Re: [XEN PATCH v10 4/5] tools: Add new function to get gsi from dev

[Anthony PERARD <anthony.perard@vates.tech>]

On Mon, Jun 17, 2024 at 05:00:34PM +0800, Jiqian Chen wrote:
> diff --git a/tools/include/xencall.h b/tools/include/xencall.h
> index fc95ed0fe58e..750aab070323 100644
> --- a/tools/include/xencall.h
> +++ b/tools/include/xencall.h
> @@ -113,6 +113,8 @@ int xencall5(xencall_handle *xcall, unsigned int op,
>               uint64_t arg1, uint64_t arg2, uint64_t arg3,
>               uint64_t arg4, uint64_t arg5);
>  
> +int xen_oscall_gsi_from_dev(xencall_handle *xcall, unsigned int sbdf);

I don't think that an appropriate library for this new feature.
libxencall is a generic lib to make hypercall.

>  /* Variant(s) of the above, as needed, returning "long" instead of "int". */
>  long xencall2L(xencall_handle *xcall, unsigned int op,
>                 uint64_t arg1, uint64_t arg2);
> diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
> index 9ceca0cffc2f..a0381f74d24b 100644
> --- a/tools/include/xenctrl.h
> +++ b/tools/include/xenctrl.h
> @@ -1641,6 +1641,8 @@ int xc_physdev_unmap_pirq(xc_interface *xch,
>                            uint32_t domid,
>                            int pirq);
>  
> +int xc_physdev_gsi_from_dev(xc_interface *xch, uint32_t sbdf);
> +
>  /*
>   *  LOGGING AND ERROR REPORTING
>   */
> diff --git a/tools/libs/call/core.c b/tools/libs/call/core.c
> index 02c4f8e1aefa..6dae50c9a6ba 100644
> --- a/tools/libs/call/core.c
> +++ b/tools/libs/call/core.c
> @@ -173,6 +173,11 @@ int xencall5(xencall_handle *xcall, unsigned int op,
>      return osdep_hypercall(xcall, &call);
>  }
>  
> +int xen_oscall_gsi_from_dev(xencall_handle *xcall, unsigned int sbdf)
> +{
> +    return osdep_oscall(xcall, sbdf);
> +}
> +
>  /*
>   * Local variables:
>   * mode: C
> diff --git a/tools/libs/call/libxencall.map b/tools/libs/call/libxencall.map
> index d18a3174e9dc..b92a0b5dc12c 100644
> --- a/tools/libs/call/libxencall.map
> +++ b/tools/libs/call/libxencall.map
> @@ -10,6 +10,8 @@ VERS_1.0 {
>  		xencall4;
>  		xencall5;
>  
> +		xen_oscall_gsi_from_dev;

FYI, never change already released version of a library, this would add
a new function to libxencall.1.0. Instead, when adding a new function
to a library that is supposed to be stable (they have a *.map file in
xen case), add it to a new section, that woud be VERS_1.4 in this case.
But libxencall isn't approriate for this new function, so just for
future reference.

>  		xencall_alloc_buffer;
>  		xencall_free_buffer;
>  		xencall_alloc_buffer_pages;
> diff --git a/tools/libs/call/linux.c b/tools/libs/call/linux.c
> index 6d588e6bea8f..92c740e176f2 100644
> --- a/tools/libs/call/linux.c
> +++ b/tools/libs/call/linux.c
> @@ -85,6 +85,21 @@ long osdep_hypercall(xencall_handle *xcall, privcmd_hypercall_t *hypercall)
>      return ioctl(xcall->fd, IOCTL_PRIVCMD_HYPERCALL, hypercall);
>  }
>  
> +int osdep_oscall(xencall_handle *xcall, unsigned int sbdf)
> +{
> +    privcmd_gsi_from_dev_t dev_gsi = {
> +        .sbdf = sbdf,
> +        .gsi = -1,
> +    };
> +
> +    if (ioctl(xcall->fd, IOCTL_PRIVCMD_GSI_FROM_DEV, &dev_gsi)) {

Looks like libxencall is only for hypercall, and so I don't think
it's the right place to introducing another ioctl() call.

> +        PERROR("failed to get gsi from dev");
> +        return -1;
> +    }
> +
> +    return dev_gsi.gsi;
> +}
> +
>  static void *alloc_pages_bufdev(xencall_handle *xcall, size_t npages)
>  {
>      void *p;
> diff --git a/tools/libs/call/private.h b/tools/libs/call/private.h
> index 9c3aa432efe2..cd6eb5a3e66f 100644
> --- a/tools/libs/call/private.h
> +++ b/tools/libs/call/private.h
> @@ -57,6 +57,15 @@ int osdep_xencall_close(xencall_handle *xcall);
>  
>  long osdep_hypercall(xencall_handle *xcall, privcmd_hypercall_t *hypercall);
>  
> +#if defined(__linux__)
> +int osdep_oscall(xencall_handle *xcall, unsigned int sbdf);
> +#else
> +static inline int osdep_oscall(xencall_handle *xcall, unsigned int sbdf)
> +{
> +    return -1;
> +}
> +#endif
> +
>  void *osdep_alloc_pages(xencall_handle *xcall, size_t nr_pages);
>  void osdep_free_pages(xencall_handle *xcall, void *p, size_t nr_pages);
>  
> diff --git a/tools/libs/ctrl/xc_physdev.c b/tools/libs/ctrl/xc_physdev.c
> index 460a8e779ce8..c1458f3a38b5 100644
> --- a/tools/libs/ctrl/xc_physdev.c
> +++ b/tools/libs/ctrl/xc_physdev.c
> @@ -111,3 +111,7 @@ int xc_physdev_unmap_pirq(xc_interface *xch,
>      return rc;
>  }
>  
> +int xc_physdev_gsi_from_dev(xc_interface *xch, uint32_t sbdf)
> +{

I'm not sure if this is the best place for this new function, but I
can't find another one, so that will do.

> +    return xen_oscall_gsi_from_dev(xch->xcall, sbdf);
> +}
> diff --git a/tools/libs/light/Makefile b/tools/libs/light/Makefile
> index 37e4d1670986..6b616d5ee9b6 100644
> --- a/tools/libs/light/Makefile
> +++ b/tools/libs/light/Makefile
> @@ -40,7 +40,7 @@ OBJS-$(CONFIG_X86) += $(ACPI_OBJS)
>  
>  CFLAGS += -Wno-format-zero-length -Wmissing-declarations -Wformat-nonliteral
>  
> -CFLAGS-$(CONFIG_X86) += -DCONFIG_PCI_SUPP_LEGACY_IRQ
> +CFLAGS-$(CONFIG_X86) += -DCONFIG_PCI_SUPP_LEGACY_IRQ -DCONFIG_X86
>  
>  OBJS-$(CONFIG_X86) += libxl_cpuid.o
>  OBJS-$(CONFIG_X86) += libxl_x86.o
> diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
> index 96cb4da0794e..376f91759ac6 100644
> --- a/tools/libs/light/libxl_pci.c
> +++ b/tools/libs/light/libxl_pci.c
> @@ -1406,6 +1406,12 @@ static bool pci_supp_legacy_irq(void)
>  #endif
>  }
>  
> +#define PCI_DEVID(bus, devfn)\
> +            ((((uint16_t)(bus)) << 8) | ((devfn) & 0xff))
> +
> +#define PCI_SBDF(seg, bus, devfn) \
> +            ((((uint32_t)(seg)) << 16) | (PCI_DEVID(bus, devfn)))
> +
>  static void pci_add_dm_done(libxl__egc *egc,
>                              pci_add_state *pas,
>                              int rc)
> @@ -1418,6 +1424,10 @@ static void pci_add_dm_done(libxl__egc *egc,
>      unsigned long long start, end, flags, size;
>      int irq, i;
>      int r;
> +#ifdef CONFIG_X86
> +    int gsi;
> +    uint32_t sbdf;
> +#endif
>      uint32_t flag = XEN_DOMCTL_DEV_RDM_RELAXED;
>      uint32_t domainid = domid;
>      bool isstubdom = libxl_is_stubdom(ctx, domid, &domainid);
> @@ -1486,6 +1496,18 @@ static void pci_add_dm_done(libxl__egc *egc,
>          goto out_no_irq;
>      }
>      if ((fscanf(f, "%u", &irq) == 1) && irq) {
> +#ifdef CONFIG_X86

Could you avoid these #ifdef, and move the new arch specific code (and
maybe existing code) into libxl_x86.c ? There's already examples of arch
specific code.

> +        sbdf = PCI_SBDF(pci->domain, pci->bus,
> +                        (PCI_DEVFN(pci->dev, pci->func)));
> +        gsi = xc_physdev_gsi_from_dev(ctx->xch, sbdf);
> +        /*
> +         * Old kernel version may not support this function,
> +         * so if fail, keep using irq; if success, use gsi
> +         */
> +        if (gsi > 0) {
> +            irq = gsi;
> +        }
> +#endif
>          r = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
>          if (r < 0) {
>              LOGED(ERROR, domainid, "xc_physdev_map_pirq irq=%d (error=%d)",
> @@ -2172,6 +2194,10 @@ static void pci_remove_detached(libxl__egc *egc,
>      int  irq = 0, i, stubdomid = 0;
>      const char *sysfs_path;
>      FILE *f;
> +#ifdef CONFIG_X86
> +    int gsi;
> +    uint32_t sbdf;
> +#endif
>      uint32_t domainid = prs->domid;
>      bool isstubdom;
>  
> @@ -2239,6 +2265,18 @@ skip_bar:
>      }
>  
>      if ((fscanf(f, "%u", &irq) == 1) && irq) {
> +#ifdef CONFIG_X86
> +        sbdf = PCI_SBDF(pci->domain, pci->bus,
> +                        (PCI_DEVFN(pci->dev, pci->func)));
> +        gsi = xc_physdev_gsi_from_dev(ctx->xch, sbdf);
> +        /*
> +         * Old kernel version may not support this function,
> +         * so if fail, keep using irq; if success, use gsi
> +         */
> +        if (gsi > 0) {
> +            irq = gsi;
> +        }
> +#endif
>          rc = xc_physdev_unmap_pirq(ctx->xch, domid, irq);
>          if (rc < 0) {
>              /*

Thanks,

-- 


Anthony Perard | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

web: https://vates.tech