Re: [PATCH v3 03/10] i386: add properoty, x-smm-compat-5, to keep compatibility of SMM

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 10 Feb 2021 22:46:39 -0800
Isaku Yamahata <isaku.yamahata@intel.com> wrote:

> The following patch will introduce incompatible behavior of SMM.
> Introduce a property to keep the old behavior for compatibility.
> To enable smm compat, use "-machine x-smm-compat-5=on"

just curious, why it has "-5" suffix
also I'd drop x- prefix.
 
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> ---
>  hw/i386/pc_piix.c     | 10 ++++++----
>  hw/i386/pc_q35.c      |  1 +
>  hw/i386/x86.c         | 18 ++++++++++++++++++
>  include/hw/i386/x86.h |  2 ++
>  4 files changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 6188c3e97e..87269e170e 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -441,6 +441,7 @@ DEFINE_I440FX_MACHINE(v6_0, "pc-i440fx-6.0", NULL,
>  static void pc_i440fx_5_2_machine_options(MachineClass *m)
>  {
>      pc_i440fx_6_0_machine_options(m);
> +    m->default_machine_opts = "firmware=bios-256k.bin,x-smm-compat-5=on";

did I point to a wrong example :/

smm machinery is part of ich9/piix4 devices, so it would be simpler
by adding 'smm-compat' property to them

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 970046f438..bcb0333ddf 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -36,7 +36,9 @@
 #include "hw/virtio/virtio.h"
 #include "hw/virtio/virtio-pci.h"
 
-GlobalProperty hw_compat_5_2[] = {};
+GlobalProperty hw_compat_5_2[] = {

it turns on compat mode on 5.2 and older machines types

+    { "ICH9-LPC", "smm-compat", "on"},
+};
 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..13003b2ac2 100644
--- a/hw/isa/lpc_ich9.c
+++ b/hw/isa/lpc_ich9.c
@@ -774,6 +774,7 @@ static const VMStateDescription vmstate_ich9_lpc = {
 };
 
 static Property ich9_lpc_properties[] = {

default would be used on new and later machine types

+    DEFINE_PROP_BOOL("smm-compat", ICH9LPCState, pm.smm_compat , false),
     DEFINE_PROP_BOOL("noreboot", ICH9LPCState, pin_strap.spkr_hi, true),
     DEFINE_PROP_BIT64("x-smi-broadcast", ICH9LPCState, smi_host_features,
                       ICH9_LPC_SMI_F_BROADCAST_BIT, true),

then do the same for piix4 pm device


>      m->alias = NULL;
>      m->is_default = false;
>      compat_props_add(m->compat_props, hw_compat_5_2, hw_compat_5_2_len);
> @@ -664,7 +665,8 @@ static void pc_i440fx_2_2_machine_options(MachineClass *m)
>  
>      pc_i440fx_2_3_machine_options(m);
>      m->hw_version = "2.2.0";
> -    m->default_machine_opts = "firmware=bios-256k.bin,suppress-vmdesc=on";
> +    m->default_machine_opts = "firmware=bios-256k.bin,suppress-vmdesc=on"
> +        ",x-smm-compat-5=on";
>      compat_props_add(m->compat_props, hw_compat_2_2, hw_compat_2_2_len);
>      compat_props_add(m->compat_props, pc_compat_2_2, pc_compat_2_2_len);
>      pcmc->rsdp_in_ram = false;
> @@ -727,7 +729,7 @@ static void pc_i440fx_1_7_machine_options(MachineClass *m)
>  
>      pc_i440fx_2_0_machine_options(m);
>      m->hw_version = "1.7.0";
> -    m->default_machine_opts = NULL;
> +    m->default_machine_opts = "x-smm-compat-5=on";
>      m->option_rom_has_mr = true;
>      compat_props_add(m->compat_props, pc_compat_1_7, pc_compat_1_7_len);
>      pcmc->smbios_defaults = false;
> @@ -999,7 +1001,7 @@ static void xenfv_4_2_machine_options(MachineClass *m)
>      pc_i440fx_4_2_machine_options(m);
>      m->desc = "Xen Fully-virtualized PC";
>      m->max_cpus = HVM_MAX_VCPUS;
> -    m->default_machine_opts = "accel=xen,suppress-vmdesc=on";
> +    m->default_machine_opts = "accel=xen,suppress-vmdesc=on,x-smm-compat-5=on";
>  }
>  
>  DEFINE_PC_MACHINE(xenfv_4_2, "xenfv-4.2", pc_xen_hvm_init,
> @@ -1011,7 +1013,7 @@ static void xenfv_3_1_machine_options(MachineClass *m)
>      m->desc = "Xen Fully-virtualized PC";
>      m->alias = "xenfv";
>      m->max_cpus = HVM_MAX_VCPUS;
> -    m->default_machine_opts = "accel=xen,suppress-vmdesc=on";
> +    m->default_machine_opts = "accel=xen,suppress-vmdesc=on,x-smm-compat-5=on";
>  }
>  
>  DEFINE_PC_MACHINE(xenfv, "xenfv-3.1", pc_xen_hvm_init,
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 0a212443aa..14974b7255 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -358,6 +358,7 @@ DEFINE_Q35_MACHINE(v6_0, "pc-q35-6.0", NULL,
>  static void pc_q35_5_2_machine_options(MachineClass *m)
>  {
>      pc_q35_6_0_machine_options(m);
> +    m->default_machine_opts = "firmware=bios-256k.bin,x-smm-compat-5=on";
>      m->alias = NULL;
>      compat_props_add(m->compat_props, hw_compat_5_2, hw_compat_5_2_len);
>      compat_props_add(m->compat_props, pc_compat_5_2, pc_compat_5_2_len);
> diff --git a/hw/i386/x86.c b/hw/i386/x86.c
> index 6329f90ef9..00eb2253d3 100644
> --- a/hw/i386/x86.c
> +++ b/hw/i386/x86.c
> @@ -1174,6 +1174,18 @@ static void x86_machine_set_smm(Object *obj, Visitor *v, const char *name,
>      visit_type_OnOffAuto(v, name, &x86ms->smm, errp);
>  }
>  
> +static bool x86_machine_get_smm_compat_5(Object *obj, Error **errp)
> +{
> +    X86MachineState *x86ms = X86_MACHINE(obj);
> +    return  x86ms->smm_compat_5;
> +}
> +
> +static void x86_machine_set_smm_compat_5(Object *obj, bool value, Error **errp)
> +{
> +    X86MachineState *x86ms = X86_MACHINE(obj);
> +    x86ms->smm_compat_5 = value;
> +}
> +
>  bool x86_machine_is_acpi_enabled(const X86MachineState *x86ms)
>  {
>      if (x86ms->acpi == ON_OFF_AUTO_OFF) {
> @@ -1204,6 +1216,7 @@ static void x86_machine_initfn(Object *obj)
>      X86MachineState *x86ms = X86_MACHINE(obj);
>  
>      x86ms->smm = ON_OFF_AUTO_AUTO;
> +    x86ms->smm_compat_5 = false;
>      x86ms->acpi = ON_OFF_AUTO_AUTO;
>      x86ms->smp_dies = 1;
>      x86ms->pci_irq_mask = ACPI_BUILD_PCI_IRQS;
> @@ -1228,6 +1241,11 @@ static void x86_machine_class_init(ObjectClass *oc, void *data)
>      object_class_property_set_description(oc, X86_MACHINE_SMM,
>          "Enable SMM");
>  
> +    object_class_property_add_bool(oc, X86_MACHINE_SMM_COMPAT_5,
> +        x86_machine_get_smm_compat_5, x86_machine_set_smm_compat_5);
> +    object_class_property_set_description(oc, X86_MACHINE_SMM_COMPAT_5,
> +        "Enable SMM compatible behavior");
> +
>      object_class_property_add(oc, X86_MACHINE_ACPI, "OnOffAuto",
>          x86_machine_get_acpi, x86_machine_set_acpi,
>          NULL, NULL);
> diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
> index 56080bd1fb..3dbe19a335 100644
> --- a/include/hw/i386/x86.h
> +++ b/include/hw/i386/x86.h
> @@ -65,6 +65,7 @@ struct X86MachineState {
>      unsigned smp_dies;
>  
>      OnOffAuto smm;
> +    bool smm_compat_5;
>      OnOffAuto acpi;
>  
>      /*
> @@ -75,6 +76,7 @@ struct X86MachineState {
>  };
>  
>  #define X86_MACHINE_SMM              "smm"
> +#define X86_MACHINE_SMM_COMPAT_5     "x-smm-compat-5"
>  #define X86_MACHINE_ACPI             "acpi"
>  
>  #define TYPE_X86_MACHINE   MACHINE_TYPE_NAME("x86")