[RFC,v3,02/15] vfio: expose MSI mapping requirement through VFIO_IOMMU_GET_INFO

Message ID 1455264797-2334-3-git-send-email-eric.auger@linaro.org
State New
Headers show

Commit Message

Auger Eric Feb. 12, 2016, 8:13 a.m.
This patch allows the user-space to retrieve whether msi write
transaction addresses must be mapped. This is returned through the
VFIO_IOMMU_GET_INFO API and its new flag: VFIO_IOMMU_INFO_REQUIRE_MSI_MAP.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>

Signed-off-by: Eric Auger <eric.auger@linaro.org>


---

RFC v1 -> v1:
- derived from
  [RFC PATCH 3/6] vfio: Extend iommu-info to return MSIs automap state
- renamed allow_msi_reconfig into require_msi_mapping
- fixed VFIO_IOMMU_GET_INFO
---
 drivers/vfio/vfio_iommu_type1.c | 26 ++++++++++++++++++++++++++
 include/uapi/linux/vfio.h       |  1 +
 2 files changed, 27 insertions(+)

-- 
1.9.1

Comments

Auger Eric Feb. 18, 2016, 3:26 p.m. | #1
Hi Marc,
On 02/18/2016 10:34 AM, Marc Zyngier wrote:
> On Fri, 12 Feb 2016 08:13:04 +0000

> Eric Auger <eric.auger@linaro.org> wrote:

> 

>> This patch allows the user-space to retrieve whether msi write

>> transaction addresses must be mapped. This is returned through the

>> VFIO_IOMMU_GET_INFO API and its new flag: VFIO_IOMMU_INFO_REQUIRE_MSI_MAP.

>>

>> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>

>> Signed-off-by: Eric Auger <eric.auger@linaro.org>

>>

>> ---

>>

>> RFC v1 -> v1:

>> - derived from

>>   [RFC PATCH 3/6] vfio: Extend iommu-info to return MSIs automap state

>> - renamed allow_msi_reconfig into require_msi_mapping

>> - fixed VFIO_IOMMU_GET_INFO

>> ---

>>  drivers/vfio/vfio_iommu_type1.c | 26 ++++++++++++++++++++++++++

>>  include/uapi/linux/vfio.h       |  1 +

>>  2 files changed, 27 insertions(+)

>>

>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c

>> index 6f1ea3d..c5b57e1 100644

>> --- a/drivers/vfio/vfio_iommu_type1.c

>> +++ b/drivers/vfio/vfio_iommu_type1.c

>> @@ -255,6 +255,29 @@ static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)

>>  }

>>  

>>  /*

>> + * vfio_domains_require_msi_mapping: indicates whether MSI write transaction

>> + * addresses must be mapped

>> + *

>> + * returns true if it does

>> + */

>> +static bool vfio_domains_require_msi_mapping(struct vfio_iommu *iommu)

>> +{

>> +	struct vfio_domain *d;

>> +	bool ret;

>> +

>> +	mutex_lock(&iommu->lock);

>> +	/* All domains have same require_msi_map property, pick first */

>> +	d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);

>> +	if (iommu_domain_get_attr(d->domain, DOMAIN_ATTR_MSI_MAPPING, NULL) < 0)

>> +		ret = false;

>> +	else

>> +		ret = true;

> 

> nit: this could be simplified as:

> 

> ret = (iommu_domain_get_attr(d->domain, DOMAIN_ATTR_MSI_MAPPING, NULL) == 0);

sure ;-)
> 

>> +	mutex_unlock(&iommu->lock);

>> +

>> +	return ret;

>> +}

>> +

>> +/*

>>   * Attempt to pin pages.  We really don't want to track all the pfns and

>>   * the iommu can only map chunks of consecutive pfns anyway, so get the

>>   * first page and all consecutive pages with the same locking.

>> @@ -997,6 +1020,9 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,

>>  

>>  		info.flags = VFIO_IOMMU_INFO_PGSIZES;

>>  

>> +		if (vfio_domains_require_msi_mapping(iommu))

>> +			info.flags |= VFIO_IOMMU_INFO_REQUIRE_MSI_MAP;

>> +

>>  		info.iova_pgsizes = vfio_pgsize_bitmap(iommu);

>>  

>>  		return copy_to_user((void __user *)arg, &info, minsz);

>> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h

>> index 7d7a4c6..43e183b 100644

>> --- a/include/uapi/linux/vfio.h

>> +++ b/include/uapi/linux/vfio.h

>> @@ -400,6 +400,7 @@ struct vfio_iommu_type1_info {

>>  	__u32	argsz;

>>  	__u32	flags;

>>  #define VFIO_IOMMU_INFO_PGSIZES (1 << 0)	/* supported page sizes info */

>> +#define VFIO_IOMMU_INFO_REQUIRE_MSI_MAP (1 << 1)/* MSI must be mapped */

>>  	__u64	iova_pgsizes;		/* Bitmap of supported page sizes */

>>  };

>>  

> 

> 

> FWIW:

> 

> Acked-by: Marc Zyngier <marc.zyngier@arm.com>

thanks

Eric
> 

> 	M.

>

Patch

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 6f1ea3d..c5b57e1 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -255,6 +255,29 @@  static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
 }
 
 /*
+ * vfio_domains_require_msi_mapping: indicates whether MSI write transaction
+ * addresses must be mapped
+ *
+ * returns true if it does
+ */
+static bool vfio_domains_require_msi_mapping(struct vfio_iommu *iommu)
+{
+	struct vfio_domain *d;
+	bool ret;
+
+	mutex_lock(&iommu->lock);
+	/* All domains have same require_msi_map property, pick first */
+	d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
+	if (iommu_domain_get_attr(d->domain, DOMAIN_ATTR_MSI_MAPPING, NULL) < 0)
+		ret = false;
+	else
+		ret = true;
+	mutex_unlock(&iommu->lock);
+
+	return ret;
+}
+
+/*
  * Attempt to pin pages.  We really don't want to track all the pfns and
  * the iommu can only map chunks of consecutive pfns anyway, so get the
  * first page and all consecutive pages with the same locking.
@@ -997,6 +1020,9 @@  static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 		info.flags = VFIO_IOMMU_INFO_PGSIZES;
 
+		if (vfio_domains_require_msi_mapping(iommu))
+			info.flags |= VFIO_IOMMU_INFO_REQUIRE_MSI_MAP;
+
 		info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
 
 		return copy_to_user((void __user *)arg, &info, minsz);
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 7d7a4c6..43e183b 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -400,6 +400,7 @@  struct vfio_iommu_type1_info {
 	__u32	argsz;
 	__u32	flags;
 #define VFIO_IOMMU_INFO_PGSIZES (1 << 0)	/* supported page sizes info */
+#define VFIO_IOMMU_INFO_REQUIRE_MSI_MAP (1 << 1)/* MSI must be mapped */
 	__u64	iova_pgsizes;		/* Bitmap of supported page sizes */
 };