[Xen-devel] [PATCH v2 10/19] xen: arm: implement handling of registers trapped by CPTR_EL2.TTA

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

Add explicit handler for 64-bit CP14 accesses, with more relevant
debug message (as per other handlers) and to provide a place for a
comment.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
v2: Changed title from "xen: arm: Annotate registers trapped by
    CPTR_EL2.TTA"
    Add "And all other unknown registers" to new annotation.
---
 xen/arch/arm/traps.c             |   45 +++++++++++++++++++++++++++++++++++++-
 xen/include/asm-arm/perfc_defn.h |    1 +
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index d908738..afa8a95 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1816,6 +1816,15 @@ static void do_cp14_32(struct cpu_user_regs *regs, const 
union hsr hsr)
 
     case HSR_CPREG32(DBGOSLAR):
         return handle_wo_wi(regs, r, cp32.read, hsr, 1);
+
+    /*
+     * CPTR_EL2.TTA
+     *
+     * ARMv7 (DDI 0406C.b): B1.14.16
+     * ARMv8 (DDI 0487A.d): D1-1507 Table D1-54
+     *
+     * And all other unknown registers.
+     */
     default:
         gdprintk(XENLOG_ERR,
                  "%s p14, %d, r%d, cr%d, cr%d, %d @ 0x%"PRIregister"\n",
@@ -1830,7 +1839,7 @@ static void do_cp14_32(struct cpu_user_regs *regs, const 
union hsr hsr)
     advance_pc(regs, hsr);
 }
 
-static void do_cp14_dbg(struct cpu_user_regs *regs, const union hsr hsr)
+static void do_cp14_64(struct cpu_user_regs *regs, const union hsr hsr)
 {
     const struct hsr_cp64 cp64 = hsr.cp64;
 
@@ -1840,12 +1849,37 @@ static void do_cp14_dbg(struct cpu_user_regs *regs, 
const union hsr hsr)
         return;
     }
 
+    /*
+     * CPTR_EL2.TTA
+     *
+     * ARMv7 (DDI 0406C.b): B1.14.16
+     * ARMv8 (DDI 0487A.d): D1-1507 Table D1-54
+     */
     gdprintk(XENLOG_ERR,
              "%s p14, %d, r%d, r%d, cr%d @ 0x%"PRIregister"\n",
              cp64.read ? "mrrc" : "mcrr",
              cp64.op1, cp64.reg1, cp64.reg2, cp64.crm, regs->pc);
     gdprintk(XENLOG_ERR, "unhandled 64-bit CP14 access %#x\n",
              hsr.bits & HSR_CP64_REGS_MASK);
+    inject_undef_exception(regs, hsr);
+}
+
+static void do_cp14_dbg(struct cpu_user_regs *regs, const union hsr hsr)
+{
+    struct hsr_cp64 cp64 = hsr.cp64;
+
+    if ( !check_conditional_instr(regs, hsr) )
+    {
+        advance_pc(regs, hsr);
+        return;
+    }
+
+    gdprintk(XENLOG_ERR,
+             "%s p14, %d, r%d, r%d, cr%d @ 0x%"PRIregister"\n",
+             cp64.read ? "mrrc" : "mcrr",
+             cp64.op1, cp64.reg1, cp64.reg2, cp64.crm, regs->pc);
+    gdprintk(XENLOG_ERR, "unhandled 64-bit CP14 DBG access %#x\n",
+             hsr.bits & HSR_CP64_REGS_MASK);
 
     inject_undef_exception(regs, hsr);
 }
@@ -1968,6 +2002,10 @@ static void do_sysreg(struct cpu_user_regs *regs,
      *
      * ARMv8 (DDI 0487A.d): D1-1501 Table D1-43
      *
+     * CPTR_EL2.TTA
+     *
+     * ARMv8 (DDI 0487A.d): D1-1507 Table D1-54
+     *
      * And all other unknown registers.
      */
     default:
@@ -2162,6 +2200,11 @@ asmlinkage void do_trap_hypervisor(struct cpu_user_regs 
*regs)
         perfc_incr(trap_cp14_32);
         do_cp14_32(regs, hsr);
         break;
+    case HSR_EC_CP14_64:
+        GUEST_BUG_ON(!psr_mode_is_32bit(regs->cpsr));
+        perfc_incr(trap_cp14_64);
+        do_cp14_64(regs, hsr);
+        break;
     case HSR_EC_CP14_DBG:
         GUEST_BUG_ON(!psr_mode_is_32bit(regs->cpsr));
         perfc_incr(trap_cp14_dbg);
diff --git a/xen/include/asm-arm/perfc_defn.h b/xen/include/asm-arm/perfc_defn.h
index 46015f5..69fabe7 100644
--- a/xen/include/asm-arm/perfc_defn.h
+++ b/xen/include/asm-arm/perfc_defn.h
@@ -9,6 +9,7 @@ PERFCOUNTER(trap_wfe,      "trap: wfe")
 PERFCOUNTER(trap_cp15_32,  "trap: cp15 32-bit access")
 PERFCOUNTER(trap_cp15_64,  "trap: cp15 64-bit access")
 PERFCOUNTER(trap_cp14_32,  "trap: cp14 32-bit access")
+PERFCOUNTER(trap_cp14_64,  "trap: cp14 64-bit access")
 PERFCOUNTER(trap_cp14_dbg, "trap: cp14 dbg access")
 PERFCOUNTER(trap_cp,       "trap: cp access")
 PERFCOUNTER(trap_smc32,    "trap: 32-bit smc")
-- 
1.7.10.4


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