From: Jeffrey Hugo quic_jhugo@quicinc.com
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.
5.15 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 DELIVERY_MODE on x86). Removed unused variable in hv_compose_msi_msg. Fixed reference to msi_desc->pci to point to the same is_msix variable.
Suggested-by: Dexuan Cui decui@microsoft.com Signed-off-by: Jeffrey Hugo quic_jhugo@quicinc.com Reviewed-by: Dexuan Cui decui@microsoft.com Tested-by: Michael Kelley mikelley@microsoft.com Link: https://lore.kernel.org/r/1652282599-21643-1-git-send-email-quic_jhugo@quici... Signed-off-by: Wei Liu wei.liu@kernel.org Signed-off-by: Carl Vanderlip quic_carlv@quicinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/controller/pci-hyperv.c | 68 ++++++++++++++++++++++++++++++------ 1 file changed, 57 insertions(+), 11 deletions(-)
--- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -1142,6 +1142,10 @@ static void hv_int_desc_free(struct hv_p 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 = @@ -1204,6 +1208,13 @@ static void hv_irq_mask(struct irq_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) { @@ -1359,12 +1370,12 @@ static void hv_pci_compose_compl(void *c
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 = APIC_DELIVERY_MODE_FIXED;
/* @@ -1387,14 +1398,14 @@ static int hv_compose_msi_req_get_cpu(st
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 = APIC_DELIVERY_MODE_FIXED; cpu = hv_compose_msi_req_get_cpu(affinity); int_pkt->int_desc.processor_array[0] = @@ -1406,7 +1417,7 @@ static u32 hv_compose_msi_req_v2(
static u32 hv_compose_msi_req_v3( struct pci_create_interrupt3 *int_pkt, struct cpumask *affinity, - u32 slot, u32 vector) + u32 slot, u32 vector, u8 vector_count) { int cpu;
@@ -1414,7 +1425,7 @@ static u32 hv_compose_msi_req_v3( int_pkt->wslot.slot = slot; int_pkt->int_desc.vector = vector; int_pkt->int_desc.reserved = 0; - int_pkt->int_desc.vector_count = 1; + int_pkt->int_desc.vector_count = vector_count; int_pkt->int_desc.delivery_mode = APIC_DELIVERY_MODE_FIXED; cpu = hv_compose_msi_req_get_cpu(affinity); int_pkt->int_desc.processor_array[0] = @@ -1437,7 +1448,6 @@ static u32 hv_compose_msi_req_v3( */ 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 vmbus_channel *channel; struct hv_pci_dev *hpdev; @@ -1446,6 +1456,8 @@ static void hv_compose_msi_msg(struct ir struct cpumask *dest; 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 { @@ -1467,7 +1479,8 @@ static void hv_compose_msi_msg(struct ir 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); @@ -1480,6 +1493,36 @@ static void hv_compose_msi_msg(struct ir 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; @@ -1490,7 +1533,8 @@ static void hv_compose_msi_msg(struct ir 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: @@ -1498,14 +1542,16 @@ static void hv_compose_msi_msg(struct ir size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2, dest, hpdev->desc.win_slot.slot, - cfg->vector); + vector, + vector_count); break;
case PCI_PROTOCOL_VERSION_1_4: size = hv_compose_msi_req_v3(&ctxt.int_pkts.v3, dest, hpdev->desc.win_slot.slot, - cfg->vector); + vector, + vector_count); break;
default: