From: Joerg Roedel <joro@8bytes.org> To: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, joro@8bytes.org, Joerg Roedel <jroedel@suse.de>, Jerry Snitselaar <jsnitsel@redhat.com>, Tom Murphy <murphyt7@tcd.ie>, Robin Murphy <robin.murphy@arm.com> Subject: [PATCH] iommu: Fix deferred domain attachment Date: Tue, 19 May 2020 15:03:40 +0200 [thread overview] Message-ID: <20200519130340.14564-1-joro@8bytes.org> (raw) From: Joerg Roedel <jroedel@suse.de> The IOMMU core code has support for deferring the attachment of a domain to a device. This is needed in kdump kernels where the new domain must not be attached to a device before the device driver takes it over. When the AMD IOMMU driver got converted to use the dma-iommu implementation, the deferred attaching got lost. The code in dma-iommu.c has support for deferred attaching, but it calls into iommu_attach_device() to actually do it. But iommu_attach_device() will check if the device should be deferred in it code-path and do nothing, breaking deferred attachment. Move the is_deferred_attach() check out of the attach_device path and into iommu_group_add_device() to make deferred attaching work from the dma-iommu code. Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Tom Murphy <murphyt7@tcd.ie> Cc: Robin Murphy <robin.murphy@arm.com> Reported-by: Jerry Snitselaar <jsnitsel@redhat.com> Suggested-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Jerry Snitselaar <jsnitsel@redhat.com> Fixes: 795bbbb9b6f8 ("iommu/dma-iommu: Handle deferred devices") Signed-off-by: Joerg Roedel <jroedel@suse.de> --- drivers/iommu/iommu.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 4050569188be..629d209b8e88 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -769,6 +769,15 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group, return ret; } +static bool iommu_is_attach_deferred(struct iommu_domain *domain, + struct device *dev) +{ + if (domain->ops->is_attach_deferred) + return domain->ops->is_attach_deferred(domain, dev); + + return false; +} + /** * iommu_group_add_device - add a device to an iommu group * @group: the group into which to add the device (reference should be held) @@ -821,7 +830,7 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices); - if (group->domain) + if (group->domain && !iommu_is_attach_deferred(group->domain, dev)) ret = __iommu_attach_device(group->domain, dev); mutex_unlock(&group->mutex); if (ret) @@ -1893,9 +1902,6 @@ static int __iommu_attach_device(struct iommu_domain *domain, struct device *dev) { int ret; - if ((domain->ops->is_attach_deferred != NULL) && - domain->ops->is_attach_deferred(domain, dev)) - return 0; if (unlikely(domain->ops->attach_dev == NULL)) return -ENODEV; @@ -1967,8 +1973,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid); static void __iommu_detach_device(struct iommu_domain *domain, struct device *dev) { - if ((domain->ops->is_attach_deferred != NULL) && - domain->ops->is_attach_deferred(domain, dev)) + if (iommu_is_attach_deferred(domain, dev)) return; if (unlikely(domain->ops->detach_dev == NULL)) -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org> To: iommu@lists.linux-foundation.org Cc: Joerg Roedel <jroedel@suse.de>, linux-kernel@vger.kernel.org, Tom Murphy <murphyt7@tcd.ie>, Robin Murphy <robin.murphy@arm.com> Subject: [PATCH] iommu: Fix deferred domain attachment Date: Tue, 19 May 2020 15:03:40 +0200 [thread overview] Message-ID: <20200519130340.14564-1-joro@8bytes.org> (raw) From: Joerg Roedel <jroedel@suse.de> The IOMMU core code has support for deferring the attachment of a domain to a device. This is needed in kdump kernels where the new domain must not be attached to a device before the device driver takes it over. When the AMD IOMMU driver got converted to use the dma-iommu implementation, the deferred attaching got lost. The code in dma-iommu.c has support for deferred attaching, but it calls into iommu_attach_device() to actually do it. But iommu_attach_device() will check if the device should be deferred in it code-path and do nothing, breaking deferred attachment. Move the is_deferred_attach() check out of the attach_device path and into iommu_group_add_device() to make deferred attaching work from the dma-iommu code. Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Tom Murphy <murphyt7@tcd.ie> Cc: Robin Murphy <robin.murphy@arm.com> Reported-by: Jerry Snitselaar <jsnitsel@redhat.com> Suggested-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Jerry Snitselaar <jsnitsel@redhat.com> Fixes: 795bbbb9b6f8 ("iommu/dma-iommu: Handle deferred devices") Signed-off-by: Joerg Roedel <jroedel@suse.de> --- drivers/iommu/iommu.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 4050569188be..629d209b8e88 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -769,6 +769,15 @@ static int iommu_create_device_direct_mappings(struct iommu_group *group, return ret; } +static bool iommu_is_attach_deferred(struct iommu_domain *domain, + struct device *dev) +{ + if (domain->ops->is_attach_deferred) + return domain->ops->is_attach_deferred(domain, dev); + + return false; +} + /** * iommu_group_add_device - add a device to an iommu group * @group: the group into which to add the device (reference should be held) @@ -821,7 +830,7 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices); - if (group->domain) + if (group->domain && !iommu_is_attach_deferred(group->domain, dev)) ret = __iommu_attach_device(group->domain, dev); mutex_unlock(&group->mutex); if (ret) @@ -1893,9 +1902,6 @@ static int __iommu_attach_device(struct iommu_domain *domain, struct device *dev) { int ret; - if ((domain->ops->is_attach_deferred != NULL) && - domain->ops->is_attach_deferred(domain, dev)) - return 0; if (unlikely(domain->ops->attach_dev == NULL)) return -ENODEV; @@ -1967,8 +1973,7 @@ EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid); static void __iommu_detach_device(struct iommu_domain *domain, struct device *dev) { - if ((domain->ops->is_attach_deferred != NULL) && - domain->ops->is_attach_deferred(domain, dev)) + if (iommu_is_attach_deferred(domain, dev)) return; if (unlikely(domain->ops->detach_dev == NULL)) -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next reply other threads:[~2020-05-19 13:03 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-19 13:03 Joerg Roedel [this message] 2020-05-19 13:03 ` [PATCH] iommu: Fix deferred domain attachment Joerg Roedel
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=20200519130340.14564-1-joro@8bytes.org \ --to=joro@8bytes.org \ --cc=iommu@lists.linux-foundation.org \ --cc=jroedel@suse.de \ --cc=jsnitsel@redhat.com \ --cc=linux-kernel@vger.kernel.org \ --cc=murphyt7@tcd.ie \ --cc=robin.murphy@arm.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: linkBe 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.