[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 08/18] arm/altp2m: Add HVMOP_altp2m_destroy_p2m.





On 05/07/16 12:37, Sergej Proskurin wrote:
On 07/04/2016 06:32 PM, Julien Grall wrote:
Hello Sergej,

On 04/07/16 12:45, Sergej Proskurin wrote:
Signed-off-by: Sergej Proskurin <proskurin@xxxxxxxxxxxxx>
---
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
---
   xen/arch/arm/hvm.c        |  2 +-
   xen/arch/arm/p2m.c        | 32 ++++++++++++++++++++++++++++++++
   xen/include/asm-arm/p2m.h |  3 +++
   3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/hvm.c b/xen/arch/arm/hvm.c
index 005d7c6..f4ec5cf 100644
--- a/xen/arch/arm/hvm.c
+++ b/xen/arch/arm/hvm.c
@@ -145,7 +145,7 @@ static int
do_altp2m_op(XEN_GUEST_HANDLE_PARAM(void) arg)
           break;

       case HVMOP_altp2m_destroy_p2m:
-        rc = -EOPNOTSUPP;
+        rc = p2m_destroy_altp2m_by_id(d, a.u.view.view);
           break;

       case HVMOP_altp2m_switch_p2m:
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 6c41b98..f82f1ea 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -2200,6 +2200,38 @@ void p2m_flush_altp2m(struct domain *d)
       altp2m_unlock(d);
   }

+int p2m_destroy_altp2m_by_id(struct domain *d, unsigned int idx)
+{
+    struct p2m_domain *p2m;
+    int rc = -EBUSY;
+
+    if ( !idx || idx >= MAX_ALTP2M )

Can you please add a comment to explain why the altp2m at index 0
cannot be destroyed.


This has been adopted from the x86 implementation. The altp2m[0] is
considered as hostp2m and is used as a safe harbor to which you can
switch as long as altp2m is active. After deactivating altp2m, the
system switches back to the original hostp2m view.That is, altp2m[0]
should only be destroyed/flushed/freed, when altp2m is deactivated.

Please add a comment in the code to explain it.

Regards,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.