[Qemu-devel] [PULL] VFIO updates 2016-03-28

[Qemu-devel] [PULL] VFIO updates 2016-03-28

[Alex Williamson]

The following changes since commit b68a80139e37e806f004237e55311ebc42151434:

  Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20160324' into staging (2016-03-24 16:24:02 +0000)

are available in the git repository at:


  git://github.com/awilliam/qemu-vfio.git tags/vfio-update-20160328.0

for you to fetch changes up to 55efcc537d330f1659d3fa171a66eebc9327e91b:

  vfio: convert to 128 bit arithmetic calculations when adding mem regions (2016-03-28 13:27:49 -0600)

----------------------------------------------------------------
VFIO updates 2016-03-28

 - Use 128bit math to avoid asserts with IOMMU regions (Bandan Das)

----------------------------------------------------------------
Bandan Das (1):
      vfio: convert to 128 bit arithmetic calculations when adding mem regions

 hw/vfio/common.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

[Qemu-devel] [PULL] vfio: convert to 128 bit arithmetic calculations when adding mem regions

[Alex Williamson]

From: Bandan Das <bsd@redhat.com>

vfio_listener_region_add for a iommu mr results in
an overflow assert since iommu memory region is initialized
with UINT64_MAX. Convert calculations to 128 bit arithmetic
for iommu memory regions and let int128_get64 assert for non iommu
regions if there's an overflow.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bandan Das <bsd@redhat.com>
[missed (end - 1) on 2nd trace call, move llsize closer to use]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/vfio/common.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index fb588d8..f27db36 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -323,7 +323,7 @@ static void vfio_listener_region_add(MemoryListener *listener,
 {
     VFIOContainer *container = container_of(listener, VFIOContainer, listener);
     hwaddr iova, end;
-    Int128 llend;
+    Int128 llend, llsize;
     void *vaddr;
     int ret;
 
@@ -349,12 +349,12 @@ static void vfio_listener_region_add(MemoryListener *listener,
     if (int128_ge(int128_make64(iova), llend)) {
         return;
     }
-    end = int128_get64(llend);
+    end = int128_get64(int128_sub(llend, int128_one()));
 
-    if ((iova < container->min_iova) || ((end - 1) > container->max_iova)) {
+    if ((iova < container->min_iova) || (end > container->max_iova)) {
         error_report("vfio: IOMMU container %p can't map guest IOVA region"
                      " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx,
-                     container, iova, end - 1);
+                     container, iova, end);
         ret = -EFAULT;
         goto fail;
     }
@@ -364,7 +364,7 @@ static void vfio_listener_region_add(MemoryListener *listener,
     if (memory_region_is_iommu(section->mr)) {
         VFIOGuestIOMMU *giommu;
 
-        trace_vfio_listener_region_add_iommu(iova, end - 1);
+        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
@@ -395,13 +395,16 @@ static void vfio_listener_region_add(MemoryListener *listener,
             section->offset_within_region +
             (iova - section->offset_within_address_space);
 
-    trace_vfio_listener_region_add_ram(iova, end - 1, vaddr);
+    trace_vfio_listener_region_add_ram(iova, end, vaddr);
 
-    ret = vfio_dma_map(container, iova, end - iova, vaddr, section->readonly);
+    llsize = int128_sub(llend, int128_make64(iova));
+
+    ret = vfio_dma_map(container, iova, int128_get64(llsize),
+                       vaddr, section->readonly);
     if (ret) {
         error_report("vfio_dma_map(%p, 0x%"HWADDR_PRIx", "
                      "0x%"HWADDR_PRIx", %p) = %d (%m)",
-                     container, iova, end - iova, vaddr, ret);
+                     container, iova, int128_get64(llsize), vaddr, ret);
         goto fail;
     }
 

Re: [Qemu-devel] [PULL] VFIO updates 2016-03-28

[Peter Maydell]

On 28 March 2016 at 23:34, Alex Williamson <alex.williamson@redhat.com> wrote:
> The following changes since commit b68a80139e37e806f004237e55311ebc42151434:
>
>   Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20160324' into staging (2016-03-24 16:24:02 +0000)
>
> are available in the git repository at:
>
>
>   git://github.com/awilliam/qemu-vfio.git tags/vfio-update-20160328.0
>
> for you to fetch changes up to 55efcc537d330f1659d3fa171a66eebc9327e91b:
>
>   vfio: convert to 128 bit arithmetic calculations when adding mem regions (2016-03-28 13:27:49 -0600)
>
> ----------------------------------------------------------------
> VFIO updates 2016-03-28
>
>  - Use 128bit math to avoid asserts with IOMMU regions (Bandan Das)
>

Applied, thanks.

-- PMM