Re: [Qemu-devel] [PATCH] spapr: ensure device trees are always associated with DRC

[Jianjun Duan <duanj@linux.vnet.ibm.com>]

Please disregard this patch. It should be part of a sequence.

Thanks,
Jianjun
On 04/15/2016 01:00 PM, Jianjun Duan wrote:
> There are possible racing situations involving hotplug events and
> guest migration. For cases where a hotplug event is migrated, or
> the guest is in the process of fetching device tree at the time of
> migration, we need to ensure the device tree is created and
> associated with the corresponding DRC for devices that were
> hotplugged on the source, but 'coldplugged' on the target.
>
> Signed-off-by: Jianjun Duan <duanj@linux.vnet.ibm.com>
> ---
>   hw/ppc/spapr.c     | 16 ++++++----------
>   hw/ppc/spapr_pci.c | 12 +++++-------
>   2 files changed, 11 insertions(+), 17 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index feaab08..af4745c 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2132,15 +2132,6 @@ static void spapr_add_lmbs(DeviceState *dev, uint64_t addr, uint64_t size,
>       int i, fdt_offset, fdt_size;
>       void *fdt;
>
> -    /*
> -     * Check for DRC connectors and send hotplug notification to the
> -     * guest only in case of hotplugged memory. This allows cold plugged
> -     * memory to be specified at boot time.
> -     */
> -    if (!dev->hotplugged) {
> -        return;
> -    }
> -
>       for (i = 0; i < nr_lmbs; i++) {
>           drc = spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_LMB,
>                   addr/SPAPR_MEMORY_BLOCK_SIZE);
> @@ -2154,7 +2145,12 @@ static void spapr_add_lmbs(DeviceState *dev, uint64_t addr, uint64_t size,
>           drck->attach(drc, dev, fdt, fdt_offset, !dev->hotplugged, errp);
>           addr += SPAPR_MEMORY_BLOCK_SIZE;
>       }
> -    spapr_hotplug_req_add_by_count(SPAPR_DR_CONNECTOR_TYPE_LMB, nr_lmbs);
> +    /* send hotplug notification to the
> +     * guest only in case of hotplugged memory
> +     */
> +    if (dev->hotplugged) {
> +       spapr_hotplug_req_add_by_count(SPAPR_DR_CONNECTOR_TYPE_LMB, nr_lmbs);
> +    }
>   }
>
>   static void spapr_memory_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 8c20d34..b179e42 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1092,13 +1092,11 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector *drc,
>           spapr_tce_set_need_vfio(tcet, true);
>       }
>
> -    if (dev->hotplugged) {
> -        fdt = create_device_tree(&fdt_size);
> -        fdt_start_offset = spapr_create_pci_child_dt(phb, pdev, fdt, 0);
> -        if (!fdt_start_offset) {
> -            error_setg(errp, "Failed to create pci child device tree node");
> -            goto out;
> -        }
> +    fdt = create_device_tree(&fdt_size);
> +    fdt_start_offset = spapr_create_pci_child_dt(phb, pdev, fdt, 0);
> +    if (!fdt_start_offset) {
> +        error_setg(errp, "Failed to create pci child device tree node");
> +        goto out;
>       }
>
>       drck->attach(drc, DEVICE(pdev),