All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joerg Roedel <joro@8bytes.org>
To: Lu Baolu <baolu.lu@linux.intel.com>,
	David Woodhouse <dwmw2@infradead.org>
Cc: jroedel@suse.de, iommu@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 3/5] iommu/vt-d: Do deferred attachment in iommu_need_mapping()
Date: Mon, 17 Feb 2020 20:38:56 +0100	[thread overview]
Message-ID: <20200217193858.26990-4-joro@8bytes.org> (raw)
In-Reply-To: <20200217193858.26990-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

The attachment of deferred devices needs to happen before the check
whether the device is identity mapped or not. Otherwise the check will
return wrong results, cause warnings boot failures in kdump kernels, like

	WARNING: CPU: 0 PID: 318 at ../drivers/iommu/intel-iommu.c:592 domain_get_iommu+0x61/0x70

	[...]

	 Call Trace:
	  __intel_map_single+0x55/0x190
	  intel_alloc_coherent+0xac/0x110
	  dmam_alloc_attrs+0x50/0xa0
	  ahci_port_start+0xfb/0x1f0 [libahci]
	  ata_host_start.part.39+0x104/0x1e0 [libata]

With the earlier check the kdump boot succeeds and a crashdump is written.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/intel-iommu.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 42cdcce1602e..32f43695a22b 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2541,9 +2541,6 @@ static void do_deferred_attach(struct device *dev)
 
 static struct dmar_domain *deferred_attach_domain(struct device *dev)
 {
-	if (unlikely(attach_deferred(dev)))
-		do_deferred_attach(dev);
-
 	return find_domain(dev);
 }
 
@@ -3595,6 +3592,9 @@ static bool iommu_need_mapping(struct device *dev)
 	if (iommu_dummy(dev))
 		return false;
 
+	if (unlikely(attach_deferred(dev)))
+		do_deferred_attach(dev);
+
 	ret = identity_mapping(dev);
 	if (ret) {
 		u64 dma_mask = *dev->dma_mask;
-- 
2.17.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: Lu Baolu <baolu.lu@linux.intel.com>,
	David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>,
	jroedel@suse.de, iommu@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 3/5] iommu/vt-d: Do deferred attachment in iommu_need_mapping()
Date: Mon, 17 Feb 2020 20:38:56 +0100	[thread overview]
Message-ID: <20200217193858.26990-4-joro@8bytes.org> (raw)
In-Reply-To: <20200217193858.26990-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

The attachment of deferred devices needs to happen before the check
whether the device is identity mapped or not. Otherwise the check will
return wrong results, cause warnings boot failures in kdump kernels, like

	WARNING: CPU: 0 PID: 318 at ../drivers/iommu/intel-iommu.c:592 domain_get_iommu+0x61/0x70

	[...]

	 Call Trace:
	  __intel_map_single+0x55/0x190
	  intel_alloc_coherent+0xac/0x110
	  dmam_alloc_attrs+0x50/0xa0
	  ahci_port_start+0xfb/0x1f0 [libahci]
	  ata_host_start.part.39+0x104/0x1e0 [libata]

With the earlier check the kdump boot succeeds and a crashdump is written.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/intel-iommu.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 42cdcce1602e..32f43695a22b 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2541,9 +2541,6 @@ static void do_deferred_attach(struct device *dev)
 
 static struct dmar_domain *deferred_attach_domain(struct device *dev)
 {
-	if (unlikely(attach_deferred(dev)))
-		do_deferred_attach(dev);
-
 	return find_domain(dev);
 }
 
@@ -3595,6 +3592,9 @@ static bool iommu_need_mapping(struct device *dev)
 	if (iommu_dummy(dev))
 		return false;
 
+	if (unlikely(attach_deferred(dev)))
+		do_deferred_attach(dev);
+
 	ret = identity_mapping(dev);
 	if (ret) {
 		u64 dma_mask = *dev->dma_mask;
-- 
2.17.1


  parent reply	other threads:[~2020-02-17 19:39 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-17 19:38 [PATCH 0/5] iommu/vt-d: Fix kdump boot with VT-d enabled Joerg Roedel
2020-02-17 19:38 ` Joerg Roedel
2020-02-17 19:38 ` [PATCH 1/5] iommu/vt-d: Add attach_deferred() helper Joerg Roedel
2020-02-17 19:38   ` Joerg Roedel
2020-02-17 19:50   ` Jerry Snitselaar
2020-02-17 19:50     ` Jerry Snitselaar
2020-02-18 17:14   ` Christoph Hellwig
2020-02-18 17:14     ` Christoph Hellwig
2020-02-19  9:29     ` Joerg Roedel
2020-02-19  9:29       ` Joerg Roedel
2020-02-17 19:38 ` [PATCH 2/5] iommu/vt-d: Move deferred device attachment into helper function Joerg Roedel
2020-02-17 19:38   ` Joerg Roedel
2020-02-17 19:50   ` Jerry Snitselaar
2020-02-17 19:50     ` Jerry Snitselaar
2020-02-18 17:16   ` Christoph Hellwig
2020-02-18 17:16     ` Christoph Hellwig
2020-02-17 19:38 ` Joerg Roedel [this message]
2020-02-17 19:38   ` [PATCH 3/5] iommu/vt-d: Do deferred attachment in iommu_need_mapping() Joerg Roedel
2020-02-17 19:51   ` Jerry Snitselaar
2020-02-17 19:51     ` Jerry Snitselaar
2020-02-18  2:38   ` Lu Baolu
2020-02-18  2:38     ` Lu Baolu
2020-02-18  9:28     ` [PATCH 3/5 v2] " Joerg Roedel
2020-02-18  9:28       ` Joerg Roedel
2020-02-18 11:54       ` Lu Baolu
2020-02-18 11:54         ` Lu Baolu
2020-02-18 16:22         ` Joerg Roedel
2020-02-18 16:22           ` Joerg Roedel
2020-02-18 15:53       ` Jerry Snitselaar
2020-02-18 15:53         ` Jerry Snitselaar
2020-02-17 19:38 ` [PATCH 4/5] iommu/vt-d: Remove deferred_attach_domain() Joerg Roedel
2020-02-17 19:38   ` Joerg Roedel
2020-02-17 19:51   ` Jerry Snitselaar
2020-02-17 19:51     ` Jerry Snitselaar
2020-02-17 19:38 ` [PATCH 5/5] iommu/vt-d: Simplify check in identity_mapping() Joerg Roedel
2020-02-17 19:38   ` Joerg Roedel
2020-02-17 19:54   ` Jerry Snitselaar
2020-02-17 19:54     ` Jerry Snitselaar

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=20200217193858.26990-4-joro@8bytes.org \
    --to=joro@8bytes.org \
    --cc=baolu.lu@linux.intel.com \
    --cc=dwmw2@infradead.org \
    --cc=iommu@lists.linux-foundation.org \
    --cc=jroedel@suse.de \
    --cc=linux-kernel@vger.kernel.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.