arch-arm,cpu: Move KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 check to Kvm

This change [1] requires performing KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 check.
However, checkExtension() is only available within the Kvm class and
the KvmVM class.

A new function, Kvm::capIRQLineLayout2(), is added for checking the
status of KVM_CAP_ARM_IRQ_LINE_LAYOUT_2.

This fixes a compilation error on Arm systems.

[1] https://gem5-review.googlesource.com/c/public/gem5/+/55964

Change-Id: Ia190e06ab451e0ff8d1c4833cd23b7de8852c6dd
Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/59310
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

src/arch/arm/kvm/gic.cc

@@ -94,15 +94,10 @@ KvmKernelGic::setIntState(unsigned type, unsigned vcpu, unsigned irq,
     const unsigned vcpu_index = vcpu & 0xff;
     const unsigned vcpu2_index = (vcpu >> 8) & 0xff;
 
-#if defined(KVM_CAP_ARM_IRQ_LINE_LAYOUT_2) && defined(KVM_ARM_IRQ_VCPU2_SHIFT)
-    static const bool vcpu2_enabled = vm.checkExtension(
-        KVM_CAP_ARM_IRQ_LINE_LAYOUT_2);
-    uint32_t kvm_vcpu = (vcpu2_index << KVM_ARM_IRQ_VCPU2_SHIFT) |
-                        (vcpu_index << KVM_ARM_IRQ_VCPU_SHIFT);
-#else
-    static const bool vcpu2_enabled = false;
+    static const bool vcpu2_enabled = vm.kvm->capIRQLineLayout2();
     uint32_t kvm_vcpu = (vcpu_index << KVM_ARM_IRQ_VCPU_SHIFT);
-#endif
+    if (vcpu2_enabled)
+        kvm_vcpu |= vcpu2_index << KVM_ARM_IRQ_VCPU2_SHIFT;
 
     panic_if((!vcpu2_enabled && vcpu2_index) || kvm_vcpu > 0xffff,
               "VCPU out of range");

src/cpu/kvm/vm.cc

@@ -204,6 +204,15 @@ Kvm::capXSave() const
 #endif
 }
 
+bool
+Kvm::capIRQLineLayout2() const
+{
+#if defined(KVM_CAP_ARM_IRQ_LINE_LAYOUT_2) && defined(KVM_ARM_IRQ_VCPU2_SHIFT)
+    return checkExtension(KVM_CAP_ARM_IRQ_LINE_LAYOUT_2) != 0;
+#else
+    return false;
+#endif
+}
 
 #if defined(__i386__) || defined(__x86_64__)
 bool

src/cpu/kvm/vm.hh

@@ -145,6 +145,10 @@ class Kvm
 
     /** Support for getting and setting the kvm_xsave structure. */
     bool capXSave() const;
+
+    /** Support for ARM IRQ line layout 2 **/
+    bool capIRQLineLayout2() const;
+
     /** @} */
 
 #if defined(__i386__) || defined(__x86_64__)