[PATCH 6/7] qemu-kvm: Move entry comparison into kvm_msi_update_message

[Jan Kiszka <jan.kiszka@xxxxxx>]

From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

Checking the the update chances the message content is a common task for
both MSI types.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
 hw/msix.c  |   26 +++++++++++++-------------
 qemu-kvm.c |   14 +++++++++++++-
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/hw/msix.c b/hw/msix.c
index 8c8bc18..9cee086 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -76,8 +76,10 @@ static void kvm_msix_message_from_vector(PCIDevice *dev, unsigned vector,
 static void kvm_msix_update(PCIDevice *dev, int vector,
                             int was_masked, int is_masked)
 {
-    KVMMsiMessage e = {}, *entry;
+    KVMMsiMessage new_entry, *entry;
     int mask_cleared = was_masked && !is_masked;
+    int r;
+
     /* It is only legal to change an entry when it is masked. Therefore, it is
      * enough to update the routing in kernel when mask is being cleared. */
     if (!mask_cleared) {
@@ -86,19 +88,17 @@ static void kvm_msix_update(PCIDevice *dev, int vector,
     if (!dev->msix_entry_used[vector]) {
         return;
     }
-    entry = dev->msix_irq_entries + vector;
-    e.gsi = entry->gsi;
-    kvm_msix_message_from_vector(dev, vector, &e);
-    if (memcmp(entry, &e, sizeof e) != 0) {
-        int r;
 
-        r = kvm_msi_message_update(entry, &e);
-        if (r) {
-            fprintf(stderr, "%s: kvm_update_msix failed: %s\n", __func__,
-		    strerror(-r));
-            exit(1);
-        }
-        *entry = e;
+    entry = dev->msix_irq_entries + vector;
+    kvm_msix_message_from_vector(dev, vector, &new_entry);
+    r = kvm_msi_message_update(entry, &new_entry);
+    if (r < 0) {
+        fprintf(stderr, "%s: kvm_update_msix failed: %s\n", __func__,
+                strerror(-r));
+        exit(1);
+    }
+    if (r > 0) {
+        *entry = new_entry;
         r = kvm_commit_irq_routes();
         if (r) {
             fprintf(stderr, "%s: kvm_commit_irq_routes failed: %s\n", __func__,
diff --git a/qemu-kvm.c b/qemu-kvm.c
index 7317f87..e8c2009 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -1011,10 +1011,22 @@ int kvm_msi_message_del(KVMMsiMessage *msg)
 int kvm_msi_message_update(KVMMsiMessage *old, KVMMsiMessage *new)
 {
     struct kvm_irq_routing_entry e1, e2;
+    int ret;
+
+    new->gsi = old->gsi;
+    if (memcmp(old, new, sizeof(KVMMsiMessage)) == 0) {
+        return 0;
+    }
 
     kvm_msi_routing_entry(&e1, old);
     kvm_msi_routing_entry(&e2, new);
-    return kvm_update_routing_entry(&e1, &e2);
+
+    ret = kvm_update_routing_entry(&e1, &e2);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return 1;
 }
 
 
-- 
1.7.1

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