acpi: fix acpi_index migration
vmstate_acpi_pcihp_use_acpi_index() was expecting AcpiPciHpState
as state but it actually received PIIX4PMState, because
VMSTATE_PCI_HOTPLUG is a macro and not another struct.
So it ended up accessing random pointer, which resulted
in 'false' return value and acpi_index field wasn't ever
sent.
However in 7.0 that pointer de-references to value > 0, and
destination QEMU starts to expect the field which isn't
sent in migratioon stream from older QEMU (6.2 and older).
As result migration fails with:
qemu-system-x86_64: Missing section footer for 0000:00:01.3/piix4_pm
qemu-system-x86_64: load of migration failed: Invalid argument
In addition with QEMU-6.2, destination due to not expected
state, also never expects the acpi_index field in migration
stream.
Q35 is not affected as it always sends/expects the field as
long as acpi based PCI hotplug is enabled.
Fix issue by introducing compat knob to never send/expect
acpi_index in migration stream for 6.2 and older PC machine
types and always send it for 7.0 and newer PC machine types.
Diagnosed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Fixes: b32bd76 ("pci: introduce acpi-index property for PCI device")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/932
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/hw/acpi/acpi-pci-hotplug-stub.c b/hw/acpi/acpi-pci-hotplug-stub.c
index 734e4c5..a43f6da 100644
--- a/hw/acpi/acpi-pci-hotplug-stub.c
+++ b/hw/acpi/acpi-pci-hotplug-stub.c
@@ -41,7 +41,3 @@
return;
}
-bool vmstate_acpi_pcihp_use_acpi_index(void *opaque, int version_id)
-{
- return false;
-}
diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 6351bd3..bf65bbe 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -554,12 +554,6 @@
OBJ_PROP_FLAG_READ);
}
-bool vmstate_acpi_pcihp_use_acpi_index(void *opaque, int version_id)
-{
- AcpiPciHpState *s = opaque;
- return s->acpi_index;
-}
-
const VMStateDescription vmstate_acpi_pcihp_pci_status = {
.name = "acpi_pcihp_pci_status",
.version_id = 1,
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index cc37fa3..fe5625d 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -82,6 +82,7 @@
AcpiPciHpState acpi_pci_hotplug;
bool use_acpi_hotplug_bridge;
bool use_acpi_root_pci_hotplug;
+ bool not_migrate_acpi_index;
uint8_t disable_s3;
uint8_t disable_s4;
@@ -267,6 +268,16 @@
return pm_smbus_vmstate_needed();
}
+/*
+ * This is a fudge to turn off the acpi_index field,
+ * whose test was always broken on piix4 with 6.2 and older machine types.
+ */
+static bool vmstate_test_migrate_acpi_index(void *opaque, int version_id)
+{
+ PIIX4PMState *s = PIIX4_PM(opaque);
+ return s->use_acpi_hotplug_bridge && !s->not_migrate_acpi_index;
+}
+
/* qemu-kvm 1.2 uses version 3 but advertised as 2
* To support incoming qemu-kvm 1.2 migration, change version_id
* and minimum_version_id to 2 below (which breaks migration from
@@ -297,7 +308,7 @@
struct AcpiPciHpPciStatus),
VMSTATE_PCI_HOTPLUG(acpi_pci_hotplug, PIIX4PMState,
vmstate_test_use_acpi_hotplug_bridge,
- vmstate_acpi_pcihp_use_acpi_index),
+ vmstate_test_migrate_acpi_index),
VMSTATE_END_OF_LIST()
},
.subsections = (const VMStateDescription*[]) {
@@ -652,6 +663,8 @@
DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
acpi_memory_hotplug.is_enabled, true),
DEFINE_PROP_BOOL("smm-compat", PIIX4PMState, smm_compat, false),
+ DEFINE_PROP_BOOL("x-not-migrate-acpi-index", PIIX4PMState,
+ not_migrate_acpi_index, false),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/core/machine.c b/hw/core/machine.c
index d856485..1e23fdc 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -37,7 +37,9 @@
#include "hw/virtio/virtio.h"
#include "hw/virtio/virtio-pci.h"
-GlobalProperty hw_compat_6_2[] = {};
+GlobalProperty hw_compat_6_2[] = {
+ { "PIIX4_PM", "x-not-migrate-acpi-index", "on"},
+};
const size_t hw_compat_6_2_len = G_N_ELEMENTS(hw_compat_6_2);
GlobalProperty hw_compat_6_1[] = {
diff --git a/include/hw/acpi/pcihp.h b/include/hw/acpi/pcihp.h
index af1a169..7e268c2 100644
--- a/include/hw/acpi/pcihp.h
+++ b/include/hw/acpi/pcihp.h
@@ -73,8 +73,6 @@
extern const VMStateDescription vmstate_acpi_pcihp_pci_status;
-bool vmstate_acpi_pcihp_use_acpi_index(void *opaque, int version_id);
-
#define VMSTATE_PCI_HOTPLUG(pcihp, state, test_pcihp, test_acpi_index) \
VMSTATE_UINT32_TEST(pcihp.hotplug_select, state, \
test_pcihp), \
