From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Date: Fri, 8 Oct 2021 05:55:32 +0000 (+0300)
Subject: libxl: Only map legacy PCI IRQs if they are supported
X-Git-Tag: archive/raspbian/4.16.0+51-g0941d6cb-1+rpi1~2^2~42^2~109
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=e26f810a6f9295afe30ea08195715ddd96e2a123;p=xen.git

libxl: Only map legacy PCI IRQs if they are supported

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>
[stefano: minor change to Makefile]
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Tested-by: Rahul Singh <rahul.singh@arm.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
---

diff --git a/tools/libs/light/Makefile b/tools/libs/light/Makefile
index 7d8c51d492..194bc5f268 100644
--- a/tools/libs/light/Makefile
+++ b/tools/libs/light/Makefile
@@ -46,6 +46,8 @@ CFLAGS += -Wno-format-zero-length -Wmissing-declarations \
 	-Wno-declaration-after-statement -Wformat-nonliteral
 CFLAGS += -I.
 
+CFLAGS-$(CONFIG_X86) += -DCONFIG_PCI_SUPP_LEGACY_IRQ
+
 SRCS-$(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 59f3686fc8..4c2d7aeefb 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");