Hi,
> > So in theory the guest turning off slot power quickly should work just
> > fine and speed up the unplug process in the common case (guest is
> > up'n'running and responsitive). Down to 1-2 secs instead of 5-7.
> > Didn't actually test that though.
Tried mean while, test patch (not polished yet) below.
> Even if this speeds up unplug, hotplug remains slow, right?
Notplug never was slow for me ...
take care,
Gerd
>From 074627a24a54203f2b4baf787fd4110c78222e23 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kra...@redhat.com>
Date: Tue, 19 Oct 2021 09:12:22 +0200
Subject: [PATCH] pciehp: fast virtual unplug for VMs
Signed-off-by: Gerd Hoffmann <kra...@redhat.com>
---
drivers/pci/hotplug/pciehp.h | 3 +++
drivers/pci/hotplug/pciehp_core.c | 5 +++++
drivers/pci/hotplug/pciehp_ctrl.c | 10 +++++++++-
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 69fd401691be..131ffec2e947 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -79,6 +79,7 @@ extern int pciehp_poll_time;
* @request_result: result of last user request submitted to the IRQ thread
* @requester: wait queue to wake up on completion of user request,
* used for synchronous slot enable/disable request via sysfs
+ * @is_virtual: virtual machine pcie port.
*
* PCIe hotplug has a 1:1 relationship between controller and slot, hence
* unlike other drivers, the two aren't represented by separate structures.
@@ -109,6 +110,8 @@ struct controller {
unsigned int ist_running;
int request_result;
wait_queue_head_t requester;
+
+ bool is_virtual;
};
/**
diff --git a/drivers/pci/hotplug/pciehp_core.c
b/drivers/pci/hotplug/pciehp_core.c
index ad3393930ecb..28867ec33f5b 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -227,6 +227,11 @@ static int pciehp_probe(struct pcie_device *dev)
goto err_out_shutdown_notification;
}
+ if (dev->port->vendor == PCI_VENDOR_ID_REDHAT &&
+ dev->port->device == 0x000c)
+ /* qemu pcie root port */
+ ctrl->is_virtual = true;
+
pciehp_check_presence(ctrl);
return 0;
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c
b/drivers/pci/hotplug/pciehp_ctrl.c
index 529c34808440..c0a05bbdb948 100644
--- a/drivers/pci/hotplug/pciehp_ctrl.c
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -21,6 +21,10 @@
#include <linux/pci.h>
#include "pciehp.h"
+static bool fast_virtual_unplug = true;
+module_param(fast_virtual_unplug, bool, 0644);
+MODULE_PARM_DESC(fast_virtual_unplug, "Fast unplug (don't wait 5 seconds) for
virtual machines.");
+
/* The following routines constitute the bulk of the
hotplug controller logic
*/
@@ -176,7 +180,11 @@ void pciehp_handle_button_press(struct controller *ctrl)
/* blink power indicator and turn off attention */
pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
PCI_EXP_SLTCTL_ATTN_IND_OFF);
- schedule_delayed_work(&ctrl->button_work, 5 * HZ);
+ if (ctrl->is_virtual && fast_virtual_unplug) {
+ schedule_delayed_work(&ctrl->button_work, 1);
+ } else {
+ schedule_delayed_work(&ctrl->button_work, 5 * HZ);
+ }
break;
case BLINKINGOFF_STATE:
case BLINKINGON_STATE:
--
2.31.1
