[Xen-changelog] [xen stable-4.8] Don't clear HCR_VM bit when updating VTTBR.

[patchbot@xxxxxxx]

commit 768b250b31361bf8acfef4b7dca61ee37c91f3f6
Author:     Jun Sun <jsun@xxxxxxxxxx>
AuthorDate: Mon Oct 10 12:27:56 2016 -0700
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Thu Mar 16 13:42:03 2017 -0700

    Don't clear HCR_VM bit when updating VTTBR.
    
    Currently function p2m_restore_state() would clear HCR_VM bit, i.e.,
    disabling stage2 translation, before updating VTTBR register. After
    some research and talking to ARM support, I got confirmed that this is not
    necessary. We are currently working on a new platform that would need this
    to be removed.
    
    The patch is tested on FVP foundation model.
    
    Signed-off-by: Jun Sun <jsun@xxxxxxxxxx>
    Acked-by: Steve Capper <steve.capper@xxxxxxxxxx>
    Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/p2m.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 927c827..fab140d 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -140,8 +140,6 @@ void p2m_restore_state(struct vcpu *n)
         return;
 
     hcr = READ_SYSREG(HCR_EL2);
-    WRITE_SYSREG(hcr & ~HCR_VM, HCR_EL2);
-    isb();
 
     WRITE_SYSREG64(p2m->vttbr, VTTBR_EL2);
     isb();
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.8

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