[PATCH v2 5/6] PCI: hv: Use hv_hvcall_*() to set up hypercall arguments

From: mhkelley58
Date: Thu Mar 13 2025 - 02:20:43 EST


From: Michael Kelley <mhklinux@xxxxxxxxxxx>

Update hypercall call sites to use the new hv_hvcall_*() functions
to set up hypercall arguments. Since these functions zero the
fixed portion of input memory, remove now redundant calls to memset().

Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---

Notes:
Changes in v2:
* In hv_arch_irq_unmask(), added check of the number of computed banks
in the hv_vpset against the batch_size. Since an hv_vpset currently
represents a maximum of 4096 CPUs, the hv_vpset size does not exceed
512 bytes and there should always be sufficent space. But do the
check just in case something changes. [Nuno Das Neves]

drivers/pci/controller/pci-hyperv.c | 18 ++++++++----------
include/hyperv/hvgdk_mini.h | 2 +-
2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index ac27bda5ba26..82ac0e09943b 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -622,7 +622,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
struct pci_dev *pdev;
unsigned long flags;
u32 var_size = 0;
- int cpu, nr_bank;
+ int cpu, nr_bank, batch_size;
u64 res;

dest = irq_data_get_effective_affinity_mask(data);
@@ -638,8 +638,8 @@ static void hv_arch_irq_unmask(struct irq_data *data)

local_irq_save(flags);

- params = *this_cpu_ptr(hyperv_pcpu_input_arg);
- memset(params, 0, sizeof(*params));
+ batch_size = hv_hvcall_in_array(&params, sizeof(*params),
+ sizeof(params->int_target.vp_set.bank_contents[0]));
params->partition_id = HV_PARTITION_ID_SELF;
params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;
params->int_entry.msi_entry.address.as_uint32 = int_desc->address & 0xffffffff;
@@ -671,7 +671,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
nr_bank = cpumask_to_vpset(&params->int_target.vp_set, tmp);
free_cpumask_var(tmp);

- if (nr_bank <= 0) {
+ if (nr_bank <= 0 || nr_bank > batch_size) {
res = 1;
goto out;
}
@@ -1034,11 +1034,9 @@ static void hv_pci_read_mmio(struct device *dev, phys_addr_t gpa, int size, u32

/*
* Must be called with interrupts disabled so it is safe
- * to use the per-cpu input argument page. Use it for
- * both input and output.
+ * to use the per-cpu argument page.
*/
- in = *this_cpu_ptr(hyperv_pcpu_input_arg);
- out = *this_cpu_ptr(hyperv_pcpu_input_arg) + sizeof(*in);
+ hv_hvcall_inout(&in, sizeof(*in), &out, sizeof(*out));
in->gpa = gpa;
in->size = size;

@@ -1067,9 +1065,9 @@ static void hv_pci_write_mmio(struct device *dev, phys_addr_t gpa, int size, u32

/*
* Must be called with interrupts disabled so it is safe
- * to use the per-cpu input argument memory.
+ * to use the per-cpu argument page.
*/
- in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ hv_hvcall_in_array(&in, sizeof(*in), sizeof(in->data[0]));
in->gpa = gpa;
in->size = size;
switch (size) {
diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
index 70e5d7ee40c8..cb25ac1e3ac5 100644
--- a/include/hyperv/hvgdk_mini.h
+++ b/include/hyperv/hvgdk_mini.h
@@ -1342,7 +1342,7 @@ struct hv_mmio_write_input {
u64 gpa;
u32 size;
u32 reserved;
- u8 data[HV_HYPERCALL_MMIO_MAX_DATA_LENGTH];
+ u8 data[];
} __packed;

#endif /* _HV_HVGDK_MINI_H */
--
2.25.1