[Qemu-devel] [PATCH 18/24] target-arm: Implement AArch64 VBAR_EL1

[Peter Maydell <peter.maydell@linaro.org>]

Implement the A64 view of the VBAR system register.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target-arm/cpu.h    | 2 +-
 target-arm/helper.c | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index a7d6274..6f4d174 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -200,7 +200,7 @@ typedef struct CPUARMState {
         uint32_t c9_pmuserenr; /* perf monitor user enable */
         uint32_t c9_pminten; /* perf monitor interrupt enables */
         uint64_t mair_el1;
-        uint32_t c12_vbar; /* vector base address register */
+        uint64_t c12_vbar; /* vector base address register */
         uint32_t c13_fcse; /* FCSE PID.  */
         uint32_t c13_context; /* Context ID.  */
         uint64_t tpidr_el0; /* User RW Thread register.  */
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 5912b13..e2ae159 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -580,6 +580,12 @@ static int pmintenclr_write(CPUARMState *env, const ARMCPRegInfo *ri,
 static int vbar_write(CPUARMState *env, const ARMCPRegInfo *ri,
                       uint64_t value)
 {
+    /* Note that even though the AArch64 view of this register has bits
+     * [10:0] all RES0 we can only mask the bottom 5, to comply with the
+     * architectural requirements for bits which are RES0 only in some
+     * contexts. (ARMv8 would permit us to do no masking at all, but ARMv7
+     * requires the bottom five bits to be RAZ/WI because they're UNK/SBZP.)
+     */
     env->cp15.c12_vbar = value & ~0x1Ful;
     return 0;
 }
@@ -669,7 +675,8 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .access = PL1_RW, .type = ARM_CP_NO_MIGRATE,
       .fieldoffset = offsetof(CPUARMState, cp15.c9_pminten),
       .resetvalue = 0, .writefn = pmintenclr_write, },
-    { .name = "VBAR", .cp = 15, .crn = 12, .crm = 0, .opc1 = 0, .opc2 = 0,
+    { .name = "VBAR", .state = ARM_CP_STATE_BOTH,
+      .opc0 = 3, .crn = 12, .crm = 0, .opc1 = 0, .opc2 = 0,
       .access = PL1_RW, .writefn = vbar_write,
       .fieldoffset = offsetof(CPUARMState, cp15.c12_vbar),
       .resetvalue = 0 },
-- 
1.8.5