xen/arm: add SVE exception class handling

SVE has a new exception class with code 0x19, introduce the new code
and handle the exception.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

xen/arch/arm/include/asm/processor.h

@@ -426,6 +426,7 @@
 #define HSR_EC_HVC64                0x16
 #define HSR_EC_SMC64                0x17
 #define HSR_EC_SYSREG               0x18
+#define HSR_EC_SVE                  0x19
 #endif
 #define HSR_EC_INSTR_ABORT_LOWER_EL 0x20
 #define HSR_EC_INSTR_ABORT_CURR_EL  0x21

xen/arch/arm/traps.c

@@ -2172,6 +2172,11 @@ void do_trap_guest_sync(struct cpu_user_regs *regs)
         perfc_incr(trap_sysreg);
         do_sysreg(regs, hsr);
         break;
+    case HSR_EC_SVE:
+        GUEST_BUG_ON(regs_mode_is_32bit(regs));
+        gprintk(XENLOG_WARNING, "Domain tried to use SVE while not allowed\n");
+        inject_undef_exception(regs, hsr);
+        break;
 #endif
 
     case HSR_EC_INSTR_ABORT_LOWER_EL:
@@ -2201,6 +2206,10 @@ void do_trap_hyp_sync(struct cpu_user_regs *regs)
     case HSR_EC_BRK:
         do_trap_brk(regs, hsr);
         break;
+    case HSR_EC_SVE:
+        /* An SVE exception is a bug somewhere in hypervisor code */
+        do_unexpected_trap("SVE trap at EL2", regs);
+        break;
 #endif
     case HSR_EC_DATA_ABORT_CURR_EL:
     case HSR_EC_INSTR_ABORT_CURR_EL: