[Qemu-devel] [RFC][PATCH 35/45] pci-assign: Polish assigned_dev_update_msix_mmio

[Jan Kiszka]

- rename to assigned_dev_set_msix_vectors
- drop unused msg_ctrl
- use pci_get_* accessors
- rename variable va to msix_page
- clarify comment on msg_data == 0 optimization
- fix coding style

Signed-off-by: Jan Kiszka <address@hidden>
---
 hw/device-assignment.c |   53 ++++++++++++++++++++++++++---------------------
 1 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 7a8f702..83951a3 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -949,42 +949,43 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev)
     }
 }
 
-static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
+static int assigned_dev_set_msix_vectors(PCIDevice *pci_dev)
 {
     AssignedDevice *adev = DO_UPCAST(AssignedDevice, dev, pci_dev);
     uint16_t entries_nr = 0, entries_max_nr;
     int pos = 0, i, r = 0;
-    uint32_t msg_addr, msg_upper_addr, msg_data, msg_ctrl;
+    uint32_t msg_addr, msg_upper_addr, msg_data;
     struct kvm_assigned_msix_nr msix_nr;
     struct kvm_assigned_msix_entry msix_entry;
-    void *va = adev->msix_table_page;
+    void *msix_page = adev->msix_table_page;
 
     pos = pci_find_capability(pci_dev, PCI_CAP_ID_MSIX);
 
-    entries_max_nr = *(uint16_t *)(pci_dev->config + pos + 2);
+    entries_max_nr = pci_get_word(pci_dev->config + pos + PCI_MSIX_FLAGS);
     entries_max_nr &= PCI_MSIX_FLAGS_QSIZE;
     entries_max_nr += 1;
 
     /* Get the usable entry number for allocating */
     for (i = 0; i < entries_max_nr; i++) {
-        memcpy(&msg_ctrl, va + i * 16 + 12, 4);
-        memcpy(&msg_data, va + i * 16 + 8, 4);
-        /* Ignore unused entry even it's unmasked */
-        if (msg_data == 0)
+        /* Assuming IA-32 MSI message format:
+         * Ignore unused entry (invalid vector) */
+        if (pci_get_long(msix_page + i * PCI_MSIX_ENTRY_SIZE +
+                         PCI_MSIX_ENTRY_DATA) == 0) {
             continue;
-        entries_nr ++;
+        }
+        entries_nr++;
     }
-
     if (entries_nr == 0) {
         fprintf(stderr, "MSI-X entry number is zero!\n");
         return -EINVAL;
     }
+
     msix_nr.assigned_dev_id = calc_assigned_dev_id(adev);
     msix_nr.entry_nr = entries_nr;
     r = kvm_assign_set_msix_nr(kvm_state, &msix_nr);
     if (r != 0) {
         fprintf(stderr, "fail to set MSI-X entry number for MSIX! %s\n",
-                       strerror(-r));
+                strerror(-r));
         return r;
     }
 
@@ -995,19 +996,23 @@ static int assigned_dev_update_msix_mmio(PCIDevice 
*pci_dev)
     msix_entry.assigned_dev_id = msix_nr.assigned_dev_id;
     entries_nr = 0;
     for (i = 0; i < entries_max_nr; i++) {
-        if (entries_nr >= msix_nr.entry_nr)
+        if (entries_nr >= msix_nr.entry_nr) {
             break;
-        memcpy(&msg_ctrl, va + i * 16 + 12, 4);
-        memcpy(&msg_data, va + i * 16 + 8, 4);
-        if (msg_data == 0)
+        }
+        msg_data = pci_get_long(msix_page + i * PCI_MSIX_ENTRY_SIZE +
+                                PCI_MSIX_ENTRY_DATA);
+        if (msg_data == 0) {
             continue;
-
-        memcpy(&msg_addr, va + i * 16, 4);
-        memcpy(&msg_upper_addr, va + i * 16 + 4, 4);
+        }
+        msg_addr = pci_get_long(msix_page + i * PCI_MSIX_ENTRY_SIZE +
+                                PCI_MSIX_ENTRY_LOWER_ADDR);
+        msg_upper_addr = pci_get_long(msix_page + i * PCI_MSIX_ENTRY_SIZE +
+                                      PCI_MSIX_ENTRY_UPPER_ADDR);
 
         r = kvm_get_irq_route_gsi();
-        if (r < 0)
+        if (r < 0) {
             return r;
+        }
 
         adev->entry[entries_nr].gsi = r;
         adev->entry[entries_nr].type = KVM_IRQ_ROUTING_MSI;
@@ -1026,13 +1031,13 @@ static int assigned_dev_update_msix_mmio(PCIDevice 
*pci_dev)
             break;
         }
         DEBUG("MSI-X entry gsi 0x%x, entry %d\n!",
-                msix_entry.gsi, msix_entry.entry);
-        entries_nr ++;
+              msix_entry.gsi, msix_entry.entry);
+        entries_nr++;
     }
 
     if (r == 0 && kvm_commit_irq_routes() < 0) {
-           perror("assigned_dev_update_msix_mmio: kvm_commit_irq_routes");
-           return -EINVAL;
+        perror("assigned_dev_update_msix_mmio: kvm_commit_irq_routes");
+        return -EINVAL;
     }
 
     return r;
@@ -1070,7 +1075,7 @@ static void assigned_dev_update_msix(PCIDevice *pci_dev)
         assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX |
                                   KVM_DEV_IRQ_GUEST_MSIX;
 
-        if (assigned_dev_update_msix_mmio(pci_dev) < 0) {
+        if (assigned_dev_set_msix_vectors(pci_dev) < 0) {
             perror("assigned_dev_update_msix_mmio");
             return;
         }
-- 
1.7.3.4