Re: [PATCH v4 09/17] whpx: add arm64 support

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 4/8/25 16:23, Mohamed Mediouni wrote:
> Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
> ---
>   accel/whpx/whpx-common.c    |   1 +
>   meson.build                 |  21 +-
>   target/arm/meson.build      |   1 +
>   target/arm/whpx/meson.build |   3 +
>   target/arm/whpx/whpx-all.c  | 845 ++++++++++++++++++++++++++++++++++++
>   5 files changed, 864 insertions(+), 7 deletions(-)
>   create mode 100644 target/arm/whpx/meson.build
>   create mode 100644 target/arm/whpx/whpx-all.c


> +int whpx_init_vcpu(CPUState *cpu)
> +{
> +    HRESULT hr;
> +    struct whpx_state *whpx = &whpx_global;
> +    AccelCPUState *vcpu = NULL;
> +    ARMCPU *arm_cpu = ARM_CPU(cpu);
> +    CPUARMState *env = &arm_cpu->env;
> +    int ret;
> +
> +    uint32_t sregs_match_len = ARRAY_SIZE(whpx_sreg_match);
> +    uint32_t sregs_cnt = 0;
> +    WHV_REGISTER_VALUE val;
> +    int i;
> +
> +    vcpu = g_new0(AccelCPUState, 1);
> +
> +    hr = whp_dispatch.WHvCreateVirtualProcessor(
> +        whpx->partition, cpu->cpu_index, 0);
> +    if (FAILED(hr)) {
> +        error_report("WHPX: Failed to create a virtual processor,"
> +                     " hr=%08lx", hr);
> +        ret = -EINVAL;
> +        goto error;
> +    }
> +
> +    /* Assumption that CNTFRQ_EL0 is the same between the VMM and the partition. */
> +    asm volatile("mrs %0, cntfrq_el0" : "=r"(arm_cpu->gt_cntfrq_hz));
> +
> +    cpu->vcpu_dirty = true;
> +    cpu->accel = vcpu;
> +    max_vcpu_index = max(max_vcpu_index, cpu->cpu_index);
> +    qemu_add_vm_change_state_handler(whpx_cpu_update_state, env);
> +
> +    env->aarch64 = true;
> +
> +    /* Allocate enough space for our sysreg sync */
> +    arm_cpu->cpreg_indexes = g_renew(uint64_t, arm_cpu->cpreg_indexes,
> +                                     sregs_match_len);
> +    arm_cpu->cpreg_values = g_renew(uint64_t, arm_cpu->cpreg_values,
> +                                    sregs_match_len);
> +    arm_cpu->cpreg_vmstate_indexes = g_renew(uint64_t,
> +                                             arm_cpu->cpreg_vmstate_indexes,
> +                                             sregs_match_len);
> +    arm_cpu->cpreg_vmstate_values = g_renew(uint64_t,
> +                                            arm_cpu->cpreg_vmstate_values,
> +                                            sregs_match_len);
> +
> +    memset(arm_cpu->cpreg_values, 0, sregs_match_len * sizeof(uint64_t));
> +
> +    /* Populate cp list for all known sysregs */
> +    for (i = 0; i < sregs_match_len; i++) {
> +        const ARMCPRegInfo *ri;
> +        uint32_t key = whpx_sreg_match[i].key;
> +
> +        ri = get_arm_cp_reginfo(arm_cpu->cp_regs, key);
> +        if (ri) {
> +            assert(!(ri->type & ARM_CP_NO_RAW));
> +            whpx_sreg_match[i].cp_idx = sregs_cnt;
> +            arm_cpu->cpreg_indexes[sregs_cnt++] = cpreg_to_kvm_id(key);
> +        } else {
> +            whpx_sreg_match[i].cp_idx = -1;
> +        }
> +    }
> +    arm_cpu->cpreg_array_len = sregs_cnt;
> +    arm_cpu->cpreg_vmstate_array_len = sregs_cnt;
> +
> +    assert(write_cpustate_to_list(arm_cpu, false));
> +
> +    /* Set CP_NO_RAW system registers on init */
> +    val.Reg64 = arm_cpu->midr;
> +    whpx_set_reg(cpu, WHvArm64RegisterMidrEl1,
> +                              val);
> +
> +    clean_whv_register_value(&val);
> +
> +    /* bit 31 of MPIDR_EL1 is RES1, and this is enforced by WHPX */
> +    val.Reg64 = 0x80000000 + arm_cpu->mp_affinity;

Preferably:

        val.Reg64 = deposit64(arm_cpu->mp_affinity, 31, 1, 1 /* RES1 */);

> +    whpx_set_reg(cpu, WHvArm64RegisterMpidrEl1,
> +                              val);

(note, your indentation is often off)

> +
> +    return 0;
> +
> +error:
> +    g_free(vcpu);
> +
> +    return ret;
> +
> +}