Re: [PATCH v4 03/10] ich9, piix4: add properoty, smm-compat, to keep compatibility of SMM

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 15 Feb 2021 17:04:08 -0800
isaku.yamahata@gmail.com wrote:

> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> The following patch will introduce incompatible behavior of SMM.
> Introduce a property to keep the old behavior for compatibility.
> To enable smm compat, use "-global ICH9-LPC.smm-compat=on" or
> "-global PIIX4.smm-compat=on"
> 
> Suggested-by: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>

looks good to me, but doesn't apply to master anymore, so needs to be rebased
> ---
>  hw/acpi/piix4.c        | 2 ++
>  hw/core/machine.c      | 5 ++++-
>  hw/isa/lpc_ich9.c      | 1 +
>  include/hw/acpi/ich9.h | 1 +
>  4 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index 669be5bbf6..30dd9b2309 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -74,6 +74,7 @@ struct PIIX4PMState {
>      qemu_irq irq;
>      qemu_irq smi_irq;
>      int smm_enabled;
> +    bool smm_compat;
>      Notifier machine_ready;
>      Notifier powerdown_notifier;
>  
> @@ -642,6 +643,7 @@ static Property piix4_pm_properties[] = {
>                       use_acpi_root_pci_hotplug, true),
>      DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
>                       acpi_memory_hotplug.is_enabled, true),
> +    DEFINE_PROP_BOOL("smm-compat", PIIX4PMState, smm_compat, false),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index de3b8f1b31..870c9201df 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -33,7 +33,10 @@
>  #include "migration/global_state.h"
>  #include "migration/vmstate.h"
>  
> -GlobalProperty hw_compat_5_2[] = {};
> +GlobalProperty hw_compat_5_2[] = {
> +    { "ICH9-LPC", "smm-compat", "on"},
> +    { "PIIX4_PM", "smm-compat", "on"},
> +};
I'd put this hunk into the 4/10, where behavior changes

and add a note to commit this message that property will be used by the next patch

>  const size_t hw_compat_5_2_len = G_N_ELEMENTS(hw_compat_5_2);
>  
>  GlobalProperty hw_compat_5_1[] = {
> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
> index d3145bf014..3963b73520 100644
> --- a/hw/isa/lpc_ich9.c
> +++ b/hw/isa/lpc_ich9.c
> @@ -775,6 +775,7 @@ static const VMStateDescription vmstate_ich9_lpc = {
>  
>  static Property ich9_lpc_properties[] = {
>      DEFINE_PROP_BOOL("noreboot", ICH9LPCState, pin_strap.spkr_hi, true),
> +    DEFINE_PROP_BOOL("smm-compat", ICH9LPCState, pm.smm_compat, false),
>      DEFINE_PROP_BIT64("x-smi-broadcast", ICH9LPCState, smi_host_features,
>                        ICH9_LPC_SMI_F_BROADCAST_BIT, true),
>      DEFINE_PROP_BIT64("x-smi-cpu-hotplug", ICH9LPCState, smi_host_features,
> diff --git a/include/hw/acpi/ich9.h b/include/hw/acpi/ich9.h
> index 54571c77e0..df519e40b5 100644
> --- a/include/hw/acpi/ich9.h
> +++ b/include/hw/acpi/ich9.h
> @@ -59,6 +59,7 @@ typedef struct ICH9LPCPMRegs {
>      uint8_t disable_s4;
>      uint8_t s4_val;
>      uint8_t smm_enabled;
> +    bool smm_compat;
>      bool enable_tco;
>      TCOIORegs tco_regs;
>  } ICH9LPCPMRegs;