Hi Paul,
On 19/10/2020 08:23, Paul Durrant wrote:
-----Original Message-----
From: Julien Grall <jul...@xen.org>
Sent: 16 October 2020 16:47
To: Paul Durrant <p...@xen.org>; xen-devel@lists.xenproject.org
Cc: Paul Durrant <pdurr...@amazon.com>; Daniel De Graaf
<dgde...@tycho.nsa.gov>; Ian Jackson
<i...@xenproject.org>; Wei Liu <w...@xen.org>; Andrew Cooper
<andrew.coop...@citrix.com>; George Dunlap
<george.dun...@citrix.com>; Jan Beulich <jbeul...@suse.com>; Stefano Stabellini
<sstabell...@kernel.org>
Subject: Re: [PATCH 2/5] iommu / domctl: introduce XEN_DOMCTL_iommu_ctl
Hi Paul,
On 05/10/2020 10:49, Paul Durrant wrote:
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 791f0a2592..75e855625a 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -1130,6 +1130,18 @@ struct xen_domctl_vuart_op {
*/
};
+/*
+ * XEN_DOMCTL_iommu_ctl
+ *
+ * Control of VM IOMMU settings
+ */
+
+#define XEN_DOMCTL_IOMMU_INVALID 0
I can't find any user of XEN_DOMCTL_IOMMU_INVALID. What's the purpose
for it?
It's just a placeholder. I think it's generally safer that a zero opcode value
is invalid.
Thanks for the explanation. I first thought the goal would to somehow
invalidate the IOMMU :).
Anyway, it might be worth adding /* Reserved - should never be used */
on top.
Cheers,
--
Julien Grall
