Re: [KERNEL PATCH v9 2/3] xen/pvh: Setup gsi for passthrough device

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 12 Sep 2024, Jiqian Chen wrote:
> In PVH dom0, the gsis don't get registered, but the gsi of
> a passthrough device must be configured for it to be able to be
> mapped into a domU.
> 
> When assigning a device to passthrough, proactively setup the gsi
> of the device during that process.
> 
> Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
> Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> v8->v9 changes:
> Moved the calling of xen_acpi_get_gsi_info under check "if 
> (xen_initial_domain() && xen_pvh_domain())" to prevent it is called in PV 
> dom0.
> Removed Reviewed-by of Stefano.
> 
> v7->v8 changes:
> Used CONFIG_XEN_ACPI instead of CONFIG_ACPI to wrap codes.
> 
> v6->v7 changes:
> Moved the implementation of function xen_acpi_get_gsi_info to file 
> drivers/xen/acpi.c, that modification is more convenient for the subsequent 
> patch to obtain gsi.
> 
> v5->v6 changes:
> No.
> 
> v4->v5 changes:
> Added Reviewed-by of Stefano.
> 
> v3->v4 changes:
> Removed map_pirq from xen_pvh_passthrough_gsi since let pvh calls map_pirq 
> here is not right.
> 
> v2->v3 changes:
> Abandoned previous implementations that called unmask_irq, and change to do 
> setup_gsi and map_pirq for passthrough device in pcistub_init_device.
> ---
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: 
> https://lore.kernel.org/oe-kbuild-all/202406090859.KW3eeESv-lkp@xxxxxxxxx/
> ---
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: 
> https://lore.kernel.org/oe-kbuild-all/202405172132.TazuVpPo-lkp@xxxxxxxxx/
> ---
>  arch/x86/xen/enlighten_pvh.c       | 23 ++++++++++++++
>  drivers/acpi/pci_irq.c             |  2 +-
>  drivers/xen/acpi.c                 | 50 ++++++++++++++++++++++++++++++
>  drivers/xen/xen-pciback/pci_stub.c | 20 ++++++++++++
>  include/linux/acpi.h               |  1 +
>  include/xen/acpi.h                 | 18 +++++++++++
>  6 files changed, 113 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
> index 728a4366ca85..bf68c329fc01 100644
> --- a/arch/x86/xen/enlighten_pvh.c
> +++ b/arch/x86/xen/enlighten_pvh.c
> @@ -4,6 +4,7 @@
>  #include <linux/mm.h>
>  
>  #include <xen/hvc-console.h>
> +#include <xen/acpi.h>
>  
>  #include <asm/bootparam.h>
>  #include <asm/io_apic.h>
> @@ -28,6 +29,28 @@
>  bool __ro_after_init xen_pvh;
>  EXPORT_SYMBOL_GPL(xen_pvh);
>  
> +#ifdef CONFIG_XEN_DOM0
> +int xen_pvh_setup_gsi(int gsi, int trigger, int polarity)
> +{
> +     int ret;
> +     struct physdev_setup_gsi setup_gsi;
> +
> +     setup_gsi.gsi = gsi;
> +     setup_gsi.triggering = (trigger == ACPI_EDGE_SENSITIVE ? 0 : 1);
> +     setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
> +
> +     ret = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
> +     if (ret == -EEXIST) {
> +             xen_raw_printk("Already setup the GSI :%d\n", gsi);
> +             ret = 0;
> +     } else if (ret)
> +             xen_raw_printk("Fail to setup GSI (%d)!\n", gsi);
> +
> +     return ret;
> +}
> +EXPORT_SYMBOL_GPL(xen_pvh_setup_gsi);
> +#endif
> +
>  /*
>   * Reserve e820 UNUSABLE regions to inflate the memory balloon.
>   *
> 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/acpi.c b/drivers/xen/acpi.c
> index 6893c79fd2a1..9e2096524fbc 100644
> --- a/drivers/xen/acpi.c
> +++ b/drivers/xen/acpi.c
> @@ -30,6 +30,7 @@
>   * IN THE SOFTWARE.
>   */
>  
> +#include <linux/pci.h>
>  #include <xen/acpi.h>
>  #include <xen/interface/platform.h>
>  #include <asm/xen/hypercall.h>
> @@ -75,3 +76,52 @@ int xen_acpi_notify_hypervisor_extended_sleep(u8 
> sleep_state,
>       return xen_acpi_notify_hypervisor_state(sleep_state, val_a,
>                                               val_b, true);
>  }
> +
> +struct acpi_prt_entry {
> +     struct acpi_pci_id      id;
> +     u8                      pin;
> +     acpi_handle             link;
> +     u32                     index;
> +};
> +
> +int xen_acpi_get_gsi_info(struct pci_dev *dev,
> +                                               int *gsi_out,
> +                                               int *trigger_out,
> +                                               int *polarity_out)
> +{
> +     int gsi;
> +     u8 pin;
> +     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 || !gsi_out || !trigger_out || !polarity_out)
> +             return -EINVAL;
> +
> +     pin = dev->pin;
> +     if (!pin)
> +             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
> +             gsi = -1;
> +
> +     if (gsi < 0)
> +             return -EINVAL;
> +
> +     *gsi_out = gsi;
> +     *trigger_out = trigger;
> +     *polarity_out = polarity;
> +
> +     return 0;
> +}
> +EXPORT_SYMBOL_GPL(xen_acpi_get_gsi_info);
> diff --git a/drivers/xen/xen-pciback/pci_stub.c 
> b/drivers/xen/xen-pciback/pci_stub.c
> index 3e162c1753e2..8ce27333f54b 100644
> --- a/drivers/xen/xen-pciback/pci_stub.c
> +++ b/drivers/xen/xen-pciback/pci_stub.c
> @@ -21,6 +21,9 @@
>  #include <xen/events.h>
>  #include <xen/pci.h>
>  #include <xen/xen.h>
> +#ifdef CONFIG_XEN_ACPI
> +#include <xen/acpi.h>
> +#endif
>  #include <asm/xen/hypervisor.h>
>  #include <xen/interface/physdev.h>
>  #include "pciback.h"
> @@ -367,6 +370,9 @@ static int pcistub_match(struct pci_dev *dev)
>  static int pcistub_init_device(struct pci_dev *dev)
>  {
>       struct xen_pcibk_dev_data *dev_data;
> +#ifdef CONFIG_XEN_ACPI
> +     int gsi, trigger, polarity;
> +#endif
>       int err = 0;
>  
>       dev_dbg(&dev->dev, "initializing...\n");
> @@ -435,6 +441,20 @@ static int pcistub_init_device(struct pci_dev *dev)
>                       goto config_release;
>               pci_restore_state(dev);
>       }
> +
> +#ifdef CONFIG_XEN_ACPI
> +     if (xen_initial_domain() && xen_pvh_domain()) {
> +             err = xen_acpi_get_gsi_info(dev, &gsi, &trigger, &polarity);
> +             if (err) {
> +                     dev_err(&dev->dev, "Fail to get gsi info!\n");
> +                     goto config_release;
> +             }
> +             err = xen_pvh_setup_gsi(gsi, trigger, polarity);
> +             if (err)
> +                     goto config_release;
> +     }
> +#endif
> +
>       /* Now disable the device (this also ensures some private device
>        * data is setup before we export)
>        */
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 0687a442fec7..02ded9f53a6b 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -362,6 +362,7 @@ 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..3bcfe82d9078 100644
> --- a/include/xen/acpi.h
> +++ b/include/xen/acpi.h
> @@ -67,10 +67,28 @@ static inline void xen_acpi_sleep_register(void)
>               acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
>       }
>  }
> +int xen_pvh_setup_gsi(int gsi, int trigger, int polarity);
> +int xen_acpi_get_gsi_info(struct pci_dev *dev,
> +                                               int *gsi_out,
> +                                               int *trigger_out,
> +                                               int *polarity_out);
>  #else
>  static inline void xen_acpi_sleep_register(void)
>  {
>  }
> +
> +static inline int xen_pvh_setup_gsi(int gsi, int trigger, int polarity)
> +{
> +     return -1;
> +}
> +
> +static inline int xen_acpi_get_gsi_info(struct pci_dev *dev,
> +                                               int *gsi_out,
> +                                               int *trigger_out,
> +                                               int *polarity_out)
> +{
> +     return -1;
> +}
>  #endif
>  
>  #endif       /* _XEN_ACPI_H */
> -- 
> 2.34.1
>