Re: [Qemu-devel] [PATCH 2/3] pseries: Fix bug with reset of VIO CRQs

["Andreas Färber" <afaerber@suse.de>]

Am 28.03.2012 23:39, schrieb David Gibson:
> PAPR specifies a Command Response Queue (CRQ) mechanism used for virtual
> IO, which we implement.  However, we don't correctly clean up registered
> CRQs when we reset the system.
> 
> This patch adds a reset handler to fix this bug.  While we're at it, add
> in some of the extra debug messages that were used to track the problem
> down.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---

As discussed on IRC, I've applied the following diff on my local branch
to drop the h_reg_crq that my __func__ comment was about:

diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index 0bf2c31..97d029a 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -431,13 +431,13 @@ static target_ulong h_reg_crq(CPUPPCState *env,
sPAPREnvironment *spapr,

     /* Check if device supports CRQs */
     if (!dev->crq.SendFunc) {
-        hcall_dprintf("Device does not support CRQ\n");
+        hcall_dprintf("h_reg_crq, device does not support CRQ\n");
         return H_NOT_FOUND;
     }

     /* Already a queue ? */
     if (dev->crq.qsize) {
-        hcall_dprintf("CRQ already registered\n");
+        hcall_dprintf("h_reg_crq, CRQ already registered\n");
         return H_RESOURCE;
     }
     dev->crq.qladdr = queue_addr;

However, I'm having trouble testing reset. Whether on vanilla master or
using this patch on top of ppc-next or this whole series on top of
ppc-next, using `ppc64-softmmu/qemu-system-ppc64 -M pseries -m 1G`:

a) 0 > reset-all
results in: "reboot not available Aborted"
Do you need to update SLOF to actually use the newly added RTAS call?

b) (qemu) system_reset
results in:
 exception 700
SRR0 = 0000000000000000  SRR1 = 800000008000000000080000
SPRG2 = 0000000000000000  SPRG3 = 000000003DCD1AD4

Could you please look into the two above issues? How did you test?

Thanks,
Andreas

>  hw/spapr_vio.c |   33 +++++++++++++++++++++++++--------
>  1 files changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
> index 1f67e64..97d029a 100644
> --- a/hw/spapr_vio.c
> +++ b/hw/spapr_vio.c
> @@ -431,12 +431,13 @@ static target_ulong h_reg_crq(CPUPPCState *env, sPAPREnvironment *spapr,
>  
>      /* Check if device supports CRQs */
>      if (!dev->crq.SendFunc) {
> +        hcall_dprintf("h_reg_crq, device does not support CRQ\n");
>          return H_NOT_FOUND;
>      }
>  
> -
>      /* Already a queue ? */
>      if (dev->crq.qsize) {
> +        hcall_dprintf("h_reg_crq, CRQ already registered\n");
>          return H_RESOURCE;
>      }
>      dev->crq.qladdr = queue_addr;
> @@ -449,6 +450,17 @@ static target_ulong h_reg_crq(CPUPPCState *env, sPAPREnvironment *spapr,
>      return H_SUCCESS;
>  }
>  
> +static target_ulong free_crq(VIOsPAPRDevice *dev)
> +{
> +    dev->crq.qladdr = 0;
> +    dev->crq.qsize = 0;
> +    dev->crq.qnext = 0;
> +
> +    dprintf("CRQ for dev 0x%" PRIx32 " freed\n", dev->reg);
> +
> +    return H_SUCCESS;
> +}
> +
>  static target_ulong h_free_crq(CPUPPCState *env, sPAPREnvironment *spapr,
>                                 target_ulong opcode, target_ulong *args)
>  {
> @@ -460,13 +472,7 @@ static target_ulong h_free_crq(CPUPPCState *env, sPAPREnvironment *spapr,
>          return H_PARAMETER;
>      }
>  
> -    dev->crq.qladdr = 0;
> -    dev->crq.qsize = 0;
> -    dev->crq.qnext = 0;
> -
> -    dprintf("CRQ for dev 0x" TARGET_FMT_lx " freed\n", reg);
> -
> -    return H_SUCCESS;
> +    return free_crq(dev);
>  }
>  
>  static target_ulong h_send_crq(CPUPPCState *env, sPAPREnvironment *spapr,
> @@ -642,6 +648,15 @@ static int spapr_vio_check_reg(VIOsPAPRDevice *sdev)
>      return 0;
>  }
>  
> +static void spapr_vio_busdev_reset(void *opaque)
> +{
> +    VIOsPAPRDevice *dev = (VIOsPAPRDevice *)opaque;
> +
> +    if (dev->crq.qsize) {
> +        free_crq(dev);
> +    }
> +}
> +
>  static int spapr_vio_busdev_init(DeviceState *qdev)
>  {
>      VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
> @@ -670,6 +685,8 @@ static int spapr_vio_busdev_init(DeviceState *qdev)
>  
>      rtce_init(dev);
>  
> +    qemu_register_reset(spapr_vio_busdev_reset, dev);
> +
>      return pc->init(dev);
>  }
>  

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