Re: [Qemu-devel] [PATCH] ahci: add migration support

[Kevin Wolf <kwolf@redhat.com>]

Am 30.08.2012 20:00, schrieb Jason Baron:
> Add support for ahci migration. This patch builds upon the patches posted
> previously by Andreas Faerber:
> 
> http://lists.gnu.org/archive/html/qemu-devel/2012-08/msg01538.html
> 
> (I hope I am giving Andreas proper credit for his work.)
> 
> I've tested these patches by migrating Windows 7 and Fedora 16 guests on
> both piix with ahci attached and on q35 (which has a built-in ahci controller).
> 
> Signed-off-by: Jason Baron <jbaron@redhat.com>
> ---
>  hw/ide/ahci.c |   64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  hw/ide/ahci.h |   10 +++++++++
>  hw/ide/ich.c  |   11 +++++++--
>  3 files changed, 81 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index b53c757..e94509b 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -1204,6 +1204,65 @@ void ahci_reset(AHCIState *s)
>      }
>  }
>  
> +static const VMStateDescription vmstate_ahci_device = {
> +    .name = "ahci port",
> +    .version_id = 1,
> +    .fields = (VMStateField []) {
> +        VMSTATE_IDE_BUS(port, AHCIDevice),
> +        VMSTATE_UINT32(port_state, AHCIDevice),
> +        VMSTATE_UINT32(finished, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.lst_addr, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.lst_addr_hi, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.fis_addr, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.fis_addr_hi, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.irq_stat, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.irq_mask, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.cmd, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.tfdata, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.sig, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.scr_stat, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.scr_ctl, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.scr_err, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.scr_act, AHCIDevice),
> +        VMSTATE_UINT32(port_regs.cmd_issue, AHCIDevice),
> +        VMSTATE_END_OF_LIST()
> +    },
> +};

This looks incomplete to me. Everything below port_regs in AHCIDevice is
missing from the saved fields:

struct AHCIDevice {
    IDEDMA dma;
    IDEBus port;
    int port_no;
    uint32_t port_state;
    uint32_t finished;
    AHCIPortRegs port_regs;
    struct AHCIState *hba;
    QEMUBH *check_bh;
    uint8_t *lst;
    uint8_t *res_fis;
    int dma_status;
    int done_atapi_packet;
    int busy_slot;
    int init_d2h_sent;
    BlockDriverCompletionFunc *dma_cb;
    AHCICmdHdr *cur_cmd;
    NCQTransferState ncq_tfs[AHCI_MAX_CMDS];
};

I haven't checked each single one, but things like done_atapi_packet or
init_d2h_sent certainly look as if they should be migrated.

Hm... Could we possibly test migration with qtest? I can imagine some
nice test cases there. It would require some new infrastructure, I
guess, but it could be doable.

Kevin