On Thu, 30 Sep 2021, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>
> Arm's PCI passthrough implementation doesn't support legacy interrupts,
> but MSI/MSI-X. This can be the case for other platforms too.
> For that reason introduce a new CONFIG_PCI_SUPP_LEGACY_IRQ and add
> it to the CFLAGS and compile the relevant code in the toolstack only if
> applicable.
>
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
> Cc: Ian Jackson <iwj@xenproject.org>
> Cc: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> ---
> Since v1:
> - Minimized #idefery by introducing pci_supp_legacy_irq function
> for relevant checks
> ---
> tools/libs/light/Makefile | 4 ++++
> tools/libs/light/libxl_pci.c | 13 +++++++++++++
> 2 files changed, 17 insertions(+)
>
> diff --git a/tools/libs/light/Makefile b/tools/libs/light/Makefile
> index 7d8c51d49242..bd3f6be2a183 100644
> --- a/tools/libs/light/Makefile
> +++ b/tools/libs/light/Makefile
> @@ -46,6 +46,10 @@ CFLAGS += -Wno-format-zero-length -Wmissing-declarations \
> -Wno-declaration-after-statement -Wformat-nonliteral
> CFLAGS += -I.
>
> +ifeq ($(CONFIG_X86),y)
> +CFLAGS += -DCONFIG_PCI_SUPP_LEGACY_IRQ
> +endif
> +
> SRCS-$(CONFIG_X86) += libxl_cpuid.c
> SRCS-$(CONFIG_X86) += libxl_x86.c
> SRCS-$(CONFIG_X86) += libxl_psr.c
> diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
> index 59f3686fc85e..4c2d7aeefbb2 100644
> --- a/tools/libs/light/libxl_pci.c
> +++ b/tools/libs/light/libxl_pci.c
> @@ -1364,6 +1364,15 @@ static void pci_add_timeout(libxl__egc *egc, libxl__ev_time *ev,
> pci_add_dm_done(egc, pas, rc);
> }
>
> +static bool pci_supp_legacy_irq(void)
> +{
> +#ifdef CONFIG_PCI_SUPP_LEGACY_IRQ
> + return true;
> +#else
> + return false;
> +#endif
> +}
> +
> static void pci_add_dm_done(libxl__egc *egc,
> pci_add_state *pas,
> int rc)
> @@ -1434,6 +1443,8 @@ static void pci_add_dm_done(libxl__egc *egc,
> }
> }
> fclose(f);
> + if (!pci_supp_legacy_irq())
> + goto out_no_irq;
> sysfs_path = GCSPRINTF(SYSFS_PCI_DEV"/"PCI_BDF"/irq", pci->domain,
> pci->bus, pci->dev, pci->func);
> f = fopen(sysfs_path, "r");
> @@ -1983,6 +1994,8 @@ static void do_pci_remove(libxl__egc *egc, pci_remove_state *prs)
> }
> fclose(f);
> skip1:
> + if (!pci_supp_legacy_irq())
> + goto skip_irq;
> sysfs_path = GCSPRINTF(SYSFS_PCI_DEV"/"PCI_BDF"/irq", pci->domain,
> pci->bus, pci->dev, pci->func);
> f = fopen(sysfs_path, "r");
> --
> 2.25.1
>