2016-11-01 22:33:38

by Long Li

Subject: [PATCH] pci-hyperv: move hypercall buffer from stack to heap

From: Long Li <[email protected]>

We need to pass a segment from a physically continuous buffer to hv_do_hypercall. Buffer allocated on the stack may not work if CONFIG_VMAP_STACK=y is set. Moving the params buffer from stack to buffer returned by kmalloc.

Signed-off-by: Long Li <[email protected]>
Reported-by: Haiyang Zhang <[email protected]>
---
drivers/pci/host/pci-hyperv.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 763ff87..97e6daf 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -378,6 +378,7 @@ struct hv_pcibus_device {
struct msi_domain_info msi_info;
struct msi_controller msi_chip;
struct irq_domain *irq_domain;
+ struct retarget_msi_interrupt retarget_msi_interrupt_params;
};

/*
@@ -774,7 +775,7 @@ void hv_irq_unmask(struct irq_data *data)
{
struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
struct irq_cfg *cfg = irqd_cfg(data);
- struct retarget_msi_interrupt params;
+ struct retarget_msi_interrupt *params;
struct hv_pcibus_device *hbus;
struct cpumask *dest;
struct pci_bus *pbus;
@@ -785,23 +786,24 @@ void hv_irq_unmask(struct irq_data *data)
pdev = msi_desc_to_pci_dev(msi_desc);
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
-
- 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.device_id = (hbus->hdev->dev_instance.b[5] << 24) |
+ 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->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->vector = cfg->vector;

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

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

pci_msi_unmask_irq(data);
}
--
2.7.4