[PATCH] target/arm: fix missing exception class

[Jamie Iles]

The DAIF and PAC checks used raise_exception_ra to raise an exception
and unwind CPU state but raise_exception_ra is currently designed for
handling data aborts as the syndrome is partially precomputed and
encoded in the TB and then merged in merge_syn_data_abort when handling
the data abort.  Using raise_exception_ra for DAIF and PAC checks
results in an empty syndrome being retrieved from data[2] in
restore_state_to_opc and setting ESR to 0.  This manifested as:

  kvm [571]: Unknown exception class: esr: 0x000000 –
  Unknown/Uncategorized

when launching a KVM guest when the host qemu used a CPU supporting
EL2+pointer authentication and enabling pointer authentication in the
guest.

As the syndrome and exception class is not encoded in the TB, use
cpu_restore_state and raise_exception to restore the CPU state and raise
the exception with the correct syndrome.

Fixes: 0d43e1a2d29a ("target/arm: Add PAuth helpers")
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
---
 target/arm/helper-a64.c   | 12 +++++++-----
 target/arm/pauth_helper.c |  4 +++-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
index 9cc3b066e28b..83991d783fc1 100644
--- a/target/arm/helper-a64.c
+++ b/target/arm/helper-a64.c
@@ -72,11 +72,13 @@ static void daif_check(CPUARMState *env, uint32_t op,
 {
     /* DAIF update to PSTATE. This is OK from EL0 only if UMA is set.  */
     if (arm_current_el(env) == 0 && !(arm_sctlr(env, 0) & SCTLR_UMA)) {
-        raise_exception_ra(env, EXCP_UDEF,
-                           syn_aa64_sysregtrap(0, extract32(op, 0, 3),
-                                               extract32(op, 3, 3), 4,
-                                               imm, 0x1f, 0),
-                           exception_target_el(env), ra);
+        CPUState *cs = env_cpu(env);
+        cpu_restore_state(cs, ra, true);
+        raise_exception(env, EXCP_UDEF,
+                        syn_aa64_sysregtrap(0, extract32(op, 0, 3),
+                                            extract32(op, 3, 3), 4,
+                                            imm, 0x1f, 0),
+                        exception_target_el(env));
     }
 }
 
diff --git a/target/arm/pauth_helper.c b/target/arm/pauth_helper.c
index cd6df18150bf..c90a3f765b9c 100644
--- a/target/arm/pauth_helper.c
+++ b/target/arm/pauth_helper.c
@@ -385,7 +385,9 @@ static uint64_t pauth_strip(CPUARMState *env, uint64_t ptr, 
bool data)
 static void QEMU_NORETURN pauth_trap(CPUARMState *env, int target_el,
                                      uintptr_t ra)
 {
-    raise_exception_ra(env, EXCP_UDEF, syn_pactrap(), target_el, ra);
+    CPUState *cs = env_cpu(env);
+    cpu_restore_state(cs, ra, true);
+    raise_exception(env, EXCP_UDEF, syn_pactrap(), target_el);
 }
 
 static void pauth_check_trap(CPUARMState *env, int el, uintptr_t ra)
-- 
2.30.2