From: Long Li <[email protected]>
hv_pci_devices_present is called in hv_pci_remove when we remove a PCI device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove, the bus is already removed before the call, so we don't need to rescan the bus in the workqueue scheduled from hv_pci_devices_present. By introducing status hv_pcibus_removed, we can avoid this situation.
Signed-off-by: Long Li <[email protected]>
Tested-by: Cathy Avery <[email protected]>
Reported-by: Xiaofeng Wang <[email protected]>
---
drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index a8deeca..4a37598 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -348,6 +348,7 @@ enum hv_pcibus_state {
hv_pcibus_init = 0,
hv_pcibus_probed,
hv_pcibus_installed,
+ hv_pcibus_removed,
hv_pcibus_maximum
};
@@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct work_struct *work)
put_pcichild(hpdev, hv_pcidev_ref_initial);
}
- /* Tell the core to rescan bus because there may have been changes. */
- if (hbus->state == hv_pcibus_installed) {
+ switch (hbus->state) {
+ case hv_pcibus_installed:
+ /*
+ * Tell the core to rescan bus
+ * because there may have been changes.
+ */
pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
- } else {
+ break;
+
+ case hv_pcibus_init:
+ case hv_pcibus_probed:
survey_child_resources(hbus);
+ break;
+
+ default:
+ break;
}
up(&hbus->enum_sem);
@@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
if (!hbus)
return -ENOMEM;
+ hbus->state = hv_pcibus_init;
/*
* The PCI bus "domain" is what is called "segment" in ACPI and
@@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
pci_stop_root_bus(hbus->pci_bus);
pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
+ hbus->state = hv_pcibus_removed;
}
ret = hv_send_resources_released(hdev);
--
1.8.5.6
> -----Original Message-----
> From: Long Li
> Sent: Monday, October 3, 2016 11:43 PM
> To: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; Bjorn Helgaas <[email protected]>
> Cc: [email protected]; [email protected]; linux-
> [email protected]; Long Li <[email protected]>
> Subject: [PATCH 1/2 v3] pci-hyperv: properly handle pci bus remove
>
> This sender failed our fraud detection checks and may not be who they
> appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing
>
> From: Long Li <[email protected]>
>
> hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove,
> the bus is already removed before the call, so we don't need to rescan the
> bus in the workqueue scheduled from hv_pci_devices_present. By
> introducing status hv_pcibus_removed, we can avoid this situation.
>
> Signed-off-by: Long Li <[email protected]>
> Tested-by: Cathy Avery <[email protected]>
> Reported-by: Xiaofeng Wang <[email protected]>
Acked-by: KY Srinivasan <[email protected]>
> ---
> drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index a8deeca..4a37598 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> hv_pcibus_init = 0,
> hv_pcibus_probed,
> hv_pcibus_installed,
> + hv_pcibus_removed,
> hv_pcibus_maximum
> };
>
> @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> work_struct *work)
> put_pcichild(hpdev, hv_pcidev_ref_initial);
> }
>
> - /* Tell the core to rescan bus because there may have been changes. */
> - if (hbus->state == hv_pcibus_installed) {
> + switch (hbus->state) {
> + case hv_pcibus_installed:
> + /*
> + * Tell the core to rescan bus
> + * because there may have been changes.
> + */
> pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_unlock_rescan_remove();
> - } else {
> + break;
> +
> + case hv_pcibus_init:
> + case hv_pcibus_probed:
> survey_child_resources(hbus);
> + break;
> +
> + default:
> + break;
> }
>
> up(&hbus->enum_sem);
> @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> if (!hbus)
> return -ENOMEM;
> + hbus->state = hv_pcibus_init;
>
> /*
> * The PCI bus "domain" is what is called "segment" in ACPI and
> @@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> pci_stop_root_bus(hbus->pci_bus);
> pci_remove_root_bus(hbus->pci_bus);
> pci_unlock_rescan_remove();
> + hbus->state = hv_pcibus_removed;
> }
>
> ret = hv_send_resources_released(hdev);
> --
> 1.8.5.6
On Mon, Oct 03, 2016 at 11:42:47PM -0700, Long Li wrote:
> From: Long Li <[email protected]>
>
> hv_pci_devices_present is called in hv_pci_remove when we remove a PCI device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove, the bus is already removed before the call, so we don't need to rescan the bus in the workqueue scheduled from hv_pci_devices_present. By introducing status hv_pcibus_removed, we can avoid this situation.
>
> Signed-off-by: Long Li <[email protected]>
> Tested-by: Cathy Avery <[email protected]>
> Reported-by: Xiaofeng Wang <[email protected]>
I need an ack from the Hyper-V maintainers. I see acks for previous
versions, but I don't know whether you've changed things that would
invalidate those acks. If the acks still apply, please include them
and repost these patches.
Also, please run "git log --oneline drivers/pci/host/pci-hyperv.c" and make
your subject line match the previous ones.
> ---
> drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index a8deeca..4a37598 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> hv_pcibus_init = 0,
> hv_pcibus_probed,
> hv_pcibus_installed,
> + hv_pcibus_removed,
> hv_pcibus_maximum
> };
>
> @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct work_struct *work)
> put_pcichild(hpdev, hv_pcidev_ref_initial);
> }
>
> - /* Tell the core to rescan bus because there may have been changes. */
> - if (hbus->state == hv_pcibus_installed) {
> + switch (hbus->state) {
> + case hv_pcibus_installed:
> + /*
> + * Tell the core to rescan bus
> + * because there may have been changes.
> + */
> pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_unlock_rescan_remove();
> - } else {
> + break;
> +
> + case hv_pcibus_init:
> + case hv_pcibus_probed:
> survey_child_resources(hbus);
> + break;
> +
> + default:
> + break;
> }
>
> up(&hbus->enum_sem);
> @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> if (!hbus)
> return -ENOMEM;
> + hbus->state = hv_pcibus_init;
>
> /*
> * The PCI bus "domain" is what is called "segment" in ACPI and
> @@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> pci_stop_root_bus(hbus->pci_bus);
> pci_remove_root_bus(hbus->pci_bus);
> pci_unlock_rescan_remove();
> + hbus->state = hv_pcibus_removed;
> }
>
> ret = hv_send_resources_released(hdev);
> --
> 1.8.5.6
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message-----
> From: Bjorn Helgaas [mailto:[email protected]]
> Sent: Friday, November 11, 2016 1:04 PM
> To: Long Li <[email protected]>
> Cc: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; Bjorn Helgaas <[email protected]>;
> [email protected]; [email protected]; linux-
> [email protected]; Long Li <[email protected]>
> Subject: Re: [PATCH 1/2 v3] pci-hyperv: properly handle pci bus remove
>
> On Mon, Oct 03, 2016 at 11:42:47PM -0700, Long Li wrote:
> > From: Long Li <[email protected]>
> >
> > hv_pci_devices_present is called in hv_pci_remove when we remove a PCI
> device from host (e.g. by disabling SRIOV on a device). In hv_pci_remove,
> the bus is already removed before the call, so we don't need to rescan the
> bus in the workqueue scheduled from hv_pci_devices_present. By
> introducing status hv_pcibus_removed, we can avoid this situation.
> >
> > Signed-off-by: Long Li <[email protected]>
> > Tested-by: Cathy Avery <[email protected]>
> > Reported-by: Xiaofeng Wang <[email protected]>
Acked-by: K. Y. Srinivasan <[email protected]>
>
> I need an ack from the Hyper-V maintainers. I see acks for previous
> versions, but I don't know whether you've changed things that would
> invalidate those acks. If the acks still apply, please include them
> and repost these patches.
>
> Also, please run "git log --oneline drivers/pci/host/pci-hyperv.c" and make
> your subject line match the previous ones.
>
> > ---
> > drivers/pci/host/pci-hyperv.c | 20 +++++++++++++++++---
> > 1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> > index a8deeca..4a37598 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -348,6 +348,7 @@ enum hv_pcibus_state {
> > hv_pcibus_init = 0,
> > hv_pcibus_probed,
> > hv_pcibus_installed,
> > + hv_pcibus_removed,
> > hv_pcibus_maximum
> > };
> >
> > @@ -1481,13 +1482,24 @@ static void pci_devices_present_work(struct
> work_struct *work)
> > put_pcichild(hpdev, hv_pcidev_ref_initial);
> > }
> >
> > - /* Tell the core to rescan bus because there may have been changes.
> */
> > - if (hbus->state == hv_pcibus_installed) {
> > + switch (hbus->state) {
> > + case hv_pcibus_installed:
> > + /*
> > + * Tell the core to rescan bus
> > + * because there may have been changes.
> > + */
> > pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > - } else {
> > + break;
> > +
> > + case hv_pcibus_init:
> > + case hv_pcibus_probed:
> > survey_child_resources(hbus);
> > + break;
> > +
> > + default:
> > + break;
> > }
> >
> > up(&hbus->enum_sem);
> > @@ -2163,6 +2175,7 @@ static int hv_pci_probe(struct hv_device *hdev,
> > hbus = kzalloc(sizeof(*hbus), GFP_KERNEL);
> > if (!hbus)
> > return -ENOMEM;
> > + hbus->state = hv_pcibus_init;
> >
> > /*
> > * The PCI bus "domain" is what is called "segment" in ACPI and
> > @@ -2305,6 +2318,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> > pci_stop_root_bus(hbus->pci_bus);
> > pci_remove_root_bus(hbus->pci_bus);
> > pci_unlock_rescan_remove();
> > + hbus->state = hv_pcibus_removed;
> > }
> >
> > ret = hv_send_resources_released(hdev);
> > --
> > 1.8.5.6
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> > the body of a message to [email protected]
> > More majordomo info at
> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fvger.ke
> rnel.org%2Fmajordomo-
> info.html&data=02%7C01%7Ckys%40microsoft.com%7C982492a275ed4126c4
> d308d40a7644da%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C6361
> 44950466092469&sdata=9cXs6P1zoQ7qB%2BxYD9bsd%2BLMN%2BjwSPQkxnj
> iqBdv9go%3D&reserved=0