Re: [Qemu-devel] [PATCH v3 10/16] i2c:pm_smbus: Fix state transfer

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* minyard@acm.org (minyard@acm.org) wrote:
> From: Corey Minyard <cminyard@mvista.com>
> 
> Transfer the state information for the SMBus registers and
> internal data so it will work on a VM transfer.
> 
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  hw/acpi/piix4.c           |  7 +++++++
>  hw/i2c/pm_smbus.c         | 31 +++++++++++++++++++++++++++++++
>  hw/i2c/smbus_ich9.c       | 10 +++++++++-
>  include/hw/i2c/pm_smbus.h |  9 +++++++++
>  4 files changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index 2f4dd03b83..91fe4821d3 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -302,6 +302,11 @@ static const VMStateDescription vmstate_cpuhp_state = {
>      }
>  };
>  
> +static bool piix4_vmstate_need_smbus(void *opaque, int version_id)
> +{
> +    return pm_smbus_vmstate_needed();
> +}
> +
>  /* 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
> @@ -321,6 +326,8 @@ static const VMStateDescription vmstate_acpi = {
>          VMSTATE_UINT16(ar.pm1.evt.en, PIIX4PMState),
>          VMSTATE_UINT16(ar.pm1.cnt.cnt, PIIX4PMState),
>          VMSTATE_STRUCT(apm, PIIX4PMState, 0, vmstate_apm, APMState),
> +        VMSTATE_STRUCT_TEST(smb, PIIX4PMState, piix4_vmstate_need_smbus, 3,
> +                            pmsmb_vmstate, PMSMBus),
>          VMSTATE_TIMER_PTR(ar.tmr.timer, PIIX4PMState),
>          VMSTATE_INT64(ar.tmr.overflow_time, PIIX4PMState),
>          VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
> diff --git a/hw/i2c/pm_smbus.c b/hw/i2c/pm_smbus.c
> index 8793113c25..2a9bc6e8c0 100644
> --- a/hw/i2c/pm_smbus.c
> +++ b/hw/i2c/pm_smbus.c
> @@ -19,6 +19,7 @@
>   */
>  #include "qemu/osdep.h"
>  #include "hw/hw.h"
> +#include "hw/boards.h"
>  #include "hw/i2c/pm_smbus.h"
>  #include "hw/i2c/smbus_master.h"
>  
> @@ -450,6 +451,36 @@ static const MemoryRegionOps pm_smbus_ops = {
>      .endianness = DEVICE_LITTLE_ENDIAN,
>  };
>  
> +bool pm_smbus_vmstate_needed(void)
> +{
> +    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
> +
> +    return !mc->smbus_no_migration_support;
> +}
> +
> +const VMStateDescription pmsmb_vmstate = {
> +    .name = "pmsmb",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT8(smb_stat, PMSMBus),
> +        VMSTATE_UINT8(smb_ctl, PMSMBus),
> +        VMSTATE_UINT8(smb_cmd, PMSMBus),
> +        VMSTATE_UINT8(smb_addr, PMSMBus),
> +        VMSTATE_UINT8(smb_data0, PMSMBus),
> +        VMSTATE_UINT8(smb_data1, PMSMBus),
> +        VMSTATE_UINT32(smb_index, PMSMBus),
> +        VMSTATE_UINT8_ARRAY(smb_data, PMSMBus, PM_SMBUS_MAX_MSG_SIZE),
> +        VMSTATE_UINT8(smb_auxctl, PMSMBus),
> +        VMSTATE_UINT8(smb_blkdata, PMSMBus),
> +        VMSTATE_BOOL(i2c_enable, PMSMBus),
> +        VMSTATE_BOOL(op_done, PMSMBus),
> +        VMSTATE_BOOL(in_i2c_block_read, PMSMBus),
> +        VMSTATE_BOOL(start_transaction_on_status_read, PMSMBus),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  void pm_smbus_init(DeviceState *parent, PMSMBus *smb, bool force_aux_blk)
>  {
>      smb->op_done = true;
> diff --git a/hw/i2c/smbus_ich9.c b/hw/i2c/smbus_ich9.c
> index e6d8d28194..7b24be8256 100644
> --- a/hw/i2c/smbus_ich9.c
> +++ b/hw/i2c/smbus_ich9.c
> @@ -43,12 +43,20 @@ typedef struct ICH9SMBState {
>      PMSMBus smb;
>  } ICH9SMBState;
>  
> +static bool ich9_vmstate_need_smbus(void *opaque, int version_id)
> +{
> +    return pm_smbus_vmstate_needed();
> +}
> +
>  static const VMStateDescription vmstate_ich9_smbus = {
>      .name = "ich9_smb",
>      .version_id = 1,
>      .minimum_version_id = 1,
>      .fields = (VMStateField[]) {
> -        VMSTATE_PCI_DEVICE(dev, struct ICH9SMBState),
> +        VMSTATE_PCI_DEVICE(dev, ICH9SMBState),
> +        VMSTATE_BOOL_TEST(irq_enabled, ICH9SMBState, ich9_vmstate_need_smbus),
> +        VMSTATE_STRUCT_TEST(smb, ICH9SMBState, ich9_vmstate_need_smbus, 1,
> +                            pmsmb_vmstate, PMSMBus),
>          VMSTATE_END_OF_LIST()
>      }
>  };
> diff --git a/include/hw/i2c/pm_smbus.h b/include/hw/i2c/pm_smbus.h
> index 7bcca97672..fb55c44444 100644
> --- a/include/hw/i2c/pm_smbus.h
> +++ b/include/hw/i2c/pm_smbus.h
> @@ -43,4 +43,13 @@ typedef struct PMSMBus {
>  
>  void pm_smbus_init(DeviceState *parent, PMSMBus *smb, bool force_aux_blk);
>  
> +/*
> + * For backwards compatibility on migration, older versions don't have
> + * working migration for pm_smbus, this lets us ignore the migrations
> + * for older machine versions.
> + */
> +bool pm_smbus_vmstate_needed(void);
> +
> +extern const VMStateDescription pmsmb_vmstate;
> +
>  #endif /* PM_SMBUS_H */
> -- 
> 2.17.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK