Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Wed, May 04, 2022 at 04:29:24PM +0100, Robin Murphy wrote: > On 2022-05-04 15:54, Jason Gunthorpe wrote: > > On Wed, May 04, 2022 at 03:42:09PM +0100, Robin Murphy wrote: > > > > > > This fixes an oops with VFIO and SMMUv3 because VFIO will call > > > > iommu_detach_group() and then immediately iommu_domain_free(), but > > > > SMMUv3 has no way to know that the domain it is holding a pointer to > > > > has been freed. Now the iommu_detach_group() will assign the blocking > > > > domain and SMMUv3 will no longer hold a stale domain reference. > > > > > > Thanks for taking this on! I do like the overall structure and naming much > > > more than my initial sketch :) > > > > Thanks, no problem! > > > > /* > > > > -* If the group has been claimed already, do not re-attach the > > > > default > > > > -* domain. > > > > +* A NULL domain means to call the detach_dev() op. New drivers > > > > should > > > > +* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL > > > > default_domain > > > > > > Nit: IOMMU_DOMAIN_DMA is the baseline of default domain support, > > > passthrough > > > is more of an optional extra. > > > > Can you elaborate on this a bit more for the comment, I'm not sure I > > understand all the historical stuff here. > > Well, the comment could effectively just be "New drivers should support > default domains." I made it this: /* * New drivers should support default domains and so the detach_dev() op * will never be called. Otheriwse the NULL domain indicates the * translation for the group should be set so it will work with the * platform DMA ops. */ It also seems clear to me we should delete a bunch of detach_dev ops from drivers? I naively see that these drivers have the word IOMMU_DOMAIN_DMA in them and also define detach_dev: amd iommu apple-dart qcom_iommu exynos-iommu intel iommu ipmmu-vmsa mtk_iommu rockchip-iommu sprd-iommu sun50i-iommu These ones have IOMMU_DOMAIN_DMA but don't define detach_dev: arm-smmuv3 arm-smmu virtio-iommu And I suppose these are the 'old' drivers: fsl_pamu omap-iommu tegra-gart tegra-smmu I can get a patch for this as well, I think it will be clarifying to remove this cruft. Thanks Jason ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On 2022-05-04 15:54, Jason Gunthorpe wrote: On Wed, May 04, 2022 at 03:42:09PM +0100, Robin Murphy wrote: This fixes an oops with VFIO and SMMUv3 because VFIO will call iommu_detach_group() and then immediately iommu_domain_free(), but SMMUv3 has no way to know that the domain it is holding a pointer to has been freed. Now the iommu_detach_group() will assign the blocking domain and SMMUv3 will no longer hold a stale domain reference. Thanks for taking this on! I do like the overall structure and naming much more than my initial sketch :) Thanks, no problem! /* -* If the group has been claimed already, do not re-attach the default -* domain. +* A NULL domain means to call the detach_dev() op. New drivers should +* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain Nit: IOMMU_DOMAIN_DMA is the baseline of default domain support, passthrough is more of an optional extra. Can you elaborate on this a bit more for the comment, I'm not sure I understand all the historical stuff here. Well, the comment could effectively just be "New drivers should support default domains." What supporting default domains means in practice is two things: that .attach_dev handles moving directly between domains without .detach_dev being called, and that .domain_alloc supports at least IOMMU_DOMAIN_DMA - other unsupported default domain types can fall back to that, but not vice versa, see iommu_group_alloc_default_domain(). Here we are looking at a case where group->domain becomes NULL - what does this mean in the historical world? ie what should the iommu driver do when detach_dev is called? I had guessed it was remove all translation - ie IOMMU_DOMAIN_IDENTITY? Historically, whatever a NULL domain means is mostly between the IOMMU driver and the platform DMA ops - I honestly have no idea what the likes of s390 and fsl-pamu do, for example. For SMMUv3 it was always configurable. Cheers, Robin. ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Wed, May 04, 2022 at 10:55:00PM +0800, Baolu Lu wrote:
> On 2022/5/4 22:38, Jason Gunthorpe wrote:
> > > @@ -3180,7 +3181,9 @@ int iommu_group_claim_dma_owner(struct iommu_group
> > > *group, void *owner)
> > > ret = -EPERM;
> > > goto unlock_out;
> > > } else {
> > > - if (group->domain && group->domain !=
> > > group->default_domain)
> > > {
> > > + if (group->domain &&
> > > + group->domain != group->default_domain &&
> > > + group->domain != group->blocking_domain) {
> > Why do we need this hunk? This is just trying to check if there is
> > some conflict with some other domain attach, group->domain can never
> > be blocking_domain here.
> This is *not* needed. Also verified with real hardware.
>
> Sorry for the noise.
Okay, great, I'll add your tested-by, thanks
Jason
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On 2022/5/4 22:38, Jason Gunthorpe wrote:
@@ -3180,7 +3181,9 @@ int iommu_group_claim_dma_owner(struct iommu_group
*group, void *owner)
ret = -EPERM;
goto unlock_out;
} else {
- if (group->domain && group->domain != group->default_domain)
{
+ if (group->domain &&
+ group->domain != group->default_domain &&
+ group->domain != group->blocking_domain) {
Why do we need this hunk? This is just trying to check if there is
some conflict with some other domain attach, group->domain can never
be blocking_domain here.
This is *not* needed. Also verified with real hardware.
Sorry for the noise.
Best regards,
baolu
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Wed, May 04, 2022 at 03:42:09PM +0100, Robin Murphy wrote: > > This fixes an oops with VFIO and SMMUv3 because VFIO will call > > iommu_detach_group() and then immediately iommu_domain_free(), but > > SMMUv3 has no way to know that the domain it is holding a pointer to > > has been freed. Now the iommu_detach_group() will assign the blocking > > domain and SMMUv3 will no longer hold a stale domain reference. > > Thanks for taking this on! I do like the overall structure and naming much > more than my initial sketch :) Thanks, no problem! > > /* > > -* If the group has been claimed already, do not re-attach the default > > -* domain. > > +* A NULL domain means to call the detach_dev() op. New drivers should > > +* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain > > Nit: IOMMU_DOMAIN_DMA is the baseline of default domain support, passthrough > is more of an optional extra. Can you elaborate on this a bit more for the comment, I'm not sure I understand all the historical stuff here. Here we are looking at a case where group->domain becomes NULL - what does this mean in the historical world? ie what should the iommu driver do when detach_dev is called? I had guessed it was remove all translation - ie IOMMU_DOMAIN_IDENTITY? > > +* and detatch_dev(). > > Nit: detach_dev > > Otherwise, modulo the other things already pointed out, this looks OK to me. Done, thanks Jason ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On 2022-05-04 01:11, Jason Gunthorpe wrote:
Once the group enters 'owned' mode it can never be assigned back to the
default_domain or to a NULL domain. It must always be actively assigned to
a current domain. If the caller hasn't provided a domain then the core
must provide an explicit DMA blocking domain that has no DMA map.
Lazily create a group-global blocking DMA domain when
iommu_group_claim_dma_owner is first called and immediately assign the
group to it. This ensures that DMA is immediately fully isolated on all
IOMMU drivers.
If the user attaches/detaches while owned then detach will set the group
back to the blocking domain.
Slightly reorganize the call chains so that
__iommu_group_attach_core_domain() is the function that removes any caller
configured domain and sets the domains back a core owned domain with an
appropriate lifetime.
__iommu_group_attach_domain() is the worker function that can change the
domain assigned to a group to any target domain, including NULL.
Add comments clarifying how the NULL vs detach_dev vs default_domain works
based on Robin's remarks.
This fixes an oops with VFIO and SMMUv3 because VFIO will call
iommu_detach_group() and then immediately iommu_domain_free(), but
SMMUv3 has no way to know that the domain it is holding a pointer to
has been freed. Now the iommu_detach_group() will assign the blocking
domain and SMMUv3 will no longer hold a stale domain reference.
Thanks for taking this on! I do like the overall structure and naming
much more than my initial sketch :)
Fixes: 1ea2a07a532b ("iommu: Add DMA ownership management interfaces")
Reported-by: Qian Cai
Co-developed-by: Robin Murphy
(so the sign-off chain makes sense - you deserve overall authorship here)
Signed-off-by: Robin Murphy
Signed-off-by: Jason Gunthorpe
---
[...]
@@ -2072,38 +2072,66 @@ static int iommu_group_do_detach_device(struct device
*dev, void *data)
return 0;
}
-static void __iommu_detach_group(struct iommu_domain *domain,
-struct iommu_group *group)
+static int __iommu_group_attach_domain(struct iommu_group *group,
+ struct iommu_domain *new_domain)
{
int ret;
+ if (group->domain == new_domain)
+ return 0;
+
/*
-* If the group has been claimed already, do not re-attach the default
-* domain.
+* A NULL domain means to call the detach_dev() op. New drivers should
+* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain
Nit: IOMMU_DOMAIN_DMA is the baseline of default domain support,
passthrough is more of an optional extra.
+* and detatch_dev().
Nit: detach_dev
Otherwise, modulo the other things already pointed out, this looks OK to me.
Cheers,
Robin.
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Wed, May 04, 2022 at 10:35:12PM +0800, Baolu Lu wrote:
> With below additional changes, this patch works on my Intel test
> machine.
Thanks!
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 513da82f2ed1..7c415e9b6906 100644
> +++ b/drivers/iommu/iommu.c
> @@ -2063,7 +2063,8 @@ static int __iommu_attach_group(struct iommu_domain
> *domain,
> {
> int ret;
>
> - if (group->domain && group->domain != group->default_domain)
> + if (group->domain && group->domain != group->default_domain &&
> + group->domain != group->blocking_domain)
> return -EBUSY;
>
> ret = __iommu_group_for_each_dev(group, domain,
> @@ -2125,7 +2126,7 @@ static int __iommu_group_attach_domain(struct
> iommu_group *group,
> * Note that this is called in error unwind paths, attaching to a
> * domain that has already been attached cannot fail.
> */
> - ret = __iommu_group_for_each_dev(group, group->default_domain,
> + ret = __iommu_group_for_each_dev(group, new_domain,
> iommu_group_do_attach_device);
> if (ret)
> return ret;
Done
> @@ -3180,7 +3181,9 @@ int iommu_group_claim_dma_owner(struct iommu_group
> *group, void *owner)
> ret = -EPERM;
> goto unlock_out;
> } else {
> - if (group->domain && group->domain != group->default_domain)
> {
> + if (group->domain &&
> + group->domain != group->default_domain &&
> + group->domain != group->blocking_domain) {
Why do we need this hunk? This is just trying to check if there is
some conflict with some other domain attach, group->domain can never
be blocking_domain here.
Jason
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
Hi Jason,
On 2022/5/4 08:11, Jason Gunthorpe wrote:
Once the group enters 'owned' mode it can never be assigned back to the
default_domain or to a NULL domain. It must always be actively assigned to
a current domain. If the caller hasn't provided a domain then the core
must provide an explicit DMA blocking domain that has no DMA map.
Lazily create a group-global blocking DMA domain when
iommu_group_claim_dma_owner is first called and immediately assign the
group to it. This ensures that DMA is immediately fully isolated on all
IOMMU drivers.
If the user attaches/detaches while owned then detach will set the group
back to the blocking domain.
Slightly reorganize the call chains so that
__iommu_group_attach_core_domain() is the function that removes any caller
configured domain and sets the domains back a core owned domain with an
appropriate lifetime.
__iommu_group_attach_domain() is the worker function that can change the
domain assigned to a group to any target domain, including NULL.
Add comments clarifying how the NULL vs detach_dev vs default_domain works
based on Robin's remarks.
This fixes an oops with VFIO and SMMUv3 because VFIO will call
iommu_detach_group() and then immediately iommu_domain_free(), but
SMMUv3 has no way to know that the domain it is holding a pointer to
has been freed. Now the iommu_detach_group() will assign the blocking
domain and SMMUv3 will no longer hold a stale domain reference.
Fixes: 1ea2a07a532b ("iommu: Add DMA ownership management interfaces")
Reported-by: Qian Cai
Signed-off-by: Robin Murphy
Signed-off-by: Jason Gunthorpe
---
drivers/iommu/iommu.c | 112 +++---
1 file changed, 82 insertions(+), 30 deletions(-)
This is based on Robins draft here:
https://lore.kernel.org/linux-iommu/18831161-473f-e04f-4a81-1c7062ad1...@arm.com/
With some rework. I re-organized the call chains instead of introducing
iommu_group_user_attached(), fixed a recursive locking for
iommu_group_get_purgatory(), and made a proper commit message.
Still only compile tested, so RFCish.
Nicolin/Lu? What do you think, can you check it?
Thank you for the patch.
With below additional changes, this patch works on my Intel test
machine.
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 513da82f2ed1..7c415e9b6906 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2063,7 +2063,8 @@ static int __iommu_attach_group(struct
iommu_domain *domain,
{
int ret;
- if (group->domain && group->domain != group->default_domain)
+ if (group->domain && group->domain != group->default_domain &&
+ group->domain != group->blocking_domain)
return -EBUSY;
ret = __iommu_group_for_each_dev(group, domain,
@@ -2125,7 +2126,7 @@ static int __iommu_group_attach_domain(struct
iommu_group *group,
* Note that this is called in error unwind paths, attaching to a
* domain that has already been attached cannot fail.
*/
- ret = __iommu_group_for_each_dev(group, group->default_domain,
+ ret = __iommu_group_for_each_dev(group, new_domain,
iommu_group_do_attach_device);
if (ret)
return ret;
@@ -3180,7 +3181,9 @@ int iommu_group_claim_dma_owner(struct iommu_group
*group, void *owner)
ret = -EPERM;
goto unlock_out;
} else {
- if (group->domain && group->domain !=
group->default_domain) {
+ if (group->domain &&
+ group->domain != group->default_domain &&
+ group->domain != group->blocking_domain) {
ret = -EBUSY;
goto unlock_out;
Best regards,
baolu
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Wed, May 04, 2022 at 01:22:00AM -0700, Nicolin Chen wrote:
> I am able to repro the issue on ARM64 and give this a quick try.
> But the patch seems to need to include the following change too.
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 94d99768023c..9bb108d01baa 100644
> +++ b/drivers/iommu/iommu.c
> @@ -2040,7 +2040,8 @@ static int __iommu_attach_group(struct iommu_domain
> *domain,
> {
> int ret;
>
> - if (group->domain && group->domain != group->default_domain)
> + if (group->domain && group->domain != group->default_domain &&
> + group->domain != group->blocking_domain)
> return -EBUSY;
>
> ret = __iommu_group_for_each_dev(group, domain,
Make sense, thanks
> > /*
> > -* If the group has been claimed already, do not re-attach the default
> > -* domain.
> > +* A NULL domain means to call the detach_dev() op. New drivers should
> > +* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain
>
> an IOMMU_DOMAIN_IDENTITY?
Done
Jason
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Wed, May 04, 2022 at 07:48:58PM +0800, Baolu Lu wrote: > > + /* > > +* New drivers do not implement detach_dev, so changing the domain is > > +* done by calling attach on the new domain. Drivers should implement > > +* this so that DMA is always translated by either the new, old, or a > > +* blocking domain. DMA should never become untranslated. > > +* > > +* Note that this is called in error unwind paths, attaching to a > > +* domain that has already been attached cannot fail. > > +*/ > > ret = __iommu_group_for_each_dev(group, group->default_domain, > ^^ > > I suppose this should be @new_domain, right? Yes, thank you Jason ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
Hi Jason,
On 2022/5/4 08:11, Jason Gunthorpe wrote:
+static int __iommu_group_attach_domain(struct iommu_group *group,
+ struct iommu_domain *new_domain)
{
int ret;
+ if (group->domain == new_domain)
+ return 0;
+
/*
-* If the group has been claimed already, do not re-attach the default
-* domain.
+* A NULL domain means to call the detach_dev() op. New drivers should
+* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain
+* and detatch_dev().
*/
- if (!group->default_domain || group->owner) {
- __iommu_group_for_each_dev(group, domain,
+ if (!new_domain) {
+ WARN_ON(!group->domain->ops->detach_dev);
+ __iommu_group_for_each_dev(group, group->domain,
iommu_group_do_detach_device);
group->domain = NULL;
- return;
+ return 0;
}
- if (group->domain == group->default_domain)
- return;
-
- /* Detach by re-attaching to the default domain */
+ /*
+* New drivers do not implement detach_dev, so changing the domain is
+* done by calling attach on the new domain. Drivers should implement
+* this so that DMA is always translated by either the new, old, or a
+* blocking domain. DMA should never become untranslated.
+*
+* Note that this is called in error unwind paths, attaching to a
+* domain that has already been attached cannot fail.
+*/
ret = __iommu_group_for_each_dev(group, group->default_domain,
^^
I suppose this should be @new_domain, right?
iommu_group_do_attach_device);
- if (ret != 0)
- WARN_ON(1);
+ if (ret)
+ return ret;
+ group->domain = new_domain;
+ return 0;
+}
Best regards,
baolu
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Re: [PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
On Tue, May 03, 2022 at 09:11:02PM -0300, Jason Gunthorpe wrote:
> This is based on Robins draft here:
>
> https://lore.kernel.org/linux-iommu/18831161-473f-e04f-4a81-1c7062ad1...@arm.com/
>
> With some rework. I re-organized the call chains instead of introducing
> iommu_group_user_attached(), fixed a recursive locking for
> iommu_group_get_purgatory(), and made a proper commit message.
>
> Still only compile tested, so RFCish.
>
> Nicolin/Lu? What do you think, can you check it?
I am able to repro the issue on ARM64 and give this a quick try.
But the patch seems to need to include the following change too.
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 94d99768023c..9bb108d01baa 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2040,7 +2040,8 @@ static int __iommu_attach_group(struct iommu_domain
*domain,
{
int ret;
- if (group->domain && group->domain != group->default_domain)
+ if (group->domain && group->domain != group->default_domain &&
+ group->domain != group->blocking_domain)
return -EBUSY;
ret = __iommu_group_for_each_dev(group, domain,
> @@ -2072,38 +2072,66 @@ static int iommu_group_do_detach_device(struct device
> *dev, void *data)
> return 0;
> }
>
> -static void __iommu_detach_group(struct iommu_domain *domain,
> - struct iommu_group *group)
> +static int __iommu_group_attach_domain(struct iommu_group *group,
> +struct iommu_domain *new_domain)
> {
> int ret;
>
> + if (group->domain == new_domain)
> + return 0;
> +
> /*
> - * If the group has been claimed already, do not re-attach the default
> - * domain.
> + * A NULL domain means to call the detach_dev() op. New drivers should
> + * use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain
an IOMMU_DOMAIN_IDENTITY?
Just a nit here. I will take a closer look at the change tomorrow.
Thanks
Nic
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[PATCH] iommu: iommu_group_claim_dma_owner() must always assign a domain
Once the group enters 'owned' mode it can never be assigned back to the
default_domain or to a NULL domain. It must always be actively assigned to
a current domain. If the caller hasn't provided a domain then the core
must provide an explicit DMA blocking domain that has no DMA map.
Lazily create a group-global blocking DMA domain when
iommu_group_claim_dma_owner is first called and immediately assign the
group to it. This ensures that DMA is immediately fully isolated on all
IOMMU drivers.
If the user attaches/detaches while owned then detach will set the group
back to the blocking domain.
Slightly reorganize the call chains so that
__iommu_group_attach_core_domain() is the function that removes any caller
configured domain and sets the domains back a core owned domain with an
appropriate lifetime.
__iommu_group_attach_domain() is the worker function that can change the
domain assigned to a group to any target domain, including NULL.
Add comments clarifying how the NULL vs detach_dev vs default_domain works
based on Robin's remarks.
This fixes an oops with VFIO and SMMUv3 because VFIO will call
iommu_detach_group() and then immediately iommu_domain_free(), but
SMMUv3 has no way to know that the domain it is holding a pointer to
has been freed. Now the iommu_detach_group() will assign the blocking
domain and SMMUv3 will no longer hold a stale domain reference.
Fixes: 1ea2a07a532b ("iommu: Add DMA ownership management interfaces")
Reported-by: Qian Cai
Signed-off-by: Robin Murphy
Signed-off-by: Jason Gunthorpe
---
drivers/iommu/iommu.c | 112 +++---
1 file changed, 82 insertions(+), 30 deletions(-)
This is based on Robins draft here:
https://lore.kernel.org/linux-iommu/18831161-473f-e04f-4a81-1c7062ad1...@arm.com/
With some rework. I re-organized the call chains instead of introducing
iommu_group_user_attached(), fixed a recursive locking for
iommu_group_get_purgatory(), and made a proper commit message.
Still only compile tested, so RFCish.
Nicolin/Lu? What do you think, can you check it?
Jason
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0c42ece2585406..94d99768023c94 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -44,6 +44,7 @@ struct iommu_group {
char *name;
int id;
struct iommu_domain *default_domain;
+ struct iommu_domain *blocking_domain;
struct iommu_domain *domain;
struct list_head entry;
unsigned int owner_cnt;
@@ -82,8 +83,7 @@ static int __iommu_attach_device(struct iommu_domain *domain,
struct device *dev);
static int __iommu_attach_group(struct iommu_domain *domain,
struct iommu_group *group);
-static void __iommu_detach_group(struct iommu_domain *domain,
-struct iommu_group *group);
+static void __iommu_group_attach_core_domain(struct iommu_group *group);
static int iommu_create_device_direct_mappings(struct iommu_group *group,
struct device *dev);
static struct iommu_group *iommu_group_get_for_dev(struct device *dev);
@@ -596,6 +596,8 @@ static void iommu_group_release(struct kobject *kobj)
if (group->default_domain)
iommu_domain_free(group->default_domain);
+ if (group->blocking_domain)
+ iommu_domain_free(group->blocking_domain);
kfree(group->name);
kfree(group);
@@ -1979,12 +1981,10 @@ void iommu_detach_device(struct iommu_domain *domain,
struct device *dev)
return;
mutex_lock(>mutex);
- if (iommu_group_device_count(group) != 1) {
- WARN_ON(1);
+ if (WARN_ON(domain != group->domain) ||
+ WARN_ON(iommu_group_device_count(group) != 1))
goto out_unlock;
- }
-
- __iommu_detach_group(domain, group);
+ __iommu_group_attach_core_domain(group);
out_unlock:
mutex_unlock(>mutex);
@@ -2072,38 +2072,66 @@ static int iommu_group_do_detach_device(struct device
*dev, void *data)
return 0;
}
-static void __iommu_detach_group(struct iommu_domain *domain,
-struct iommu_group *group)
+static int __iommu_group_attach_domain(struct iommu_group *group,
+ struct iommu_domain *new_domain)
{
int ret;
+ if (group->domain == new_domain)
+ return 0;
+
/*
-* If the group has been claimed already, do not re-attach the default
-* domain.
+* A NULL domain means to call the detach_dev() op. New drivers should
+* use a IOMMU_DOMAIN_IDENTITY domain instead of a NULL default_domain
+* and detatch_dev().
*/
- if (!group->default_domain || group->owner) {
- __iommu_group_for_each_dev(group, domain,
+ if (!new_domain) {
+ WARN_ON(!group->domain->ops->detach_dev);
