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[Xen-devel,v3,3/3] AMD IOMMU: Check io_handler before registering mmio handler

Message ID 1463874151-6950-4-git-send-email-suravee.suthikulpanit@amd.com
State New
Headers show

Commit Message

Suthikulpanit, Suravee May 21, 2016, 11:42 p.m. UTC 
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

guest_iommu_init tries to register mmio handler before HVM domain
is initialized. This cause registration to silently failing.
This patch adds a sanitiy check and puts out error message.

Signed-off-by: Suravee Suthikulapanit <suravee.suthikulpanit@amd.com>
---
 xen/drivers/passthrough/amd/iommu_guest.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Suthikulpanit, Suravee May 25, 2016, 6:52 p.m. UTC | #1 
On 5/23/2016 3:23 AM, Paul Durrant wrote:
>> -----Original Message-----
>> > From: suravee.suthikulpanit@amd.com
>> > [mailto:suravee.suthikulpanit@amd.com]
>> > Sent: 22 May 2016 00:43
>> > To: xen-devel@lists.xen.org; Paul Durrant; jbeulich@suse.com; George
>> > Dunlap
>> > Cc: Keir (Xen.org); Suravee Suthikulpanit; Suravee Suthikulapanit
>> > Subject: [PATCH v3 3/3] AMD IOMMU: Check io_handler before registering
>> > mmio handler
>> >
>> > From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
>> >
>> > guest_iommu_init tries to register mmio handler before HVM domain
>> > is initialized. This cause registration to silently failing.
>> > This patch adds a sanitiy check and puts out error message.
>> >
>> > Signed-off-by: Suravee Suthikulapanit <suravee.suthikulpanit@amd.com>
> This patch is now defunct isn't it?
>
>   Paul
>

It is no longer required, but I think this is a good sanity check in 
case something changes in the future and causing this to be called 
before the HVM I/O handler initialized.

Thanks,
Suravee
diff mbox

Patch

diff --git a/xen/drivers/passthrough/amd/iommu_guest.c b/xen/drivers/passthrough/amd/iommu_guest.c
index f96fbf4..49f00de 100644
--- a/xen/drivers/passthrough/amd/iommu_guest.c
+++ b/xen/drivers/passthrough/amd/iommu_guest.c
@@ -890,6 +890,12 @@  int guest_iommu_init(struct domain* d)
          !has_viommu(d) )
         return 0;
 
+    if ( d->arch.hvm_domain.io_handler == NULL )
+    {
+        AMD_IOMMU_DEBUG("Error: uninitalized hvm io handler\n");
+        return 1;
+    }
+
     iommu = xzalloc(struct guest_iommu);
     if ( !iommu )
     {