Re: [PATCH for-8.2 2/2] arm/kvm: convert to kvm_get_one_reg

[Gavin Shan <gshan@xxxxxxxxxx>]

Hi Connie,

On 7/18/23 21:14, Cornelia Huck wrote:
> We can neaten the code by switching the callers that work on a
> CPUstate to the kvm_get_one_reg function.
>
> Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> ---
>   target/arm/kvm.c   | 15 +++---------
>   target/arm/kvm64.c | 57 ++++++++++++----------------------------------
>   2 files changed, 18 insertions(+), 54 deletions(-)

The replacements look good to me. However, I guess it's worty to apply
the same replacements for target/arm/kvm64.c since we're here?

[gshan@gshan arm]$ pwd
/home/gshan/sandbox/q/target/arm
[gshan@gshan arm]$ git grep KVM_GET_ONE_REG
kvm64.c:    err = ioctl(fd, KVM_GET_ONE_REG, &idreg);
kvm64.c:    return ioctl(fd, KVM_GET_ONE_REG, &idreg);
kvm64.c:        ret = ioctl(fdarray[2], KVM_GET_ONE_REG, &reg);

Thanks,
Gavin

> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> index cdbffc3c6e0d..4123f6dc9d72 100644
> --- a/target/arm/kvm.c
> +++ b/target/arm/kvm.c
> @@ -525,24 +525,19 @@ bool write_kvmstate_to_list(ARMCPU *cpu)
>       bool ok = true;
>   
>       for (i = 0; i < cpu->cpreg_array_len; i++) {
> -        struct kvm_one_reg r;
>           uint64_t regidx = cpu->cpreg_indexes[i];
>           uint32_t v32;
>           int ret;
>   
> -        r.id = regidx;
> -
>           switch (regidx & KVM_REG_SIZE_MASK) {
>           case KVM_REG_SIZE_U32:
> -            r.addr = (uintptr_t)&v32;
> -            ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r);
> +            ret = kvm_get_one_reg(cs, regidx, &v32);
>               if (!ret) {
>                   cpu->cpreg_values[i] = v32;
>               }
>               break;
>           case KVM_REG_SIZE_U64:
> -            r.addr = (uintptr_t)(cpu->cpreg_values + i);
> -            ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r);
> +            ret = kvm_get_one_reg(cs, regidx, cpu->cpreg_values + i);
>               break;
>           default:
>               g_assert_not_reached();
> @@ -678,17 +673,13 @@ int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu)
>   void kvm_arm_get_virtual_time(CPUState *cs)
>   {
>       ARMCPU *cpu = ARM_CPU(cs);
> -    struct kvm_one_reg reg = {
> -        .id = KVM_REG_ARM_TIMER_CNT,
> -        .addr = (uintptr_t)&cpu->kvm_vtime,
> -    };
>       int ret;
>   
>       if (cpu->kvm_vtime_dirty) {
>           return;
>       }
>   
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, KVM_REG_ARM_TIMER_CNT, &cpu->kvm_vtime);
>       if (ret) {
>           error_report("Failed to get KVM_REG_ARM_TIMER_CNT");
>           abort();
> diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
> index b4d02dff5381..66b52d6f8d23 100644
> --- a/target/arm/kvm64.c
> +++ b/target/arm/kvm64.c
> @@ -908,14 +908,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)
>   static int kvm_arch_get_fpsimd(CPUState *cs)
>   {
>       CPUARMState *env = &ARM_CPU(cs)->env;
> -    struct kvm_one_reg reg;
>       int i, ret;
>   
>       for (i = 0; i < 32; i++) {
>           uint64_t *q = aa64_vfp_qreg(env, i);
> -        reg.id = AARCH64_SIMD_CORE_REG(fp_regs.vregs[i]);
> -        reg.addr = (uintptr_t)q;
> -        ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +        ret = kvm_get_one_reg(cs, AARCH64_SIMD_CORE_REG(fp_regs.vregs[i]), q);
>           if (ret) {
>               return ret;
>           } else {
> @@ -939,15 +936,12 @@ static int kvm_arch_get_sve(CPUState *cs)
>   {
>       ARMCPU *cpu = ARM_CPU(cs);
>       CPUARMState *env = &cpu->env;
> -    struct kvm_one_reg reg;
>       uint64_t *r;
>       int n, ret;
>   
>       for (n = 0; n < KVM_ARM64_SVE_NUM_ZREGS; ++n) {
>           r = &env->vfp.zregs[n].d[0];
> -        reg.addr = (uintptr_t)r;
> -        reg.id = KVM_REG_ARM64_SVE_ZREG(n, 0);
> -        ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +        ret = kvm_get_one_reg(cs, KVM_REG_ARM64_SVE_ZREG(n, 0), r);
>           if (ret) {
>               return ret;
>           }
> @@ -956,9 +950,7 @@ static int kvm_arch_get_sve(CPUState *cs)
>   
>       for (n = 0; n < KVM_ARM64_SVE_NUM_PREGS; ++n) {
>           r = &env->vfp.pregs[n].p[0];
> -        reg.addr = (uintptr_t)r;
> -        reg.id = KVM_REG_ARM64_SVE_PREG(n, 0);
> -        ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +        ret = kvm_get_one_reg(cs, KVM_REG_ARM64_SVE_PREG(n, 0), r);
>           if (ret) {
>               return ret;
>           }
> @@ -966,9 +958,7 @@ static int kvm_arch_get_sve(CPUState *cs)
>       }
>   
>       r = &env->vfp.pregs[FFR_PRED_NUM].p[0];
> -    reg.addr = (uintptr_t)r;
> -    reg.id = KVM_REG_ARM64_SVE_FFR(0);
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, KVM_REG_ARM64_SVE_FFR(0), r);
>       if (ret) {
>           return ret;
>       }
> @@ -979,7 +969,6 @@ static int kvm_arch_get_sve(CPUState *cs)
>   
>   int kvm_arch_get_registers(CPUState *cs)
>   {
> -    struct kvm_one_reg reg;
>       uint64_t val;
>       unsigned int el;
>       uint32_t fpr;
> @@ -989,31 +978,24 @@ int kvm_arch_get_registers(CPUState *cs)
>       CPUARMState *env = &cpu->env;
>   
>       for (i = 0; i < 31; i++) {
> -        reg.id = AARCH64_CORE_REG(regs.regs[i]);
> -        reg.addr = (uintptr_t) &env->xregs[i];
> -        ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +        ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(regs.regs[i]),
> +                              &env->xregs[i]);
>           if (ret) {
>               return ret;
>           }
>       }
>   
> -    reg.id = AARCH64_CORE_REG(regs.sp);
> -    reg.addr = (uintptr_t) &env->sp_el[0];
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(regs.sp), &env->sp_el[0]);
>       if (ret) {
>           return ret;
>       }
>   
> -    reg.id = AARCH64_CORE_REG(sp_el1);
> -    reg.addr = (uintptr_t) &env->sp_el[1];
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(sp_el1), &env->sp_el[1]);
>       if (ret) {
>           return ret;
>       }
>   
> -    reg.id = AARCH64_CORE_REG(regs.pstate);
> -    reg.addr = (uintptr_t) &val;
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(regs.pstate), &val);
>       if (ret) {
>           return ret;
>       }
> @@ -1030,9 +1012,7 @@ int kvm_arch_get_registers(CPUState *cs)
>        */
>       aarch64_restore_sp(env, 1);
>   
> -    reg.id = AARCH64_CORE_REG(regs.pc);
> -    reg.addr = (uintptr_t) &env->pc;
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(regs.pc), &env->pc);
>       if (ret) {
>           return ret;
>       }
> @@ -1046,9 +1026,7 @@ int kvm_arch_get_registers(CPUState *cs)
>           aarch64_sync_64_to_32(env);
>       }
>   
> -    reg.id = AARCH64_CORE_REG(elr_el1);
> -    reg.addr = (uintptr_t) &env->elr_el[1];
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(elr_el1), &env->elr_el[1]);
>       if (ret) {
>           return ret;
>       }
> @@ -1058,9 +1036,8 @@ int kvm_arch_get_registers(CPUState *cs)
>        * KVM SPSRs 0-4 map to QEMU banks 1-5
>        */
>       for (i = 0; i < KVM_NR_SPSR; i++) {
> -        reg.id = AARCH64_CORE_REG(spsr[i]);
> -        reg.addr = (uintptr_t) &env->banked_spsr[i + 1];
> -        ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +        ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(spsr[i]),
> +                              &env->banked_spsr[i + 1]);
>           if (ret) {
>               return ret;
>           }
> @@ -1081,17 +1058,13 @@ int kvm_arch_get_registers(CPUState *cs)
>           return ret;
>       }
>   
> -    reg.addr = (uintptr_t)(&fpr);
> -    reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpsr);
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_SIMD_CTRL_REG(fp_regs.fpsr), &fpr);
>       if (ret) {
>           return ret;
>       }
>       vfp_set_fpsr(env, fpr);
>   
> -    reg.addr = (uintptr_t)(&fpr);
> -    reg.id = AARCH64_SIMD_CTRL_REG(fp_regs.fpcr);
> -    ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
> +    ret = kvm_get_one_reg(cs, AARCH64_SIMD_CTRL_REG(fp_regs.fpcr), &fpr);
>       if (ret) {
>           return ret;
>       }