Re: [PATCH v2 3/3] target-i386: post memory failure event to uplayer

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 9/22/20 11:56 AM, zhenwei pi wrote:
> Post memory failure event to uplayer to handle hardware memory
> corrupted event. Rather than simple QEMU log, QEMU could report more
> effective message to uplayer. For example, guest crashes by MCE,
> selecting another host server is a better choice.
> 
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
>  target/i386/helper.c | 15 +++++++++++++++
>  target/i386/kvm.c    |  7 ++++++-
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/target/i386/helper.c b/target/i386/helper.c
> index 0c7fd32491..47823c29e4 100644
> --- a/target/i386/helper.c
> +++ b/target/i386/helper.c
> @@ -18,6 +18,7 @@
>   */
>  
>  #include "qemu/osdep.h"
> +#include "qapi/qapi-events-run-state.h"
>  #include "cpu.h"
>  #include "exec/exec-all.h"
>  #include "qemu/qemu-print.h"
> @@ -858,6 +859,7 @@ static void do_inject_x86_mce(CPUState *cs, run_on_cpu_data data)
>      CPUX86State *cenv = &cpu->env;
>      uint64_t *banks = cenv->mce_banks + 4 * params->bank;
>      char msg[64];
> +    MemoryFailureFlags mf_flags = {0};
>      bool need_reset = false;
>  
>      cpu_synchronize_state(cs);
> @@ -869,6 +871,12 @@ static void do_inject_x86_mce(CPUState *cs, run_on_cpu_data data)
>      if (!(params->flags & MCE_INJECT_UNCOND_AO)
>          && !(params->status & MCI_STATUS_AR)
>          && (cenv->mcg_status & MCG_STATUS_MCIP)) {
> +        mf_flags.has_action_required = true;
> +        mf_flags.action_required = false;
> +        mf_flags.has_recursive = true;
> +        mf_flags.recursive = true;
> +        qapi_event_send_memory_failure(MEMORY_FAILURE_ACTION_GUEST_MCE_INJECT,
> +                                       true, &mf_flags);

Can you extract a function such:

static void emit_guest_mce_failure(bool action_required, bool recursive)
{
  ...
}

To use as:

           emit_guest_mce_failure(true, true);

>          return;
>      }
>  
> @@ -909,6 +917,8 @@ static void do_inject_x86_mce(CPUState *cs, run_on_cpu_data data)
>          }
>  
>          if (need_reset) {
> +            qapi_event_send_memory_failure(
> +                 MEMORY_FAILURE_ACTION_GUEST_MCE_FATAL, false, NULL);
>              monitor_printf(params->mon, "%s", msg);
>              qemu_log_mask(CPU_LOG_RESET, "%s\n", msg);
>              qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
> @@ -934,6 +944,11 @@ static void do_inject_x86_mce(CPUState *cs, run_on_cpu_data data)
>      } else {
>          banks[1] |= MCI_STATUS_OVER;
>      }
> +
> +    mf_flags.has_action_required = true;
> +    mf_flags.action_required = !!(params->status & MCI_STATUS_AR);
> +    qapi_event_send_memory_failure(MEMORY_FAILURE_ACTION_GUEST_MCE_INJECT,
> +                                   true, &mf_flags);

And here:

       emit_guest_mce_failure(params->status & MCI_STATUS_AR, false);

>  }
>  
>  void cpu_x86_inject_mce(Monitor *mon, X86CPU *cpu, int bank,
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 9efb07e7c8..989889c291 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -14,6 +14,7 @@
>  
>  #include "qemu/osdep.h"
>  #include "qapi/error.h"
> +#include "qapi/qapi-events-run-state.h"
>  #include <sys/ioctl.h>
>  #include <sys/utsname.h>
>  
> @@ -577,6 +578,8 @@ static void kvm_mce_inject(X86CPU *cpu, hwaddr paddr, int code)
>  
>  static void hardware_memory_error(void *host_addr)
>  {
> +    qapi_event_send_memory_failure(MEMORY_FAILURE_ACTION_HYPERVISOR_FATAL,
> +                                   false, NULL);
>      error_report("QEMU got Hardware memory error at addr %p", host_addr);
>      exit(1);
>  }
> @@ -631,7 +634,9 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
>          hardware_memory_error(addr);
>      }
>  
> -    /* Hope we are lucky for AO MCE */
> +    /* Hope we are lucky for AO MCE, just notify a event */
> +    qapi_event_send_memory_failure(MEMORY_FAILURE_ACTION_HYPERVISOR_IGNORE,
> +                                   false, NULL);
>  }
>  
>  static void kvm_reset_exception(CPUX86State *env)
>