Re: [RFC v3 8/8] cpus: extract out hvf-specific code to target/i386/hvf/

[Roman Bolshakov]

On Mon, Aug 03, 2020 at 11:05:33AM +0200, Claudio Fontana wrote:
> register a "CpusAccel" interface for HVF as well.
> 
> Signed-off-by: Claudio Fontana <cfontana@suse.de>
> ---
>  softmmu/cpus.c                |  63 --------------------
>  target/i386/hvf/Makefile.objs |   2 +-
>  target/i386/hvf/hvf-cpus.c    | 131 
> ++++++++++++++++++++++++++++++++++++++++++
>  target/i386/hvf/hvf-cpus.h    |  17 ++++++
>  target/i386/hvf/hvf.c         |   3 +
>  5 files changed, 152 insertions(+), 64 deletions(-)
>  create mode 100644 target/i386/hvf/hvf-cpus.c
>  create mode 100644 target/i386/hvf/hvf-cpus.h
> 
> diff --git a/softmmu/cpus.c b/softmmu/cpus.c
> index 586b4acaab..d327b2685c 100644
> --- a/softmmu/cpus.c
> +++ b/softmmu/cpus.c
> @@ -33,7 +33,6 @@
>  #include "exec/gdbstub.h"
>  #include "sysemu/hw_accel.h"
>  #include "sysemu/kvm.h"
> -#include "sysemu/hvf.h"

I wonder if the declarations should be moved from sysemu/hvf.h to
someplace inside target/i386/hvf/:

int hvf_init_vcpu(CPUState *);
int hvf_vcpu_exec(CPUState *);
void hvf_cpu_synchronize_state(CPUState *);
void hvf_cpu_synchronize_post_reset(CPUState *);
void hvf_cpu_synchronize_post_init(CPUState *);
void hvf_cpu_synchronize_pre_loadvm(CPUState *);
void hvf_vcpu_destroy(CPUState *);

They're not used outside of target/i386/hvf/

I also wonder if we need stubs at all?

>  #include "exec/exec-all.h"
>  #include "qemu/thread.h"
>  #include "qemu/plugin.h"
> @@ -391,48 +390,6 @@ void qemu_wait_io_event(CPUState *cpu)
>      qemu_wait_io_event_common(cpu);
>  }
>  
> -/* The HVF-specific vCPU thread function. This one should only run when the 
> host
> - * CPU supports the VMX "unrestricted guest" feature. */
> -static void *qemu_hvf_cpu_thread_fn(void *arg)
> -{
> -    CPUState *cpu = arg;
> -
> -    int r;
> -
> -    assert(hvf_enabled());
> -
> -    rcu_register_thread();
> -
> -    qemu_mutex_lock_iothread();
> -    qemu_thread_get_self(cpu->thread);
> -
> -    cpu->thread_id = qemu_get_thread_id();
> -    cpu->can_do_io = 1;
> -    current_cpu = cpu;
> -
> -    hvf_init_vcpu(cpu);
> -
> -    /* signal CPU creation */
> -    cpu_thread_signal_created(cpu);
> -    qemu_guest_random_seed_thread_part2(cpu->random_seed);
> -
> -    do {
> -        if (cpu_can_run(cpu)) {
> -            r = hvf_vcpu_exec(cpu);
> -            if (r == EXCP_DEBUG) {
> -                cpu_handle_guest_debug(cpu);
> -            }
> -        }
> -        qemu_wait_io_event(cpu);
> -    } while (!cpu->unplug || cpu_can_run(cpu));
> -
> -    hvf_vcpu_destroy(cpu);
> -    cpu_thread_signal_destroyed(cpu);
> -    qemu_mutex_unlock_iothread();
> -    rcu_unregister_thread();
> -    return NULL;
> -}
> -
>  void cpus_kick_thread(CPUState *cpu)
>  {
>  #ifndef _WIN32
> @@ -603,24 +560,6 @@ void cpu_remove_sync(CPUState *cpu)
>      qemu_mutex_lock_iothread();
>  }
>  
> -static void qemu_hvf_start_vcpu(CPUState *cpu)
> -{
> -    char thread_name[VCPU_THREAD_NAME_SIZE];
> -
> -    /* HVF currently does not support TCG, and only runs in
> -     * unrestricted-guest mode. */
> -    assert(hvf_enabled());
> -
> -    cpu->thread = g_malloc0(sizeof(QemuThread));
> -    cpu->halt_cond = g_malloc0(sizeof(QemuCond));
> -    qemu_cond_init(cpu->halt_cond);
> -
> -    snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/HVF",
> -             cpu->cpu_index);
> -    qemu_thread_create(cpu->thread, thread_name, qemu_hvf_cpu_thread_fn,
> -                       cpu, QEMU_THREAD_JOINABLE);
> -}
> -
>  void cpus_register_accel(CpusAccel *ca)
>  {
>      assert(ca != NULL);
> @@ -648,8 +587,6 @@ void qemu_init_vcpu(CPUState *cpu)
>      if (cpus_accel) {
>          /* accelerator already implements the CpusAccel interface */
>          cpus_accel->create_vcpu_thread(cpu);
> -    } else if (hvf_enabled()) {
> -        qemu_hvf_start_vcpu(cpu);
>      } else {
>          assert(0);
>      }
> diff --git a/target/i386/hvf/Makefile.objs b/target/i386/hvf/Makefile.objs
> index 927b86bc67..af9f7dcfc1 100644
> --- a/target/i386/hvf/Makefile.objs
> +++ b/target/i386/hvf/Makefile.objs
> @@ -1,2 +1,2 @@
> -obj-y += hvf.o
> +obj-y += hvf.o hvf-cpus.o
>  obj-y += x86.o x86_cpuid.o x86_decode.o x86_descr.o x86_emu.o x86_flags.o 
> x86_mmu.o x86hvf.o x86_task.o
> diff --git a/target/i386/hvf/hvf-cpus.c b/target/i386/hvf/hvf-cpus.c
> new file mode 100644
> index 0000000000..9540157f1e
> --- /dev/null
> +++ b/target/i386/hvf/hvf-cpus.c

I'd prefer singular form in variables and file names. More on that in
the comment to patch 2.

Besides that it works fine,

Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Tested-by: Roman Bolshakov <r.bolshakov@yadro.com>

Regards,
Roman