Re: [Qemu-devel] [PATCH qemu v17 09/12] vfio: Add host side DMA window capabilities

[Alex Williamson]

On Wed,  1 Jun 2016 18:57:40 +1000
Alexey Kardashevskiy  wrote:

> There are going to be multiple IOMMUs per a container. This moves
> the single host IOMMU parameter set to a list of VFIOHostDMAWindow.
> 
> This should cause no behavioral change and will be used later by
> the SPAPR TCE IOMMU v2 which will also add a vfio_host_win_del() helper.
> 
> Signed-off-by: Alexey Kardashevskiy 
> Reviewed-by: David Gibson 
> ---
> Changes:
> v17:
> * vfio_host_win_add() uses vfio_host_win_lookup() for overlap check and
> aborts if any found instead of returning an error (as recovery is not
> possible anyway)
> * hw_error() when overlapped iommu is detected
> 
> v16:
> * adjusted commit log with changes from v15
> 
> v15:
> * s/vfio_host_iommu_add/vfio_host_win_add/
> * s/VFIOHostIOMMU/VFIOHostDMAWindow/
> ---
>  hw/vfio/common.c  | 59 
> +++
>  include/hw/vfio/vfio-common.h |  9 +--
>  2 files changed, 50 insertions(+), 18 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 770f630..52b08fd 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -29,6 +29,7 @@
>  #include "exec/memory.h"
>  #include "hw/hw.h"
>  #include "qemu/error-report.h"
> +#include "qemu/range.h"
>  #include "sysemu/kvm.h"
>  #ifdef CONFIG_KVM
>  #include "linux/kvm.h"
> @@ -242,6 +243,38 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr 
> iova,
>  return -errno;
>  }
>  
> +static VFIOHostDMAWindow *vfio_host_win_lookup(VFIOContainer *container,
> +   hwaddr min_iova, hwaddr 
> max_iova)
> +{
> +VFIOHostDMAWindow *hostwin;
> +
> +QLIST_FOREACH(hostwin, >hostwin_list, hostwin_next) {
> +if (hostwin->min_iova <= min_iova && max_iova <= hostwin->max_iova) {
> +return hostwin;
> +}
> +}
> +
> +return NULL;
> +}
> +
> +static void vfio_host_win_add(VFIOContainer *container,
> + hwaddr min_iova, hwaddr max_iova,
> + uint64_t iova_pgsizes)
> +{
> +VFIOHostDMAWindow *hostwin;
> +
> +if (vfio_host_win_lookup(container, min_iova, max_iova)) {
> +hw_error("%s: Overlapped IOMMU are not enabled", __func__);
> +}
> +
> +hostwin = g_malloc0(sizeof(*hostwin));
> +
> +hostwin->min_iova = min_iova;
> +hostwin->max_iova = max_iova;
> +hostwin->iova_pgsizes = iova_pgsizes;
> +QLIST_INSERT_HEAD(>hostwin_list, hostwin, hostwin_next);
> +}
> +
>  static bool vfio_listener_skipped_section(MemoryRegionSection *section)
>  {
>  return (!memory_region_is_ram(section->mr) &&
> @@ -355,7 +388,7 @@ static void vfio_listener_region_add(MemoryListener 
> *listener,
>  }
>  end = int128_get64(int128_sub(llend, int128_one()));
>  
> -if ((iova < container->min_iova) || (end > container->max_iova)) {
> +if (!vfio_host_win_lookup(container, iova, end)) {
>  error_report("vfio: IOMMU container %p can't map guest IOVA region"
>   " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx,
>   container, iova, end);
> @@ -370,10 +403,6 @@ static void vfio_listener_region_add(MemoryListener 
> *listener,
>  
>  trace_vfio_listener_region_add_iommu(iova, end);
>  /*
> - * FIXME: We should do some checking to see if the
> - * capabilities of the host VFIO IOMMU are adequate to model
> - * the guest IOMMU
> - *
>   * FIXME: For VFIO iommu types which have KVM acceleration to
>   * avoid bouncing all map/unmaps through qemu this way, this
>   * would be the right place to wire that up (tell the KVM
> @@ -880,17 +909,14 @@ static int vfio_connect_container(VFIOGroup *group, 
> AddressSpace *as)
>   * existing Type1 IOMMUs generally support any IOVA we're
>   * going to actually try in practice.
>   */
> -container->min_iova = 0;
> -container->max_iova = (hwaddr)-1;
> -
> -/* Assume just 4K IOVA page size */
> -container->iova_pgsizes = 0x1000;
>  info.argsz = sizeof(info);
>  ret = ioctl(fd, VFIO_IOMMU_GET_INFO, );
>  /* Ignore errors */
> -if ((ret == 0) && (info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> -container->iova_pgsizes = info.iova_pgsizes;
> +if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> +/* Assume 4k IOVA page size */
> +info.iova_pgsizes = 4096;
>  }
> +vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);
>  } 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;
> @@ -946,11 +972,12 @@ static int vfio_connect_container(VFIOGroup *group, 
> AddressSpace *as)
>  ret = -errno;
>  goto 

Re: [Qemu-devel] [PATCH qemu v17 09/12] vfio: Add host side DMA window capabilities

[David Gibson]

On Wed, Jun 01, 2016 at 06:57:40PM +1000, Alexey Kardashevskiy wrote:
> There are going to be multiple IOMMUs per a container. This moves
> the single host IOMMU parameter set to a list of VFIOHostDMAWindow.
> 
> This should cause no behavioral change and will be used later by
> the SPAPR TCE IOMMU v2 which will also add a vfio_host_win_del() helper.
> 
> Signed-off-by: Alexey Kardashevskiy 
> Reviewed-by: David Gibson 
> ---
> Changes:
> v17:
> * vfio_host_win_add() uses vfio_host_win_lookup() for overlap check and
> aborts if any found instead of returning an error (as recovery is not
> possible anyway)
> * hw_error() when overlapped iommu is detected
> 
> v16:
> * adjusted commit log with changes from v15
> 
> v15:
> * s/vfio_host_iommu_add/vfio_host_win_add/
> * s/VFIOHostIOMMU/VFIOHostDMAWindow/
> ---
>  hw/vfio/common.c  | 59 
> +++
>  include/hw/vfio/vfio-common.h |  9 +--
>  2 files changed, 50 insertions(+), 18 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 770f630..52b08fd 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -29,6 +29,7 @@
>  #include "exec/memory.h"
>  #include "hw/hw.h"
>  #include "qemu/error-report.h"
> +#include "qemu/range.h"
>  #include "sysemu/kvm.h"
>  #ifdef CONFIG_KVM
>  #include "linux/kvm.h"
> @@ -242,6 +243,38 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr 
> iova,
>  return -errno;
>  }
>  
> +static VFIOHostDMAWindow *vfio_host_win_lookup(VFIOContainer *container,
> +   hwaddr min_iova, hwaddr 
> max_iova)
> +{
> +VFIOHostDMAWindow *hostwin;
> +
> +QLIST_FOREACH(hostwin, >hostwin_list, hostwin_next) {
> +if (hostwin->min_iova <= min_iova && max_iova <= hostwin->max_iova) {

This is not an overlaps test, but a strictly includes test..

> +return hostwin;
> +}
> +}
> +
> +return NULL;
> +}
> +
> +static void vfio_host_win_add(VFIOContainer *container,
> + hwaddr min_iova, hwaddr max_iova,
> + uint64_t iova_pgsizes)
> +{
> +VFIOHostDMAWindow *hostwin;
> +
> +if (vfio_host_win_lookup(container, min_iova, max_iova)) {

..which means this no longer catches (partially) overlapping regions.

> +hw_error("%s: Overlapped IOMMU are not enabled", __func__);
> +}
> +
> +hostwin = g_malloc0(sizeof(*hostwin));
> +
> +hostwin->min_iova = min_iova;
> +hostwin->max_iova = max_iova;
> +hostwin->iova_pgsizes = iova_pgsizes;
> +QLIST_INSERT_HEAD(>hostwin_list, hostwin, hostwin_next);
> +}
> +
>  static bool vfio_listener_skipped_section(MemoryRegionSection *section)
>  {
>  return (!memory_region_is_ram(section->mr) &&
> @@ -355,7 +388,7 @@ static void vfio_listener_region_add(MemoryListener 
> *listener,
>  }
>  end = int128_get64(int128_sub(llend, int128_one()));
>  
> -if ((iova < container->min_iova) || (end > container->max_iova)) {
> +if (!vfio_host_win_lookup(container, iova, end)) {
>  error_report("vfio: IOMMU container %p can't map guest IOVA region"
>   " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx,
>   container, iova, end);
> @@ -370,10 +403,6 @@ static void vfio_listener_region_add(MemoryListener 
> *listener,
>  
>  trace_vfio_listener_region_add_iommu(iova, end);
>  /*
> - * FIXME: We should do some checking to see if the
> - * capabilities of the host VFIO IOMMU are adequate to model
> - * the guest IOMMU
> - *
>   * FIXME: For VFIO iommu types which have KVM acceleration to
>   * avoid bouncing all map/unmaps through qemu this way, this
>   * would be the right place to wire that up (tell the KVM
> @@ -880,17 +909,14 @@ static int vfio_connect_container(VFIOGroup *group, 
> AddressSpace *as)
>   * existing Type1 IOMMUs generally support any IOVA we're
>   * going to actually try in practice.
>   */
> -container->min_iova = 0;
> -container->max_iova = (hwaddr)-1;
> -
> -/* Assume just 4K IOVA page size */
> -container->iova_pgsizes = 0x1000;
>  info.argsz = sizeof(info);
>  ret = ioctl(fd, VFIO_IOMMU_GET_INFO, );
>  /* Ignore errors */
> -if ((ret == 0) && (info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> -container->iova_pgsizes = info.iova_pgsizes;
> +if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
> +/* Assume 4k IOVA page size */
> +info.iova_pgsizes = 4096;
>  }
> +vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);
>  } 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;
> @@ -946,11 +972,12 @@ static 

[Qemu-devel] [PATCH qemu v17 09/12] vfio: Add host side DMA window capabilities

[Alexey Kardashevskiy]

There are going to be multiple IOMMUs per a container. This moves
the single host IOMMU parameter set to a list of VFIOHostDMAWindow.

This should cause no behavioral change and will be used later by
the SPAPR TCE IOMMU v2 which will also add a vfio_host_win_del() helper.

Signed-off-by: Alexey Kardashevskiy 
Reviewed-by: David Gibson 
---
Changes:
v17:
* vfio_host_win_add() uses vfio_host_win_lookup() for overlap check and
aborts if any found instead of returning an error (as recovery is not
possible anyway)
* hw_error() when overlapped iommu is detected

v16:
* adjusted commit log with changes from v15

v15:
* s/vfio_host_iommu_add/vfio_host_win_add/
* s/VFIOHostIOMMU/VFIOHostDMAWindow/
---
 hw/vfio/common.c  | 59 +++
 include/hw/vfio/vfio-common.h |  9 +--
 2 files changed, 50 insertions(+), 18 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 770f630..52b08fd 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -29,6 +29,7 @@
 #include "exec/memory.h"
 #include "hw/hw.h"
 #include "qemu/error-report.h"
+#include "qemu/range.h"
 #include "sysemu/kvm.h"
 #ifdef CONFIG_KVM
 #include "linux/kvm.h"
@@ -242,6 +243,38 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr 
iova,
 return -errno;
 }
 
+static VFIOHostDMAWindow *vfio_host_win_lookup(VFIOContainer *container,
+   hwaddr min_iova, hwaddr 
max_iova)
+{
+VFIOHostDMAWindow *hostwin;
+
+QLIST_FOREACH(hostwin, >hostwin_list, hostwin_next) {
+if (hostwin->min_iova <= min_iova && max_iova <= hostwin->max_iova) {
+return hostwin;
+}
+}
+
+return NULL;
+}
+
+static void vfio_host_win_add(VFIOContainer *container,
+ hwaddr min_iova, hwaddr max_iova,
+ uint64_t iova_pgsizes)
+{
+VFIOHostDMAWindow *hostwin;
+
+if (vfio_host_win_lookup(container, min_iova, max_iova)) {
+hw_error("%s: Overlapped IOMMU are not enabled", __func__);
+}
+
+hostwin = g_malloc0(sizeof(*hostwin));
+
+hostwin->min_iova = min_iova;
+hostwin->max_iova = max_iova;
+hostwin->iova_pgsizes = iova_pgsizes;
+QLIST_INSERT_HEAD(>hostwin_list, hostwin, hostwin_next);
+}
+
 static bool vfio_listener_skipped_section(MemoryRegionSection *section)
 {
 return (!memory_region_is_ram(section->mr) &&
@@ -355,7 +388,7 @@ static void vfio_listener_region_add(MemoryListener 
*listener,
 }
 end = int128_get64(int128_sub(llend, int128_one()));
 
-if ((iova < container->min_iova) || (end > container->max_iova)) {
+if (!vfio_host_win_lookup(container, iova, end)) {
 error_report("vfio: IOMMU container %p can't map guest IOVA region"
  " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx,
  container, iova, end);
@@ -370,10 +403,6 @@ static void vfio_listener_region_add(MemoryListener 
*listener,
 
 trace_vfio_listener_region_add_iommu(iova, end);
 /*
- * FIXME: We should do some checking to see if the
- * capabilities of the host VFIO IOMMU are adequate to model
- * the guest IOMMU
- *
  * FIXME: For VFIO iommu types which have KVM acceleration to
  * avoid bouncing all map/unmaps through qemu this way, this
  * would be the right place to wire that up (tell the KVM
@@ -880,17 +909,14 @@ static int vfio_connect_container(VFIOGroup *group, 
AddressSpace *as)
  * existing Type1 IOMMUs generally support any IOVA we're
  * going to actually try in practice.
  */
-container->min_iova = 0;
-container->max_iova = (hwaddr)-1;
-
-/* Assume just 4K IOVA page size */
-container->iova_pgsizes = 0x1000;
 info.argsz = sizeof(info);
 ret = ioctl(fd, VFIO_IOMMU_GET_INFO, );
 /* Ignore errors */
-if ((ret == 0) && (info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
-container->iova_pgsizes = info.iova_pgsizes;
+if (ret || !(info.flags & VFIO_IOMMU_INFO_PGSIZES)) {
+/* Assume 4k IOVA page size */
+info.iova_pgsizes = 4096;
 }
+vfio_host_win_add(container, 0, (hwaddr)-1, info.iova_pgsizes);
 } 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;
@@ -946,11 +972,12 @@ static int vfio_connect_container(VFIOGroup *group, 
AddressSpace *as)
 ret = -errno;
 goto listener_release_exit;
 }
-container->min_iova = info.dma32_window_start;
-container->max_iova = container->min_iova + info.dma32_window_size - 1;
 
-/* Assume just 4K IOVA pages for now */
-container->iova_pgsizes = 0x1000;
+/* The default table uses 4K pages */
+vfio_host_win_add(container,