On 3/12/2025 11:19 PM, mhkelley58@xxxxxxxxx wrote:
> 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(¶ms, 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(¶ms->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[];
As with the prior patch, I don't think this is worth changing. The
code in hv_pci_write_mmio() is more complicated as a result, and
changing the array means the struct no longer matches the Hyper-V
struct 1:1.
Thanks
Nuno
> } __packed;
>
> #endif /* _HV_HVGDK_MINI_H */
