Re: [Qemu-devel] [PATCH] spapr: pci: clean msi info when releasing it

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 05/07/2014 04:51 PM, Liu Ping Fan wrote:
> In current code, we use phb->msi_table[ndev].nvec to indicate whether
> this msi entries are used by a device or not. So when unplug a pci
> device, we should reset nvec to zero.
> 
> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
> ---
>  hw/ppc/spapr_pci.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index cbef095..7b1dfe1 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -316,6 +316,7 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, sPAPREnvironment *spapr,
>              rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
>              return;
>          }
> +        phb->msi_table[ndev].nvec = 0;
>          trace_spapr_pci_msi("Released MSIs", ndev, config_addr);
>          rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>          rtas_st(rets, 1, 0);


ibm,change-msi is called with 0 to disable MSIs. If later the guest decides
to reenable MSI on the same device (rmmod + modprobe in the guest can do
that I suppose), new block will be allocated because of this patch which is
bad.

And there is no PCI hotplug for SPAPR in upstream QEMU so this patch cannot
possibly fix it :)


-- 
Alexey