[Xen-devel] [PATCH 1/2] vpci/msi: split code to bind pirq

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

And put it in a separate update function. This is required in order to
improve binding of MSI PIRQs when using vPCI.

No functional change.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/hvm/vmsi.c | 73 +++++++++++++++++++++++++----------------
 1 file changed, 45 insertions(+), 28 deletions(-)

diff --git a/xen/arch/x86/hvm/vmsi.c b/xen/arch/x86/hvm/vmsi.c
index 900d4f67d4..6e19851439 100644
--- a/xen/arch/x86/hvm/vmsi.c
+++ b/xen/arch/x86/hvm/vmsi.c
@@ -663,6 +663,42 @@ void vpci_msi_arch_mask(struct vpci_msi *msi, const struct 
pci_dev *pdev,
     vpci_mask_pirq(pdev->domain, msi->arch.pirq + entry, mask);
 }
 
+static int vpci_msi_update(const struct pci_dev *pdev, uint32_t data,
+                           uint64_t address, unsigned int vectors,
+                           unsigned int pirq, uint32_t mask)
+{
+    unsigned int i;
+
+    ASSERT(pcidevs_locked());
+
+    for ( i = 0; i < vectors; i++ )
+    {
+        uint8_t vector = MASK_EXTR(data, MSI_DATA_VECTOR_MASK);
+        uint8_t vector_mask = 0xff >> (8 - fls(vectors) + 1);
+        struct xen_domctl_bind_pt_irq bind = {
+            .machine_irq = pirq + i,
+            .irq_type = PT_IRQ_TYPE_MSI,
+            .u.msi.gvec = (vector & ~vector_mask) |
+                          ((vector + i) & vector_mask),
+            .u.msi.gflags = msi_gflags(data, address, (mask >> i) & 1),
+        };
+        int rc = pt_irq_create_bind(pdev->domain, &bind);
+
+        if ( rc )
+        {
+            gdprintk(XENLOG_ERR,
+                     "%04x:%02x:%02x.%u: failed to bind PIRQ %u: %d\n",
+                     pdev->seg, pdev->bus, PCI_SLOT(pdev->devfn),
+                     PCI_FUNC(pdev->devfn), pirq + i, rc);
+            while ( bind.machine_irq-- )
+                pt_irq_destroy_bind(pdev->domain, &bind);
+            return rc;
+        }
+    }
+
+    return 0;
+}
+
 static int vpci_msi_enable(const struct pci_dev *pdev, uint32_t data,
                            uint64_t address, unsigned int nr,
                            paddr_t table_base, uint32_t mask)
@@ -674,7 +710,7 @@ static int vpci_msi_enable(const struct pci_dev *pdev, 
uint32_t data,
         .table_base = table_base,
         .entry_nr = nr,
     };
-    unsigned int i, vectors = table_base ? 1 : nr;
+    unsigned vectors = table_base ? 1 : nr;
     int rc, pirq = INVALID_PIRQ;
 
     /* Get a PIRQ. */
@@ -690,36 +726,17 @@ static int vpci_msi_enable(const struct pci_dev *pdev, 
uint32_t data,
         return rc;
     }
 
-    for ( i = 0; i < vectors; i++ )
+    pcidevs_lock();
+    rc = vpci_msi_update(pdev, data, address, vectors, pirq, mask);
+    if ( rc )
     {
-        uint8_t vector = MASK_EXTR(data, MSI_DATA_VECTOR_MASK);
-        uint8_t vector_mask = 0xff >> (8 - fls(vectors) + 1);
-        struct xen_domctl_bind_pt_irq bind = {
-            .machine_irq = pirq + i,
-            .irq_type = PT_IRQ_TYPE_MSI,
-            .u.msi.gvec = (vector & ~vector_mask) |
-                          ((vector + i) & vector_mask),
-            .u.msi.gflags = msi_gflags(data, address, (mask >> i) & 1),
-        };
-
-        pcidevs_lock();
-        rc = pt_irq_create_bind(pdev->domain, &bind);
-        if ( rc )
-        {
-            gdprintk(XENLOG_ERR,
-                     "%04x:%02x:%02x.%u: failed to bind PIRQ %u: %d\n",
-                     pdev->seg, pdev->bus, PCI_SLOT(pdev->devfn),
-                     PCI_FUNC(pdev->devfn), pirq + i, rc);
-            while ( bind.machine_irq-- )
-                pt_irq_destroy_bind(pdev->domain, &bind);
-            spin_lock(&pdev->domain->event_lock);
-            unmap_domain_pirq(pdev->domain, pirq);
-            spin_unlock(&pdev->domain->event_lock);
-            pcidevs_unlock();
-            return rc;
-        }
+        spin_lock(&pdev->domain->event_lock);
+        unmap_domain_pirq(pdev->domain, pirq);
+        spin_unlock(&pdev->domain->event_lock);
         pcidevs_unlock();
+        return rc;
     }
+    pcidevs_unlock();
 
     return pirq;
 }
-- 
2.17.0


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