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[PATCH] hw/virtio/virtio-iommu: Enforce power-of-two notify for both MAP and UNMAP

Jean-Philippe Brucker posted 1 patch 3 years, 6 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20220714095418.261387-1-jean-philippe@linaro.org
Maintainers: Eric Auger <eric.auger@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>
There is a newer version of this series
hw/virtio/virtio-iommu.c | 44 +++++++++++++++++++++++-----------------
1 file changed, 25 insertions(+), 19 deletions(-)
[PATCH] hw/virtio/virtio-iommu: Enforce power-of-two notify for both MAP and UNMAP
Posted by Jean-Philippe Brucker 3 years, 6 months ago 
Currently we only enforce power-of-two mappings (required by the QEMU
notifier) for UNMAP requests. A MAP request not aligned on a
power-of-two may be successfully handled by VFIO, and then the
corresponding UNMAP notify will fail because it will attempt to split
that mapping. Ensure MAP and UNMAP notifications are consistent.

Fixes: dde3f08b5cab ("virtio-iommu: Handle non power of 2 range invalidations")
Reported-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 hw/virtio/virtio-iommu.c | 44 +++++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 281152d338..f3ecbc71af 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -197,6 +197,29 @@ static gint interval_cmp(gconstpointer a, gconstpointer b, gpointer user_data)
     }
 }
 
+static void virtio_iommu_notify_map_unmap(IOMMUMemoryRegion *mr,
+                                          IOMMUTLBEvent *event,
+                                          hwaddr virt_start, hwaddr virt_end)
+{
+    uint64_t delta = virt_end - virt_start;
+
+    event->entry.iova = virt_start;
+    event->entry.addr_mask = delta;
+
+    if (delta == UINT64_MAX) {
+        memory_region_notify_iommu(mr, 0, *event);
+    }
+
+    while (virt_start != virt_end + 1) {
+        uint64_t mask = dma_aligned_pow2_mask(virt_start, virt_end, 64);
+
+        event->entry.addr_mask = mask;
+        event->entry.iova = virt_start;
+        memory_region_notify_iommu(mr, 0, *event);
+        virt_start += mask + 1;
+    }
+}
+
 static void virtio_iommu_notify_map(IOMMUMemoryRegion *mr, hwaddr virt_start,
                                     hwaddr virt_end, hwaddr paddr,
                                     uint32_t flags)
@@ -215,19 +238,16 @@ static void virtio_iommu_notify_map(IOMMUMemoryRegion *mr, hwaddr virt_start,
 
     event.type = IOMMU_NOTIFIER_MAP;
     event.entry.target_as = &address_space_memory;
-    event.entry.addr_mask = virt_end - virt_start;
-    event.entry.iova = virt_start;
     event.entry.perm = perm;
     event.entry.translated_addr = paddr;
 
-    memory_region_notify_iommu(mr, 0, event);
+    virtio_iommu_notify_map_unmap(mr, &event, virt_start, virt_end);
 }
 
 static void virtio_iommu_notify_unmap(IOMMUMemoryRegion *mr, hwaddr virt_start,
                                       hwaddr virt_end)
 {
     IOMMUTLBEvent event;
-    uint64_t delta = virt_end - virt_start;
 
     if (!(mr->iommu_notify_flags & IOMMU_NOTIFIER_UNMAP)) {
         return;
@@ -239,22 +259,8 @@ static void virtio_iommu_notify_unmap(IOMMUMemoryRegion *mr, hwaddr virt_start,
     event.entry.target_as = &address_space_memory;
     event.entry.perm = IOMMU_NONE;
     event.entry.translated_addr = 0;
-    event.entry.addr_mask = delta;
-    event.entry.iova = virt_start;
-
-    if (delta == UINT64_MAX) {
-        memory_region_notify_iommu(mr, 0, event);
-    }
 
-
-    while (virt_start != virt_end + 1) {
-        uint64_t mask = dma_aligned_pow2_mask(virt_start, virt_end, 64);
-
-        event.entry.addr_mask = mask;
-        event.entry.iova = virt_start;
-        memory_region_notify_iommu(mr, 0, event);
-        virt_start += mask + 1;
-    }
+    virtio_iommu_notify_map_unmap(mr, &event, virt_start, virt_end);
 }
 
 static gboolean virtio_iommu_notify_unmap_cb(gpointer key, gpointer value,
-- 
2.36.1
RE: [PATCH] hw/virtio/virtio-iommu: Enforce power-of-two notify for both MAP and UNMAP
Posted by Zhang, Tina 3 years, 6 months ago 

> -----Original Message-----
> From: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Sent: Thursday, July 14, 2022 5:54 PM
> To: eric.auger@redhat.com
> Cc: mst@redhat.com; qemu-devel@nongnu.org; Jean-Philippe Brucker
> <jean-philippe@linaro.org>; Zhang, Tina <tina.zhang@intel.com>
> Subject: [PATCH] hw/virtio/virtio-iommu: Enforce power-of-two notify for
> both MAP and UNMAP
> 
> Currently we only enforce power-of-two mappings (required by the QEMU
> notifier) for UNMAP requests. A MAP request not aligned on a power-of-two
> may be successfully handled by VFIO, and then the corresponding UNMAP
> notify will fail because it will attempt to split that mapping. Ensure MAP and
> UNMAP notifications are consistent.
> 
> Fixes: dde3f08b5cab ("virtio-iommu: Handle non power of 2 range
> invalidations")
> Reported-by: Tina Zhang <tina.zhang@intel.com>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> ---
>  hw/virtio/virtio-iommu.c | 44 +++++++++++++++++++++++-----------------
>  1 file changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c index
> 281152d338..f3ecbc71af 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -197,6 +197,29 @@ static gint interval_cmp(gconstpointer a,
> gconstpointer b, gpointer user_data)
>      }
>  }
> 
> +static void virtio_iommu_notify_map_unmap(IOMMUMemoryRegion *mr,
> +                                          IOMMUTLBEvent *event,
> +                                          hwaddr virt_start, hwaddr
> +virt_end) {
> +    uint64_t delta = virt_end - virt_start;
> +
> +    event->entry.iova = virt_start;
> +    event->entry.addr_mask = delta;
> +
> +    if (delta == UINT64_MAX) {
> +        memory_region_notify_iommu(mr, 0, *event);
> +    }
> +
> +    while (virt_start != virt_end + 1) {
> +        uint64_t mask = dma_aligned_pow2_mask(virt_start, virt_end,
> + 64);
> +
> +        event->entry.addr_mask = mask;
> +        event->entry.iova = virt_start;
> +        memory_region_notify_iommu(mr, 0, *event);
> +        virt_start += mask + 1;

Hi Jean, 

We also need to increase the event->translated_addr for the map request here.

Thanks,
Tina

> +    }
> +}
> +
>  static void virtio_iommu_notify_map(IOMMUMemoryRegion *mr, hwaddr
> virt_start,
>                                      hwaddr virt_end, hwaddr paddr,
>                                      uint32_t flags) @@ -215,19 +238,16 @@ static void
> virtio_iommu_notify_map(IOMMUMemoryRegion *mr, hwaddr virt_start,
> 
>      event.type = IOMMU_NOTIFIER_MAP;
>      event.entry.target_as = &address_space_memory;
> -    event.entry.addr_mask = virt_end - virt_start;
> -    event.entry.iova = virt_start;
>      event.entry.perm = perm;
>      event.entry.translated_addr = paddr;
> 
> -    memory_region_notify_iommu(mr, 0, event);
> +    virtio_iommu_notify_map_unmap(mr, &event, virt_start, virt_end);
>  }
> 
>  static void virtio_iommu_notify_unmap(IOMMUMemoryRegion *mr,
> hwaddr virt_start,
>                                        hwaddr virt_end)  {
>      IOMMUTLBEvent event;
> -    uint64_t delta = virt_end - virt_start;
> 
>      if (!(mr->iommu_notify_flags & IOMMU_NOTIFIER_UNMAP)) {
>          return;
> @@ -239,22 +259,8 @@ static void
> virtio_iommu_notify_unmap(IOMMUMemoryRegion *mr, hwaddr virt_start,
>      event.entry.target_as = &address_space_memory;
>      event.entry.perm = IOMMU_NONE;
>      event.entry.translated_addr = 0;
> -    event.entry.addr_mask = delta;
> -    event.entry.iova = virt_start;
> -
> -    if (delta == UINT64_MAX) {
> -        memory_region_notify_iommu(mr, 0, event);
> -    }
> 
> -
> -    while (virt_start != virt_end + 1) {
> -        uint64_t mask = dma_aligned_pow2_mask(virt_start, virt_end, 64);
> -
> -        event.entry.addr_mask = mask;
> -        event.entry.iova = virt_start;
> -        memory_region_notify_iommu(mr, 0, event);
> -        virt_start += mask + 1;
> -    }
> +    virtio_iommu_notify_map_unmap(mr, &event, virt_start, virt_end);
>  }
> 
>  static gboolean virtio_iommu_notify_unmap_cb(gpointer key, gpointer value,
> --
> 2.36.1
Re: [PATCH] hw/virtio/virtio-iommu: Enforce power-of-two notify for both MAP and UNMAP
Posted by Jean-Philippe Brucker 3 years, 6 months ago 
Hi Tina,

On Fri, Jul 15, 2022 at 12:09:23AM +0000, Zhang, Tina wrote:
> > +static void virtio_iommu_notify_map_unmap(IOMMUMemoryRegion *mr,
> > +                                          IOMMUTLBEvent *event,
> > +                                          hwaddr virt_start, hwaddr
> > +virt_end) {
> > +    uint64_t delta = virt_end - virt_start;
> > +
> > +    event->entry.iova = virt_start;
> > +    event->entry.addr_mask = delta;
> > +
> > +    if (delta == UINT64_MAX) {
> > +        memory_region_notify_iommu(mr, 0, *event);
> > +    }
> > +
> > +    while (virt_start != virt_end + 1) {
> > +        uint64_t mask = dma_aligned_pow2_mask(virt_start, virt_end,
> > + 64);
> > +
> > +        event->entry.addr_mask = mask;
> > +        event->entry.iova = virt_start;
> > +        memory_region_notify_iommu(mr, 0, *event);
> > +        virt_start += mask + 1;
> 
> Hi Jean, 
> 
> We also need to increase the event->translated_addr for the map request here.

Ah right, I'll fix this

Thanks,
Jean

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