+ if (kvm_run->request_interrupt_window &&
+ !vcpu->irq_summary &&
+ (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF)) {
+ kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
+ ++kvm_stat.irq_window_exits;
+ return 0;
+ }
return 1;
}
static int handle_halt(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
skip_emulated_instruction(vcpu);
- if (vcpu->irq_summary && (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF))
+ if (vcpu->irq_summary)
return 1;
kvm_run->exit_reason = KVM_EXIT_HLT;
+ ++kvm_stat.halt_exits;
return 0;
}
@@ -1632,6 +1664,21 @@ static int kvm_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
return 0;
}
+/*
+ * Check if userspace requested an interrupt window, and that the
+ * interrupt window is open.
+ *
+ * No need to exit to userspace if we already have an interrupt queued.
+ */
+static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu,
+ struct kvm_run *kvm_run)
+{
+ return (!vcpu->irq_summary &&
+ kvm_run->request_interrupt_window &&
+ vcpu->interrupt_window_open &&
+ (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF));
+}
+
static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
u8 fail;
@@ -1663,9 +1710,7 @@ again:
vmcs_writel(HOST_GS_BASE, segment_base(gs_sel));
#endif
- if (vcpu->irq_summary &&
- !(vmcs_read32(VM_ENTRY_INTR_INFO_FIELD) & INTR_INFO_VALID_MASK))
- kvm_try_inject_irq(vcpu);
+ do_interrupt_requests(vcpu, kvm_run);
if (vcpu->guest_debug.enabled)
kvm_guest_debug_pre(vcpu);
@@ -1802,6 +1847,7 @@ again:
fx_save(vcpu->guest_fx_image);
fx_restore(vcpu->host_fx_image);
+ vcpu->interrupt_window_open = (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0;
#ifndef CONFIG_X86_64
asm ("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));
@@ -1834,12 +1880,22 @@ again:
/* Give scheduler a change to reschedule. */
if (signal_pending(current)) {
++kvm_stat.signal_exits;
+ post_kvm_run_save(vcpu, kvm_run);
+ return -EINTR;
+ }
+
+ if (dm_request_for_irq_injection(vcpu, kvm_run)) {
+ ++kvm_stat.request_irq_exits;
+ post_kvm_run_save(vcpu, kvm_run);
return -EINTR;
}
+
kvm_resched(vcpu);
goto again;
}
}
+
+ post_kvm_run_save(vcpu, kvm_run);
return 0;
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 28fdce1ac1d..bc8b4616bad 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -11,7 +11,7 @@
#include <asm/types.h>
#include <linux/ioctl.h>
-#define KVM_API_VERSION 1
+#define KVM_API_VERSION 2
/*
* Architectural interrupt line count, and the size of the bitmap needed
@@ -45,6 +45,7 @@ enum kvm_exit_reason {
KVM_EXIT_DEBUG = 4,
KVM_EXIT_HLT = 5,
KVM_EXIT_MMIO = 6,
+ KVM_EXIT_IRQ_WINDOW_OPEN = 7,
};
/* for KVM_RUN */
@@ -53,11 +54,19 @@ struct kvm_run {
__u32 vcpu;
__u32 emulated; /* skip current instruction */
__u32 mmio_completed; /* mmio request completed */
+ __u8 request_interrupt_window;
+ __u8 padding1[3];
/* out */
__u32 exit_type;
__u32 exit_reason;
__u32 instruction_length;
+ __u8 ready_for_interrupt_injection;
+ __u8 if_flag;
+ __u16 padding2;
+ __u64 cr8;
+ __u64 apic_base;
+
union {
/* KVM_EXIT_UNKNOWN */
struct {
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-19 01:14:02 +0000