Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20191220' into staging

target-arm queue:
 * Support emulating the generic timers at frequencies other than 62.5MHz
 * Various fixes for SMMUv3 emulation bugs
 * Improve assert error message for hflags mismatches
 * arm-powerctl: rebuild hflags after setting CP15 bits in arm_set_cpu_on()

# gpg: Signature made Fri 20 Dec 2019 14:25:51 GMT
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20191220:
  arm/arm-powerctl: rebuild hflags after setting CP15 bits in arm_set_cpu_on()
  target/arm: Display helpful message when hflags mismatch
  hw/arm/smmuv3: Report F_STE_FETCH fault address in correct word position
  hw/arm/smmuv3: Use correct bit positions in EVT_SET_ADDR2 macro
  hw/arm/smmuv3: Align stream table base address to table size
  hw/arm/smmuv3: Check stream IDs against actual table LOG2SIZE
  hw/arm/smmuv3: Correct SMMU_BASE_ADDR_MASK value
  hw/arm/smmuv3: Apply address mask to linear strtab base address
  ast2600: Configure CNTFRQ at 1125MHz
  target/arm: Prepare generic timer for per-platform CNTFRQ
  target/arm: Abstract the generic timer frequency
  target/arm: Remove redundant scaling of nexttick

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 98 insertions, 17 deletions

diff --git a/target/arm/arm-powerctl.c b/target/arm/arm-powerctl.c
index b064513..b75f813 100644
--- a/target/arm/arm-powerctl.c
+++ b/target/arm/arm-powerctl.c
@@ -127,6 +127,9 @@ static void arm_set_cpu_on_async_work(CPUState *target_cpu_state,
         target_cpu->env.regs[0] = info->context_id;
     }
 
+    /* CP15 update requires rebuilding hflags */
+    arm_rebuild_hflags(&target_cpu->env);
+
     /* Start the new CPU at the requested address */
     cpu_set_pc(target_cpu_state, info->entry);
 
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index dd51ada..d62fd5f 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -976,6 +976,10 @@ static void arm_cpu_initfn(Object *obj)
     }
 }
 
+static Property arm_cpu_gt_cntfrq_property =
+            DEFINE_PROP_UINT64("cntfrq", ARMCPU, gt_cntfrq_hz,
+                               NANOSECONDS_PER_SECOND / GTIMER_SCALE);
+
 static Property arm_cpu_reset_cbar_property =
             DEFINE_PROP_UINT64("reset-cbar", ARMCPU, reset_cbar, 0);
 
@@ -1055,6 +1059,30 @@ static void arm_set_init_svtor(Object *obj, Visitor *v, const char *name,
     visit_type_uint32(v, name, &cpu->init_svtor, errp);
 }
 
+unsigned int gt_cntfrq_period_ns(ARMCPU *cpu)
+{
+    /*
+     * The exact approach to calculating guest ticks is:
+     *
+     *     muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), cpu->gt_cntfrq_hz,
+     *              NANOSECONDS_PER_SECOND);
+     *
+     * We don't do that. Rather we intentionally use integer division
+     * truncation below and in the caller for the conversion of host monotonic
+     * time to guest ticks to provide the exact inverse for the semantics of
+     * the QEMUTimer scale factor. QEMUTimer's scale facter is an integer, so
+     * it loses precision when representing frequencies where
+     * `(NANOSECONDS_PER_SECOND % cpu->gt_cntfrq) > 0` holds. Failing to
+     * provide an exact inverse leads to scheduling timers with negative
+     * periods, which in turn leads to sticky behaviour in the guest.
+     *
+     * Finally, CNTFRQ is effectively capped at 1GHz to ensure our scale factor
+     * cannot become zero.
+     */
+    return NANOSECONDS_PER_SECOND > cpu->gt_cntfrq_hz ?
+      NANOSECONDS_PER_SECOND / cpu->gt_cntfrq_hz : 1;
+}
+
 void arm_cpu_post_init(Object *obj)
 {
     ARMCPU *cpu = ARM_CPU(obj);
@@ -1172,6 +1200,11 @@ void arm_cpu_post_init(Object *obj)
 
     qdev_property_add_static(DEVICE(obj), &arm_cpu_cfgend_property,
                              &error_abort);
+
+    if (arm_feature(&cpu->env, ARM_FEATURE_GENERIC_TIMER)) {
+        qdev_property_add_static(DEVICE(cpu), &arm_cpu_gt_cntfrq_property,
+                                 &error_abort);
+    }
 }
 
 static void arm_cpu_finalizefn(Object *obj)
@@ -1251,14 +1284,30 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
         }
     }
 
-    cpu->gt_timer[GTIMER_PHYS] = timer_new(QEMU_CLOCK_VIRTUAL, GTIMER_SCALE,
-                                           arm_gt_ptimer_cb, cpu);
-    cpu->gt_timer[GTIMER_VIRT] = timer_new(QEMU_CLOCK_VIRTUAL, GTIMER_SCALE,
-                                           arm_gt_vtimer_cb, cpu);
-    cpu->gt_timer[GTIMER_HYP] = timer_new(QEMU_CLOCK_VIRTUAL, GTIMER_SCALE,
-                                          arm_gt_htimer_cb, cpu);
-    cpu->gt_timer[GTIMER_SEC] = timer_new(QEMU_CLOCK_VIRTUAL, GTIMER_SCALE,
-                                          arm_gt_stimer_cb, cpu);
+
+    {
+        uint64_t scale;
+
+        if (arm_feature(env, ARM_FEATURE_GENERIC_TIMER)) {
+            if (!cpu->gt_cntfrq_hz) {
+                error_setg(errp, "Invalid CNTFRQ: %"PRId64"Hz",
+                           cpu->gt_cntfrq_hz);
+                return;
+            }
+            scale = gt_cntfrq_period_ns(cpu);
+        } else {
+            scale = GTIMER_SCALE;
+        }
+
+        cpu->gt_timer[GTIMER_PHYS] = timer_new(QEMU_CLOCK_VIRTUAL, scale,
+                                               arm_gt_ptimer_cb, cpu);
+        cpu->gt_timer[GTIMER_VIRT] = timer_new(QEMU_CLOCK_VIRTUAL, scale,
+                                               arm_gt_vtimer_cb, cpu);
+        cpu->gt_timer[GTIMER_HYP] = timer_new(QEMU_CLOCK_VIRTUAL, scale,
+                                              arm_gt_htimer_cb, cpu);
+        cpu->gt_timer[GTIMER_SEC] = timer_new(QEMU_CLOCK_VIRTUAL, scale,
+                                              arm_gt_stimer_cb, cpu);
+    }
 #endif
 
     cpu_exec_realizefn(cs, &local_err);
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 5f70e9e..40f2c45 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -932,8 +932,13 @@ struct ARMCPU {
      */
     DECLARE_BITMAP(sve_vq_map, ARM_MAX_VQ);
     DECLARE_BITMAP(sve_vq_init, ARM_MAX_VQ);
+
+    /* Generic timer counter frequency, in Hz */
+    uint64_t gt_cntfrq_hz;
 };
 
+unsigned int gt_cntfrq_period_ns(ARMCPU *cpu);
+
 void arm_cpu_post_init(Object *obj);
 
 uint64_t arm_cpu_mp_affinity(int idx, uint8_t clustersz);
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 5074b5f..b6bec42 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -2449,7 +2449,9 @@ static CPAccessResult gt_stimer_access(CPUARMState *env,
 
 static uint64_t gt_get_countervalue(CPUARMState *env)
 {
-    return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / GTIMER_SCALE;
+    ARMCPU *cpu = env_archcpu(env);
+
+    return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / gt_cntfrq_period_ns(cpu);
 }
 
 static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
@@ -2485,10 +2487,11 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
          * set the timer for as far in the future as possible. When the
          * timer expires we will reset the timer for any remaining period.
          */
-        if (nexttick > INT64_MAX / GTIMER_SCALE) {
-            nexttick = INT64_MAX / GTIMER_SCALE;
+        if (nexttick > INT64_MAX / gt_cntfrq_period_ns(cpu)) {
+            timer_mod_ns(cpu->gt_timer[timeridx], INT64_MAX);
+        } else {
+            timer_mod(cpu->gt_timer[timeridx], nexttick);
         }
-        timer_mod(cpu->gt_timer[timeridx], nexttick);
         trace_arm_gt_recalc(timeridx, irqstate, nexttick);
     } else {
         /* Timer disabled: ISTATUS and timer output always clear */
@@ -2720,6 +2723,13 @@ void arm_gt_stimer_cb(void *opaque)
     gt_recalc_timer(cpu, GTIMER_SEC);
 }
 
+static void arm_gt_cntfrq_reset(CPUARMState *env, const ARMCPRegInfo *opaque)
+{
+    ARMCPU *cpu = env_archcpu(env);
+
+    cpu->env.cp15.c14_cntfrq = cpu->gt_cntfrq_hz;
+}
+
 static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
     /* Note that CNTFRQ is purely reads-as-written for the benefit
      * of software; writing it doesn't actually change the timer frequency.
@@ -2734,7 +2744,7 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
       .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 0,
       .access = PL1_RW | PL0_R, .accessfn = gt_cntfrq_access,
       .fieldoffset = offsetof(CPUARMState, cp15.c14_cntfrq),
-      .resetvalue = (1000 * 1000 * 1000) / GTIMER_SCALE,
+      .resetfn = arm_gt_cntfrq_reset,
     },
     /* overall control: mostly access permissions */
     { .name = "CNTKCTL", .state = ARM_CP_STATE_BOTH,
@@ -2913,11 +2923,13 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
 
 static uint64_t gt_virt_cnt_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
+    ARMCPU *cpu = env_archcpu(env);
+
     /* Currently we have no support for QEMUTimer in linux-user so we
      * can't call gt_get_countervalue(env), instead we directly
      * call the lower level functions.
      */
-    return cpu_get_clock() / GTIMER_SCALE;
+    return cpu_get_clock() / gt_cntfrq_period_ns(cpu);
 }
 
 static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
@@ -11500,6 +11512,20 @@ void HELPER(rebuild_hflags_a64)(CPUARMState *env, int el)
     env->hflags = rebuild_hflags_a64(env, el, fp_el, mmu_idx);
 }
 
+static inline void assert_hflags_rebuild_correctly(CPUARMState *env)
+{
+#ifdef CONFIG_DEBUG_TCG
+    uint32_t env_flags_current = env->hflags;
+    uint32_t env_flags_rebuilt = rebuild_hflags_internal(env);
+
+    if (unlikely(env_flags_current != env_flags_rebuilt)) {
+        fprintf(stderr, "TCG hflags mismatch (current:0x%08x rebuilt:0x%08x)\n",
+                env_flags_current, env_flags_rebuilt);
+        abort();
+    }
+#endif
+}
+
 void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
                           target_ulong *cs_base, uint32_t *pflags)
 {
@@ -11507,9 +11533,7 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
     uint32_t pstate_for_ss;
 
     *cs_base = 0;
-#ifdef CONFIG_DEBUG_TCG
-    assert(flags == rebuild_hflags_internal(env));
-#endif
+    assert_hflags_rebuild_correctly(env);
 
     if (FIELD_EX32(flags, TBFLAG_ANY, AARCH64_STATE)) {
         *pc = env->pc;