2020-07-12 11:17:30

by Yi Liu

[permalink] [raw]
Subject: [PATCH v5 09/15] iommu/vt-d: Check ownership for PASIDs from user-space

When an IOMMU domain with nesting attribute is used for guest SVA, a
system-wide PASID is allocated for binding with the device and the domain.
For security reason, we need to check the PASID passsed from user-space.
e.g. page table bind/unbind and PASID related cache invalidation.

Cc: Kevin Tian <[email protected]>
CC: Jacob Pan <[email protected]>
Cc: Alex Williamson <[email protected]>
Cc: Eric Auger <[email protected]>
Cc: Jean-Philippe Brucker <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Lu Baolu <[email protected]>
Signed-off-by: Liu Yi L <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
---
drivers/iommu/intel/iommu.c | 10 ++++++++++
drivers/iommu/intel/svm.c | 7 +++++--
2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 4d54198..a9504cb 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5436,6 +5436,7 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain, struct device *dev,
int granu = 0;
u64 pasid = 0;
u64 addr = 0;
+ void *pdata;

granu = to_vtd_granularity(cache_type, inv_info->granularity);
if (granu == -EINVAL) {
@@ -5456,6 +5457,15 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain, struct device *dev,
(inv_info->granu.addr_info.flags & IOMMU_INV_ADDR_FLAGS_PASID))
pasid = inv_info->granu.addr_info.pasid;

+ pdata = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
+ if (!pdata) {
+ ret = -EINVAL;
+ goto out_unlock;
+ } else if (IS_ERR(pdata)) {
+ ret = PTR_ERR(pdata);
+ goto out_unlock;
+ }
+
switch (BIT(cache_type)) {
case IOMMU_CACHE_INV_TYPE_IOTLB:
/* HW will ignore LSB bits based on address mask */
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index d2c0e1a..212dee0 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -319,7 +319,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
dmar_domain = to_dmar_domain(domain);

mutex_lock(&pasid_mutex);
- svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
+ svm = ioasid_find(dmar_domain->ioasid_sid, data->hpasid, NULL);
if (IS_ERR(svm)) {
ret = PTR_ERR(svm);
goto out;
@@ -436,6 +436,7 @@ int intel_svm_unbind_gpasid(struct iommu_domain *domain,
struct device *dev, ioasid_t pasid)
{
struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
+ struct dmar_domain *dmar_domain;
struct intel_svm_dev *sdev;
struct intel_svm *svm;
int ret = -EINVAL;
@@ -443,8 +444,10 @@ int intel_svm_unbind_gpasid(struct iommu_domain *domain,
if (WARN_ON(!iommu))
return -EINVAL;

+ dmar_domain = to_dmar_domain(domain);
+
mutex_lock(&pasid_mutex);
- svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
+ svm = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
if (!svm) {
ret = -EINVAL;
goto out;
--
2.7.4


2020-07-19 16:09:55

by Eric Auger

[permalink] [raw]
Subject: Re: [PATCH v5 09/15] iommu/vt-d: Check ownership for PASIDs from user-space

Hi Yi,

On 7/12/20 1:21 PM, Liu Yi L wrote:
> When an IOMMU domain with nesting attribute is used for guest SVA, a
> system-wide PASID is allocated for binding with the device and the domain.
> For security reason, we need to check the PASID passsed from user-space.
passed
> e.g. page table bind/unbind and PASID related cache invalidation.
>
> Cc: Kevin Tian <[email protected]>
> CC: Jacob Pan <[email protected]>
> Cc: Alex Williamson <[email protected]>
> Cc: Eric Auger <[email protected]>
> Cc: Jean-Philippe Brucker <[email protected]>
> Cc: Joerg Roedel <[email protected]>
> Cc: Lu Baolu <[email protected]>
> Signed-off-by: Liu Yi L <[email protected]>
> Signed-off-by: Jacob Pan <[email protected]>
> ---
> drivers/iommu/intel/iommu.c | 10 ++++++++++
> drivers/iommu/intel/svm.c | 7 +++++--
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 4d54198..a9504cb 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -5436,6 +5436,7 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain, struct device *dev,
> int granu = 0;
> u64 pasid = 0;
> u64 addr = 0;
> + void *pdata;
>
> granu = to_vtd_granularity(cache_type, inv_info->granularity);
> if (granu == -EINVAL) {
> @@ -5456,6 +5457,15 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain, struct device *dev,
> (inv_info->granu.addr_info.flags & IOMMU_INV_ADDR_FLAGS_PASID))
> pasid = inv_info->granu.addr_info.pasid;
>
> + pdata = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
> + if (!pdata) {
> + ret = -EINVAL;
> + goto out_unlock;
> + } else if (IS_ERR(pdata)) {
> + ret = PTR_ERR(pdata);
> + goto out_unlock;
> + }
> +
> switch (BIT(cache_type)) {
> case IOMMU_CACHE_INV_TYPE_IOTLB:
> /* HW will ignore LSB bits based on address mask */
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index d2c0e1a..212dee0 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -319,7 +319,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
> dmar_domain = to_dmar_domain(domain);
>
> mutex_lock(&pasid_mutex);
> - svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
I do not get what the call was supposed to do before that patch?
> + svm = ioasid_find(dmar_domain->ioasid_sid, data->hpasid, NULL);
> if (IS_ERR(svm)) {
> ret = PTR_ERR(svm);
> goto out;
> @@ -436,6 +436,7 @@ int intel_svm_unbind_gpasid(struct iommu_domain *domain,
> struct device *dev, ioasid_t pasid)
> {
> struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> + struct dmar_domain *dmar_domain;
> struct intel_svm_dev *sdev;
> struct intel_svm *svm;
> int ret = -EINVAL;
> @@ -443,8 +444,10 @@ int intel_svm_unbind_gpasid(struct iommu_domain *domain,
> if (WARN_ON(!iommu))
> return -EINVAL;
>
> + dmar_domain = to_dmar_domain(domain);
> +
> mutex_lock(&pasid_mutex);
> - svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> + svm = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
just to make sure, about the locking, can't domain->ioasid_sid change
under the hood?

Thanks

Eric
> if (!svm) {
> ret = -EINVAL;
> goto out;
>

2020-07-20 10:19:27

by Yi Liu

[permalink] [raw]
Subject: RE: [PATCH v5 09/15] iommu/vt-d: Check ownership for PASIDs from user-space

Hi Eric,

> From: Auger Eric <[email protected]>
> Sent: Monday, July 20, 2020 12:06 AM
>
> Hi Yi,
>
> On 7/12/20 1:21 PM, Liu Yi L wrote:
> > When an IOMMU domain with nesting attribute is used for guest SVA, a
> > system-wide PASID is allocated for binding with the device and the domain.
> > For security reason, we need to check the PASID passsed from user-space.
> passed

got it.

> > e.g. page table bind/unbind and PASID related cache invalidation.
> >
> > Cc: Kevin Tian <[email protected]>
> > CC: Jacob Pan <[email protected]>
> > Cc: Alex Williamson <[email protected]>
> > Cc: Eric Auger <[email protected]>
> > Cc: Jean-Philippe Brucker <[email protected]>
> > Cc: Joerg Roedel <[email protected]>
> > Cc: Lu Baolu <[email protected]>
> > Signed-off-by: Liu Yi L <[email protected]>
> > Signed-off-by: Jacob Pan <[email protected]>
> > ---
> > drivers/iommu/intel/iommu.c | 10 ++++++++++
> > drivers/iommu/intel/svm.c | 7 +++++--
> > 2 files changed, 15 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index 4d54198..a9504cb 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -5436,6 +5436,7 @@ intel_iommu_sva_invalidate(struct iommu_domain
> *domain, struct device *dev,
> > int granu = 0;
> > u64 pasid = 0;
> > u64 addr = 0;
> > + void *pdata;
> >
> > granu = to_vtd_granularity(cache_type, inv_info->granularity);
> > if (granu == -EINVAL) {
> > @@ -5456,6 +5457,15 @@ intel_iommu_sva_invalidate(struct iommu_domain
> *domain, struct device *dev,
> > (inv_info->granu.addr_info.flags &
> IOMMU_INV_ADDR_FLAGS_PASID))
> > pasid = inv_info->granu.addr_info.pasid;
> >
> > + pdata = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
> > + if (!pdata) {
> > + ret = -EINVAL;
> > + goto out_unlock;
> > + } else if (IS_ERR(pdata)) {
> > + ret = PTR_ERR(pdata);
> > + goto out_unlock;
> > + }
> > +
> > switch (BIT(cache_type)) {
> > case IOMMU_CACHE_INV_TYPE_IOTLB:
> > /* HW will ignore LSB bits based on address mask */
> > diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> > index d2c0e1a..212dee0 100644
> > --- a/drivers/iommu/intel/svm.c
> > +++ b/drivers/iommu/intel/svm.c
> > @@ -319,7 +319,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain,
> struct device *dev,
> > dmar_domain = to_dmar_domain(domain);
> >
> > mutex_lock(&pasid_mutex);
> > - svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
> I do not get what the call was supposed to do before that patch?

you mean patch 10/15 by "that patch", right? the ownership check should
be done as to prevent illegal bind request from userspace. before patch
10/15, it should be added.

> > + svm = ioasid_find(dmar_domain->ioasid_sid, data->hpasid, NULL);
> > if (IS_ERR(svm)) {
> > ret = PTR_ERR(svm);
> > goto out;
> > @@ -436,6 +436,7 @@ int intel_svm_unbind_gpasid(struct iommu_domain
> *domain,
> > struct device *dev, ioasid_t pasid)
> > {
> > struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> > + struct dmar_domain *dmar_domain;
> > struct intel_svm_dev *sdev;
> > struct intel_svm *svm;
> > int ret = -EINVAL;
> > @@ -443,8 +444,10 @@ int intel_svm_unbind_gpasid(struct iommu_domain
> *domain,
> > if (WARN_ON(!iommu))
> > return -EINVAL;
> >
> > + dmar_domain = to_dmar_domain(domain);
> > +
> > mutex_lock(&pasid_mutex);
> > - svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> > + svm = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
> just to make sure, about the locking, can't domain->ioasid_sid change
> under the hood?

I guess not. intel_svm_unbind_gpasid() and iommu_domain_set_attr()
is called by vfio today, and within vfio, there is vfio_iommu->lock.

Regards,
Yi Liu

>
> Thanks
>
> Eric
> > if (!svm) {
> > ret = -EINVAL;
> > goto out;
> >

2020-07-20 12:39:12

by Eric Auger

[permalink] [raw]
Subject: Re: [PATCH v5 09/15] iommu/vt-d: Check ownership for PASIDs from user-space

Yi,

On 7/20/20 12:18 PM, Liu, Yi L wrote:
> Hi Eric,
>
>> From: Auger Eric <[email protected]>
>> Sent: Monday, July 20, 2020 12:06 AM
>>
>> Hi Yi,
>>
>> On 7/12/20 1:21 PM, Liu Yi L wrote:
>>> When an IOMMU domain with nesting attribute is used for guest SVA, a
>>> system-wide PASID is allocated for binding with the device and the domain.
>>> For security reason, we need to check the PASID passsed from user-space.
>> passed
>
> got it.
>
>>> e.g. page table bind/unbind and PASID related cache invalidation.
>>>
>>> Cc: Kevin Tian <[email protected]>
>>> CC: Jacob Pan <[email protected]>
>>> Cc: Alex Williamson <[email protected]>
>>> Cc: Eric Auger <[email protected]>
>>> Cc: Jean-Philippe Brucker <[email protected]>
>>> Cc: Joerg Roedel <[email protected]>
>>> Cc: Lu Baolu <[email protected]>
>>> Signed-off-by: Liu Yi L <[email protected]>
>>> Signed-off-by: Jacob Pan <[email protected]>
>>> ---
>>> drivers/iommu/intel/iommu.c | 10 ++++++++++
>>> drivers/iommu/intel/svm.c | 7 +++++--
>>> 2 files changed, 15 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>>> index 4d54198..a9504cb 100644
>>> --- a/drivers/iommu/intel/iommu.c
>>> +++ b/drivers/iommu/intel/iommu.c
>>> @@ -5436,6 +5436,7 @@ intel_iommu_sva_invalidate(struct iommu_domain
>> *domain, struct device *dev,
>>> int granu = 0;
>>> u64 pasid = 0;
>>> u64 addr = 0;
>>> + void *pdata;
>>>
>>> granu = to_vtd_granularity(cache_type, inv_info->granularity);
>>> if (granu == -EINVAL) {
>>> @@ -5456,6 +5457,15 @@ intel_iommu_sva_invalidate(struct iommu_domain
>> *domain, struct device *dev,
>>> (inv_info->granu.addr_info.flags &
>> IOMMU_INV_ADDR_FLAGS_PASID))
>>> pasid = inv_info->granu.addr_info.pasid;
>>>
>>> + pdata = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
>>> + if (!pdata) {
>>> + ret = -EINVAL;
>>> + goto out_unlock;
>>> + } else if (IS_ERR(pdata)) {
>>> + ret = PTR_ERR(pdata);
>>> + goto out_unlock;
>>> + }
>>> +
>>> switch (BIT(cache_type)) {
>>> case IOMMU_CACHE_INV_TYPE_IOTLB:
>>> /* HW will ignore LSB bits based on address mask */
>>> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
>>> index d2c0e1a..212dee0 100644
>>> --- a/drivers/iommu/intel/svm.c
>>> +++ b/drivers/iommu/intel/svm.c
>>> @@ -319,7 +319,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain,
>> struct device *dev,
>>> dmar_domain = to_dmar_domain(domain);
>>>
>>> mutex_lock(&pasid_mutex);
>>> - svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
I meant while using INVALID_IOASID_SET instead of the actual
dmar_domain->ioasid_sid. But I think I've now recovered, the asset is
simply not used ;-)
>> I do not get what the call was supposed to do before that patch?
>
> you mean patch 10/15 by "that patch", right? the ownership check should
> be done as to prevent illegal bind request from userspace. before patch
> 10/15, it should be added.
>
>>> + svm = ioasid_find(dmar_domain->ioasid_sid, data->hpasid, NULL);
>>> if (IS_ERR(svm)) {
>>> ret = PTR_ERR(svm);
>>> goto out;
>>> @@ -436,6 +436,7 @@ int intel_svm_unbind_gpasid(struct iommu_domain
>> *domain,
>>> struct device *dev, ioasid_t pasid)
>>> {
>>> struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
>>> + struct dmar_domain *dmar_domain;
>>> struct intel_svm_dev *sdev;
>>> struct intel_svm *svm;
>>> int ret = -EINVAL;
>>> @@ -443,8 +444,10 @@ int intel_svm_unbind_gpasid(struct iommu_domain
>> *domain,
>>> if (WARN_ON(!iommu))
>>> return -EINVAL;
>>>
>>> + dmar_domain = to_dmar_domain(domain);
>>> +
>>> mutex_lock(&pasid_mutex);
>>> - svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
>>> + svm = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
>> just to make sure, about the locking, can't domain->ioasid_sid change
>> under the hood?
>
> I guess not. intel_svm_unbind_gpasid() and iommu_domain_set_attr()
> is called by vfio today, and within vfio, there is vfio_iommu->lock.
OK

Thanks

Eric
>
> Regards,
> Yi Liu
>
>>
>> Thanks
>>
>> Eric
>>> if (!svm) {
>>> ret = -EINVAL;
>>> goto out;
>>>
>

2020-07-20 12:58:17

by Yi Liu

[permalink] [raw]
Subject: RE: [PATCH v5 09/15] iommu/vt-d: Check ownership for PASIDs from user-space

Eric,

> From: Auger Eric <[email protected]>
> Sent: Monday, July 20, 2020 8:38 PM
>
> Yi,
>
> On 7/20/20 12:18 PM, Liu, Yi L wrote:
> > Hi Eric,
> >
> >> From: Auger Eric <[email protected]>
> >> Sent: Monday, July 20, 2020 12:06 AM
> >>
> >> Hi Yi,
> >>
> >> On 7/12/20 1:21 PM, Liu Yi L wrote:
> >>> When an IOMMU domain with nesting attribute is used for guest SVA, a
> >>> system-wide PASID is allocated for binding with the device and the domain.
> >>> For security reason, we need to check the PASID passsed from user-space.
> >> passed
> >
> > got it.
> >
> >>> e.g. page table bind/unbind and PASID related cache invalidation.
> >>>
> >>> Cc: Kevin Tian <[email protected]>
> >>> CC: Jacob Pan <[email protected]>
> >>> Cc: Alex Williamson <[email protected]>
> >>> Cc: Eric Auger <[email protected]>
> >>> Cc: Jean-Philippe Brucker <[email protected]>
> >>> Cc: Joerg Roedel <[email protected]>
> >>> Cc: Lu Baolu <[email protected]>
> >>> Signed-off-by: Liu Yi L <[email protected]>
> >>> Signed-off-by: Jacob Pan <[email protected]>
> >>> ---
> >>> drivers/iommu/intel/iommu.c | 10 ++++++++++
> >>> drivers/iommu/intel/svm.c | 7 +++++--
> >>> 2 files changed, 15 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> >>> index 4d54198..a9504cb 100644
> >>> --- a/drivers/iommu/intel/iommu.c
> >>> +++ b/drivers/iommu/intel/iommu.c
> >>> @@ -5436,6 +5436,7 @@ intel_iommu_sva_invalidate(struct iommu_domain
> >> *domain, struct device *dev,
> >>> int granu = 0;
> >>> u64 pasid = 0;
> >>> u64 addr = 0;
> >>> + void *pdata;
> >>>
> >>> granu = to_vtd_granularity(cache_type, inv_info->granularity);
> >>> if (granu == -EINVAL) {
> >>> @@ -5456,6 +5457,15 @@ intel_iommu_sva_invalidate(struct iommu_domain
> >> *domain, struct device *dev,
> >>> (inv_info->granu.addr_info.flags &
> >> IOMMU_INV_ADDR_FLAGS_PASID))
> >>> pasid = inv_info->granu.addr_info.pasid;
> >>>
> >>> + pdata = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
> >>> + if (!pdata) {
> >>> + ret = -EINVAL;
> >>> + goto out_unlock;
> >>> + } else if (IS_ERR(pdata)) {
> >>> + ret = PTR_ERR(pdata);
> >>> + goto out_unlock;
> >>> + }
> >>> +
> >>> switch (BIT(cache_type)) {
> >>> case IOMMU_CACHE_INV_TYPE_IOTLB:
> >>> /* HW will ignore LSB bits based on address mask */
> >>> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> >>> index d2c0e1a..212dee0 100644
> >>> --- a/drivers/iommu/intel/svm.c
> >>> +++ b/drivers/iommu/intel/svm.c
> >>> @@ -319,7 +319,7 @@ int intel_svm_bind_gpasid(struct iommu_domain
> *domain,
> >> struct device *dev,
> >>> dmar_domain = to_dmar_domain(domain);
> >>>
> >>> mutex_lock(&pasid_mutex);
> >>> - svm = ioasid_find(INVALID_IOASID_SET, data->hpasid, NULL);
> I meant while using INVALID_IOASID_SET instead of the actual
> dmar_domain->ioasid_sid. But I think I've now recovered, the asset is
> simply not used ;-)

oh, I think should be using dmar_domain->ioasid_sid from the beginning.
does it look good so far? :-)

Regards,
Yi Liu

> >> I do not get what the call was supposed to do before that patch?
> >
> > you mean patch 10/15 by "that patch", right? the ownership check should
> > be done as to prevent illegal bind request from userspace. before patch
> > 10/15, it should be added.
> >
> >>> + svm = ioasid_find(dmar_domain->ioasid_sid, data->hpasid, NULL);
> >>> if (IS_ERR(svm)) {
> >>> ret = PTR_ERR(svm);
> >>> goto out;
> >>> @@ -436,6 +436,7 @@ int intel_svm_unbind_gpasid(struct iommu_domain
> >> *domain,
> >>> struct device *dev, ioasid_t pasid)
> >>> {
> >>> struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> >>> + struct dmar_domain *dmar_domain;
> >>> struct intel_svm_dev *sdev;
> >>> struct intel_svm *svm;
> >>> int ret = -EINVAL;
> >>> @@ -443,8 +444,10 @@ int intel_svm_unbind_gpasid(struct iommu_domain
> >> *domain,
> >>> if (WARN_ON(!iommu))
> >>> return -EINVAL;
> >>>
> >>> + dmar_domain = to_dmar_domain(domain);
> >>> +
> >>> mutex_lock(&pasid_mutex);
> >>> - svm = ioasid_find(INVALID_IOASID_SET, pasid, NULL);
> >>> + svm = ioasid_find(dmar_domain->ioasid_sid, pasid, NULL);
> >> just to make sure, about the locking, can't domain->ioasid_sid change
> >> under the hood?
> >
> > I guess not. intel_svm_unbind_gpasid() and iommu_domain_set_attr()
> > is called by vfio today, and within vfio, there is vfio_iommu->lock.
> OK
>
> Thanks
>
> Eric
> >
> > Regards,
> > Yi Liu
> >
> >>
> >> Thanks
> >>
> >> Eric
> >>> if (!svm) {
> >>> ret = -EINVAL;
> >>> goto out;
> >>>
> >