Messages in this thread | | | Date | Thu, 17 Nov 2022 15:16:38 +0000 | From | Wei Liu <> | Subject | Re: [Patch v3 13/14] PCI: hv: Add hypercalls to read/write MMIO space |
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On Wed, Nov 16, 2022 at 10:41:36AM -0800, Michael Kelley wrote: [...] > > +static void hv_pci_read_mmio(struct device *dev, phys_addr_t gpa, int size, u32 *val) > +{ > + struct hv_mmio_read_input *in; > + struct hv_mmio_read_output *out; > + u64 ret; > + > + /* > + * 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. > + */
Perhaps adding something along this line?
WARN_ON(!irqs_disabled());
I can fold this in if you agree.
> + in = *this_cpu_ptr(hyperv_pcpu_input_arg); > + out = *this_cpu_ptr(hyperv_pcpu_input_arg) + sizeof(*in); > + in->gpa = gpa; > + in->size = size; > + > + ret = hv_do_hypercall(HVCALL_MMIO_READ, in, out); > + if (hv_result_success(ret)) { > + switch (size) { > + case 1: > + *val = *(u8 *)(out->data); > + break; > + case 2: > + *val = *(u16 *)(out->data); > + break; > + default: > + *val = *(u32 *)(out->data); > + break; > + } > + } else > + dev_err(dev, "MMIO read hypercall error %llx addr %llx size %d\n", > + ret, gpa, size); > +} > + > +static void hv_pci_write_mmio(struct device *dev, phys_addr_t gpa, int size, u32 val) > +{ > + struct hv_mmio_write_input *in; > + u64 ret; > + > + /* > + * Must be called with interrupts disabled so it is safe > + * to use the per-cpu input argument memory. > + */
Ditto.
Thanks, Wei.
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