From: Chas Williams <3chas3@gmail.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: "Burakov, Anatoly" <anatoly.burakov@intel.com>,
dev@dpdk.org, stable@dpdk.org,
Jianfeng Tan <jianfeng.tan@intel.com>,
"Zhang, Qi Z" <qi.z.zhang@intel.com>,
Stephen Hemminger <stephen@networkplumber.org>,
santosh.shukla@caviumnetworks.com,
Thomas Monjalon <thomas@monjalon.net>,
peterx@redhat.com
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v3] bus/pci: forbid VA as IOVA mode if IOMMU address width too small
Date: Fri, 12 Jan 2018 17:46:25 -0500 [thread overview]
Message-ID: <CAG2-GknMwMoKqA2y4asyUT4eUkzfsDfL1dCfOOasreTOFPeYHg@mail.gmail.com> (raw)
In-Reply-To: <f5a652bc-9b59-2358-497d-74d36178ad20@redhat.com>
Tested-by: Chas Williams <chas@att.com>
On Fri, Jan 12, 2018 at 8:18 AM, Maxime Coquelin <maxime.coquelin@redhat.com
> wrote:
> Hi Anatoly,
>
>
> On 01/12/2018 12:10 PM, Burakov, Anatoly wrote:
>
>> <snip>
>>
>> +#if defined(RTE_ARCH_X86)
>>> +static bool
>>> +pci_one_device_iommu_support_va(struct rte_pci_device *dev)
>>> +{
>>> +#define VTD_CAP_MGAW_SHIFT 16
>>> +#define VTD_CAP_MGAW_MASK (0x3fULL << VTD_CAP_MGAW_SHIFT)
>>> +#define X86_VA_WIDTH 47 /* From Documentation/x86/x86_64/mm.txt */
>>> + struct rte_pci_addr *addr = &dev->addr;
>>> + char filename[PATH_MAX];
>>> + FILE *fp;
>>> + uint64_t mgaw, vtd_cap_reg = 0;
>>> +
>>> + snprintf(filename, sizeof(filename),
>>> + "%s/" PCI_PRI_FMT "/iommu/intel-iommu/cap",
>>> + rte_pci_get_sysfs_path(), addr->domain, addr->bus, addr->devid,
>>> + addr->function);
>>> + if (access(filename, F_OK) == -1) {
>>> + /* We don't have an Intel IOMMU, assume VA supported*/
>>> + return true;
>>> + }
>>> +
>>> + /* We have an intel IOMMU */
>>> + fp = fopen(filename, "r");
>>> + if (fp == NULL) {
>>> + RTE_LOG(ERR, EAL, "%s(): can't open %s\n", __func__, filename);
>>> + return false;
>>> + }
>>> +
>>> + if (fscanf(fp, "%lx", &vtd_cap_reg) != 1) {
>>> + RTE_LOG(ERR, EAL, "%s(): can't read %s\n", __func__, filename);
>>> + fclose(fp);
>>> + return false;
>>> + }
>>> +
>>> + fclose(fp);
>>>
>>
>> Hi Maxime,
>>
>> You probably want to use eal_parse_sysfs_value() for this.
>>
>
> I initially planned to use it, but the sysfs value is hexadecimal, but
> not prefixed with "0x". For example:
>
> # cat /sys/devices/pci0000\:00/0000\:00\:02.0/iommu/intel-iommu/cap
> 1c0000c40660462
>
> So strtoul() assumes the value is decimal in this case, as explained in
> its man page:
>
> "
> DESCRIPTION
> <snip\>
> If base is zero or 16, the string may then include a "0x" prefix, and
> the number will be read in base 16; otherwise, a zero base is taken as
> 10 (decimal)
> "
>
> Thanks,
> Maxime
>
next prev parent reply other threads:[~2018-01-12 22:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-12 10:22 [dpdk-stable] " Maxime Coquelin
2018-01-12 11:10 ` Burakov, Anatoly
2018-01-12 13:18 ` Maxime Coquelin
2018-01-12 22:46 ` Chas Williams [this message]
2018-01-20 15:30 ` Thomas Monjalon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAG2-GknMwMoKqA2y4asyUT4eUkzfsDfL1dCfOOasreTOFPeYHg@mail.gmail.com \
--to=3chas3@gmail.com \
--cc=anatoly.burakov@intel.com \
--cc=dev@dpdk.org \
--cc=jianfeng.tan@intel.com \
--cc=maxime.coquelin@redhat.com \
--cc=peterx@redhat.com \
--cc=qi.z.zhang@intel.com \
--cc=santosh.shukla@caviumnetworks.com \
--cc=stable@dpdk.org \
--cc=stephen@networkplumber.org \
--cc=thomas@monjalon.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).