[Xen-devel] [PATCH v3 1/4] iommu / x86: move call to scan_pci_devices() out of vendor code

From: Paul Durrant <paul.durrant@citrix.com>
To: <xen-devel@lists.xenproject.org>
Cc: Kevin Tian <kevin.tian@intel.com>,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
	Wei Liu <wl@xen.org>, Andrew Cooper <andrew.cooper3@citrix.com>,
	Paul Durrant <paul.durrant@citrix.com>,
	Jan Beulich <jbeulich@suse.com>,
	Brian Woods <brian.woods@amd.com>
Subject: [Xen-devel] [PATCH v3 1/4] iommu / x86: move call to scan_pci_devices() out of vendor code
Date: Tue, 16 Jul 2019 11:16:54 +0100	[thread overview]
Message-ID: <20190716101657.23327-2-paul.durrant@citrix.com> (raw)
In-Reply-To: <20190716101657.23327-1-paul.durrant@citrix.com>

It's not vendor specific so it doesn't really belong there.

Scanning the PCI topology also really doesn't have much to do with IOMMU
initialization. It doesn't depend on there even being an IOMMU. This patch
moves to the call to the beginning of iommu_hardware_setup() but only
places it there because the topology information would be otherwise unused.

Subsequent patches will actually make use of the PCI topology during
(x86) IOMMU initialization.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: "Roger Pau Monné" <roger.pau@citrix.com>
---
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Brian Woods <brian.woods@amd.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Wei Liu <wl@xen.org>

v2:
 - Expanded commit comment.
 - Moved PCI scan to before IOMMU initialization, rather than after it.
---
 xen/drivers/passthrough/amd/pci_amd_iommu.c | 3 ++-
 xen/drivers/passthrough/vtd/iommu.c         | 4 ----
 xen/drivers/passthrough/x86/iommu.c         | 6 ++++++
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 4afbcd1609..3338a8e0e8 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -180,7 +180,8 @@ static int __init iov_detect(void)
 
     if ( !amd_iommu_perdev_intremap )
         printk(XENLOG_WARNING "AMD-Vi: Using global interrupt remap table is not recommended (see XSA-36)!\n");
-    return scan_pci_devices();
+
+    return 0;
 }
 
 int amd_iommu_alloc_root(struct domain_iommu *hd)
diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 8b27d7e775..b0e3bf26b5 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2372,10 +2372,6 @@ static int __init vtd_setup(void)
     P(iommu_hap_pt_share, "Shared EPT tables");
 #undef P
 
-    ret = scan_pci_devices();
-    if ( ret )
-        goto error;
-
     ret = init_vtd_hw();
     if ( ret )
         goto error;
diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c
index 0fa6dcc3fd..a7438c9c25 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -28,9 +28,15 @@ struct iommu_ops __read_mostly iommu_ops;
 
 int __init iommu_hardware_setup(void)
 {
+    int rc;
+
     if ( !iommu_init_ops )
         return -ENODEV;
 
+    rc = scan_pci_devices();
+    if ( rc )
+        return rc;
+
     if ( !iommu_ops.init )
         iommu_ops = *iommu_init_ops->ops;
     else
-- 
2.11.0


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