[Xen-changelog] [xen master] arm/mem_access: don't reinject stage 2 access exceptions

[patchbot@xxxxxxx]

commit a6f681cf110a1833cfe46d514cb8824e9b63fe22
Author:     Tamas K Lengyel <tamas.lengyel@xxxxxxxxxxxx>
AuthorDate: Wed Sep 28 16:23:05 2016 -0700
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Wed Sep 28 16:26:59 2016 -0700

    arm/mem_access: don't reinject stage 2 access exceptions
    
    The only way a guest may trip with stage 2 access violation is if 
mem_access is
    or was in-use, so reinjecting these exceptions to the guest is never 
required.
    
    Requested-by: Julien Grall <julien.grall@xxxxxxx>
    Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxxxxx>
    Signed-off-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
    Reviewed-by: Julien Grall <julien.grall@xxxxxxx>
    Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/traps.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 98928d7..bc5b29e 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -2440,12 +2440,12 @@ static void do_trap_instr_abort_guest(struct 
cpu_user_regs *regs,
             .kind = hsr.iabt.s1ptw ? npfec_kind_in_gpt : npfec_kind_with_gla
         };
 
-        rc = p2m_mem_access_check(gpa, gva, npfec);
-
-        /* Trap was triggered by mem_access, work here is done */
-        if ( !rc )
-            return;
-        break;
+        p2m_mem_access_check(gpa, gva, npfec);
+        /*
+         * The only way to get here right now is because of mem_access,
+         * thus reinjecting the exception to the guest is never required.
+         */
+        return;
     }
     case FSC_FLT_TRANS:
         /*
@@ -2534,12 +2534,12 @@ static void do_trap_data_abort_guest(struct 
cpu_user_regs *regs,
             .kind = dabt.s1ptw ? npfec_kind_in_gpt : npfec_kind_with_gla
         };
 
-        rc = p2m_mem_access_check(info.gpa, info.gva, npfec);
-
-        /* Trap was triggered by mem_access, work here is done */
-        if ( !rc )
-            return;
-        break;
+        p2m_mem_access_check(info.gpa, info.gva, npfec);
+        /*
+         * The only way to get here right now is because of mem_access,
+         * thus reinjecting the exception to the guest is never required.
+         */
+        return;
     }
     case FSC_FLT_TRANS:
         /*
--
generated by git-patchbot for /home/xen/git/xen.git#master

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