[Xen-devel] [PATCH v2 1/4] xen: make logdirty and iommu mutually exclusive

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Prevent the usage of global logdirty if the domain is using the IOMMU,
and also prevent passthrough of devices if logdirty is enabled.

Signed-off-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/mm/hap/hap.c       |    9 +++++++++
 xen/arch/x86/mm/shadow/common.c |    9 +++++++++
 xen/drivers/passthrough/iommu.c |    3 ++-
 3 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index 68a0c25..352edfd 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -175,6 +175,15 @@ out:
  */
 static int hap_enable_log_dirty(struct domain *d, bool_t log_global)
 {
+
+    if ( iommu_enabled && need_iommu(d) && log_global )
+    {
+        /*
+         * Refuse to turn on global log-dirty mode
+         * if the domain is using the IOMMU.
+         */
+        return -EINVAL;
+    }
     /* turn on PG_log_dirty bit in paging mode */
     paging_lock(d);
     d->arch.paging.mode |= PG_log_dirty;
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 9258d2a..dd55455 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -3422,6 +3422,15 @@ int shadow_enable_log_dirty(struct domain *d, bool_t 
log_global)
 {
     int ret;
 
+    if ( iommu_enabled && need_iommu(d) && log_global )
+    {
+        /*
+         * Refuse to turn on global log-dirty mode
+         * if the domain is using the IOMMU.
+         */
+        return -EINVAL;
+    }
+
     paging_lock(d);
     if ( shadow_mode_enabled(d) )
     {
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 0cf0748..ef6660f 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -292,7 +292,8 @@ static int assign_device(struct domain *d, u16 seg, u8 bus, 
u8 devfn)
      * enabled for this domain */
     if ( unlikely(!need_iommu(d) &&
             (d->arch.hvm_domain.mem_sharing_enabled ||
-             d->mem_event->paging.ring_page)) )
+             d->mem_event->paging.ring_page ||
+             paging_mode_log_dirty(d))) )
         return -EXDEV;
 
     if ( !spin_trylock(&pcidevs_lock) )
-- 
1.7.7.5 (Apple Git-26)


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