In some cases a failing VMSTATE_*_EQUAL does not mean we detected a bug, but it's actually the best we can do. Especially in these cases a verbose error message is required.
Let's introduce infrastructure for specifying a error hint to be used if equal check fails. Let's do this by adding a parameter to the _EQUAL macros called _err_hint. Also change all current users to pass NULL as last parameter so nothing changes for them. Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com> --- I have already had an RFC series prior to this patch trying to do the same: https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg01413.html We decided with the migration maintainers to rather add an parameter than introduce a load of new macros. All the other feedback from there was incorporated too. The RFC also contains the direct motivation for this change, which is vmstate conversion of virtio-ccw, and is intended to happen on top of this. --- hw/display/virtio-gpu.c | 2 +- hw/nvram/eeprom93xx.c | 2 +- hw/pci/pci.c | 2 +- hw/pci/pcie_aer.c | 2 +- include/migration/vmstate.h | 51 +++++++++++++++++++++++++++++++-------------- migration/vmstate-types.c | 15 +++++++++++++ 6 files changed, 54 insertions(+), 20 deletions(-) diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c index 58dc0b2737..0506d2c1b0 100644 --- a/hw/display/virtio-gpu.c +++ b/hw/display/virtio-gpu.c @@ -962,7 +962,7 @@ static const VMStateDescription vmstate_virtio_gpu_scanouts = { .version_id = 1, .fields = (VMStateField[]) { VMSTATE_INT32(enable, struct VirtIOGPU), - VMSTATE_UINT32_EQUAL(conf.max_outputs, struct VirtIOGPU), + VMSTATE_UINT32_EQUAL(conf.max_outputs, struct VirtIOGPU, NULL), VMSTATE_STRUCT_VARRAY_UINT32(scanout, struct VirtIOGPU, conf.max_outputs, 1, vmstate_virtio_gpu_scanout, diff --git a/hw/nvram/eeprom93xx.c b/hw/nvram/eeprom93xx.c index 848692abc0..2fd0e3c29f 100644 --- a/hw/nvram/eeprom93xx.c +++ b/hw/nvram/eeprom93xx.c @@ -143,7 +143,7 @@ static const VMStateDescription vmstate_eeprom = { VMSTATE_UINT8(addrbits, eeprom_t), VMSTATE_UINT16_HACK_TEST(size, eeprom_t, is_old_eeprom_version), VMSTATE_UNUSED_TEST(is_old_eeprom_version, 1), - VMSTATE_UINT16_EQUAL_V(size, eeprom_t, EEPROM_VERSION), + VMSTATE_UINT16_EQUAL_V(size, eeprom_t, EEPROM_VERSION, NULL), VMSTATE_UINT16(data, eeprom_t), VMSTATE_VARRAY_UINT16_UNSAFE(contents, eeprom_t, size, 0, vmstate_info_uint16, uint16_t), diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 98ccc27533..b7fee4bdf2 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -74,7 +74,7 @@ static const VMStateDescription vmstate_pcibus = { .version_id = 1, .minimum_version_id = 1, .fields = (VMStateField[]) { - VMSTATE_INT32_EQUAL(nirq, PCIBus), + VMSTATE_INT32_EQUAL(nirq, PCIBus, NULL), VMSTATE_VARRAY_INT32(irq_count, PCIBus, nirq, 0, vmstate_info_int32, int32_t), diff --git a/hw/pci/pcie_aer.c b/hw/pci/pcie_aer.c index 828052b0c0..97200742b4 100644 --- a/hw/pci/pcie_aer.c +++ b/hw/pci/pcie_aer.c @@ -813,7 +813,7 @@ const VMStateDescription vmstate_pcie_aer_log = { .minimum_version_id = 1, .fields = (VMStateField[]) { VMSTATE_UINT16(log_num, PCIEAERLog), - VMSTATE_UINT16_EQUAL(log_max, PCIEAERLog), + VMSTATE_UINT16_EQUAL(log_max, PCIEAERLog, NULL), VMSTATE_VALIDATE("log_num <= log_max", pcie_aer_state_log_num_valid), VMSTATE_STRUCT_VARRAY_POINTER_UINT16(log, PCIEAERLog, log_num, vmstate_pcie_aer_err, PCIEAERErr), diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index e85fbd81fc..85e43da568 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -155,6 +155,7 @@ typedef enum { struct VMStateField { const char *name; + const char *err_hint; size_t offset; size_t size; size_t start; @@ -256,6 +257,18 @@ extern const VMStateInfo vmstate_info_qtailq; .offset = vmstate_offset_value(_state, _field, _type), \ } +#define VMSTATE_SINGLE_FULL(_field, _state, _test, _version, _info, \ + _type, _err_hint) { \ + .name = (stringify(_field)), \ + .err_hint = (_err_hint), \ + .version_id = (_version), \ + .field_exists = (_test), \ + .size = sizeof(_type), \ + .info = &(_info), \ + .flags = VMS_SINGLE, \ + .offset = vmstate_offset_value(_state, _field, _type), \ +} + /* Validate state using a boolean predicate. */ #define VMSTATE_VALIDATE(_name, _test) { \ .name = (_name), \ @@ -762,29 +775,35 @@ extern const VMStateInfo vmstate_info_qtailq; #define VMSTATE_UINT64(_f, _s) \ VMSTATE_UINT64_V(_f, _s, 0) -#define VMSTATE_UINT8_EQUAL(_f, _s) \ - VMSTATE_SINGLE(_f, _s, 0, vmstate_info_uint8_equal, uint8_t) +#define VMSTATE_UINT8_EQUAL(_f, _s, _err_hint) \ + VMSTATE_SINGLE_FULL(_f, _s, 0, 0, \ + vmstate_info_uint8_equal, uint8_t, _err_hint) -#define VMSTATE_UINT16_EQUAL(_f, _s) \ - VMSTATE_SINGLE(_f, _s, 0, vmstate_info_uint16_equal, uint16_t) +#define VMSTATE_UINT16_EQUAL(_f, _s, _err_hint) \ + VMSTATE_SINGLE_FULL(_f, _s, 0, 0, \ + vmstate_info_uint16_equal, uint16_t, _err_hint) -#define VMSTATE_UINT16_EQUAL_V(_f, _s, _v) \ - VMSTATE_SINGLE(_f, _s, _v, vmstate_info_uint16_equal, uint16_t) +#define VMSTATE_UINT16_EQUAL_V(_f, _s, _v, _err_hint) \ + VMSTATE_SINGLE_FULL(_f, _s, 0, _v, \ + vmstate_info_uint16_equal, uint16_t, _err_hint) -#define VMSTATE_INT32_EQUAL(_f, _s) \ - VMSTATE_SINGLE(_f, _s, 0, vmstate_info_int32_equal, int32_t) +#define VMSTATE_INT32_EQUAL(_f, _s, _err_hint) \ + VMSTATE_SINGLE_FULL(_f, _s, 0, 0, \ + vmstate_info_int32_equal, int32_t, _err_hint) -#define VMSTATE_UINT32_EQUAL_V(_f, _s, _v) \ - VMSTATE_SINGLE(_f, _s, _v, vmstate_info_uint32_equal, uint32_t) +#define VMSTATE_UINT32_EQUAL_V(_f, _s, _v, _err_hint) \ + VMSTATE_SINGLE_FULL(_f, _s, 0, _v, \ + vmstate_info_uint32_equal, uint32_t, _err_hint) -#define VMSTATE_UINT32_EQUAL(_f, _s) \ - VMSTATE_UINT32_EQUAL_V(_f, _s, 0) +#define VMSTATE_UINT32_EQUAL(_f, _s, _err_hint) \ + VMSTATE_UINT32_EQUAL_V(_f, _s, 0, _err_hint) -#define VMSTATE_UINT64_EQUAL_V(_f, _s, _v) \ - VMSTATE_SINGLE(_f, _s, _v, vmstate_info_uint64_equal, uint64_t) +#define VMSTATE_UINT64_EQUAL_V(_f, _s, _v, _err_hint) \ + VMSTATE_SINGLE_FULL(_f, _s, 0, _v, \ + vmstate_info_uint64_equal, uint64_t, _err_hint) -#define VMSTATE_UINT64_EQUAL(_f, _s) \ - VMSTATE_UINT64_EQUAL_V(_f, _s, 0) +#define VMSTATE_UINT64_EQUAL(_f, _s, _err_hint) \ + VMSTATE_UINT64_EQUAL_V(_f, _s, 0, _err_hint) #define VMSTATE_INT32_POSITIVE_LE(_f, _s) \ VMSTATE_SINGLE(_f, _s, 0, vmstate_info_int32_le, int32_t) diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c index 02f05a3359..c056c98bdb 100644 --- a/migration/vmstate-types.c +++ b/migration/vmstate-types.c @@ -126,6 +126,9 @@ static int get_int32_equal(QEMUFile *f, void *pv, size_t size, return 0; } error_report("%" PRIx32 " != %" PRIx32, *v, v2); + if (field->err_hint) { + error_printf("%s\n", field->err_hint); + } return -EINVAL; } @@ -267,6 +270,9 @@ static int get_uint32_equal(QEMUFile *f, void *pv, size_t size, return 0; } error_report("%" PRIx32 " != %" PRIx32, *v, v2); + if (field->err_hint) { + error_printf("%s\n", field->err_hint); + } return -EINVAL; } @@ -341,6 +347,9 @@ static int get_uint64_equal(QEMUFile *f, void *pv, size_t size, return 0; } error_report("%" PRIx64 " != %" PRIx64, *v, v2); + if (field->err_hint) { + error_printf("%s\n", field->err_hint); + } return -EINVAL; } @@ -364,6 +373,9 @@ static int get_uint8_equal(QEMUFile *f, void *pv, size_t size, return 0; } error_report("%x != %x", *v, v2); + if (field->err_hint) { + error_printf("%s\n", field->err_hint); + } return -EINVAL; } @@ -387,6 +399,9 @@ static int get_uint16_equal(QEMUFile *f, void *pv, size_t size, return 0; } error_report("%x != %x", *v, v2); + if (field->err_hint) { + error_printf("%s\n", field->err_hint); + } return -EINVAL; } -- 2.11.2