target/riscv/kvm: set 'aia_mode' to default in error path

When failing to set the selected AIA mode, 'aia_mode' is left untouched.
This means that 'aia_mode' will not reflect the actual AIA mode,
retrieved in 'default_aia_mode',

This is benign for now, but it will impact QMP query commands that will
expose the 'aia_mode' value, retrieving the wrong value.

Set 'aia_mode' to 'default_aia_mode' if we fail to change the AIA mode
in KVM.

While we're at it, rework the log/warning messages to be a bit less
verbose. Instead of:

KVM AIA: default mode is emul
qemu-system-riscv64: warning: KVM AIA: failed to set KVM AIA mode

We can use a single warning message:

qemu-system-riscv64: warning: KVM AIA: failed to set KVM AIA mode 'auto', using default host mode 'emul'

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241028182037.290171-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 15 insertions, 7 deletions

diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
index 8233a32102..acc713c56a 100644
--- a/target/riscv/kvm/kvm-cpu.c
+++ b/target/riscv/kvm/kvm-cpu.c
@@ -1711,18 +1711,26 @@ void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
         error_report("KVM AIA: failed to get current KVM AIA mode");
         exit(1);
     }
-    qemu_log("KVM AIA: default mode is %s\n",
-             kvm_aia_mode_str(default_aia_mode));
 
-    if (default_aia_mode != aia_mode) {
+    if (default_aia_mode == aia_mode) {
+        qemu_log("KVM AIA: using default host mode '%s'\n",
+                  kvm_aia_mode_str(default_aia_mode));
+    } else {
         ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,
                                 KVM_DEV_RISCV_AIA_CONFIG_MODE,
                                 &aia_mode, true, NULL);
-        if (ret < 0)
-            warn_report("KVM AIA: failed to set KVM AIA mode");
-        else
-            qemu_log("KVM AIA: set current mode to %s\n",
+        if (ret < 0) {
+            warn_report("KVM AIA: failed to set KVM AIA mode '%s', using "
+                        "default host mode '%s'",
+                        kvm_aia_mode_str(aia_mode),
+                        kvm_aia_mode_str(default_aia_mode));
+
+            /* failed to change AIA mode, use default */
+            aia_mode = default_aia_mode;
+        } else {
+            qemu_log("KVM AIA: setting current mode to %s\n",
                      kvm_aia_mode_str(aia_mode));
+        }
     }
 
     ret = kvm_device_access(aia_fd, KVM_DEV_RISCV_AIA_GRP_CONFIG,