From: Lu Baolu <baolu.lu@linux.intel.com>
To: Tina Zhang <tina.zhang@intel.com>
Cc: iommu@lists.linux-foundation.org, Yi Sun <yi.sun@intel.com>
Subject: Re: [PATCH] iommu/vt-d: debugfs: Check irq_remapping_cap before PI info dump
Date: Wed, 20 Jan 2021 10:34:50 +0800 [thread overview]
Message-ID: <d084772f-6364-34d9-1c89-e1c3d6a35301@linux.intel.com> (raw)
In-Reply-To: <20210119182526.2927-1-tina.zhang@intel.com>
On 1/20/21 2:25 AM, Tina Zhang wrote:
> irq_remapping_cap() was introduced to detect whether irq remapping
> supports new features, such as VT-d Posted-Interrupts", according to
> commit 959c870f7305 ("iommu, x86: Provide irq_remapping_cap() interface").
>
> The VT-d Posted-Interrupts support can be disabled by the command
> line parameter "intremap=nopost".
>
> So, it's better to use irq_remapping_cap() to check if the VT-d
> Posted-Interrupts is enabled before any Posted Interrupt Descriptor
> info dump.
>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Sohil Mehta <sohil.mehta@intel.com>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Reported-by: Yi Sun <yi.sun@intel.com>
> Signed-off-by: Tina Zhang <tina.zhang@intel.com>
> ---
> drivers/iommu/intel/debugfs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel/debugfs.c b/drivers/iommu/intel/debugfs.c
> index efea7f02abd9..87a4a76866f4 100644
> --- a/drivers/iommu/intel/debugfs.c
> +++ b/drivers/iommu/intel/debugfs.c
> @@ -516,7 +516,8 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
> seq_puts(m, "****\n\n");
>
> for_each_active_iommu(iommu, drhd) {
> - if (!cap_pi_support(iommu->cap))
> + if (!irq_remapping_cap(IRQ_POSTING_CAP) ||
> + !cap_pi_support(iommu->cap))
With irq_remapping_cap(IRQ_POSTING_CAP), do you still need
cap_pi_support(iommu->cap)?
> continue;
>
> seq_printf(m, "Posted Interrupt supported on IOMMU: %s\n",
>
Best regards,
baolu
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-01-20 2:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-19 18:25 [PATCH] iommu/vt-d: debugfs: Check irq_remapping_cap before PI info dump Tina Zhang
2021-01-20 2:34 ` Lu Baolu [this message]
2021-01-20 8:41 ` Zhang, Tina
2021-01-20 11:37 ` Lu Baolu
2021-01-20 12:21 ` Zhang, Tina
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=d084772f-6364-34d9-1c89-e1c3d6a35301@linux.intel.com \
--to=baolu.lu@linux.intel.com \
--cc=iommu@lists.linux-foundation.org \
--cc=tina.zhang@intel.com \
--cc=yi.sun@intel.com \
/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