forked from Minki/linux
Merge branch 'remotes/lorenzo/pci/hv'
- Add hibernation support for Hyper-V virtual PCI devices (Dexuan Cui) - Track Hyper-V pci_protocol_version per-hbus, not globally (Dexuan Cui) - Avoid kmemleak false positive on hv hbus buffer (Dexuan Cui) * remotes/lorenzo/pci/hv: PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer PCI: hv: Change pci_protocol_version to per-hbus PCI: hv: Add hibernation support PCI: hv: Reorganize the code in preparation of hibernation
This commit is contained in:
Bjorn Helgaas
commit
4eb87ddf39
@ -76,11 +76,6 @@ static enum pci_protocol_version_t pci_protocol_versions[] = {
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PCI_PROTOCOL_VERSION_1_1,
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};
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/*
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* Protocol version negotiated by hv_pci_protocol_negotiation().
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*/
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static enum pci_protocol_version_t pci_protocol_version;
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#define PCI_CONFIG_MMIO_LENGTH 0x2000
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#define CFG_PAGE_OFFSET 0x1000
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#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
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@ -455,12 +450,15 @@ enum hv_pcibus_state {
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hv_pcibus_init = 0,
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hv_pcibus_probed,
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hv_pcibus_installed,
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hv_pcibus_removing,
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hv_pcibus_removed,
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hv_pcibus_maximum
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};
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struct hv_pcibus_device {
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struct pci_sysdata sysdata;
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/* Protocol version negotiated with the host */
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enum pci_protocol_version_t protocol_version;
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enum hv_pcibus_state state;
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refcount_t remove_lock;
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struct hv_device *hdev;
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@ -1224,7 +1222,7 @@ static void hv_irq_unmask(struct irq_data *data)
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* negative effect (yet?).
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*/
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if (pci_protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
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if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
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/*
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* PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
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* HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
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@ -1394,7 +1392,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
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ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
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ctxt.pci_pkt.compl_ctxt = ∁
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switch (pci_protocol_version) {
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switch (hbus->protocol_version) {
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case PCI_PROTOCOL_VERSION_1_1:
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size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
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dest,
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@ -1681,6 +1679,23 @@ static void prepopulate_bars(struct hv_pcibus_device *hbus)
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spin_lock_irqsave(&hbus->device_list_lock, flags);
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/*
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* Clear the memory enable bit, in case it's already set. This occurs
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* in the suspend path of hibernation, where the device is suspended,
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* resumed and suspended again: see hibernation_snapshot() and
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* hibernation_platform_enter().
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*
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* If the memory enable bit is already set, Hyper-V sliently ignores
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* the below BAR updates, and the related PCI device driver can not
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* work, because reading from the device register(s) always returns
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* 0xFFFFFFFF.
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*/
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list_for_each_entry(hpdev, &hbus->children, list_entry) {
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_hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command);
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command &= ~PCI_COMMAND_MEMORY;
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_hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command);
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}
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/* Pick addresses for the BARs. */
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do {
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list_for_each_entry(hpdev, &hbus->children, list_entry) {
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@ -2107,6 +2122,12 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
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unsigned long flags;
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bool pending_dr;
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if (hbus->state == hv_pcibus_removing) {
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dev_info(&hbus->hdev->device,
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"PCI VMBus BUS_RELATIONS: ignored\n");
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return;
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}
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dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
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if (!dr_wrk)
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return;
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@ -2223,11 +2244,19 @@ static void hv_eject_device_work(struct work_struct *work)
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*/
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static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
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{
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struct hv_pcibus_device *hbus = hpdev->hbus;
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struct hv_device *hdev = hbus->hdev;
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if (hbus->state == hv_pcibus_removing) {
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dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n");
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return;
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}
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hpdev->state = hv_pcichild_ejecting;
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get_pcichild(hpdev);
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INIT_WORK(&hpdev->wrk, hv_eject_device_work);
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get_hvpcibus(hpdev->hbus);
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queue_work(hpdev->hbus->wq, &hpdev->wrk);
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get_hvpcibus(hbus);
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queue_work(hbus->wq, &hpdev->wrk);
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}
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/**
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@ -2379,8 +2408,11 @@ static void hv_pci_onchannelcallback(void *context)
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* failing if the host doesn't support the necessary protocol
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* level.
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*/
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static int hv_pci_protocol_negotiation(struct hv_device *hdev)
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static int hv_pci_protocol_negotiation(struct hv_device *hdev,
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enum pci_protocol_version_t version[],
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int num_version)
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{
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struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
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struct pci_version_request *version_req;
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struct hv_pci_compl comp_pkt;
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struct pci_packet *pkt;
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@ -2403,8 +2435,8 @@ static int hv_pci_protocol_negotiation(struct hv_device *hdev)
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version_req = (struct pci_version_request *)&pkt->message;
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version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
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for (i = 0; i < ARRAY_SIZE(pci_protocol_versions); i++) {
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version_req->protocol_version = pci_protocol_versions[i];
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for (i = 0; i < num_version; i++) {
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version_req->protocol_version = version[i];
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ret = vmbus_sendpacket(hdev->channel, version_req,
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sizeof(struct pci_version_request),
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(unsigned long)pkt, VM_PKT_DATA_INBAND,
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@ -2420,10 +2452,10 @@ static int hv_pci_protocol_negotiation(struct hv_device *hdev)
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}
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if (comp_pkt.completion_status >= 0) {
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pci_protocol_version = pci_protocol_versions[i];
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hbus->protocol_version = version[i];
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dev_info(&hdev->device,
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"PCI VMBus probing: Using version %#x\n",
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pci_protocol_version);
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hbus->protocol_version);
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goto exit;
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}
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@ -2707,7 +2739,7 @@ static int hv_send_resources_allocated(struct hv_device *hdev)
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u32 wslot;
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int ret;
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size_res = (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2)
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size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
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? sizeof(*res_assigned) : sizeof(*res_assigned2);
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pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
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@ -2726,7 +2758,7 @@ static int hv_send_resources_allocated(struct hv_device *hdev)
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pkt->completion_func = hv_pci_generic_compl;
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pkt->compl_ctxt = &comp_pkt;
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if (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2) {
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if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) {
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res_assigned =
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(struct pci_resources_assigned *)&pkt->message;
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res_assigned->message_type.type =
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@ -2870,9 +2902,27 @@ static int hv_pci_probe(struct hv_device *hdev,
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* hv_pcibus_device contains the hypercall arguments for retargeting in
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* hv_irq_unmask(). Those must not cross a page boundary.
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*/
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BUILD_BUG_ON(sizeof(*hbus) > PAGE_SIZE);
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BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE);
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hbus = (struct hv_pcibus_device *)get_zeroed_page(GFP_KERNEL);
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/*
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* With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural
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* alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate
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* a 4KB buffer that is guaranteed to be 4KB-aligned. Here the size and
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* alignment of hbus is important because hbus's field
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* retarget_msi_interrupt_params must not cross a 4KB page boundary.
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*
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* Here we prefer kzalloc to get_zeroed_page(), because a buffer
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* allocated by the latter is not tracked and scanned by kmemleak, and
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* hence kmemleak reports the pointer contained in the hbus buffer
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* (i.e. the hpdev struct, which is created in new_pcichild_device() and
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* is tracked by hbus->children) as memory leak (false positive).
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*
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* If the kernel doesn't have 59bb47985c1d, get_zeroed_page() *must* be
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* used to allocate the hbus buffer and we can avoid the kmemleak false
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* positive by using kmemleak_alloc() and kmemleak_free() to ask
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* kmemleak to track and scan the hbus buffer.
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*/
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hbus = (struct hv_pcibus_device *)kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
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if (!hbus)
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return -ENOMEM;
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hbus->state = hv_pcibus_init;
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@ -2930,7 +2980,8 @@ static int hv_pci_probe(struct hv_device *hdev,
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hv_set_drvdata(hdev, hbus);
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ret = hv_pci_protocol_negotiation(hdev);
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ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions,
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ARRAY_SIZE(pci_protocol_versions));
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if (ret)
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goto close;
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@ -3011,7 +3062,7 @@ free_bus:
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return ret;
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}
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static void hv_pci_bus_exit(struct hv_device *hdev)
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static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating)
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{
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struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
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struct {
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@ -3027,16 +3078,20 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
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* access the per-channel ringbuffer any longer.
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*/
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if (hdev->channel->rescind)
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return;
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return 0;
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/* Delete any children which might still exist. */
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memset(&relations, 0, sizeof(relations));
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hv_pci_devices_present(hbus, &relations);
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if (!hibernating) {
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/* Delete any children which might still exist. */
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memset(&relations, 0, sizeof(relations));
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hv_pci_devices_present(hbus, &relations);
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}
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ret = hv_send_resources_released(hdev);
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if (ret)
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if (ret) {
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dev_err(&hdev->device,
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"Couldn't send resources released packet(s)\n");
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return ret;
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}
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memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet));
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init_completion(&comp_pkt.host_event);
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@ -3049,8 +3104,13 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
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(unsigned long)&pkt.teardown_packet,
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VM_PKT_DATA_INBAND,
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VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
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if (!ret)
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wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ);
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if (ret)
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return ret;
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if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0)
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return -ETIMEDOUT;
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return 0;
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}
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/**
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@ -3062,6 +3122,7 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
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static int hv_pci_remove(struct hv_device *hdev)
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{
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struct hv_pcibus_device *hbus;
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int ret;
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hbus = hv_get_drvdata(hdev);
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if (hbus->state == hv_pcibus_installed) {
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@ -3074,7 +3135,7 @@ static int hv_pci_remove(struct hv_device *hdev)
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hbus->state = hv_pcibus_removed;
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}
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hv_pci_bus_exit(hdev);
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ret = hv_pci_bus_exit(hdev, false);
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vmbus_close(hdev->channel);
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@ -3090,10 +3151,97 @@ static int hv_pci_remove(struct hv_device *hdev)
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hv_put_dom_num(hbus->sysdata.domain);
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free_page((unsigned long)hbus);
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kfree(hbus);
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return ret;
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}
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static int hv_pci_suspend(struct hv_device *hdev)
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{
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struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
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enum hv_pcibus_state old_state;
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int ret;
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/*
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* hv_pci_suspend() must make sure there are no pending work items
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* before calling vmbus_close(), since it runs in a process context
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* as a callback in dpm_suspend(). When it starts to run, the channel
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* callback hv_pci_onchannelcallback(), which runs in a tasklet
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* context, can be still running concurrently and scheduling new work
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* items onto hbus->wq in hv_pci_devices_present() and
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* hv_pci_eject_device(), and the work item handlers can access the
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* vmbus channel, which can be being closed by hv_pci_suspend(), e.g.
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* the work item handler pci_devices_present_work() ->
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* new_pcichild_device() writes to the vmbus channel.
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*
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* To eliminate the race, hv_pci_suspend() disables the channel
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* callback tasklet, sets hbus->state to hv_pcibus_removing, and
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* re-enables the tasklet. This way, when hv_pci_suspend() proceeds,
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* it knows that no new work item can be scheduled, and then it flushes
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* hbus->wq and safely closes the vmbus channel.
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*/
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tasklet_disable(&hdev->channel->callback_event);
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/* Change the hbus state to prevent new work items. */
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old_state = hbus->state;
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if (hbus->state == hv_pcibus_installed)
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hbus->state = hv_pcibus_removing;
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tasklet_enable(&hdev->channel->callback_event);
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if (old_state != hv_pcibus_installed)
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return -EINVAL;
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flush_workqueue(hbus->wq);
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ret = hv_pci_bus_exit(hdev, true);
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if (ret)
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return ret;
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vmbus_close(hdev->channel);
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return 0;
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}
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static int hv_pci_resume(struct hv_device *hdev)
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{
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struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
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enum pci_protocol_version_t version[1];
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int ret;
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hbus->state = hv_pcibus_init;
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ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
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hv_pci_onchannelcallback, hbus);
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if (ret)
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return ret;
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/* Only use the version that was in use before hibernation. */
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version[0] = hbus->protocol_version;
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ret = hv_pci_protocol_negotiation(hdev, version, 1);
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if (ret)
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goto out;
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ret = hv_pci_query_relations(hdev);
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if (ret)
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goto out;
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ret = hv_pci_enter_d0(hdev);
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if (ret)
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goto out;
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ret = hv_send_resources_allocated(hdev);
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if (ret)
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goto out;
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prepopulate_bars(hbus);
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hbus->state = hv_pcibus_installed;
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return 0;
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out:
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vmbus_close(hdev->channel);
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return ret;
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}
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static const struct hv_vmbus_device_id hv_pci_id_table[] = {
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/* PCI Pass-through Class ID */
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/* 44C4F61D-4444-4400-9D52-802E27EDE19F */
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@ -3108,6 +3256,8 @@ static struct hv_driver hv_pci_drv = {
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.id_table = hv_pci_id_table,
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.probe = hv_pci_probe,
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.remove = hv_pci_remove,
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.suspend = hv_pci_suspend,
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.resume = hv_pci_resume,
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};
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static void __exit exit_hv_pci_drv(void)
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