Re: [PATCH 4/4] Hyper-V vPCI: use vPCI protocol version 1.2

From: Vitaly Kuznetsov
Date: Fri May 19 2017 - 05:59:21 EST

Jork Loeser <jloeser@xxxxxxxxxxxxxxxxx> writes:

> From: Jork Loeser <jloeser@xxxxxxxxxxxxx>
>
> Update the Hyper-V vPCI driver to use the Server-2016 version
> of the vPCI protocol, fixing MSI creation and retargeting issues.
>
> Signed-off-by: Jork Loeser <jloeser@xxxxxxxxxxxxx>
> ---
> arch/x86/include/uapi/asm/hyperv.h | 6 +
> drivers/pci/host/pci-hyperv.c | 297 ++++++++++++++++++++++++++++++------
> 2 files changed, 255 insertions(+), 48 deletions(-)
>
> diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
> index 432df4b..237ec6c 100644
> --- a/arch/x86/include/uapi/asm/hyperv.h
> +++ b/arch/x86/include/uapi/asm/hyperv.h
> @@ -153,6 +153,12 @@
> #define HV_X64_DEPRECATING_AEOI_RECOMMENDED (1 << 9)
>
> /*
> + * HV_VP_SET available
> + */
> +#define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED (1 << 11)
> +
> +
> +/*
> * Crash notification flag.
> */
> #define HV_CRASH_CTL_CRASH_NOTIFY (1ULL << 63)
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index 5f4e136..9780050 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -70,6 +70,7 @@
>
> enum pci_protocol_version_t {
> PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */
> + PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */
> };
>
> #define CPU_AFFINITY_ALL -1ULL
> @@ -79,6 +80,7 @@ enum pci_protocol_version_t {
> * first.
> */
> static enum pci_protocol_version_t pci_protocol_versions[] = {
> + PCI_PROTOCOL_VERSION_1_2,
> PCI_PROTOCOL_VERSION_1_1,
> };
>
> @@ -124,6 +126,9 @@ enum pci_message_type {
> PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13,
> PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14,
> PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15,
> + PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16,
> + PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17,
> + PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */
> PCI_MESSAGE_MAXIMUM
> };
>
> @@ -194,6 +199,30 @@ struct hv_msi_desc {
> } __packed;
>
> /**
> + * struct hv_msi_desc2 - 1.2 version of hv_msi_desc
> + * @vector: IDT entry
> + * @delivery_mode: As defined in Intel's Programmer's
> + * Reference Manual, Volume 3, Chapter 8.
> + * @vector_count: Number of contiguous entries in the
> + * Interrupt Descriptor Table that are
> + * occupied by this Message-Signaled
> + * Interrupt. For "MSI", as first defined
> + * in PCI 2.2, this can be between 1 and
> + * 32. For "MSI-X," as first defined in PCI
> + * 3.0, this must be 1, as each MSI-X table
> + * entry would have its own descriptor.
> + * @processor_count: number of bits enabled in array.
> + * @processor_array: All the target virtual processors.
> + */
> +struct hv_msi_desc2 {
> + u8 vector;
> + u8 delivery_mode;
> + u16 vector_count;
> + u16 processor_count;
> + u16 processor_array[32];
> +} __packed;
> +
> +/**
> * struct tran_int_desc
> * @reserved: unused, padding
> * @vector_count: same as in hv_msi_desc
> @@ -309,6 +338,14 @@ struct pci_resources_assigned {
> u32 reserved[4];
> } __packed;
>
> +struct pci_resources_assigned2 {
> + struct pci_message message_type;
> + union win_slot_encoding wslot;
> + u8 memory_range[0x14][6]; /* not used here */
> + u32 msi_descriptor_count;
> + u8 reserved[70];
> +} __packed;
> +
> struct pci_create_interrupt {
> struct pci_message message_type;
> union win_slot_encoding wslot;
> @@ -321,6 +358,12 @@ struct pci_create_int_response {
> struct tran_int_desc int_desc;
> } __packed;
>
> +struct pci_create_interrupt2 {
> + struct pci_message message_type;
> + union win_slot_encoding wslot;
> + struct hv_msi_desc2 int_desc;
> +} __packed;
> +
> struct pci_delete_interrupt {
> struct pci_message message_type;
> union win_slot_encoding wslot;
> @@ -346,17 +389,42 @@ struct pci_eject_response {
> #define HV_PARTITION_ID_SELF ((u64)-1)
> #define HVCALL_RETARGET_INTERRUPT 0x7e
>
> -struct retarget_msi_interrupt {
> - u64 partition_id; /* use "self" */
> - u64 device_id;
> +struct hv_interrupt_entry {
> u32 source; /* 1 for MSI(-X) */
> u32 reserved1;
> u32 address;
> u32 data;
> - u64 reserved2;
> +};
> +
> +#define HV_VP_SET_BANK_COUNT_MAX 5 /* current implementation limit */
> +
> +struct hv_vp_set {
> + u64 format; /* 0 (HvGenericSetSparse4k) */
> + u64 valid_banks;
> + u64 masks[HV_VP_SET_BANK_COUNT_MAX];
> +};
> +
> +/*
> + * flags for hv_device_interrupt_target.flags
> + */
> +#define HV_DEVICE_INTERRUPT_TARGET_MULTICAST 1
> +#define HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET 2
> +
> +struct hv_device_interrupt_target {
> u32 vector;
> u32 flags;
> - u64 vp_mask;
> + union {
> + u64 vp_mask;
> + struct hv_vp_set vp_set;
> + };
> +};
> +
> +struct retarget_msi_interrupt {
> + u64 partition_id; /* use "self" */
> + u64 device_id;
> + struct hv_interrupt_entry int_entry;
> + u64 reserved2;
> + struct hv_device_interrupt_target int_target;
> } __packed;
>
> /*
> @@ -397,7 +465,10 @@ struct hv_pcibus_device {
> struct msi_domain_info msi_info;
> struct msi_controller msi_chip;
> struct irq_domain *irq_domain;
> +
> + /* hypercall arg, must not cross page boundary */
> struct retarget_msi_interrupt retarget_msi_interrupt_params;
> +
> spinlock_t retarget_msi_interrupt_lock;
> };
>
> @@ -802,7 +873,10 @@ static void hv_irq_unmask(struct irq_data *data)
> struct pci_bus *pbus;
> struct pci_dev *pdev;
> int cpu;
> + int cpu_vmbus;
> unsigned long flags;
> + u64 res;
> + u32 var_size = 0;
>
> dest = irq_data_get_affinity_mask(data);
> pdev = msi_desc_to_pci_dev(msi_desc);
> @@ -814,23 +888,74 @@ static void hv_irq_unmask(struct irq_data *data)
> params = &hbus->retarget_msi_interrupt_params;
> memset(params, 0, sizeof(*params));
> params->partition_id = HV_PARTITION_ID_SELF;
> - params->source = 1; /* MSI(-X) */
> - params->address = msi_desc->msg.address_lo;
> - params->data = msi_desc->msg.data;
> + params->int_entry.source = 1; /* MSI(-X) */
> + params->int_entry.address = msi_desc->msg.address_lo;
> + params->int_entry.data = msi_desc->msg.data;
> params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
> (hbus->hdev->dev_instance.b[4] << 16) |
> (hbus->hdev->dev_instance.b[7] << 8) |
> (hbus->hdev->dev_instance.b[6] & 0xf8) |
> PCI_FUNC(pdev->devfn);
> - params->vector = cfg->vector;
> + params->int_target.vector = cfg->vector;
>
> - for_each_cpu_and(cpu, dest, cpu_online_mask)
> - params->vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu));
> + /*
> + * Honoring apic->irq_delivery_mode set to dest_Fixed by
> + * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
> + * spurious interrupt storm. Not doing so does not seem to have a
> + * negative effect (yet?).
> + */
>
> - hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, params, NULL);
> + if (pci_protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
> + /*
> + * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
> + * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
> + * with >64 VP support.
> + * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED
> + * is not sufficient for this hypercall.
> + */
> + params->int_target.flags |=
> + HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
> + params->int_target.vp_set.valid_banks =
> + (1ull << HV_VP_SET_BANK_COUNT_MAX) - 1;
>
> + /*
> + * var-sized hypercall, var-size starts after vp_mask (thus
> + * vp_set.format does not count, but vp_set.valid_banks does).
> + */
> + var_size = 1 + HV_VP_SET_BANK_COUNT_MAX;
> +
> + for_each_cpu_and(cpu, dest, cpu_online_mask) {
> + cpu_vmbus = vmbus_cpu_number_to_vp_number(cpu);
> +
> + if (cpu_vmbus >= HV_VP_SET_BANK_COUNT_MAX * 64) {
> + dev_err(&hbus->hdev->device,
> + "too high CPU %d", cpu_vmbus);
> + res = 1;
> + goto exit_unlock;
> + }
> +
> + params->int_target.vp_set.masks[cpu_vmbus / 64] |=
> + (1ULL << (cpu_vmbus & 63));
> + }
> + } else {
> + for_each_cpu_and(cpu, dest, cpu_online_mask) {
> + params->int_target.vp_mask |=
> + (1ULL << vmbus_cpu_number_to_vp_number(cpu));
> + }
> + }
> +
> + res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),
> + params, NULL);

In my 'remote tbl flush' series I defined 'union hv_hypercall_input',
you can use it instead of hardcoding ' | (var_size << 17)'

> +
> +exit_unlock:
> spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
>
> + if (res) {
> + dev_err(&hbus->hdev->device,
> + "%s() failed: %#llx", __func__, res);
> + return;
> + }
> +
> pci_msi_unmask_irq(data);
> }
>
> @@ -851,6 +976,53 @@ static void hv_pci_compose_compl(void *context, struct pci_response *resp,
> complete(&comp_pkt->comp_pkt.host_event);
> }
>
> +static u32 hv_compose_msi_req_v1(
> + struct pci_create_interrupt *int_pkt, struct cpumask *affinity,
> + u32 slot, u8 vector)
> +{
> + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
> + int_pkt->wslot.slot = slot;
> + int_pkt->int_desc.vector = vector;
> + int_pkt->int_desc.vector_count = 1;
> + int_pkt->int_desc.delivery_mode =
> + (apic->irq_delivery_mode == dest_LowestPrio) ?
> + dest_LowestPrio : dest_Fixed;
> +
> + /*
> + * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
> + * hv_irq_unmask().
> + */
> + int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
> +
> + return sizeof(*int_pkt);
> +}
> +
> +static u32 hv_compose_msi_req_v2(
> + struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity,
> + u32 slot, u8 vector)
> +{
> + int cpu;
> +
> + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2;
> + int_pkt->wslot.slot = slot;
> + int_pkt->int_desc.vector = vector;
> + int_pkt->int_desc.vector_count = 1;
> + int_pkt->int_desc.delivery_mode =
> + (apic->irq_delivery_mode == dest_LowestPrio) ?
> + dest_LowestPrio : dest_Fixed;
> +
> + /*
> + * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
> + * by subsequent retarget in hv_irq_unmask().
> + */
> + cpu = cpumask_first_and(affinity, cpu_online_mask);
> + int_pkt->int_desc.processor_array[0] =
> + vmbus_cpu_number_to_vp_number(cpu);
> + int_pkt->int_desc.processor_count = 1;
> +
> + return sizeof(*int_pkt);
> +}
> +
> /**
> * hv_compose_msi_msg() - Supplies a valid MSI address/data
> * @data: Everything about this MSI
> @@ -869,15 +1041,17 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> struct hv_pci_dev *hpdev;
> struct pci_bus *pbus;
> struct pci_dev *pdev;
> - struct pci_create_interrupt *int_pkt;
> struct compose_comp_ctxt comp;
> struct tran_int_desc *int_desc;
> - struct cpumask *affinity;
> struct {
> - struct pci_packet pkt;
> - u8 buffer[sizeof(struct pci_create_interrupt)];
> - } ctxt;
> - int cpu;
> + struct pci_packet pci_pkt;
> + union {
> + struct pci_create_interrupt v1;
> + struct pci_create_interrupt2 v2;
> + } int_pkts;
> + } __packed ctxt;
> +
> + u32 size;
> int ret;
>
> pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));
> @@ -900,36 +1074,42 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
>
> memset(&ctxt, 0, sizeof(ctxt));
> init_completion(&comp.comp_pkt.host_event);
> - ctxt.pkt.completion_func = hv_pci_compose_compl;
> - ctxt.pkt.compl_ctxt = &comp;
> - int_pkt = (struct pci_create_interrupt *)&ctxt.pkt.message;
> - int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
> - int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
> - int_pkt->int_desc.vector = cfg->vector;
> - int_pkt->int_desc.vector_count = 1;
> - int_pkt->int_desc.delivery_mode =
> - (apic->irq_delivery_mode == dest_LowestPrio) ? 1 : 0;
> + ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
> + ctxt.pci_pkt.compl_ctxt = &comp;
> +
> + switch (pci_protocol_version) {
> + case PCI_PROTOCOL_VERSION_1_1:
> + size = hv_compose_msi_req_v1(
> + &ctxt.int_pkts.v1, irq_data_get_affinity_mask(data),
> + hpdev->desc.win_slot.slot, cfg->vector);
> + break;
>
> - /*
> - * This bit doesn't have to work on machines with more than 64
> - * processors because Hyper-V only supports 64 in a guest.
> - */
> - affinity = irq_data_get_affinity_mask(data);
> - if (cpumask_weight(affinity) >= 32) {
> - int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
> - } else {
> - for_each_cpu_and(cpu, affinity, cpu_online_mask) {
> - int_pkt->int_desc.cpu_mask |=
> - (1ULL << vmbus_cpu_number_to_vp_number(cpu));
> - }
> + case PCI_PROTOCOL_VERSION_1_2:
> + size = hv_compose_msi_req_v2(
> + &ctxt.int_pkts.v2, irq_data_get_affinity_mask(data),
> + hpdev->desc.win_slot.slot, cfg->vector);
> + break;
> +
> + default:
> + /* As we only negotiate protocol versions known to this driver,
> + * this path should never hit. However, this is it not a hot
> + * path so we print a message to aid future updates.
> + */
> + dev_err(&hbus->hdev->device,
> + "Unexpected vPCI protocol, update driver.");
> + goto free_int_desc;
> }
>
> - ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt,
> - sizeof(*int_pkt), (unsigned long)&ctxt.pkt,
> + ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, &ctxt.int_pkts,
> + size, (unsigned long)&ctxt.pci_pkt,
> VM_PKT_DATA_INBAND,
> VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> - if (ret)
> + if (ret) {
> + dev_err(&hbus->hdev->device,
> + "Sending request for interrupt failed: 0x%x",
> + comp.comp_pkt.completion_status);
> goto free_int_desc;
> + }
>
> wait_for_completion(&comp.comp_pkt.host_event);
>
> @@ -1834,7 +2014,12 @@ static int hv_pci_protocol_negotiation(struct hv_device *hdev)
> version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
>
> for (i = 0; i < ARRAY_SIZE(pci_protocol_versions); i++) {
> +
> + dev_info(&hdev->device, "PCI VMBus probing version %x\n",
> + pci_protocol_versions[i]);
> +
> version_req->protocol_version = pci_protocol_versions[i];
> +
> ret = vmbus_sendpacket(
> hdev->channel, version_req,
> sizeof(struct pci_version_request),
> @@ -2126,13 +2311,18 @@ static int hv_send_resources_allocated(struct hv_device *hdev)
> {
> struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
> struct pci_resources_assigned *res_assigned;
> + struct pci_resources_assigned2 *res_assigned2;
> struct hv_pci_compl comp_pkt;
> struct hv_pci_dev *hpdev;
> struct pci_packet *pkt;
> u32 wslot;
> int ret;
> + size_t sizeRes;
>
> - pkt = kmalloc(sizeof(*pkt) + sizeof(*res_assigned), GFP_KERNEL);
> + sizeRes = (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2)
> + ? sizeof(*res_assigned) : sizeof(*res_assigned2);
> +
> + pkt = kmalloc(sizeof(*pkt) + sizeRes, GFP_KERNEL);
> if (!pkt)
> return -ENOMEM;
>
> @@ -2143,19 +2333,29 @@ static int hv_send_resources_allocated(struct hv_device *hdev)
> if (!hpdev)
> continue;
>
> - memset(pkt, 0, sizeof(*pkt) + sizeof(*res_assigned));
> + memset(pkt, 0, sizeof(*pkt) + sizeRes);
> init_completion(&comp_pkt.host_event);
> pkt->completion_func = hv_pci_generic_compl;
> pkt->compl_ctxt = &comp_pkt;
> - res_assigned = (struct pci_resources_assigned *)&pkt->message;
> - res_assigned->message_type.type = PCI_RESOURCES_ASSIGNED;
> - res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
>
> + if (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2) {
> + res_assigned =
> + (struct pci_resources_assigned *)&pkt->message;
> + res_assigned->message_type.type =
> + PCI_RESOURCES_ASSIGNED;
> + res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
> + } else {
> + res_assigned2 =
> + (struct pci_resources_assigned2 *)&pkt->message;
> + res_assigned2->message_type.type =
> + PCI_RESOURCES_ASSIGNED2;
> + res_assigned2->wslot.slot = hpdev->desc.win_slot.slot;
> + }
> put_pcichild(hpdev, hv_pcidev_ref_by_slot);
>
> ret = vmbus_sendpacket(
> hdev->channel, &pkt->message,
> - sizeof(*res_assigned),
> + sizeRes,
> (unsigned long)pkt,
> VM_PKT_DATA_INBAND,
> VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
> @@ -2424,6 +2624,7 @@ static int hv_pci_remove(struct hv_device *hdev)
> irq_domain_free_fwnode(hbus->sysdata.fwnode);
> put_hvpcibus(hbus);
> wait_for_completion(&hbus->remove_event);
> +
> free_page((unsigned long)hbus);
> return 0;
> }

--
Vitaly