Commit 7f359375fc for qemu.org

commit 7f359375fc8dd4c503b6a0b078fc253fdae4f3e2
Author: Philippe Mathieu-Daudé <philmd@linaro.org>
Date:   Wed Jun 18 08:06:13 2025 +0200

    target/arm/hvf: Really set Generic Timer counter frequency

    Setting ARMCPU::gt_cntfrq_hz in hvf_arch_init_vcpu() is
    not correct because the timers have already be initialized
    with the default frequency.

    Set it earlier in the AccelOpsClass::cpu_target_realize()
    handler instead, and assert the value is correct when
    reaching hvf_arch_init_vcpu().

    Fixes: a1477da3dde ("hvf: Add Apple Silicon support")
    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
    Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
    Message-ID: <20251103101034.59039-19-philmd@linaro.org>

diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index bf8bed1495..e4c0d936f1 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -897,6 +897,13 @@ cleanup:
     return ret;
 }

+static uint64_t get_cntfrq_el0(void)
+{
+    uint64_t freq_hz = 0;
+    asm volatile("mrs %0, cntfrq_el0" : "=r"(freq_hz));
+    return freq_hz;
+}
+
 int hvf_arch_init_vcpu(CPUState *cpu)
 {
     ARMCPU *arm_cpu = ARM_CPU(cpu);
@@ -908,7 +915,9 @@ int hvf_arch_init_vcpu(CPUState *cpu)
     int i;

     env->aarch64 = true;
-    asm volatile("mrs %0, cntfrq_el0" : "=r"(arm_cpu->gt_cntfrq_hz));
+
+    /* system count frequency sanity check */
+    assert(arm_cpu->gt_cntfrq_hz == get_cntfrq_el0());

     /* Allocate enough space for our sysreg sync */
     arm_cpu->cpreg_indexes = g_renew(uint64_t, arm_cpu->cpreg_indexes,
@@ -974,6 +983,15 @@ int hvf_arch_init_vcpu(CPUState *cpu)

 bool hvf_arch_cpu_realize(CPUState *cs, Error **errp)
 {
+    ARMCPU *cpu = ARM_CPU(cs);
+
+    /*
+     * We must set the counter frequency HVF will be using
+     * early, before arm_cpu_realizefn initializes the timers
+     * with it.
+     */
+    cpu->gt_cntfrq_hz = get_cntfrq_el0();
+
     return true;
 }