From 93d16d81c8af0fe93a04bee8a4cb3259f480cab6 Mon Sep 17 00:00:00 2001 From: Yi Min Zhao Date: Wed, 27 Apr 2016 17:44:17 +0800 Subject: [PATCH] s390x/pci: make hot-unplug handler smoother The current implementation of hot-unplug handler is abrupt. Any pci operation will be just rejected if pci device is unconfigured. Thus a pci device can not be reset or destroyed in a right, smooth and safe way. Improve this as follows: - Notify the guest via a HP_EVENT_DECONFIGURE_REQUEST(0x303) event in the unplug handler, giving it a chance to deconfigure the device via sclp and allowing us to continue hot-unplug afterwards. - Set up a timer that will generate the HP_EVENT_CONFIGURE_TO_STBRES (0x304) event as before if the guest did not react after an adequate time. Signed-off-by: Yi Min Zhao Reviewed-by: Pierre Morel Signed-off-by: Cornelia Huck --- hw/s390x/s390-pci-bus.c | 35 ++++++++++++++++++++++++++++++++++- hw/s390x/s390-pci-bus.h | 3 +++ 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c index 630a826202..640a4eaa61 100644 --- a/hw/s390x/s390-pci-bus.c +++ b/hw/s390x/s390-pci-bus.c @@ -192,6 +192,10 @@ void s390_pci_sclp_deconfigure(SCCB *sccb) } pbdev->state = ZPCI_FS_STANDBY; rc = SCLP_RC_NORMAL_COMPLETION; + + if (pbdev->release_timer) { + qdev_unplug(DEVICE(pbdev->pdev), NULL); + } } out: psccb->header.response_code = cpu_to_be16(rc); @@ -679,6 +683,23 @@ static void s390_pcihost_hot_plug(HotplugHandler *hotplug_dev, } } +static void s390_pcihost_timer_cb(void *opaque) +{ + S390PCIBusDevice *pbdev = opaque; + + if (pbdev->summary_ind) { + pci_dereg_irqs(pbdev); + } + if (pbdev->iommu_enabled) { + pci_dereg_ioat(pbdev); + } + + pbdev->state = ZPCI_FS_STANDBY; + s390_pci_generate_plug_event(HP_EVENT_CONFIGURED_TO_STBRES, + pbdev->fh, pbdev->fid); + qdev_unplug(DEVICE(pbdev), NULL); +} + static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev, DeviceState *dev, Error **errp) { @@ -712,8 +733,20 @@ static void s390_pcihost_hot_unplug(HotplugHandler *hotplug_dev, case ZPCI_FS_STANDBY: break; default: - s390_pci_generate_plug_event(HP_EVENT_CONFIGURED_TO_STBRES, + s390_pci_generate_plug_event(HP_EVENT_DECONFIGURE_REQUEST, pbdev->fh, pbdev->fid); + pbdev->release_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, + s390_pcihost_timer_cb, + pbdev); + timer_mod(pbdev->release_timer, + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + HOT_UNPLUG_TIMEOUT); + return; + } + + if (pbdev->release_timer && timer_pending(pbdev->release_timer)) { + timer_del(pbdev->release_timer); + timer_free(pbdev->release_timer); + pbdev->release_timer = NULL; } s390_pci_generate_plug_event(HP_EVENT_STANDBY_TO_RESERVED, diff --git a/hw/s390x/s390-pci-bus.h b/hw/s390x/s390-pci-bus.h index 71cdd7aa22..f1fbd3c1b6 100644 --- a/hw/s390x/s390-pci-bus.h +++ b/hw/s390x/s390-pci-bus.h @@ -34,6 +34,7 @@ #define ZPCI_MAX_UID 0xffff #define UID_UNDEFINED 0 #define UID_CHECKING_ENABLED 0x01 +#define HOT_UNPLUG_TIMEOUT (NANOSECONDS_PER_SECOND * 60 * 5) #define S390_PCI_HOST_BRIDGE(obj) \ OBJECT_CHECK(S390pciState, (obj), TYPE_S390_PCI_HOST_BRIDGE) @@ -44,6 +45,7 @@ #define HP_EVENT_TO_CONFIGURED 0x0301 #define HP_EVENT_RESERVED_TO_STANDBY 0x0302 +#define HP_EVENT_DECONFIGURE_REQUEST 0x0303 #define HP_EVENT_CONFIGURED_TO_STBRES 0x0304 #define HP_EVENT_STANDBY_TO_RESERVED 0x0308 @@ -283,6 +285,7 @@ typedef struct S390PCIBusDevice { MemoryRegion iommu_mr; IndAddr *summary_ind; IndAddr *indicator; + QEMUTimer *release_timer; } S390PCIBusDevice; typedef struct S390PCIBus { -- GitLab