[PATCH v2] migration: Fix migration failure when aia is configured as 'aplic-imsic'

[liu.xuemei1]

From: Xuemei Liu <liu.xuem...@zte.com.cn>

Address an error in migration when aia is configured as 'aplic-imsic' in
riscv kvm vm by adding riscv_aplic_state_needed() and
riscv_imsic_state_needed() to determine whether the corresponding sates are
needed.

Previously, the fields in the vmsds of 'riscv_aplic' and 'riscv_imsic' can
only be initialized under certain special conditions in commit 95a97b3fd2.
However, the corresponding ses of these vmsds are inserted into the
savevm_state.handlers unconditionally. This led to migration failure
characterized by uninitialized fields when save vm state:
qemu-system-riscv64: ../migration/vmstate.c:433: vmstate_save_state_v:
Assertion 'first_elem || !n_elems || !size' failed.

Fixes: 95a97b3fd2 ("target/riscv: update APLIC and IMSIC to support KVM AIA")

Signed-off-by: Xuemei Liu <liu.xuem...@zte.com.cn>
---

 Changes in v2:

 - Dropped the modifications in vmstate_register_with_alias_id()
 - Added riscv_aplic_state_needed() and riscv_imsic_state_needed()

 hw/intc/riscv_aplic.c | 8 ++++++++
 hw/intc/riscv_imsic.c | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/hw/intc/riscv_aplic.c b/hw/intc/riscv_aplic.c
index 8bcd9f4697..c9abef2e0f 100644
--- a/hw/intc/riscv_aplic.c
+++ b/hw/intc/riscv_aplic.c
@@ -962,10 +962,18 @@ static const Property riscv_aplic_properties[] = {
     DEFINE_PROP_BOOL("mmode", RISCVAPLICState, mmode, 0),
 };

+static bool riscv_aplic_state_needed(void *opaque)
+{
+    RISCVAPLICState *aplic = opaque;
+
+    return riscv_use_emulated_aplic(aplic->msimode);
+}
+
 static const VMStateDescription vmstate_riscv_aplic = {
     .name = "riscv_aplic",
     .version_id = 2,
     .minimum_version_id = 2,
+    .needed = riscv_aplic_state_needed,
     .fields = (const VMStateField[]) {
             VMSTATE_UINT32(domaincfg, RISCVAPLICState),
             VMSTATE_UINT32(mmsicfgaddr, RISCVAPLICState),
diff --git a/hw/intc/riscv_imsic.c b/hw/intc/riscv_imsic.c
index 2169988167..92a7254076 100644
--- a/hw/intc/riscv_imsic.c
+++ b/hw/intc/riscv_imsic.c
@@ -398,10 +398,16 @@ static const Property riscv_imsic_properties[] = {
     DEFINE_PROP_UINT32("num-irqs", RISCVIMSICState, num_irqs, 0),
 };

+static bool riscv_imsic_state_needed(void *opaque)
+{
+    return !kvm_irqchip_in_kernel();
+}
+
 static const VMStateDescription vmstate_riscv_imsic = {
     .name = "riscv_imsic",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = riscv_imsic_state_needed,
     .fields = (const VMStateField[]) {
             VMSTATE_VARRAY_UINT32(eidelivery, RISCVIMSICState,
                                   num_pages, 0,
-- 
2.27.0