Re: [PULL 20/20] pcie: expire pending delete

[Igor Mammedov]

On Mon, 15 Nov 2021 11:39:09 -0500
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> From: Gerd Hoffmann <kraxel@redhat.com>
> 
> Add an expire time for pending delete, once the time is over allow
> pressing the attention button again.
> 
> This makes pcie hotplug behave more like acpi hotplug, where one can
> try sending an 'device_del' monitor command again in case the guest
> didn't respond to the first attempt.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> Message-Id: <20211111130859.1171890-7-kraxel@redhat.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  include/hw/qdev-core.h | 1 +
>  hw/pci/pcie.c          | 2 ++
>  softmmu/qdev-monitor.c | 4 +++-
>  3 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index 72622bd337..20d3066595 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -181,6 +181,7 @@ struct DeviceState {
>      char *canonical_path;
>      bool realized;
>      bool pending_deleted_event;
> +    int64_t pending_deleted_expires_ms;
>      QDict *opts;
>      int hotplugged;
>      bool allow_unplug_during_migration;
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index a930ac738a..c5ed266337 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -548,6 +548,8 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler 
> *hotplug_dev,
>      }
>  
>      dev->pending_deleted_event = true;
> +    dev->pending_deleted_expires_ms =
> +        qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 5000; /* 5 secs */

do we block migration if unplug was requested?
(if not we might loose this state on destionatio, do we care about it?)

>  
>      /* In case user cancel the operation of multi-function hot-add,
>       * remove the function that is unexposed to guest individually,
> diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
> index 588a62b88d..5925f1ae5f 100644
> --- a/softmmu/qdev-monitor.c
> +++ b/softmmu/qdev-monitor.c
> @@ -943,7 +943,9 @@ void qmp_device_del(const char *id, Error **errp)
>  {
>      DeviceState *dev = find_device_state(id, errp);
>      if (dev != NULL) {
> -        if (dev->pending_deleted_event) {
> +        if (dev->pending_deleted_event &&
> +            (dev->pending_deleted_expires_ms == 0 ||
> +             dev->pending_deleted_expires_ms > 
> qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL))) {
>              error_setg(errp, "Device %s is already in the "
>                               "process of unplug", id);
>              return;