All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: Anthony Perard <anthony.perard@citrix.com>,
	Ian Jackson <iwj@xenproject.org>, Paul Durrant <paul@xen.org>,
	George Dunlap <george.dunlap@citrix.com>, Wei Liu <wl@xen.org>
Subject: PCI pass-through vs PoD
Date: Mon, 13 Sep 2021 11:02:24 +0200	[thread overview]
Message-ID: <b6d598cd-c244-2b7f-c731-fe839df3382e@suse.com> (raw)

Hello,

libxl__domain_config_setdefault() checks whether PoD is going to be
enabled and fails domain creation if at the same time devices would get
assigned. Nevertheless setting up of IOMMU page tables is allowed.
However, when later assigning a device to a domain which has IOMMU page
tables, libxl__device_pci_add() does not appear to be concerned of PoD:
- xc_test_assign_device() / XEN_DOMCTL_test_assign_device only check the
  device for being available to assign,
- libxl__device_pci_setdefault() is only concerned about the RDM policy,
- other functions called look to not be related to such checking at all.

IMO assignment should fail if pod.count != pod.entry_count, and all PoD
entries should be resolved otherwise (whether explicitly by the
hypervisor or through some suitable existing hypercalls - didn't check
yet whether there are any reasonable candidates - by the tool stack is
secondary).

Jan



             reply	other threads:[~2021-09-13  9:02 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13  9:02 Jan Beulich [this message]
2021-11-17  8:39 ` PCI pass-through vs PoD Jan Beulich
2021-11-17  8:55   ` Roger Pau Monné
2021-11-17 10:13     ` Jan Beulich
2021-11-17 11:09       ` Andrew Cooper
2021-11-17 11:23         ` Jan Beulich
2021-11-17 13:07           ` Andrew Cooper
2021-11-18  8:08             ` Jan Beulich

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=b6d598cd-c244-2b7f-c731-fe839df3382e@suse.com \
    --to=jbeulich@suse.com \
    --cc=anthony.perard@citrix.com \
    --cc=george.dunlap@citrix.com \
    --cc=iwj@xenproject.org \
    --cc=paul@xen.org \
    --cc=wl@xen.org \
    --cc=xen-devel@lists.xenproject.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.