Re: [RFC KERNEL PATCH v2 2/3] xen/pvh: Unmask irq for passthrough device in PVH dom0

["Chen, Jiqian" <Jiqian.Chen@xxxxxxx>]

Thank Stefano and Juergen, I will use this approach in next version.

On 2023/12/7 14:43, Juergen Gross wrote:
> On 07.12.23 03:18, Stefano Stabellini wrote:
>> On Tue, 5 Dec 2023, Chen, Jiqian wrote:
>>> When PVH dom0 enable a device, it will get trigger and polarity from ACPI 
>>> (see acpi_pci_irq_enable)
>>> I have a version of patch which tried that way, see below:
>>
>> This approach looks much better. I think this patch is OKish. Juergen,
>> what do you think?
> 
> The approach seems to be fine.
> 
> 
> Juergen
> 
>>
>>
>>> diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
>>> index ada3868c02c2..43e1bda9f946 100644
>>> --- a/arch/x86/xen/enlighten_pvh.c
>>> +++ b/arch/x86/xen/enlighten_pvh.c
>>> @@ -1,6 +1,7 @@
>>>   // SPDX-License-Identifier: GPL-2.0
>>>   #include <linux/acpi.h>
>>>   #include <linux/export.h>
>>> +#include <linux/pci.h>
>>>
>>>   #include <xen/hvc-console.h>
>>>
>>> @@ -25,6 +26,127 @@
>>>   bool __ro_after_init xen_pvh;
>>>   EXPORT_SYMBOL_GPL(xen_pvh);
>>>
>>> +typedef struct gsi_info {
>>> +       int gsi;
>>> +       int trigger;
>>> +       int polarity;
>>> +       int pirq;
>>> +} gsi_info_t;
>>> +
>>> +struct acpi_prt_entry {
>>> +       struct acpi_pci_id      id;
>>> +       u8                      pin;
>>> +       acpi_handle             link;
>>> +       u32                     index;          /* GSI, or link _CRS index 
>>> */
>>> +};
>>> +
>>> +static int xen_pvh_get_gsi_info(struct pci_dev *dev,
>>> +                                                               gsi_info_t 
>>> *gsi_info)
>>> +{
>>> +       int gsi;
>>> +       u8 pin = 0;
>>> +       struct acpi_prt_entry *entry;
>>> +       int trigger = ACPI_LEVEL_SENSITIVE;
>>> +       int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
>>> +                                     ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
>>> +
>>> +       if (dev)
>>> +               pin = dev->pin;
>>> +       if (!pin) {
>>> +               xen_raw_printk("No interrupt pin configured\n");
>>> +               return -EINVAL;
>>> +       }
>>> +
>>> +       entry = acpi_pci_irq_lookup(dev, pin);
>>> +       if (entry) {
>>> +               if (entry->link)
>>> +                       gsi = acpi_pci_link_allocate_irq(entry->link,
>>> +                                                        entry->index,
>>> +                                                        &trigger, 
>>> &polarity,
>>> +                                                        NULL);
>>> +               else
>>> +                       gsi = entry->index;
>>> +       } else
>>> +               return -EINVAL;
>>> +
>>> +       gsi_info->gsi = gsi;
>>> +       gsi_info->trigger = trigger;
>>> +       gsi_info->polarity = polarity;
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int xen_pvh_map_pirq(gsi_info_t *gsi_info)
>>> +{
>>> +       struct physdev_map_pirq map_irq;
>>> +       int ret;
>>> +
>>> +       map_irq.domid = DOMID_SELF;
>>> +       map_irq.type = MAP_PIRQ_TYPE_GSI;
>>> +       map_irq.index = gsi_info->gsi;
>>> +       map_irq.pirq = gsi_info->gsi;
>>> +
>>> +       ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
>>> +       gsi_info->pirq = map_irq.pirq;
>>> +
>>> +       return ret;
>>> +}
>>> +
>>> +static int xen_pvh_unmap_pirq(gsi_info_t *gsi_info)
>>> +{
>>> +       struct physdev_unmap_pirq unmap_irq;
>>> +
>>> +       unmap_irq.domid = DOMID_SELF;
>>> +       unmap_irq.pirq = gsi_info->pirq;
>>> +
>>> +       return HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
>>> +}
>>> +
>>> +static int xen_pvh_setup_gsi(gsi_info_t *gsi_info)
>>> +{
>>> +       struct physdev_setup_gsi setup_gsi;
>>> +
>>> +       setup_gsi.gsi = gsi_info->gsi;
>>> +       setup_gsi.triggering = (gsi_info->trigger == ACPI_EDGE_SENSITIVE ? 
>>> 0 : 1);
>>> +       setup_gsi.polarity = (gsi_info->polarity == ACPI_ACTIVE_HIGH ? 0 : 
>>> 1);
>>> +
>>> +       return HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
>>> +}
>>> +
>>> +int xen_pvh_passthrough_gsi(struct pci_dev *dev)
>>> +{
>>> +       int ret;
>>> +       gsi_info_t gsi_info;
>>> +
>>> +       if (!dev) {
>>> +               return -EINVAL;
>>> +       }
>>> +
>>> +       ret = xen_pvh_get_gsi_info(dev, &gsi_info);
>>> +       if (ret) {
>>> +               xen_raw_printk("Fail to get gsi info!\n");
>>> +               return ret;
>>> +       }
>>> +
>>> +       ret = xen_pvh_map_pirq(&gsi_info);
>>> +       if (ret) {
>>> +               xen_raw_printk("Fail to map pirq for gsi (%d)!\n", 
>>> gsi_info.gsi);
>>> +               return ret;
>>> +       }
>>> +
>>> +       ret = xen_pvh_setup_gsi(&gsi_info);
>>> +       if (ret == -EEXIST) {
>>> +               ret = 0;
>>> +               xen_raw_printk("Already setup the GSI :%u\n", gsi_info.gsi);
>>> +       } else if (ret) {
>>> +               xen_raw_printk("Fail to setup gsi (%d)!\n", gsi_info.gsi);
>>> +               xen_pvh_unmap_pirq(&gsi_info);
>>> +       }
>>> +
>>> +       return ret;
>>> +}
>>> +EXPORT_SYMBOL_GPL(xen_pvh_passthrough_gsi);
>>> +
>>>   void __init xen_pvh_init(struct boot_params *boot_params)
>>>   {
>>>          u32 msr;
>>> diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
>>> index ff30ceca2203..630fe0a34bc6 100644
>>> --- a/drivers/acpi/pci_irq.c
>>> +++ b/drivers/acpi/pci_irq.c
>>> @@ -288,7 +288,7 @@ static int acpi_reroute_boot_interrupt(struct pci_dev 
>>> *dev,
>>>   }
>>>   #endif /* CONFIG_X86_IO_APIC */
>>>
>>> -static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int 
>>> pin)
>>> +struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
>>>   {
>>>          struct acpi_prt_entry *entry = NULL;
>>>          struct pci_dev *bridge;
>>> diff --git a/drivers/xen/xen-pciback/pci_stub.c 
>>> b/drivers/xen/xen-pciback/pci_stub.c
>>> index e34b623e4b41..1abd4dad6f40 100644
>>> --- a/drivers/xen/xen-pciback/pci_stub.c
>>> +++ b/drivers/xen/xen-pciback/pci_stub.c
>>> @@ -20,6 +20,7 @@
>>>   #include <linux/atomic.h>
>>>   #include <xen/events.h>
>>>   #include <xen/pci.h>
>>> +#include <xen/acpi.h>
>>>   #include <xen/xen.h>
>>>   #include <asm/xen/hypervisor.h>
>>>   #include <xen/interface/physdev.h>
>>> @@ -399,6 +400,12 @@ static int pcistub_init_device(struct pci_dev *dev)
>>>          if (err)
>>>                  goto config_release;
>>>
>>> +       if (xen_initial_domain() && xen_pvh_domain()) {
>>> +               err = xen_pvh_passthrough_gsi(dev);
>>> +               if (err)
>>> +                       goto config_release;
>>> +       }
>>> +
>>>          if (dev->msix_cap) {
>>>                  struct physdev_pci_device ppdev = {
>>>                          .seg = pci_domain_nr(dev->bus),
>>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>>> index 641dc4843987..368d56ba2c5e 100644
>>> --- a/include/linux/acpi.h
>>> +++ b/include/linux/acpi.h
>>> @@ -375,6 +375,7 @@ void acpi_unregister_gsi (u32 gsi);
>>>
>>>   struct pci_dev;
>>>
>>> +struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin);
>>>   int acpi_pci_irq_enable (struct pci_dev *dev);
>>>   void acpi_penalize_isa_irq(int irq, int active);
>>>   bool acpi_isa_irq_available(int irq);
>>> diff --git a/include/xen/acpi.h b/include/xen/acpi.h
>>> index b1e11863144d..ce7f5554f88e 100644
>>> --- a/include/xen/acpi.h
>>> +++ b/include/xen/acpi.h
>>> @@ -67,6 +67,7 @@ static inline void xen_acpi_sleep_register(void)
>>>                  acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
>>>          }
>>>   }
>>> +int xen_pvh_passthrough_gsi(struct pci_dev *dev);
>>>   #else
>>>   static inline void xen_acpi_sleep_register(void)
>>>   {
>>>
>>>>
>>>> Jan
>>>
>>> -- 
>>> Best regards,
>>> Jiqian Chen.
>>>
> 

-- 
Best regards,
Jiqian Chen.