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[RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used

Julia Suvorova posted 7 patches 5 years, 4 months ago
Maintainers: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Aurelien Jarno <aurelien@aurel32.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Michael S. Tsirkin" <mst@redhat.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Richard Henderson <rth@twiddle.net>, Igor Mammedov <imammedo@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>
There is a newer version of this series
[RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Julia Suvorova 5 years, 4 months ago 
Instead of changing the hot-plug type in _OSC register, do not
initialize the slot capability or set the 'Slot Implemented' flag.
This way guest will choose ACPI hot-plug if it is preferred and leave
the option to use SHPC with pcie-pci-bridge.

Signed-off-by: Julia Suvorova <jusual@redhat.com>
---
 hw/i386/acpi-build.h |  2 ++
 hw/i386/acpi-build.c |  2 +-
 hw/pci/pcie.c        | 16 ++++++++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
index 487ec7710f..4c5bfb3d0b 100644
--- a/hw/i386/acpi-build.h
+++ b/hw/i386/acpi-build.h
@@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
 
 void acpi_setup(void);
 
+Object *object_resolve_type_unambiguous(const char *typename);
+
 #endif
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index cf503b16af..b7811a8912 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
     *data = fadt;
 }
 
-static Object *object_resolve_type_unambiguous(const char *typename)
+Object *object_resolve_type_unambiguous(const char *typename)
 {
     bool ambig;
     Object *o = object_resolve_path_type("", typename, &ambig);
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 5b48bae0f6..c1a082e8b9 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -27,6 +27,8 @@
 #include "hw/pci/pci_bus.h"
 #include "hw/pci/pcie_regs.h"
 #include "hw/pci/pcie_port.h"
+#include "hw/i386/ich9.h"
+#include "hw/i386/acpi-build.h"
 #include "qemu/range.h"
 
 //#define DEBUG_PCIE
@@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
     pcie_cap_slot_push_attention_button(hotplug_pdev);
 }
 
+static bool acpi_pcihp_enabled(void)
+{
+    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
+
+    return lpc &&
+           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
+                                    NULL);
+
+}
+
 /* pci express slot for pci express root/downstream port
    PCI express capability slot registers */
 void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
 {
     uint32_t pos = dev->exp.exp_cap;
 
+    if (acpi_pcihp_enabled()) {
+        return;
+    }
+
     pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
                                PCI_EXP_FLAGS_SLOT);
 
-- 
2.25.4
Re: [RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Igor Mammedov 5 years, 4 months ago 
On Thu, 24 Sep 2020 09:00:09 +0200
Julia Suvorova <jusual@redhat.com> wrote:

> Instead of changing the hot-plug type in _OSC register, do not
> initialize the slot capability or set the 'Slot Implemented' flag.
> This way guest will choose ACPI hot-plug if it is preferred and leave
> the option to use SHPC with pcie-pci-bridge.
> 
> Signed-off-by: Julia Suvorova <jusual@redhat.com>
> ---
>  hw/i386/acpi-build.h |  2 ++
>  hw/i386/acpi-build.c |  2 +-
>  hw/pci/pcie.c        | 16 ++++++++++++++++
>  3 files changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
> index 487ec7710f..4c5bfb3d0b 100644
> --- a/hw/i386/acpi-build.h
> +++ b/hw/i386/acpi-build.h
> @@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
>  
>  void acpi_setup(void);
>  
> +Object *object_resolve_type_unambiguous(const char *typename);
> +
>  #endif
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index cf503b16af..b7811a8912 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
>      *data = fadt;
>  }
>  
> -static Object *object_resolve_type_unambiguous(const char *typename)
> +Object *object_resolve_type_unambiguous(const char *typename)
>  {
>      bool ambig;
>      Object *o = object_resolve_path_type("", typename, &ambig);
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 5b48bae0f6..c1a082e8b9 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -27,6 +27,8 @@
>  #include "hw/pci/pci_bus.h"
>  #include "hw/pci/pcie_regs.h"
>  #include "hw/pci/pcie_port.h"
> +#include "hw/i386/ich9.h"
> +#include "hw/i386/acpi-build.h"
>  #include "qemu/range.h"
>  
>  //#define DEBUG_PCIE
> @@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
>      pcie_cap_slot_push_attention_button(hotplug_pdev);
>  }
>  
> +static bool acpi_pcihp_enabled(void)
> +{
> +    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
> +
> +    return lpc &&
> +           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
> +                                    NULL);
> +
> +}
> +
>  /* pci express slot for pci express root/downstream port
>     PCI express capability slot registers */
>  void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
>  {
>      uint32_t pos = dev->exp.exp_cap;
>  
> +    if (acpi_pcihp_enabled()) {
> +        return;
> +    }
> +
>      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
>                                 PCI_EXP_FLAGS_SLOT);
>  
why do you drop all slot caps instead of disabling just "if (s->hotplug) {" branch?
Re: [RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Ani Sinha 5 years, 4 months ago 

On Thu, 24 Sep 2020, Igor Mammedov wrote:

> On Thu, 24 Sep 2020 09:00:09 +0200
> Julia Suvorova <jusual@redhat.com> wrote:
>
>> Instead of changing the hot-plug type in _OSC register, do not
>> initialize the slot capability or set the 'Slot Implemented' flag.
>> This way guest will choose ACPI hot-plug if it is preferred and leave
>> the option to use SHPC with pcie-pci-bridge.
>>
>> Signed-off-by: Julia Suvorova <jusual@redhat.com>
>> ---
>>  hw/i386/acpi-build.h |  2 ++
>>  hw/i386/acpi-build.c |  2 +-
>>  hw/pci/pcie.c        | 16 ++++++++++++++++
>>  3 files changed, 19 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
>> index 487ec7710f..4c5bfb3d0b 100644
>> --- a/hw/i386/acpi-build.h
>> +++ b/hw/i386/acpi-build.h
>> @@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
>>
>>  void acpi_setup(void);
>>
>> +Object *object_resolve_type_unambiguous(const char *typename);
>> +
>>  #endif
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index cf503b16af..b7811a8912 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
>>      *data = fadt;
>>  }
>>
>> -static Object *object_resolve_type_unambiguous(const char *typename)
>> +Object *object_resolve_type_unambiguous(const char *typename)
>>  {
>>      bool ambig;
>>      Object *o = object_resolve_path_type("", typename, &ambig);
>> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
>> index 5b48bae0f6..c1a082e8b9 100644
>> --- a/hw/pci/pcie.c
>> +++ b/hw/pci/pcie.c
>> @@ -27,6 +27,8 @@
>>  #include "hw/pci/pci_bus.h"
>>  #include "hw/pci/pcie_regs.h"
>>  #include "hw/pci/pcie_port.h"
>> +#include "hw/i386/ich9.h"
>> +#include "hw/i386/acpi-build.h"
>>  #include "qemu/range.h"
>>
>>  //#define DEBUG_PCIE
>> @@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
>>      pcie_cap_slot_push_attention_button(hotplug_pdev);
>>  }
>>
>> +static bool acpi_pcihp_enabled(void)
>> +{
>> +    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
>> +
>> +    return lpc &&
>> +           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
>> +                                    NULL);
>> +
>> +}
>> +
>>  /* pci express slot for pci express root/downstream port
>>     PCI express capability slot registers */
>>  void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
>>  {
>>      uint32_t pos = dev->exp.exp_cap;
>>
>> +    if (acpi_pcihp_enabled()) {
>> +        return;
>> +    }
>> +
>>      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
>>                                 PCI_EXP_FLAGS_SLOT);
>>
> why do you drop all slot caps instead of disabling just "if (s->hotplug) {" branch?

+1 to Igor's suggestion.


>
>
Re: [RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Michael S. Tsirkin 5 years, 4 months ago 
On Thu, Sep 24, 2020 at 09:00:09AM +0200, Julia Suvorova wrote:
> Instead of changing the hot-plug type in _OSC register, do not
> initialize the slot capability or set the 'Slot Implemented' flag.
> This way guest will choose ACPI hot-plug if it is preferred and leave
> the option to use SHPC with pcie-pci-bridge.
> 
> Signed-off-by: Julia Suvorova <jusual@redhat.com>
> ---
>  hw/i386/acpi-build.h |  2 ++
>  hw/i386/acpi-build.c |  2 +-
>  hw/pci/pcie.c        | 16 ++++++++++++++++
>  3 files changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
> index 487ec7710f..4c5bfb3d0b 100644
> --- a/hw/i386/acpi-build.h
> +++ b/hw/i386/acpi-build.h
> @@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
>  
>  void acpi_setup(void);
>  
> +Object *object_resolve_type_unambiguous(const char *typename);
> +
>  #endif
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index cf503b16af..b7811a8912 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
>      *data = fadt;
>  }
>  
> -static Object *object_resolve_type_unambiguous(const char *typename)
> +Object *object_resolve_type_unambiguous(const char *typename)
>  {
>      bool ambig;
>      Object *o = object_resolve_path_type("", typename, &ambig);
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 5b48bae0f6..c1a082e8b9 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -27,6 +27,8 @@
>  #include "hw/pci/pci_bus.h"
>  #include "hw/pci/pcie_regs.h"
>  #include "hw/pci/pcie_port.h"
> +#include "hw/i386/ich9.h"
> +#include "hw/i386/acpi-build.h"
>  #include "qemu/range.h"
>  
>  //#define DEBUG_PCIE


Not really happy with pcie.c getting an i386 dependency.



> @@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
>      pcie_cap_slot_push_attention_button(hotplug_pdev);
>  }
>  
> +static bool acpi_pcihp_enabled(void)
> +{
> +    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
> +
> +    return lpc &&
> +           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
> +                                    NULL);
> +
> +}
> +

Why not just check the property unconditionally?


>  /* pci express slot for pci express root/downstream port
>     PCI express capability slot registers */
>  void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
>  {
>      uint32_t pos = dev->exp.exp_cap;
>  
> +    if (acpi_pcihp_enabled()) {
> +        return;
> +    }
> +

I think I would rather not teach pcie about acpi. How about we
change the polarity, name the property
"pci-native-hotplug" or whatever makes sense.

>      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
>                                 PCI_EXP_FLAGS_SLOT);
>  
> -- 
> 2.25.4
Re: [RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Julia Suvorova 5 years, 4 months ago 
On Thu, Sep 24, 2020 at 9:36 AM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Thu, Sep 24, 2020 at 09:00:09AM +0200, Julia Suvorova wrote:
> > Instead of changing the hot-plug type in _OSC register, do not
> > initialize the slot capability or set the 'Slot Implemented' flag.
> > This way guest will choose ACPI hot-plug if it is preferred and leave
> > the option to use SHPC with pcie-pci-bridge.
> >
> > Signed-off-by: Julia Suvorova <jusual@redhat.com>
> > ---
> >  hw/i386/acpi-build.h |  2 ++
> >  hw/i386/acpi-build.c |  2 +-
> >  hw/pci/pcie.c        | 16 ++++++++++++++++
> >  3 files changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
> > index 487ec7710f..4c5bfb3d0b 100644
> > --- a/hw/i386/acpi-build.h
> > +++ b/hw/i386/acpi-build.h
> > @@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
> >
> >  void acpi_setup(void);
> >
> > +Object *object_resolve_type_unambiguous(const char *typename);
> > +
> >  #endif
> > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > index cf503b16af..b7811a8912 100644
> > --- a/hw/i386/acpi-build.c
> > +++ b/hw/i386/acpi-build.c
> > @@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
> >      *data = fadt;
> >  }
> >
> > -static Object *object_resolve_type_unambiguous(const char *typename)
> > +Object *object_resolve_type_unambiguous(const char *typename)
> >  {
> >      bool ambig;
> >      Object *o = object_resolve_path_type("", typename, &ambig);
> > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> > index 5b48bae0f6..c1a082e8b9 100644
> > --- a/hw/pci/pcie.c
> > +++ b/hw/pci/pcie.c
> > @@ -27,6 +27,8 @@
> >  #include "hw/pci/pci_bus.h"
> >  #include "hw/pci/pcie_regs.h"
> >  #include "hw/pci/pcie_port.h"
> > +#include "hw/i386/ich9.h"
> > +#include "hw/i386/acpi-build.h"
> >  #include "qemu/range.h"
> >
> >  //#define DEBUG_PCIE
>
>
> Not really happy with pcie.c getting an i386 dependency.
>
>
>
> > @@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
> >      pcie_cap_slot_push_attention_button(hotplug_pdev);
> >  }
> >
> > +static bool acpi_pcihp_enabled(void)
> > +{
> > +    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
> > +
> > +    return lpc &&
> > +           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
> > +                                    NULL);
> > +
> > +}
> > +
>
> Why not just check the property unconditionally?

Ok.

> >  /* pci express slot for pci express root/downstream port
> >     PCI express capability slot registers */
> >  void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
> >  {
> >      uint32_t pos = dev->exp.exp_cap;
> >
> > +    if (acpi_pcihp_enabled()) {
> > +        return;
> > +    }
> > +
>
> I think I would rather not teach pcie about acpi. How about we
> change the polarity, name the property
> "pci-native-hotplug" or whatever makes sense.

I'd prefer not to change the property name since the common code in
hw/i386/acpi-build.c depends on it, but I can add a new one if it
makes any sense.

> >      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
> >                                 PCI_EXP_FLAGS_SLOT);
> >
> > --
> > 2.25.4
>
Re: [RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Michael S. Tsirkin 5 years, 4 months ago 
On Thu, Sep 24, 2020 at 10:23:13AM +0200, Julia Suvorova wrote:
> On Thu, Sep 24, 2020 at 9:36 AM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > On Thu, Sep 24, 2020 at 09:00:09AM +0200, Julia Suvorova wrote:
> > > Instead of changing the hot-plug type in _OSC register, do not
> > > initialize the slot capability or set the 'Slot Implemented' flag.
> > > This way guest will choose ACPI hot-plug if it is preferred and leave
> > > the option to use SHPC with pcie-pci-bridge.
> > >
> > > Signed-off-by: Julia Suvorova <jusual@redhat.com>
> > > ---
> > >  hw/i386/acpi-build.h |  2 ++
> > >  hw/i386/acpi-build.c |  2 +-
> > >  hw/pci/pcie.c        | 16 ++++++++++++++++
> > >  3 files changed, 19 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
> > > index 487ec7710f..4c5bfb3d0b 100644
> > > --- a/hw/i386/acpi-build.h
> > > +++ b/hw/i386/acpi-build.h
> > > @@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
> > >
> > >  void acpi_setup(void);
> > >
> > > +Object *object_resolve_type_unambiguous(const char *typename);
> > > +
> > >  #endif
> > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > > index cf503b16af..b7811a8912 100644
> > > --- a/hw/i386/acpi-build.c
> > > +++ b/hw/i386/acpi-build.c
> > > @@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
> > >      *data = fadt;
> > >  }
> > >
> > > -static Object *object_resolve_type_unambiguous(const char *typename)
> > > +Object *object_resolve_type_unambiguous(const char *typename)
> > >  {
> > >      bool ambig;
> > >      Object *o = object_resolve_path_type("", typename, &ambig);
> > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> > > index 5b48bae0f6..c1a082e8b9 100644
> > > --- a/hw/pci/pcie.c
> > > +++ b/hw/pci/pcie.c
> > > @@ -27,6 +27,8 @@
> > >  #include "hw/pci/pci_bus.h"
> > >  #include "hw/pci/pcie_regs.h"
> > >  #include "hw/pci/pcie_port.h"
> > > +#include "hw/i386/ich9.h"
> > > +#include "hw/i386/acpi-build.h"
> > >  #include "qemu/range.h"
> > >
> > >  //#define DEBUG_PCIE
> >
> >
> > Not really happy with pcie.c getting an i386 dependency.
> >
> >
> >
> > > @@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
> > >      pcie_cap_slot_push_attention_button(hotplug_pdev);
> > >  }
> > >
> > > +static bool acpi_pcihp_enabled(void)
> > > +{
> > > +    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
> > > +
> > > +    return lpc &&
> > > +           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
> > > +                                    NULL);
> > > +
> > > +}
> > > +
> >
> > Why not just check the property unconditionally?
> 
> Ok.
> 
> > >  /* pci express slot for pci express root/downstream port
> > >     PCI express capability slot registers */
> > >  void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
> > >  {
> > >      uint32_t pos = dev->exp.exp_cap;
> > >
> > > +    if (acpi_pcihp_enabled()) {
> > > +        return;
> > > +    }
> > > +
> >
> > I think I would rather not teach pcie about acpi. How about we
> > change the polarity, name the property
> > "pci-native-hotplug" or whatever makes sense.
> 
> I'd prefer not to change the property name since the common code in
> hw/i386/acpi-build.c depends on it, but I can add a new one if it
> makes any sense.

And maybe prefix with "x-" so we don't commit to it as an
external API.


> > >      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
> > >                                 PCI_EXP_FLAGS_SLOT);
> > >
> > > --
> > > 2.25.4
> >
Re: [RFC PATCH v3 3/7] hw/pci/pcie: Do not initialize slot capability if acpihp is used
Posted by Ani Sinha 5 years, 4 months ago 

On Thu, 24 Sep 2020, Julia Suvorova wrote:

> On Thu, Sep 24, 2020 at 9:36 AM Michael S. Tsirkin <mst@redhat.com> wrote:
>>
>> On Thu, Sep 24, 2020 at 09:00:09AM +0200, Julia Suvorova wrote:
>>> Instead of changing the hot-plug type in _OSC register, do not
>>> initialize the slot capability or set the 'Slot Implemented' flag.
>>> This way guest will choose ACPI hot-plug if it is preferred and leave
>>> the option to use SHPC with pcie-pci-bridge.
>>>
>>> Signed-off-by: Julia Suvorova <jusual@redhat.com>
>>> ---
>>>  hw/i386/acpi-build.h |  2 ++
>>>  hw/i386/acpi-build.c |  2 +-
>>>  hw/pci/pcie.c        | 16 ++++++++++++++++
>>>  3 files changed, 19 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/hw/i386/acpi-build.h b/hw/i386/acpi-build.h
>>> index 487ec7710f..4c5bfb3d0b 100644
>>> --- a/hw/i386/acpi-build.h
>>> +++ b/hw/i386/acpi-build.h
>>> @@ -11,4 +11,6 @@ extern const struct AcpiGenericAddress x86_nvdimm_acpi_dsmio;
>>>
>>>  void acpi_setup(void);
>>>
>>> +Object *object_resolve_type_unambiguous(const char *typename);
>>> +
>>>  #endif
>>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>>> index cf503b16af..b7811a8912 100644
>>> --- a/hw/i386/acpi-build.c
>>> +++ b/hw/i386/acpi-build.c
>>> @@ -174,7 +174,7 @@ static void init_common_fadt_data(MachineState *ms, Object *o,
>>>      *data = fadt;
>>>  }
>>>
>>> -static Object *object_resolve_type_unambiguous(const char *typename)
>>> +Object *object_resolve_type_unambiguous(const char *typename)
>>>  {
>>>      bool ambig;
>>>      Object *o = object_resolve_path_type("", typename, &ambig);
>>> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
>>> index 5b48bae0f6..c1a082e8b9 100644
>>> --- a/hw/pci/pcie.c
>>> +++ b/hw/pci/pcie.c
>>> @@ -27,6 +27,8 @@
>>>  #include "hw/pci/pci_bus.h"
>>>  #include "hw/pci/pcie_regs.h"
>>>  #include "hw/pci/pcie_port.h"
>>> +#include "hw/i386/ich9.h"
>>> +#include "hw/i386/acpi-build.h"
>>>  #include "qemu/range.h"
>>>
>>>  //#define DEBUG_PCIE
>>
>>
>> Not really happy with pcie.c getting an i386 dependency.
>>
>>
>>
>>> @@ -515,12 +517,26 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
>>>      pcie_cap_slot_push_attention_button(hotplug_pdev);
>>>  }
>>>
>>> +static bool acpi_pcihp_enabled(void)
>>> +{
>>> +    Object *lpc = object_resolve_type_unambiguous(TYPE_ICH9_LPC_DEVICE);
>>> +
>>> +    return lpc &&
>>> +           object_property_get_bool(lpc, "acpi-pci-hotplug-with-bridge-support",
>>> +                                    NULL);
>>> +
>>> +}
>>> +
>>
>> Why not just check the property unconditionally?
>
> Ok.

I do not see how that would work if lpc is NULL.
object_resolve_type_unambiguous() can return NULL, at least in theory.

>
>>>  /* pci express slot for pci express root/downstream port
>>>     PCI express capability slot registers */
>>>  void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
>>>  {
>>>      uint32_t pos = dev->exp.exp_cap;
>>>
>>> +    if (acpi_pcihp_enabled()) {
>>> +        return;
>>> +    }
>>> +
>>
>> I think I would rather not teach pcie about acpi. How about we
>> change the polarity, name the property
>> "pci-native-hotplug" or whatever makes sense.
>
> I'd prefer not to change the property name since the common code in
> hw/i386/acpi-build.c depends on it, but I can add a new one if it
> makes any sense.
>
>>>      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
>>>                                 PCI_EXP_FLAGS_SLOT);
>>>
>>> --
>>> 2.25.4
>>
>
>

Patchew 2.1-devel-b67e4c2

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