diff mbox series

[RFC,v2,1/6] hw/vfio: Retrieve valid iova ranges from kernel

Message ID 20180516152026.2920-2-shameerali.kolothum.thodi@huawei.com
State New
Headers show
Series hw/arm: Add support for non-contiguous iova regions | expand

Commit Message

Shameerali Kolothum Thodi May 16, 2018, 3:20 p.m. UTC 
This makes use of the newly introduced iova cap chains added
to the  type1 VFIO_IOMMU_GET_INFO ioctl.

The retrieved iova info is stored in a list for later use.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

---
 hw/vfio/common.c              | 108 +++++++++++++++++++++++++++++++++++++++---
 include/hw/vfio/vfio-common.h |   7 +++
 linux-headers/linux/vfio.h    |  23 +++++++++
 3 files changed, 132 insertions(+), 6 deletions(-)

-- 
2.7.4

Comments

Eric Auger May 28, 2018, 2:21 p.m. UTC | #1 
Hi Shameer,
On 05/16/2018 05:20 PM, Shameer Kolothum wrote:
> This makes use of the newly introduced iova cap chains added

> to the  type1 VFIO_IOMMU_GET_INFO ioctl.

> 

> The retrieved iova info is stored in a list for later use.

> 

> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> ---

>  hw/vfio/common.c              | 108 +++++++++++++++++++++++++++++++++++++++---

>  include/hw/vfio/vfio-common.h |   7 +++

>  linux-headers/linux/vfio.h    |  23 +++++++++

>  3 files changed, 132 insertions(+), 6 deletions(-)

> 

> diff --git a/hw/vfio/common.c b/hw/vfio/common.c

> index 07ffa0b..94d7b24 100644

> --- a/hw/vfio/common.c

> +++ b/hw/vfio/common.c

> @@ -40,6 +40,8 @@ struct vfio_group_head vfio_group_list =

>      QLIST_HEAD_INITIALIZER(vfio_group_list);

>  struct vfio_as_head vfio_address_spaces =

>      QLIST_HEAD_INITIALIZER(vfio_address_spaces);

> +struct vfio_iova_head vfio_iova_regions =

> +    QLIST_HEAD_INITIALIZER(vfio_iova_regions);

>  

>  #ifdef CONFIG_KVM

>  /*

> @@ -1030,6 +1032,85 @@ static void vfio_put_address_space(VFIOAddressSpace *space)

>      }

>  }

>  

> +static void vfio_iommu_get_iova_ranges(struct vfio_iommu_type1_info *info)

> +{

> +    struct vfio_info_cap_header *hdr;

> +    struct vfio_iommu_type1_info_cap_iova_range *cap_iova;

> +    VFIOIovaRange *iova, *tmp, *prev = NULL;

nit: s/iova/iova_range?
> +    void *ptr = info;

> +    bool found = false;

> +    int i;

> +

> +    if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {

> +        return;

> +    }

> +

> +    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {

> +        if (hdr->id == VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE) {

> +            found = true;

> +            break;

> +        }

> +    }

> +

> +    if (!found) {

> +        return;

> +    }

> +

> +    /* purge the current iova list, if any */

> +    QLIST_FOREACH_SAFE(iova, &vfio_iova_regions, next, tmp) {

> +        QLIST_REMOVE(iova, next);

> +        g_free(iova);

> +    }

> +

> +    cap_iova = container_of(hdr, struct vfio_iommu_type1_info_cap_iova_range,

> +                            header);

> +

> +    /* populate the list */

> +    for (i = 0; i < cap_iova->nr_iovas; i++) {

> +        iova = g_malloc0(sizeof(*iova));

nit: g_new0 is preferred
> +        iova->start = cap_iova->iova_ranges[i].start;

> +        iova->end = cap_iova->iova_ranges[i].end;

> +

> +        if (prev) {

> +            QLIST_INSERT_AFTER(prev, iova, next);

> +        } else {

> +            QLIST_INSERT_HEAD(&vfio_iova_regions, iova, next);

> +        }

> +        prev = iova;

> +    }

> +

> +    return;

> +}

> +

> +static int vfio_get_iommu_info(VFIOContainer *container,

> +                         struct vfio_iommu_type1_info **info)

> +{

> +

> +    size_t argsz = sizeof(struct vfio_iommu_type1_info);

> +

> +

> +    *info = g_malloc0(argsz);

> +

> +retry:

> +    (*info)->argsz = argsz;

> +

> +    if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) {

> +        g_free(*info);

> +        *info = NULL;

> +        return -errno;

> +    }

> +

> +    if (((*info)->argsz > argsz)) {

> +        argsz = (*info)->argsz;

> +        *info = g_realloc(*info, argsz);

> +        goto retry;

> +    }

> +

> +    vfio_iommu_get_iova_ranges(*info);

> +

> +    return 0;

> +}

> +

>  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,

>                                    Error **errp)

>  {

> @@ -1044,6 +1125,15 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,

>              group->container = container;

>              QLIST_INSERT_HEAD(&container->group_list, group, container_next);

>              vfio_kvm_device_add_group(group);

> +

> +            /* New group might change the valid iovas. Get the updated list */

> +            if ((container->iommu_type == VFIO_TYPE1_IOMMU) ||

> +                (container->iommu_type == VFIO_TYPE1v2_IOMMU)) {

> +                struct vfio_iommu_type1_info *info;

> +

> +                vfio_get_iommu_info(container, &info);

> +                g_free(info);

> +            }

>              return 0;

>          }

>      }

> @@ -1071,7 +1161,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,

>      if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) ||

>          ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU)) {

>          bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU);

> -        struct vfio_iommu_type1_info info;

> +        struct vfio_iommu_type1_info *info;

>  

>          ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);

>          if (ret) {

> @@ -1095,14 +1185,14 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,

>           * existing Type1 IOMMUs generally support any IOVA we're

>           * going to actually try in practice.

>           */

> -        info.argsz = sizeof(info);

> -        ret = ioctl(fd, VFIO_IOMMU_GET_INFO, &info);

> +        ret = vfio_get_iommu_info(container, &info);

>          /* Ignore errors */

> -        if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {

> +        if (ret || !(info->flags & VFIO_IOMMU_INFO_PGSIZES)) {

>              /* Assume 4k IOVA page size */

> -            info.iova_pgsizes = 4096;

> +            info->iova_pgsizes = 4096;

>          }

> -        vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);

> +        vfio_host_win_add(container, 0, (hwaddr)-1, info->iova_pgsizes);

> +        g_free(info);

>      } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) ||

>                 ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) {

>          struct vfio_iommu_spapr_tce_info info;

> @@ -1256,6 +1346,7 @@ static void vfio_disconnect_container(VFIOGroup *group)

>      if (QLIST_EMPTY(&container->group_list)) {

>          VFIOAddressSpace *space = container->space;

>          VFIOGuestIOMMU *giommu, *tmp;

> +        VFIOIovaRange *iova, *next_iova;

not: I would prefer range naming

>  

>          QLIST_REMOVE(container, next);

>  

> @@ -1266,6 +1357,11 @@ static void vfio_disconnect_container(VFIOGroup *group)

>              g_free(giommu);

>          }

>  

> +        QLIST_FOREACH_SAFE(iova, &vfio_iova_regions, next, next_iova) {

> +            QLIST_REMOVE(iova, next);

> +            g_free(iova);

> +        }

> +

>          trace_vfio_disconnect_container(container->fd);

>          close(container->fd);

>          g_free(container);

> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h

> index d936014..874fe2c 100644

> --- a/include/hw/vfio/vfio-common.h

> +++ b/include/hw/vfio/vfio-common.h

> @@ -164,6 +164,12 @@ typedef struct VFIODisplay {

>      } dmabuf;

>  } VFIODisplay;

>  

> +typedef struct VFIOIovaRange {

> +    uint64_t start;

> +    uint64_t end;

> +    QLIST_ENTRY(VFIOIovaRange) next;

> +} VFIOIovaRange;

> +

>  void vfio_put_base_device(VFIODevice *vbasedev);

>  void vfio_disable_irqindex(VFIODevice *vbasedev, int index);

>  void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index);

> @@ -187,6 +193,7 @@ int vfio_get_device(VFIOGroup *group, const char *name,

>  extern const MemoryRegionOps vfio_region_ops;

>  extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;

>  extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces;

> +extern QLIST_HEAD(vfio_iova_head, VFIOIovaRange) vfio_iova_regions;

>  

>  #ifdef CONFIG_LINUX

>  int vfio_get_region_info(VFIODevice *vbasedev, int index,

> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h

> index 3a0a305..117341d 100644

> --- a/linux-headers/linux/vfio.h

> +++ b/linux-headers/linux/vfio.h

> @@ -589,7 +589,30 @@ struct vfio_iommu_type1_info {

>  	__u32	argsz;

>  	__u32	flags;

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

> +#define VFIO_IOMMU_INFO_CAPS	(1 << 1)	/* Info supports caps */

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

> +	__u32   cap_offset;	/* Offset within info struct of first cap */

> +};

> +

> +/*

> + * The IOVA capability allows to report the valid IOVA range(s)

> + * excluding any reserved regions associated with dev group. Any dma

> + * map attempt outside the valid iova range will return error.

> + *

> + * The structures below define version 1 of this capability.

> + */

> +#define VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE  1

> +

> +struct vfio_iova_range {

> +	__u64	start;

> +	__u64	end;

> +};

> +

> +struct vfio_iommu_type1_info_cap_iova_range {

> +	struct vfio_info_cap_header header;

> +	__u32	nr_iovas;

> +	__u32	reserved;

> +	struct vfio_iova_range iova_ranges[];

>  };

>  

>  #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)

> 

You need to update the header in a separate patch using
scripts/update-linux-headers.sh

Until the kernel series is not fully upstream you can just pickup the
VFIO related changes you are interested in (partial update) but when
this series becomes a patch, a full header update is generally used.

Thanks

Eric
Shameerali Kolothum Thodi May 30, 2018, 2:43 p.m. UTC | #2 
Hi Eric,

> -----Original Message-----

> From: Auger Eric [mailto:eric.auger@redhat.com]

> Sent: Monday, May 28, 2018 3:21 PM

> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;

> qemu-devel@nongnu.org; qemu-arm@nongnu.org

> Cc: peter.maydell@linaro.org; drjones@redhat.com; Jonathan Cameron

> <jonathan.cameron@huawei.com>; Linuxarm <linuxarm@huawei.com>;

> alex.williamson@redhat.com; Zhaoshenglong <zhaoshenglong@huawei.com>;

> imammedo@redhat.com

> Subject: Re: [Qemu-devel] [RFC v2 1/6] hw/vfio: Retrieve valid iova ranges

> from kernel

> 

> Hi Shameer,

> On 05/16/2018 05:20 PM, Shameer Kolothum wrote:

> > This makes use of the newly introduced iova cap chains added

> > to the  type1 VFIO_IOMMU_GET_INFO ioctl.

> >

> > The retrieved iova info is stored in a list for later use.

> >

> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> > ---

> >  hw/vfio/common.c              | 108

> +++++++++++++++++++++++++++++++++++++++---

> >  include/hw/vfio/vfio-common.h |   7 +++

> >  linux-headers/linux/vfio.h    |  23 +++++++++

> >  3 files changed, 132 insertions(+), 6 deletions(-)

> >

> > diff --git a/hw/vfio/common.c b/hw/vfio/common.c

> > index 07ffa0b..94d7b24 100644

> > --- a/hw/vfio/common.c

> > +++ b/hw/vfio/common.c

> > @@ -40,6 +40,8 @@ struct vfio_group_head vfio_group_list =

> >      QLIST_HEAD_INITIALIZER(vfio_group_list);

> >  struct vfio_as_head vfio_address_spaces =

> >      QLIST_HEAD_INITIALIZER(vfio_address_spaces);

> > +struct vfio_iova_head vfio_iova_regions =

> > +    QLIST_HEAD_INITIALIZER(vfio_iova_regions);

> >

> >  #ifdef CONFIG_KVM

> >  /*

> > @@ -1030,6 +1032,85 @@ static void

> vfio_put_address_space(VFIOAddressSpace *space)

> >      }

> >  }

> >

> > +static void vfio_iommu_get_iova_ranges(struct vfio_iommu_type1_info

> *info)

> > +{

> > +    struct vfio_info_cap_header *hdr;

> > +    struct vfio_iommu_type1_info_cap_iova_range *cap_iova;

> > +    VFIOIovaRange *iova, *tmp, *prev = NULL;

> nit: s/iova/iova_range?


Ok.

> > +    void *ptr = info;

> > +    bool found = false;

> > +    int i;

> > +

> > +    if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {

> > +        return;

> > +    }

> > +

> > +    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {

> > +        if (hdr->id == VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE) {

> > +            found = true;

> > +            break;

> > +        }

> > +    }

> > +

> > +    if (!found) {

> > +        return;

> > +    }

> > +

> > +    /* purge the current iova list, if any */

> > +    QLIST_FOREACH_SAFE(iova, &vfio_iova_regions, next, tmp) {

> > +        QLIST_REMOVE(iova, next);

> > +        g_free(iova);

> > +    }

> > +

> > +    cap_iova = container_of(hdr, struct

> vfio_iommu_type1_info_cap_iova_range,

> > +                            header);

> > +

> > +    /* populate the list */

> > +    for (i = 0; i < cap_iova->nr_iovas; i++) {

> > +        iova = g_malloc0(sizeof(*iova));

> nit: g_new0 is preferred


Sure.

> > +        iova->start = cap_iova->iova_ranges[i].start;

> > +        iova->end = cap_iova->iova_ranges[i].end;

> > +

> > +        if (prev) {

> > +            QLIST_INSERT_AFTER(prev, iova, next);

> > +        } else {

> > +            QLIST_INSERT_HEAD(&vfio_iova_regions, iova, next);

> > +        }

> > +        prev = iova;

> > +    }

> > +

> > +    return;

> > +}

> > +

> > +static int vfio_get_iommu_info(VFIOContainer *container,

> > +                         struct vfio_iommu_type1_info **info)

> > +{

> > +

> > +    size_t argsz = sizeof(struct vfio_iommu_type1_info);

> > +

> > +

> > +    *info = g_malloc0(argsz);

> > +

> > +retry:

> > +    (*info)->argsz = argsz;

> > +

> > +    if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) {

> > +        g_free(*info);

> > +        *info = NULL;

> > +        return -errno;

> > +    }

> > +

> > +    if (((*info)->argsz > argsz)) {

> > +        argsz = (*info)->argsz;

> > +        *info = g_realloc(*info, argsz);

> > +        goto retry;

> > +    }

> > +

> > +    vfio_iommu_get_iova_ranges(*info);

> > +

> > +    return 0;

> > +}

> > +

> >  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,

> >                                    Error **errp)

> >  {

> > @@ -1044,6 +1125,15 @@ static int vfio_connect_container(VFIOGroup

> *group, AddressSpace *as,

> >              group->container = container;

> >              QLIST_INSERT_HEAD(&container->group_list, group, container_next);

> >              vfio_kvm_device_add_group(group);

> > +

> > +            /* New group might change the valid iovas. Get the updated list */

> > +            if ((container->iommu_type == VFIO_TYPE1_IOMMU) ||

> > +                (container->iommu_type == VFIO_TYPE1v2_IOMMU)) {

> > +                struct vfio_iommu_type1_info *info;

> > +

> > +                vfio_get_iommu_info(container, &info);

> > +                g_free(info);

> > +            }

> >              return 0;

> >          }

> >      }

> > @@ -1071,7 +1161,7 @@ static int vfio_connect_container(VFIOGroup

> *group, AddressSpace *as,

> >      if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) ||

> >          ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU)) {

> >          bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU);

> > -        struct vfio_iommu_type1_info info;

> > +        struct vfio_iommu_type1_info *info;

> >

> >          ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);

> >          if (ret) {

> > @@ -1095,14 +1185,14 @@ static int vfio_connect_container(VFIOGroup

> *group, AddressSpace *as,

> >           * existing Type1 IOMMUs generally support any IOVA we're

> >           * going to actually try in practice.

> >           */

> > -        info.argsz = sizeof(info);

> > -        ret = ioctl(fd, VFIO_IOMMU_GET_INFO, &info);

> > +        ret = vfio_get_iommu_info(container, &info);

> >          /* Ignore errors */

> > -        if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {

> > +        if (ret || !(info->flags & VFIO_IOMMU_INFO_PGSIZES)) {

> >              /* Assume 4k IOVA page size */

> > -            info.iova_pgsizes = 4096;

> > +            info->iova_pgsizes = 4096;

> >          }

> > -        vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);

> > +        vfio_host_win_add(container, 0, (hwaddr)-1, info->iova_pgsizes);

> > +        g_free(info);

> >      } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) ||

> >                 ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) {

> >          struct vfio_iommu_spapr_tce_info info;

> > @@ -1256,6 +1346,7 @@ static void vfio_disconnect_container(VFIOGroup

> *group)

> >      if (QLIST_EMPTY(&container->group_list)) {

> >          VFIOAddressSpace *space = container->space;

> >          VFIOGuestIOMMU *giommu, *tmp;

> > +        VFIOIovaRange *iova, *next_iova;

> not: I would prefer range naming


Ok.
 
> >

> >          QLIST_REMOVE(container, next);

> >

> > @@ -1266,6 +1357,11 @@ static void vfio_disconnect_container(VFIOGroup

> *group)

> >              g_free(giommu);

> >          }

> >

> > +        QLIST_FOREACH_SAFE(iova, &vfio_iova_regions, next, next_iova) {

> > +            QLIST_REMOVE(iova, next);

> > +            g_free(iova);

> > +        }

> > +

> >          trace_vfio_disconnect_container(container->fd);

> >          close(container->fd);

> >          g_free(container);

> > diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h

> > index d936014..874fe2c 100644

> > --- a/include/hw/vfio/vfio-common.h

> > +++ b/include/hw/vfio/vfio-common.h

> > @@ -164,6 +164,12 @@ typedef struct VFIODisplay {

> >      } dmabuf;

> >  } VFIODisplay;

> >

> > +typedef struct VFIOIovaRange {

> > +    uint64_t start;

> > +    uint64_t end;

> > +    QLIST_ENTRY(VFIOIovaRange) next;

> > +} VFIOIovaRange;

> > +

> >  void vfio_put_base_device(VFIODevice *vbasedev);

> >  void vfio_disable_irqindex(VFIODevice *vbasedev, int index);

> >  void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index);

> > @@ -187,6 +193,7 @@ int vfio_get_device(VFIOGroup *group, const char

> *name,

> >  extern const MemoryRegionOps vfio_region_ops;

> >  extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;

> >  extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces;

> > +extern QLIST_HEAD(vfio_iova_head, VFIOIovaRange) vfio_iova_regions;

> >

> >  #ifdef CONFIG_LINUX

> >  int vfio_get_region_info(VFIODevice *vbasedev, int index,

> > diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h

> > index 3a0a305..117341d 100644

> > --- a/linux-headers/linux/vfio.h

> > +++ b/linux-headers/linux/vfio.h

> > @@ -589,7 +589,30 @@ struct vfio_iommu_type1_info {

> >  	__u32	argsz;

> >  	__u32	flags;

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

> > +#define VFIO_IOMMU_INFO_CAPS	(1 << 1)	/* Info supports caps */

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

> > +	__u32   cap_offset;	/* Offset within info struct of first cap */

> > +};

> > +

> > +/*

> > + * The IOVA capability allows to report the valid IOVA range(s)

> > + * excluding any reserved regions associated with dev group. Any dma

> > + * map attempt outside the valid iova range will return error.

> > + *

> > + * The structures below define version 1 of this capability.

> > + */

> > +#define VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE  1

> > +

> > +struct vfio_iova_range {

> > +	__u64	start;

> > +	__u64	end;

> > +};

> > +

> > +struct vfio_iommu_type1_info_cap_iova_range {

> > +	struct vfio_info_cap_header header;

> > +	__u32	nr_iovas;

> > +	__u32	reserved;

> > +	struct vfio_iova_range iova_ranges[];

> >  };

> >

> >  #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)

> >

> You need to update the header in a separate patch using

> scripts/update-linux-headers.sh

> 

> Until the kernel series is not fully upstream you can just pickup the

> VFIO related changes you are interested in (partial update) but when

> this series becomes a patch, a full header update is generally used.


Ok. I will take care of this in the next revision.

Thanks,
Shameer
 
> Thanks

> 

> Eric
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 07ffa0b..94d7b24 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -40,6 +40,8 @@  struct vfio_group_head vfio_group_list =
     QLIST_HEAD_INITIALIZER(vfio_group_list);
 struct vfio_as_head vfio_address_spaces =
     QLIST_HEAD_INITIALIZER(vfio_address_spaces);
+struct vfio_iova_head vfio_iova_regions =
+    QLIST_HEAD_INITIALIZER(vfio_iova_regions);
 
 #ifdef CONFIG_KVM
 /*
@@ -1030,6 +1032,85 @@  static void vfio_put_address_space(VFIOAddressSpace *space)
     }
 }
 
+static void vfio_iommu_get_iova_ranges(struct vfio_iommu_type1_info *info)
+{
+    struct vfio_info_cap_header *hdr;
+    struct vfio_iommu_type1_info_cap_iova_range *cap_iova;
+    VFIOIovaRange *iova, *tmp, *prev = NULL;
+    void *ptr = info;
+    bool found = false;
+    int i;
+
+    if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) {
+        return;
+    }
+
+    for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) {
+        if (hdr->id == VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE) {
+            found = true;
+            break;
+        }
+    }
+
+    if (!found) {
+        return;
+    }
+
+    /* purge the current iova list, if any */
+    QLIST_FOREACH_SAFE(iova, &vfio_iova_regions, next, tmp) {
+        QLIST_REMOVE(iova, next);
+        g_free(iova);
+    }
+
+    cap_iova = container_of(hdr, struct vfio_iommu_type1_info_cap_iova_range,
+                            header);
+
+    /* populate the list */
+    for (i = 0; i < cap_iova->nr_iovas; i++) {
+        iova = g_malloc0(sizeof(*iova));
+        iova->start = cap_iova->iova_ranges[i].start;
+        iova->end = cap_iova->iova_ranges[i].end;
+
+        if (prev) {
+            QLIST_INSERT_AFTER(prev, iova, next);
+        } else {
+            QLIST_INSERT_HEAD(&vfio_iova_regions, iova, next);
+        }
+        prev = iova;
+    }
+
+    return;
+}
+
+static int vfio_get_iommu_info(VFIOContainer *container,
+                         struct vfio_iommu_type1_info **info)
+{
+
+    size_t argsz = sizeof(struct vfio_iommu_type1_info);
+
+
+    *info = g_malloc0(argsz);
+
+retry:
+    (*info)->argsz = argsz;
+
+    if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) {
+        g_free(*info);
+        *info = NULL;
+        return -errno;
+    }
+
+    if (((*info)->argsz > argsz)) {
+        argsz = (*info)->argsz;
+        *info = g_realloc(*info, argsz);
+        goto retry;
+    }
+
+    vfio_iommu_get_iova_ranges(*info);
+
+    return 0;
+}
+
 static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
                                   Error **errp)
 {
@@ -1044,6 +1125,15 @@  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
             group->container = container;
             QLIST_INSERT_HEAD(&container->group_list, group, container_next);
             vfio_kvm_device_add_group(group);
+
+            /* New group might change the valid iovas. Get the updated list */
+            if ((container->iommu_type == VFIO_TYPE1_IOMMU) ||
+                (container->iommu_type == VFIO_TYPE1v2_IOMMU)) {
+                struct vfio_iommu_type1_info *info;
+
+                vfio_get_iommu_info(container, &info);
+                g_free(info);
+            }
             return 0;
         }
     }
@@ -1071,7 +1161,7 @@  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) ||
         ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU)) {
         bool v2 = !!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1v2_IOMMU);
-        struct vfio_iommu_type1_info info;
+        struct vfio_iommu_type1_info *info;
 
         ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);
         if (ret) {
@@ -1095,14 +1185,14 @@  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
          * existing Type1 IOMMUs generally support any IOVA we're
          * going to actually try in practice.
          */
-        info.argsz = sizeof(info);
-        ret = ioctl(fd, VFIO_IOMMU_GET_INFO, &info);
+        ret = vfio_get_iommu_info(container, &info);
         /* Ignore errors */
-        if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
+        if (ret || !(info->flags & VFIO_IOMMU_INFO_PGSIZES)) {
             /* Assume 4k IOVA page size */
-            info.iova_pgsizes = 4096;
+            info->iova_pgsizes = 4096;
         }
-        vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);
+        vfio_host_win_add(container, 0, (hwaddr)-1, info->iova_pgsizes);
+        g_free(info);
     } else if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU) ||
                ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_v2_IOMMU)) {
         struct vfio_iommu_spapr_tce_info info;
@@ -1256,6 +1346,7 @@  static void vfio_disconnect_container(VFIOGroup *group)
     if (QLIST_EMPTY(&container->group_list)) {
         VFIOAddressSpace *space = container->space;
         VFIOGuestIOMMU *giommu, *tmp;
+        VFIOIovaRange *iova, *next_iova;
 
         QLIST_REMOVE(container, next);
 
@@ -1266,6 +1357,11 @@  static void vfio_disconnect_container(VFIOGroup *group)
             g_free(giommu);
         }
 
+        QLIST_FOREACH_SAFE(iova, &vfio_iova_regions, next, next_iova) {
+            QLIST_REMOVE(iova, next);
+            g_free(iova);
+        }
+
         trace_vfio_disconnect_container(container->fd);
         close(container->fd);
         g_free(container);
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index d936014..874fe2c 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -164,6 +164,12 @@  typedef struct VFIODisplay {
     } dmabuf;
 } VFIODisplay;
 
+typedef struct VFIOIovaRange {
+    uint64_t start;
+    uint64_t end;
+    QLIST_ENTRY(VFIOIovaRange) next;
+} VFIOIovaRange;
+
 void vfio_put_base_device(VFIODevice *vbasedev);
 void vfio_disable_irqindex(VFIODevice *vbasedev, int index);
 void vfio_unmask_single_irqindex(VFIODevice *vbasedev, int index);
@@ -187,6 +193,7 @@  int vfio_get_device(VFIOGroup *group, const char *name,
 extern const MemoryRegionOps vfio_region_ops;
 extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;
 extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces;
+extern QLIST_HEAD(vfio_iova_head, VFIOIovaRange) vfio_iova_regions;
 
 #ifdef CONFIG_LINUX
 int vfio_get_region_info(VFIODevice *vbasedev, int index,
diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
index 3a0a305..117341d 100644
--- a/linux-headers/linux/vfio.h
+++ b/linux-headers/linux/vfio.h
@@ -589,7 +589,30 @@  struct vfio_iommu_type1_info {
 	__u32	argsz;
 	__u32	flags;
 #define VFIO_IOMMU_INFO_PGSIZES (1 << 0)	/* supported page sizes info */
+#define VFIO_IOMMU_INFO_CAPS	(1 << 1)	/* Info supports caps */
 	__u64	iova_pgsizes;		/* Bitmap of supported page sizes */
+	__u32   cap_offset;	/* Offset within info struct of first cap */
+};
+
+/*
+ * The IOVA capability allows to report the valid IOVA range(s)
+ * excluding any reserved regions associated with dev group. Any dma
+ * map attempt outside the valid iova range will return error.
+ *
+ * The structures below define version 1 of this capability.
+ */
+#define VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE  1
+
+struct vfio_iova_range {
+	__u64	start;
+	__u64	end;
+};
+
+struct vfio_iommu_type1_info_cap_iova_range {
+	struct vfio_info_cap_header header;
+	__u32	nr_iovas;
+	__u32	reserved;
+	struct vfio_iova_range iova_ranges[];
 };
 
 #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)