[RFC PATCH v8 18/20] target/arm/kvm: Add an error handle to kvm_arm_create_scratch_host_vcpu

[Eric Auger]

This allows to report a precise error message if any error occurs.

Signed-off-by: Eric Auger <eric.au...@redhat.com>
---
 target/arm/kvm_arm.h |  3 ++-
 target/arm/kvm.c     | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index 68e0597ac6..d049334d6d 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -105,6 +105,7 @@ struct kvm_vcpu_init;
  * @init: filled in with the necessary values for creating a host
  * vcpu. If NULL is provided, will not init the vCPU (though the cpufd
  * will still be set up).
+ * @errp: Error handle
  *
  * Create a scratch vcpu in its own VM of the type preferred by the host
  * kernel (as would be used for '-cpu host'), for purposes of probing it
@@ -114,7 +115,7 @@ struct kvm_vcpu_init;
  * false on failure (and fdarray and init are not valid).
  */
 bool kvm_arm_create_scratch_host_vcpu(int *fdarray,
-                                      struct kvm_vcpu_init *init);
+                                      struct kvm_vcpu_init *init, Error 
**errp);
 
 /**
  * kvm_arm_destroy_scratch_host_vcpu:
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index bb1c49d44e..8a7f5982fb 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -107,13 +107,14 @@ static int kvm_arm_vcpu_finalize(ARMCPU *cpu, int feature)
 }
 
 bool kvm_arm_create_scratch_host_vcpu(int *fdarray,
-                                      struct kvm_vcpu_init *init)
+                                      struct kvm_vcpu_init *init, Error **errp)
 {
     int ret = 0, kvmfd = -1, vmfd = -1, cpufd = -1;
     int max_vm_pa_size;
 
     kvmfd = qemu_open_old("/dev/kvm", O_RDWR);
     if (kvmfd < 0) {
+        error_setg(errp, "Failed opening /dev/kvm");
         goto err;
     }
     max_vm_pa_size = ioctl(kvmfd, KVM_CHECK_EXTENSION, 
KVM_CAP_ARM_VM_IPA_SIZE);
@@ -124,6 +125,7 @@ bool kvm_arm_create_scratch_host_vcpu(int *fdarray,
         vmfd = ioctl(kvmfd, KVM_CREATE_VM, max_vm_pa_size);
     } while (vmfd == -1 && errno == EINTR);
     if (vmfd < 0) {
+        error_setg(errp, "Failed creating the scratch VM");
         goto err;
     }
 
@@ -143,6 +145,7 @@ bool kvm_arm_create_scratch_host_vcpu(int *fdarray,
 
     cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
     if (cpufd < 0) {
+        error_setg(errp, "Failed creating the scratch VCPU");
         goto err;
     }
 
@@ -156,12 +159,14 @@ bool kvm_arm_create_scratch_host_vcpu(int *fdarray,
 
         ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, &preferred);
         if (ret < 0) {
+            error_setg(errp, "Failed getting the preferred target");
             goto err;
         }
         init->target = preferred.target;
     }
     ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
     if (ret < 0) {
+        error_setg(errp, "Failed the init of the scratch vcpu");
         goto err;
     }
 
@@ -542,6 +547,7 @@ kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     bool el2_supported;
     bool pmu_supported = false;
     uint64_t features = 0;
+    Error *local_err = NULL;
     int err;
 
     ahcf->target = QEMU_KVM_ARM_TARGET_NONE;
@@ -589,7 +595,8 @@ kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
         features |= 1ULL << ARM_FEATURE_PMU;
     }
 
-    if (!kvm_arm_create_scratch_host_vcpu(fdarray, &init)) {
+    if (!kvm_arm_create_scratch_host_vcpu(fdarray, &init, &local_err)) {
+        error_report_err(local_err);
         return;
     }
 
@@ -2956,8 +2963,10 @@ void arm_cpu_kvm_set_irq(void *arm_cpu, int irq, int 
level)
 void arm_gic_cap_kvm_probe(GICCapability *v2, GICCapability *v3)
 {
     int fdarray[3];
+    Error *err = NULL;
 
-    if (!kvm_arm_create_scratch_host_vcpu(fdarray, NULL)) {
+    if (!kvm_arm_create_scratch_host_vcpu(fdarray, NULL, &err)) {
+        error_report_err(err);
         return;
     }
 
-- 
2.53.0