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[Xen-devel] how to properly reset event channel in PVonHVM after kexec boot

From: Olaf Hering <olaf@xxxxxxxxx>

Date: Wed, 14 Mar 2012 11:52:54 +0100

Delivery-date: Wed, 14 Mar 2012 10:53:13 +0000

List-id: Xen developer discussion <xen-devel.lists.xen.org>

What is the best way to reset all registered event channels after an kexec boot in a PVonHVM guest? Right now repeated kexec boots will fail after 1300 iterations because no more event channels can be registered. EVTCHNOP_reset can not be used because it expects the domid, which the guest does not know. My attempt to close ports is shown below, it works in my guest. The patch prints this output: initial before kexec: [ 1.129469] xen-platform-pci 0000:00:03.0: I/O protocol version 1 [ 1.233591] xen_reset_event_channels: 1 p 0 s 0 v 0 i 0 d 0 0/0 [ 1.238435] xen_reset_event_channels: 2 p 1 s 2 v 0 i 0 d 0 0/0 [ 1.243227] xen_reset_event_channels: 3 p 2 s 2 v 1 i 0 d 0 0/0 [ 1.247953] xen_reset_event_channels: 4 p 3 s 2 v 2 i 0 d 0 0/0 [ 1.252695] xen_reset_event_channels: 5 p 4 s 2 v 3 i 0 d 0 0/0 [ 1.256625] xen_reset_event_channels: 6 p 5 s 2 v 0 i 0 d 0 0/0 [ 1.259299] xen_reset_event_channels: 7 p 6 s 1 v 0 i 0 d 0 0/0 [ 1.261870] xen_reset_event_channels: close 7 p 6 s 1 v 0 i 0 d 0 0/0 [ 1.264412] xen_reset_event_channels: 1 p 7 s 0 v 0 i 0 d 0 0/0 [ 1.267555] xen_reset_event_channels: 2 p 8 s 0 v 0 i 0 d 0 0/0 [ 1.270264] xen_reset_event_channels: 3 p 9 s 0 v 0 i 0 d 0 0/0 [ 1.272518] xen_reset_event_channels: 4 p 10 s 0 v 0 i 0 d 0 0/0 [ 1.274753] xen_reset_event_channels: 5 p 11 s 0 v 0 i 0 d 0 0/0 [ 1.277322] xen_reset_event_channels: 6 p 12 s 0 v 0 i 0 d 0 0/0 [ 1.280539] xen_reset_event_channels: 7 p 13 s 0 v 0 i 0 d 0 0/0 [ 1.283734] xen_reset_event_channels: 8 p 14 s 0 v 0 i 0 d 0 0/0 [ 1.286982] xen_reset_event_channels: 9 p 15 s 0 v 0 i 0 d 0 0/0 [ 1.290188] xen_reset_event_channels: 10 p 16 s 0 v 0 i 0 d 0 0/0 [ 1.293461] xen_reset_event_channels: 11 p 17 s 0 v 0 i 0 d 0 0/0 [ 1.296732] xen_reset_event_channels: 12 p 18 s 0 v 0 i 0 d 0 0/0 [ 1.299958] xen_reset_event_channels: 13 p 19 s 0 v 0 i 0 d 0 0/0 [ 1.303239] xen_reset_event_channels: c 14 20 [ 1.307028] suspend: event channel 6 after first kexec: [ 1.126930] xen-platform-pci 0000:00:03.0: I/O protocol version 1 [ 1.131203] xen_reset_event_channels: 1 p 0 s 0 v 0 i 0 d 0 0/0 [ 1.133496] xen_reset_event_channels: 2 p 1 s 2 v 0 i 0 d 0 0/0 [ 1.135716] xen_reset_event_channels: 3 p 2 s 2 v 1 i 0 d 0 0/0 [ 1.137983] xen_reset_event_channels: 4 p 3 s 2 v 2 i 0 d 0 0/0 [ 1.140260] xen_reset_event_channels: 5 p 4 s 2 v 3 i 0 d 0 0/0 [ 1.142482] xen_reset_event_channels: 6 p 5 s 2 v 0 i 0 d 0 0/0 [ 1.144769] xen_reset_event_channels: 7 p 6 s 1 v 0 i 0 d 0 0/0 [ 1.146987] xen_reset_event_channels: close 7 p 6 s 1 v 0 i 0 d 0 0/0 [ 1.149488] xen_reset_event_channels: 1 p 7 s 1 v 0 i 0 d 0 0/0 [ 1.151706] xen_reset_event_channels: close 1 p 7 s 1 v 0 i 0 d 0 0/0 [ 1.154192] xen_reset_event_channels: 1 p 8 s 1 v 0 i 0 d 0 0/0 [ 1.156466] xen_reset_event_channels: close 1 p 8 s 1 v 0 i 0 d 0 0/0 [ 1.158880] xen_reset_event_channels: 1 p 9 s 0 v 0 i 0 d 0 0/0 [ 1.161165] xen_reset_event_channels: 2 p 10 s 0 v 0 i 0 d 0 0/0 [ 1.163388] xen_reset_event_channels: 3 p 11 s 0 v 0 i 0 d 0 0/0 [ 1.165659] xen_reset_event_channels: 4 p 12 s 0 v 0 i 0 d 0 0/0 [ 1.167882] xen_reset_event_channels: 5 p 13 s 0 v 0 i 0 d 0 0/0 [ 1.170173] xen_reset_event_channels: 6 p 14 s 0 v 0 i 0 d 0 0/0 [ 1.172621] xen_reset_event_channels: 7 p 15 s 0 v 0 i 0 d 0 0/0 [ 1.175762] xen_reset_event_channels: 8 p 16 s 0 v 0 i 0 d 0 0/0 [ 1.178161] xen_reset_event_channels: 9 p 17 s 0 v 0 i 0 d 0 0/0 [ 1.180470] xen_reset_event_channels: 10 p 18 s 0 v 0 i 0 d 0 0/0 [ 1.182752] xen_reset_event_channels: 11 p 19 s 0 v 0 i 0 d 0 0/0 [ 1.185124] xen_reset_event_channels: 12 p 20 s 0 v 0 i 0 d 0 0/0 [ 1.187402] xen_reset_event_channels: 13 p 21 s 0 v 0 i 0 d 0 0/0 [ 1.189736] xen_reset_event_channels: c 14 22 [ 1.191915] XENBUS: frontend device/vbd/768 Closed [ 1.193901] XENBUS: backend /local/domain/0/backend/vbd/19/768 Closed [ 1.196402] XENBUS: triggering reconnect on /local/domain/0/backend/vbd/19/768 [ 1.199330] XENBUS: backend /local/domain/0/backend/vbd/19/768/state Closed [ 1.202927] XENBUS: backend /local/domain/0/backend/vbd/19/768/state InitWait [ 1.205689] XENBUS: reconnect done on /local/domain/0/backend/vbd/19/768 [ 1.208306] XENBUS: frontend device/vbd/5632 Closed [ 1.210277] XENBUS: backend /local/domain/0/backend/vbd/19/5632 Closed [ 1.212783] XENBUS: triggering reconnect on /local/domain/0/backend/vbd/19/5632 [ 1.215788] XENBUS: backend /local/domain/0/backend/vbd/19/5632/state Closed [ 1.220149] XENBUS: backend /local/domain/0/backend/vbd/19/5632/state InitWait [ 1.222940] XENBUS: reconnect done on /local/domain/0/backend/vbd/19/5632 [ 1.225673] XENBUS: frontend device/vif/0 Closed [ 1.227548] XENBUS: backend /local/domain/0/backend/vif/19/0 Closed [ 1.229975] XENBUS: triggering reconnect on /local/domain/0/backend/vif/19/0 [ 1.232903] XENBUS: backend /local/domain/0/backend/vif/19/0/state Closed [ 1.236079] XENBUS: backend /local/domain/0/backend/vif/19/0/state InitWait [ 1.239787] XENBUS: reconnect done on /local/domain/0/backend/vif/19/0 [ 1.243467] suspend: event channel 6 --- Index: xen-4.1.2-testing/unmodified_drivers/linux-2.6/platform-pci/evtchn.c =================================================================== --- xen-4.1.2-testing.orig/unmodified_drivers/linux-2.6/platform-pci/evtchn.c +++ xen-4.1.2-testing/unmodified_drivers/linux-2.6/platform-pci/evtchn.c @@ -341,6 +341,38 @@ void irq_resume(void) irq_evtchn[irq].evtchn = 0; } +/* BITS_PER_LONG is used in Xen */ +#define MAX_EVTCHNS (64 * 64) + +static void xen_reset_event_channels(void) +{ + struct evtchn_status status = { .dom = DOMID_SELF }; + struct evtchn_close close; + int port, rc, count = 0; + + for (port = 0; port <= MAX_EVTCHNS; port++) { + status.port = port; + if (count++ > 12) + break; + rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status); + printk("%s: %d p %d s %x v %x i %x d %x %d/%x\n", __func__, count, port, status.status, status.vcpu, status.u.pirq, status.u.unbound.dom, rc, rc); + if (rc < 0) + continue; + switch (status.status) { + case EVTCHNSTAT_closed: + case EVTCHNSTAT_interdomain: + break; + default: + close.port = port; + rc = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close); + printk("%s: close %d p %d s %x v %x i %x d %x %d/%x\n", __func__, count, port, status.status, status.vcpu, status.u.pirq, status.u.unbound.dom, rc, rc); + count = 0; + break; + } + } + printk("%s: c %d %d\n", __func__, count, port); +} + int xen_irq_init(struct pci_dev *pdev) { int irq; @@ -348,6 +380,8 @@ int xen_irq_init(struct pci_dev *pdev) for (irq = 0; irq < ARRAY_SIZE(irq_evtchn); irq++) spin_lock_init(&irq_evtchn[irq].lock); + xen_reset_event_channels(); + return request_irq(pdev->irq, evtchn_interrupt, #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22) SA_SHIRQ | SA_SAMPLE_RANDOM | SA_INTERRUPT, _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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