target/arm: Flush tlb for ASID changes in EL2&0 translation regime

Since we only support a single ASID, flush the tlb when it changes.

Note that TCR_EL2, like TCR_EL1, has the A1 bit that chooses between
the two TTBR* registers for the location of the ASID.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200206105448.4726-31-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/helper.c

@@ -3763,7 +3763,7 @@ static void vmsa_ttbcr_reset(CPUARMState *env, const ARMCPRegInfo *ri)
     tcr->base_mask = 0xffffc000u;
 }
 
-static void vmsa_tcr_el1_write(CPUARMState *env, const ARMCPRegInfo *ri,
+static void vmsa_tcr_el12_write(CPUARMState *env, const ARMCPRegInfo *ri,
                                uint64_t value)
 {
     ARMCPU *cpu = env_archcpu(env);
@@ -3789,7 +3789,17 @@ static void vmsa_ttbr_write(CPUARMState *env, const ARMCPRegInfo *ri,
 static void vmsa_tcr_ttbr_el2_write(CPUARMState *env, const ARMCPRegInfo *ri,
                                     uint64_t value)
 {
-    /* TODO: There are ASID fields in here with HCR_EL2.E2H */
+    /*
+     * If we are running with E2&0 regime, then an ASID is active.
+     * Flush if that might be changing.  Note we're not checking
+     * TCR_EL2.A1 to know if this is really the TTBRx_EL2 that
+     * holds the active ASID, only checking the field that might.
+     */
+    if (extract64(raw_read(env, ri) ^ value, 48, 16) &&
+        (arm_hcr_el2_eff(env) & HCR_E2H)) {
+        tlb_flush_by_mmuidx(env_cpu(env),
+                            ARMMMUIdxBit_E20_2 | ARMMMUIdxBit_E20_0);
+    }
     raw_write(env, ri, value);
 }
 
@@ -3849,7 +3859,7 @@ static const ARMCPRegInfo vmsa_cp_reginfo[] = {
                              offsetof(CPUARMState, cp15.ttbr1_ns) } },
     { .name = "TCR_EL1", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 2,
-      .access = PL1_RW, .writefn = vmsa_tcr_el1_write,
+      .access = PL1_RW, .writefn = vmsa_tcr_el12_write,
       .resetfn = vmsa_ttbcr_reset, .raw_writefn = raw_write,
       .fieldoffset = offsetof(CPUARMState, cp15.tcr_el[1]) },
     { .name = "TTBCR", .cp = 15, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 2,
@@ -5175,10 +5185,8 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
       .resetvalue = 0 },
     { .name = "TCR_EL2", .state = ARM_CP_STATE_BOTH,
       .opc0 = 3, .opc1 = 4, .crn = 2, .crm = 0, .opc2 = 2,
-      .access = PL2_RW,
-      /* no .writefn needed as this can't cause an ASID change;
-       * no .raw_writefn or .resetfn needed as we never use mask/base_mask
-       */
+      .access = PL2_RW, .writefn = vmsa_tcr_el12_write,
+      /* no .raw_writefn or .resetfn needed as we never use mask/base_mask */
       .fieldoffset = offsetof(CPUARMState, cp15.tcr_el[2]) },
     { .name = "VTCR", .state = ARM_CP_STATE_AA32,
       .cp = 15, .opc1 = 4, .crn = 2, .crm = 1, .opc2 = 2,