[PATCH v5 18/18] qapi: introduce DEVICE_ON event

[Vladimir Sementsov-Ogievskiy]

We have DEVICE_DELETED event, that signals that device_del command is
actually completed. But we don't have a counter-part for device_add.
Still it's sensible for SHPC and PCIe-native hotplug, as there are time
when the device in some intermediate state. Let's add an event that say
that the device is finally powered on, power indicator is on and
everything is OK for next manipulation on that device.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 qapi/qdev.json | 10 ++++++++++
 hw/pci/pcie.c  | 14 ++++++++++++++
 hw/pci/shpc.c  | 12 ++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/qapi/qdev.json b/qapi/qdev.json
index 6f2d8d6647..116a8a7de8 100644
--- a/qapi/qdev.json
+++ b/qapi/qdev.json
@@ -348,3 +348,13 @@
 { 'command': 'query-hotplug',
   'data': { 'id': 'str' },
   'returns': 'HotplugInfo' }
+
+##
+# @DEVICE_ON:
+#
+# Emitted whenever the device insertion completion is acknowledged by the 
guest.
+# For now only emitted for SHPC and PCIe-native hotplug.
+#
+# Since: 8.0
+##
+{ 'event': 'DEVICE_ON', 'data': 'DeviceAndPath' }
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 636f962a23..4297e4e8dc 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -22,6 +22,7 @@
 
 #include "monitor/qdev.h"
 #include "qapi/error.h"
+#include "qapi/qapi-events-qdev.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pcie.h"
 #include "hw/pci/msix.h"
@@ -47,6 +48,13 @@ static bool pcie_sltctl_powered_off(uint16_t sltctl)
         && (sltctl & PCI_EXP_SLTCTL_PIC) == PCI_EXP_SLTCTL_PWR_IND_OFF;
 }
 
+static bool pcie_sltctl_powered_on(uint16_t sltctl)
+{
+    return (sltctl & PCI_EXP_SLTCTL_PCC) == PCI_EXP_SLTCTL_PWR_ON &&
+        (sltctl & PCI_EXP_SLTCTL_PIC) == PCI_EXP_SLTCTL_PWR_IND_ON &&
+        (sltctl & PCI_EXP_SLTCTL_AIC) == PCI_EXP_SLTCTL_ATTN_IND_OFF;
+}
+
 static LedActivity pcie_led_state_to_qapi(uint16_t value)
 {
     switch (value) {
@@ -816,6 +824,12 @@ void pcie_cap_slot_write_config(PCIDevice *dev,
         qdev_hotplug_state_event(DEVICE(dev), NULL, child_dev, &changed_state);
     }
 
+    if ((sltsta & PCI_EXP_SLTSTA_PDS) && pcie_sltctl_powered_on(val) &&
+        !pcie_sltctl_powered_on(old_slt_ctl) && child_dev)
+    {
+        qapi_event_send_device_on(child_dev->id, child_dev->canonical_path);
+    }
+
     /*
      * If the slot is populated, power indicator is off and power
      * controller is off, it is safe to detach the devices.
diff --git a/hw/pci/shpc.c b/hw/pci/shpc.c
index 6a4f93949d..380b2b83b3 100644
--- a/hw/pci/shpc.c
+++ b/hw/pci/shpc.c
@@ -299,6 +299,12 @@ static bool shpc_slot_is_off(uint8_t state, uint8_t power, 
uint8_t attn)
     return state == SHPC_STATE_DISABLED && power == SHPC_LED_OFF;
 }
 
+static bool shpc_slot_is_on(uint8_t state, uint8_t power, uint8_t attn)
+{
+    return state == SHPC_STATE_ENABLED && power == SHPC_LED_ON &&
+        attn == SHPC_LED_OFF;
+}
+
 static void shpc_slot_command(PCIDevice *d, uint8_t target,
                               uint8_t state, uint8_t power, uint8_t attn)
 {
@@ -366,6 +372,12 @@ static void shpc_slot_command(PCIDevice *d, uint8_t target,
             SHPC_SLOT_EVENT_MRL |
             SHPC_SLOT_EVENT_PRESENCE;
     }
+
+    if (!shpc_slot_is_on(old_state, old_power, old_attn) &&
+        shpc_slot_is_on(state, power, attn) && child_dev)
+    {
+        qapi_event_send_device_on(child_dev->id, child_dev->canonical_path);
+    }
 }
 
 static void shpc_command(PCIDevice *d)
-- 
2.34.1