KVM: pending irq save/restore

Add in kernel irqchip save/restore support for pending vectors.

[avi: fix compile warning on i386]
[avi: remove printk]

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

4 files changed, 54 insertions, 3 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index bb506b71797d..f8fe87d3ddbd 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -490,6 +490,8 @@ struct kvm_arch_ops {
         void (*skip_emulated_instruction)(struct kvm_vcpu *vcpu);
         void (*patch_hypercall)(struct kvm_vcpu *vcpu,
                                 unsigned char *hypercall_addr);
+        int (*get_irq)(struct kvm_vcpu *vcpu);
+        void (*set_irq)(struct kvm_vcpu *vcpu, int vec);
 };
 
 extern struct kvm_arch_ops *kvm_arch_ops;
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index a012d70d9eff..d56964a6eb80 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2126,6 +2126,7 @@ static int kvm_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                                     struct kvm_sregs *sregs)
 {
         struct descriptor_table dt;
+        int pending_vec;
 
         vcpu_load(vcpu);
 
@@ -2155,10 +2156,13 @@ static int kvm_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
         sregs->efer = vcpu->shadow_efer;
         sregs->apic_base = kvm_get_apic_base(vcpu);
 
-        if (irqchip_in_kernel(vcpu->kvm))
+        if (irqchip_in_kernel(vcpu->kvm)) {
                 memset(sregs->interrupt_bitmap, 0,
                        sizeof sregs->interrupt_bitmap);
-        else
+                pending_vec = kvm_arch_ops->get_irq(vcpu);
+                if (pending_vec >= 0)
+                        set_bit(pending_vec, (unsigned long *)sregs->interrupt_bitmap);
+        } else
                 memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
                        sizeof sregs->interrupt_bitmap);
 
@@ -2177,7 +2181,7 @@ static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                                     struct kvm_sregs *sregs)
 {
         int mmu_reset_needed = 0;
-        int i;
+        int i, pending_vec, max_bits;
         struct descriptor_table dt;
 
         vcpu_load(vcpu);
@@ -2221,6 +2225,16 @@ static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                 for (i = 0; i < ARRAY_SIZE(vcpu->irq_pending); ++i)
                         if (vcpu->irq_pending[i])
                                 __set_bit(i, &vcpu->irq_summary);
+        } else {
+                max_bits = (sizeof sregs->interrupt_bitmap) << 3;
+                pending_vec = find_first_bit(
+                        (const unsigned long *)sregs->interrupt_bitmap,
+                        max_bits);
+                /* Only pending external irq is handled here */
+                if (pending_vec < max_bits) {
+                        kvm_arch_ops->set_irq(vcpu, pending_vec);
+                        printk("Set back pending irq %d\n", pending_vec);
+                }
         }
 
         set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index a347b61644cd..c8cd242f36ff 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -843,6 +843,16 @@ static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg)
         return -EOPNOTSUPP;
 }
 
+static int svm_get_irq(struct kvm_vcpu *vcpu)
+{
+        struct vcpu_svm *svm = to_svm(vcpu);
+        u32 exit_int_info = svm->vmcb->control.exit_int_info;
+
+        if (is_external_interrupt(exit_int_info))
+                return exit_int_info & SVM_EVTINJ_VEC_MASK;
+        return -1;
+}
+
 static void load_host_msrs(struct kvm_vcpu *vcpu)
 {
 #ifdef CONFIG_X86_64
@@ -1310,6 +1320,13 @@ static inline void svm_inject_irq(struct vcpu_svm *svm, int irq)
                 ((/*control->int_vector >> 4*/ 0xf) << V_INTR_PRIO_SHIFT);
 }
 
+static void svm_set_irq(struct kvm_vcpu *vcpu, int irq)
+{
+        struct vcpu_svm *svm = to_svm(vcpu);
+
+        svm_inject_irq(svm, irq);
+}
+
 static void svm_intr_assist(struct vcpu_svm *svm)
 {
         struct vmcb *vmcb = svm->vmcb;
@@ -1783,6 +1800,8 @@ static struct kvm_arch_ops svm_arch_ops = {
         .run = svm_vcpu_run,
         .skip_emulated_instruction = skip_emulated_instruction,
         .patch_hypercall = svm_patch_hypercall,
+        .get_irq = svm_get_irq,
+        .set_irq = svm_set_irq,
 };
 
 static int __init svm_init(void)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 7ec8cf84e6ea..6c371ea21046 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -790,6 +790,20 @@ static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg)
         return 0;
 }
 
+static int vmx_get_irq(struct kvm_vcpu *vcpu)
+{
+        u32 idtv_info_field;
+
+        idtv_info_field = vmcs_read32(IDT_VECTORING_INFO_FIELD);
+        if (idtv_info_field & INTR_INFO_VALID_MASK) {
+                if (is_external_interrupt(idtv_info_field))
+                        return idtv_info_field & VECTORING_INFO_VECTOR_MASK;
+                else
+                        printk("pending exception: not handled yet\n");
+        }
+        return -1;
+}
+
 static __init int cpu_has_kvm_support(void)
 {
         unsigned long ecx = cpuid_ecx(1);
@@ -2500,6 +2514,8 @@ static struct kvm_arch_ops vmx_arch_ops = {
         .run = vmx_vcpu_run,
         .skip_emulated_instruction = skip_emulated_instruction,
         .patch_hypercall = vmx_patch_hypercall,
+        .get_irq = vmx_get_irq,
+        .set_irq = vmx_inject_irq,
 };
 
 static int __init vmx_init(void)