[PATCH 3/3] PCI: hv: Use vPCI protocol version 1.2 for v4.9

From: Ajay Kaher
Date: Thu Jan 17 2019 - 08:05:10 EST

Update the Hyper-V vPCI driver to use the Server-2016 version of the vPCI
protocol, fixing MSI creation and retargeting issues.

Replaced hv_tmp_cpu_nr_to_vp_nr() with vmbus_cpu_number_to_vp_number()
to make this patch compatibale for linux v4.9.

Signed-off-by: Jork Loeser <jloeser@xxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Signed-off-by: Ajay Kaher <akaher@xxxxxxxxxx>
---
drivers/pci/host/pci-hyperv.c | 300 ++++++++++++++++++++++++++++++++++--------
1 file changed, 246 insertions(+), 54 deletions(-)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 6eed85b..37d70b1 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -71,6 +71,7 @@

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
@@ -80,6 +81,7 @@ 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,
};

@@ -125,6 +127,9 @@ 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
};

@@ -195,6 +200,30 @@ 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
@@ -310,6 +339,14 @@ 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;
@@ -322,6 +359,12 @@ 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;
@@ -347,17 +390,42 @@ static int pci_ring_size = (4 * PAGE_SIZE);
#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;

/*
@@ -802,8 +870,11 @@ void hv_irq_unmask(struct irq_data *data)
struct cpumask *dest;
struct pci_bus *pbus;
struct pci_dev *pdev;
- int cpu;
unsigned long flags;
+ u32 var_size = 0;
+ int cpu_vmbus;
+ int cpu;
+ u64 res;

dest = irq_data_get_affinity_mask(data);
pdev = msi_desc_to_pci_dev(msi_desc);
@@ -815,23 +886,74 @@ 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;
+
+ /*
+ * 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?).
+ */
+
+ 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;

- for_each_cpu_and(cpu, dest, cpu_online_mask)
- params->vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu));
+ /*
+ * 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;

- hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, params, NULL);
+ 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);
+
+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);
}

@@ -852,6 +974,53 @@ 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
@@ -870,15 +1039,17 @@ 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));
@@ -901,36 +1072,44 @@ 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);

@@ -2117,13 +2296,18 @@ 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;
+ size_t size_res;
u32 wslot;
int ret;

- pkt = kmalloc(sizeof(*pkt) + sizeof(*res_assigned), GFP_KERNEL);
+ size_res = (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2)
+ ? sizeof(*res_assigned) : sizeof(*res_assigned2);
+
+ pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
if (!pkt)
return -ENOMEM;

@@ -2134,22 +2318,30 @@ 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) + size_res);
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),
- (unsigned long)pkt,
- VM_PKT_DATA_INBAND,
- VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+ ret = vmbus_sendpacket(hdev->channel, &pkt->message,
+ size_res, (unsigned long)pkt,
+ VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
break;

--
2.7.4