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Commit ae5e8a3f authored by Jeffrey Hugo's avatar Jeffrey Hugo Committed by Greg Kroah-Hartman
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PCI: hv: Fix interrupt mapping for multi-MSI 



commit a2bad844a67b1c7740bda63e87453baf63c3a7f7 upstream.

According to Dexuan, the hypervisor folks beleive that multi-msi
allocations are not correct.  compose_msi_msg() will allocate multi-msi
one by one.  However, multi-msi is a block of related MSIs, with alignment
requirements.  In order for the hypervisor to allocate properly aligned
and consecutive entries in the IOMMU Interrupt Remapping Table, there
should be a single mapping request that requests all of the multi-msi
vectors in one shot.

Dexuan suggests detecting the multi-msi case and composing a single
request related to the first MSI.  Then for the other MSIs in the same
block, use the cached information.  This appears to be viable, so do it.

4.19 backport - add hv_msi_get_int_vector helper function. Fixed merge
conflict due to delivery_mode name change (APIC_DELIVERY_MODE_FIXED
is the value given to dest_Fixed). Removed unused variable in
hv_compose_msi_msg. Fixed reference to msi_desc->pci to point to
the same is_msix variable. Removed changes to compose_msi_req_v3 since
it doesn't exist yet.

Suggested-by: default avatarDexuan Cui <decui@microsoft.com>
Signed-off-by: default avatarJeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: default avatarDexuan Cui <decui@microsoft.com>
Tested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1652282599-21643-1-git-send-email-quic_jhugo@quicinc.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
Signed-off-by: default avatarCarl Vanderlip <quic_carlv@quicinc.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c51ff8cf

drivers/pci/controller/pci-hyperv.c

+53 −8
Original line number Diff line number Diff line
@@ -831,6 +831,10 @@ static void hv_int_desc_free(struct hv_pci_dev *hpdev, 
		u8 buffer[sizeof(struct pci_delete_interrupt)];

	} ctxt;



	if (!int_desc->vector_count) {

		kfree(int_desc);

		return;

	}

	memset(&ctxt, 0, sizeof(ctxt));

	int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;

	int_pkt->message_type.type =
@@ -893,6 +897,13 @@ static void hv_irq_mask(struct irq_data *data) 
	pci_msi_mask_irq(data);

}



static unsigned int hv_msi_get_int_vector(struct irq_data *data)

{

	struct irq_cfg *cfg = irqd_cfg(data);



	return cfg->vector;

}



static int hv_msi_prepare(struct irq_domain *domain, struct device *dev,

			  int nvec, msi_alloc_info_t *info)

{
@@ -1035,12 +1046,12 @@ static void hv_pci_compose_compl(void *context, struct pci_response *resp, 


static u32 hv_compose_msi_req_v1(

	struct pci_create_interrupt *int_pkt, struct cpumask *affinity,

	u32 slot, u8 vector)

	u32 slot, u8 vector, u8 vector_count)

{

	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.vector_count = vector_count;

	int_pkt->int_desc.delivery_mode = dest_Fixed;



	/*
@@ -1054,14 +1065,14 @@ static u32 hv_compose_msi_req_v1( 


static u32 hv_compose_msi_req_v2(

	struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity,

	u32 slot, u8 vector)

	u32 slot, u8 vector, u8 vector_count)

{

	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.vector_count = vector_count;

	int_pkt->int_desc.delivery_mode = dest_Fixed;



	/*
@@ -1089,7 +1100,6 @@ static u32 hv_compose_msi_req_v2( 
 */

static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)

{

	struct irq_cfg *cfg = irqd_cfg(data);

	struct hv_pcibus_device *hbus;

	struct hv_pci_dev *hpdev;

	struct pci_bus *pbus;
@@ -1098,6 +1108,8 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
	unsigned long flags;

	struct compose_comp_ctxt comp;

	struct tran_int_desc *int_desc;

	struct msi_desc *msi_desc;

	u8 vector, vector_count;

	struct {

		struct pci_packet pci_pkt;

		union {
@@ -1118,7 +1130,8 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
		return;

	}



	pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));

	msi_desc  = irq_data_get_msi_desc(data);

	pdev = msi_desc_to_pci_dev(msi_desc);

	dest = irq_data_get_effective_affinity_mask(data);

	pbus = pdev->bus;

	hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
@@ -1130,6 +1143,36 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
	if (!int_desc)

		goto drop_reference;



	if (!msi_desc->msi_attrib.is_msix && msi_desc->nvec_used > 1) {

		/*

		 * If this is not the first MSI of Multi MSI, we already have

		 * a mapping.  Can exit early.

		 */

		if (msi_desc->irq != data->irq) {

			data->chip_data = int_desc;

			int_desc->address = msi_desc->msg.address_lo |

					    (u64)msi_desc->msg.address_hi << 32;

			int_desc->data = msi_desc->msg.data +

					 (data->irq - msi_desc->irq);

			msg->address_hi = msi_desc->msg.address_hi;

			msg->address_lo = msi_desc->msg.address_lo;

			msg->data = int_desc->data;

			put_pcichild(hpdev);

			return;

		}

		/*

		 * The vector we select here is a dummy value.  The correct

		 * value gets sent to the hypervisor in unmask().  This needs

		 * to be aligned with the count, and also not zero.  Multi-msi

		 * is powers of 2 up to 32, so 32 will always work here.

		 */

		vector = 32;

		vector_count = msi_desc->nvec_used;

	} else {

		vector = hv_msi_get_int_vector(data);

		vector_count = 1;

	}



	memset(&ctxt, 0, sizeof(ctxt));

	init_completion(&comp.comp_pkt.host_event);

	ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
@@ -1140,14 +1183,16 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
		size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,

					dest,

					hpdev->desc.win_slot.slot,

					cfg->vector);

					vector,

					vector_count);

		break;



	case PCI_PROTOCOL_VERSION_1_2:

		size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,

					dest,

					hpdev->desc.win_slot.slot,

					cfg->vector);

					vector,

					vector_count);

		break;



	default: