[PATCH 1/2] kvm: Add support for KVM_CAP_HAS_SMALLER_MAXPHYADDR

[Mohammed Gamal]

This adds the KVM_CAP_HAS_SMALLER_MAXPHYADDR capability
and a helper function to check for this capability.
This will allow QEMU to decide to what to do if the host
CPU can't handle GUEST_MAXPHYADDR < HOST_MAXPHYADDR properly.

Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
---
 linux-headers/linux/kvm.h | 1 +
 target/i386/kvm.c         | 5 +++++
 target/i386/kvm_i386.h    | 1 +
 3 files changed, 7 insertions(+)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 9804495a46..9eb61a303f 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -1017,6 +1017,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_S390_VCPU_RESETS 179
 #define KVM_CAP_S390_PROTECTED 180
 #define KVM_CAP_PPC_SECURE_GUEST 181
+#define KVM_CAP_SMALLER_MAXPHYADDR 184
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index b3c13cb898..01100dbf20 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -136,6 +136,11 @@ bool kvm_has_smm(void)
     return kvm_check_extension(kvm_state, KVM_CAP_X86_SMM);
 }
 
+bool kvm_has_smaller_maxphyaddr(void)
+{
+    return kvm_check_extension(kvm_state, KVM_CAP_SMALLER_MAXPHYADDR);
+}
+
 bool kvm_has_adjust_clock_stable(void)
 {
     int ret = kvm_check_extension(kvm_state, KVM_CAP_ADJUST_CLOCK);
diff --git a/target/i386/kvm_i386.h b/target/i386/kvm_i386.h
index 00bde7acaf..513f8eebbb 100644
--- a/target/i386/kvm_i386.h
+++ b/target/i386/kvm_i386.h
@@ -34,6 +34,7 @@
 
 bool kvm_allows_irq0_override(void);
 bool kvm_has_smm(void);
+bool kvm_has_smaller_maxphyaddr(void);
 bool kvm_has_adjust_clock_stable(void);
 bool kvm_has_exception_payload(void);
 void kvm_synchronize_all_tsc(void);
-- 
2.26.2