[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Y3ZQVpkS0Hr4LsI2@liuwe-devbox-debian-v2>
Date: Thu, 17 Nov 2022 15:16:38 +0000
From: Wei Liu <wei.liu@...nel.org>
To: Michael Kelley <mikelley@...rosoft.com>
Cc: hpa@...or.com, kys@...rosoft.com, haiyangz@...rosoft.com,
wei.liu@...nel.org, decui@...rosoft.com, luto@...nel.org,
peterz@...radead.org, davem@...emloft.net, edumazet@...gle.com,
kuba@...nel.org, pabeni@...hat.com, lpieralisi@...nel.org,
robh@...nel.org, kw@...ux.com, bhelgaas@...gle.com, arnd@...db.de,
hch@...radead.org, m.szyprowski@...sung.com, robin.murphy@....com,
thomas.lendacky@....com, brijesh.singh@....com, tglx@...utronix.de,
mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
Tianyu.Lan@...rosoft.com, kirill.shutemov@...ux.intel.com,
sathyanarayanan.kuppuswamy@...ux.intel.com, ak@...ux.intel.com,
isaku.yamahata@...el.com, dan.j.williams@...el.com,
jane.chu@...cle.com, seanjc@...gle.com, tony.luck@...el.com,
x86@...nel.org, linux-kernel@...r.kernel.org,
linux-hyperv@...r.kernel.org, netdev@...r.kernel.org,
linux-pci@...r.kernel.org, linux-arch@...r.kernel.org,
iommu@...ts.linux.dev
Subject: Re: [Patch v3 13/14] PCI: hv: Add hypercalls to read/write MMIO space
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.
Powered by blists - more mailing lists