[v4,4/6] iommu/dma: Pass address limit rather than size to iommu_setup_dma_ops()

Message ID 20210610075130.67517-5-jean-philippe@linaro.org
State Superseded
Headers show
Series
  • Add support for ACPI VIOT
Related show

Commit Message

Jean-Philippe Brucker June 10, 2021, 7:51 a.m.
Passing a 64-bit address width to iommu_setup_dma_ops() is valid on
virtual platforms, but isn't currently possible. The overflow check in
iommu_dma_init_domain() prevents this even when @dma_base isn't 0. Pass
a limit address instead of a size, so callers don't have to fake a size
to work around the check.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

---
 include/linux/dma-iommu.h   |  4 ++--
 arch/arm64/mm/dma-mapping.c |  2 +-
 drivers/iommu/amd/iommu.c   |  2 +-
 drivers/iommu/dma-iommu.c   | 12 ++++++------
 drivers/iommu/intel/iommu.c |  2 +-
 5 files changed, 11 insertions(+), 11 deletions(-)

-- 
2.31.1

Comments

Eric Auger June 16, 2021, 3:28 p.m. | #1
Hi Jean,

On 6/10/21 9:51 AM, Jean-Philippe Brucker wrote:
> Passing a 64-bit address width to iommu_setup_dma_ops() is valid on

> virtual platforms, but isn't currently possible. The overflow check in

> iommu_dma_init_domain() prevents this even when @dma_base isn't 0. Pass

> a limit address instead of a size, so callers don't have to fake a size

> to work around the check.

>

> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

> ---

>  include/linux/dma-iommu.h   |  4 ++--

>  arch/arm64/mm/dma-mapping.c |  2 +-

>  drivers/iommu/amd/iommu.c   |  2 +-

>  drivers/iommu/dma-iommu.c   | 12 ++++++------

>  drivers/iommu/intel/iommu.c |  2 +-

>  5 files changed, 11 insertions(+), 11 deletions(-)

>

> diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h

> index 6e75a2d689b4..758ca4694257 100644

> --- a/include/linux/dma-iommu.h

> +++ b/include/linux/dma-iommu.h

> @@ -19,7 +19,7 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);

>  void iommu_put_dma_cookie(struct iommu_domain *domain);

>  

>  /* Setup call for arch DMA mapping code */

> -void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size);

> +void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit);

>  

>  /* The DMA API isn't _quite_ the whole story, though... */

>  /*

> @@ -50,7 +50,7 @@ struct msi_msg;

>  struct device;

>  

>  static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,

> -		u64 size)

> +				       u64 dma_limit)

>  {

>  }

>  

> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c

> index 4bf1dd3eb041..7bd1d2199141 100644

> --- a/arch/arm64/mm/dma-mapping.c

> +++ b/arch/arm64/mm/dma-mapping.c

> @@ -50,7 +50,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

>  

>  	dev->dma_coherent = coherent;

>  	if (iommu)

> -		iommu_setup_dma_ops(dev, dma_base, size);

> +		iommu_setup_dma_ops(dev, dma_base, size - dma_base - 1);

I don't get  size - dma_base - 1?
>  

>  #ifdef CONFIG_XEN

>  	if (xen_swiotlb_detect())

> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c

> index 3ac42bbdefc6..94b96d81fcfd 100644

> --- a/drivers/iommu/amd/iommu.c

> +++ b/drivers/iommu/amd/iommu.c

> @@ -1713,7 +1713,7 @@ static void amd_iommu_probe_finalize(struct device *dev)

>  	/* Domains are initialized for this device - have a look what we ended up with */

>  	domain = iommu_get_domain_for_dev(dev);

>  	if (domain->type == IOMMU_DOMAIN_DMA)

> -		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0);

> +		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, U64_MAX);

>  	else

>  		set_dma_ops(dev, NULL);

>  }

> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c

> index 7bcdd1205535..c62e19bed302 100644

> --- a/drivers/iommu/dma-iommu.c

> +++ b/drivers/iommu/dma-iommu.c

> @@ -319,16 +319,16 @@ static bool dev_is_untrusted(struct device *dev)

>   * iommu_dma_init_domain - Initialise a DMA mapping domain

>   * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()

>   * @base: IOVA at which the mappable address space starts

> - * @size: Size of IOVA space

> + * @limit: Last address of the IOVA space

>   * @dev: Device the domain is being initialised for

>   *

> - * @base and @size should be exact multiples of IOMMU page granularity to

> + * @base and @limit + 1 should be exact multiples of IOMMU page granularity to

>   * avoid rounding surprises. If necessary, we reserve the page at address 0

>   * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but

>   * any change which could make prior IOVAs invalid will fail.

>   */

>  static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,

> -		u64 size, struct device *dev)

> +				 dma_addr_t limit, struct device *dev)

>  {

>  	struct iommu_dma_cookie *cookie = domain->iova_cookie;

>  	unsigned long order, base_pfn;

> @@ -346,7 +346,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,

>  	/* Check the domain allows at least some access to the device... */

>  	if (domain->geometry.force_aperture) {

>  		if (base > domain->geometry.aperture_end ||

> -		    base + size <= domain->geometry.aperture_start) {

> +		    limit < domain->geometry.aperture_start) {

>  			pr_warn("specified DMA range outside IOMMU capability\n");

>  			return -EFAULT;

>  		}

> @@ -1308,7 +1308,7 @@ static const struct dma_map_ops iommu_dma_ops = {

>   * The IOMMU core code allocates the default DMA domain, which the underlying

>   * IOMMU driver needs to support via the dma-iommu layer.

>   */

> -void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size)

> +void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)

>  {

>  	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);

>  

> @@ -1320,7 +1320,7 @@ void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size)

>  	 * underlying IOMMU driver needs to support via the dma-iommu layer.

>  	 */

>  	if (domain->type == IOMMU_DOMAIN_DMA) {

> -		if (iommu_dma_init_domain(domain, dma_base, size, dev))

> +		if (iommu_dma_init_domain(domain, dma_base, dma_limit, dev))

>  			goto out_err;

>  		dev->dma_ops = &iommu_dma_ops;

>  	}

> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c

> index be35284a2016..85f18342603c 100644

> --- a/drivers/iommu/intel/iommu.c

> +++ b/drivers/iommu/intel/iommu.c

> @@ -5171,7 +5171,7 @@ static void intel_iommu_probe_finalize(struct device *dev)

>  

>  	if (domain && domain->type == IOMMU_DOMAIN_DMA)

>  		iommu_setup_dma_ops(dev, base,

> -				    __DOMAIN_MAX_ADDR(dmar_domain->gaw) - base);

> +				    __DOMAIN_MAX_ADDR(dmar_domain->gaw));

>  	else

>  		set_dma_ops(dev, NULL);

>  }

Thanks

Eric
Jean-Philippe Brucker June 18, 2021, 9:18 a.m. | #2
On Wed, Jun 16, 2021 at 05:28:59PM +0200, Eric Auger wrote:
> Hi Jean,

> 

> On 6/10/21 9:51 AM, Jean-Philippe Brucker wrote:

> > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c

> > index 4bf1dd3eb041..7bd1d2199141 100644

> > --- a/arch/arm64/mm/dma-mapping.c

> > +++ b/arch/arm64/mm/dma-mapping.c

> > @@ -50,7 +50,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,

> >  

> >  	dev->dma_coherent = coherent;

> >  	if (iommu)

> > -		iommu_setup_dma_ops(dev, dma_base, size);

> > +		iommu_setup_dma_ops(dev, dma_base, size - dma_base - 1);

> I don't get  size - dma_base - 1?


Because it's wrong, should be dma_base + size - 1. Thanks for catching it!

Thanks,
Jean

Patch

diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 6e75a2d689b4..758ca4694257 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -19,7 +19,7 @@  int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
 
 /* Setup call for arch DMA mapping code */
-void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size);
+void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit);
 
 /* The DMA API isn't _quite_ the whole story, though... */
 /*
@@ -50,7 +50,7 @@  struct msi_msg;
 struct device;
 
 static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
-		u64 size)
+				       u64 dma_limit)
 {
 }
 
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 4bf1dd3eb041..7bd1d2199141 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -50,7 +50,7 @@  void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 
 	dev->dma_coherent = coherent;
 	if (iommu)
-		iommu_setup_dma_ops(dev, dma_base, size);
+		iommu_setup_dma_ops(dev, dma_base, size - dma_base - 1);
 
 #ifdef CONFIG_XEN
 	if (xen_swiotlb_detect())
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 3ac42bbdefc6..94b96d81fcfd 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1713,7 +1713,7 @@  static void amd_iommu_probe_finalize(struct device *dev)
 	/* Domains are initialized for this device - have a look what we ended up with */
 	domain = iommu_get_domain_for_dev(dev);
 	if (domain->type == IOMMU_DOMAIN_DMA)
-		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0);
+		iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, U64_MAX);
 	else
 		set_dma_ops(dev, NULL);
 }
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7bcdd1205535..c62e19bed302 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -319,16 +319,16 @@  static bool dev_is_untrusted(struct device *dev)
  * iommu_dma_init_domain - Initialise a DMA mapping domain
  * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
  * @base: IOVA at which the mappable address space starts
- * @size: Size of IOVA space
+ * @limit: Last address of the IOVA space
  * @dev: Device the domain is being initialised for
  *
- * @base and @size should be exact multiples of IOMMU page granularity to
+ * @base and @limit + 1 should be exact multiples of IOMMU page granularity to
  * avoid rounding surprises. If necessary, we reserve the page at address 0
  * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but
  * any change which could make prior IOVAs invalid will fail.
  */
 static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
-		u64 size, struct device *dev)
+				 dma_addr_t limit, struct device *dev)
 {
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	unsigned long order, base_pfn;
@@ -346,7 +346,7 @@  static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 	/* Check the domain allows at least some access to the device... */
 	if (domain->geometry.force_aperture) {
 		if (base > domain->geometry.aperture_end ||
-		    base + size <= domain->geometry.aperture_start) {
+		    limit < domain->geometry.aperture_start) {
 			pr_warn("specified DMA range outside IOMMU capability\n");
 			return -EFAULT;
 		}
@@ -1308,7 +1308,7 @@  static const struct dma_map_ops iommu_dma_ops = {
  * The IOMMU core code allocates the default DMA domain, which the underlying
  * IOMMU driver needs to support via the dma-iommu layer.
  */
-void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size)
+void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)
 {
 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
 
@@ -1320,7 +1320,7 @@  void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size)
 	 * underlying IOMMU driver needs to support via the dma-iommu layer.
 	 */
 	if (domain->type == IOMMU_DOMAIN_DMA) {
-		if (iommu_dma_init_domain(domain, dma_base, size, dev))
+		if (iommu_dma_init_domain(domain, dma_base, dma_limit, dev))
 			goto out_err;
 		dev->dma_ops = &iommu_dma_ops;
 	}
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index be35284a2016..85f18342603c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5171,7 +5171,7 @@  static void intel_iommu_probe_finalize(struct device *dev)
 
 	if (domain && domain->type == IOMMU_DOMAIN_DMA)
 		iommu_setup_dma_ops(dev, base,
-				    __DOMAIN_MAX_ADDR(dmar_domain->gaw) - base);
+				    __DOMAIN_MAX_ADDR(dmar_domain->gaw));
 	else
 		set_dma_ops(dev, NULL);
 }