[Qemu-devel] [PULL 1/1] target-i386: kvm: Report kvm_pv_unhalt as unsupported w/o kernel_irqchip

[Eduardo Habkost <ehabkost@redhat.com>]

The kvm_pv_unhalt feature doesn't work if kernel_irqchip is
disabled, so we need to report it as unsupported.

Tested-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 target-i386/kvm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 0b2016a..d1a25c5 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -329,6 +329,13 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function,
          */
         cpuid_1_edx = kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX);
         ret |= cpuid_1_edx & CPUID_EXT2_AMD_ALIASES;
+    } else if (function == KVM_CPUID_FEATURES && reg == R_EAX) {
+        /* kvm_pv_unhalt is reported by GET_SUPPORTED_CPUID, but it can't
+         * be enabled without the in-kernel irqchip
+         */
+        if (!kvm_irqchip_in_kernel()) {
+            ret &= ~(1U << KVM_FEATURE_PV_UNHALT);
+        }
     }
 
     /* fallback for older kernels */
-- 
2.7.4