[PATCH 5.4 16/98] KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint

[Greg Kroah-Hartman]

From: Paolo Bonzini <pbonz...@redhat.com>

commit 72c3bcdcda494cbd600712a32e67702cdee60c07 upstream.

Centralize handling of interrupts from the userspace APIC
in kvm_cpu_has_extint and kvm_cpu_get_extint, since
userspace APIC interrupts are handled more or less the
same as ExtINTs are with split irqchip.  This removes
duplicated code from kvm_cpu_has_injectable_intr and
kvm_cpu_has_interrupt, and makes the code more similar
between kvm_cpu_has_{extint,interrupt} on one side
and kvm_cpu_get_{extint,interrupt} on the other.

Cc: sta...@vger.kernel.org
Reviewed-by: Filippo Sironi <sir...@amazon.de>
Reviewed-by: David Woodhouse <d...@amazon.co.uk>
Tested-by: David Woodhouse <d...@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/x86/kvm/irq.c   |   83 ++++++++++++++++++++-------------------------------
 arch/x86/kvm/lapic.c |    2 -
 2 files changed, 34 insertions(+), 51 deletions(-)

--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -42,27 +42,8 @@ static int pending_userspace_extint(stru
  */
 static int kvm_cpu_has_extint(struct kvm_vcpu *v)
 {
-       u8 accept = kvm_apic_accept_pic_intr(v);
-
-       if (accept) {
-               if (irqchip_split(v->kvm))
-                       return pending_userspace_extint(v);
-               else
-                       return v->kvm->arch.vpic->output;
-       } else
-               return 0;
-}
-
-/*
- * check if there is injectable interrupt:
- * when virtual interrupt delivery enabled,
- * interrupt from apic will handled by hardware,
- * we don't need to check it here.
- */
-int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
-{
        /*
-        * FIXME: interrupt.injected represents an interrupt that it's
+        * FIXME: interrupt.injected represents an interrupt whose
         * side-effects have already been applied (e.g. bit from IRR
         * already moved to ISR). Therefore, it is incorrect to rely
         * on interrupt.injected to know if there is a pending
@@ -75,6 +56,23 @@ int kvm_cpu_has_injectable_intr(struct k
        if (!lapic_in_kernel(v))
                return v->arch.interrupt.injected;
 
+       if (!kvm_apic_accept_pic_intr(v))
+               return 0;
+
+       if (irqchip_split(v->kvm))
+               return pending_userspace_extint(v);
+       else
+               return v->kvm->arch.vpic->output;
+}
+
+/*
+ * check if there is injectable interrupt:
+ * when virtual interrupt delivery enabled,
+ * interrupt from apic will handled by hardware,
+ * we don't need to check it here.
+ */
+int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
+{
        if (kvm_cpu_has_extint(v))
                return 1;
 
@@ -90,20 +88,6 @@ int kvm_cpu_has_injectable_intr(struct k
  */
 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
 {
-       /*
-        * FIXME: interrupt.injected represents an interrupt that it's
-        * side-effects have already been applied (e.g. bit from IRR
-        * already moved to ISR). Therefore, it is incorrect to rely
-        * on interrupt.injected to know if there is a pending
-        * interrupt in the user-mode LAPIC.
-        * This leads to nVMX/nSVM not be able to distinguish
-        * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
-        * pending interrupt or should re-inject an injected
-        * interrupt.
-        */
-       if (!lapic_in_kernel(v))
-               return v->arch.interrupt.injected;
-
        if (kvm_cpu_has_extint(v))
                return 1;
 
@@ -117,16 +101,21 @@ EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt)
  */
 static int kvm_cpu_get_extint(struct kvm_vcpu *v)
 {
-       if (kvm_cpu_has_extint(v)) {
-               if (irqchip_split(v->kvm)) {
-                       int vector = v->arch.pending_external_vector;
-
-                       v->arch.pending_external_vector = -1;
-                       return vector;
-               } else
-                       return kvm_pic_read_irq(v->kvm); /* PIC */
-       } else
+       if (!kvm_cpu_has_extint(v)) {
+               WARN_ON(!lapic_in_kernel(v));
                return -1;
+       }
+
+       if (!lapic_in_kernel(v))
+               return v->arch.interrupt.nr;
+
+       if (irqchip_split(v->kvm)) {
+               int vector = v->arch.pending_external_vector;
+
+               v->arch.pending_external_vector = -1;
+               return vector;
+       } else
+               return kvm_pic_read_irq(v->kvm); /* PIC */
 }
 
 /*
@@ -134,13 +123,7 @@ static int kvm_cpu_get_extint(struct kvm
  */
 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
 {
-       int vector;
-
-       if (!lapic_in_kernel(v))
-               return v->arch.interrupt.nr;
-
-       vector = kvm_cpu_get_extint(v);
-
+       int vector = kvm_cpu_get_extint(v);
        if (vector != -1)
                return vector;                  /* PIC */
 
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2330,7 +2330,7 @@ int kvm_apic_has_interrupt(struct kvm_vc
        struct kvm_lapic *apic = vcpu->arch.apic;
        u32 ppr;
 
-       if (!kvm_apic_hw_enabled(apic))
+       if (!kvm_apic_present(vcpu))
                return -1;
 
        __apic_update_ppr(apic, &ppr);