fix(vm): regressions: provider always tries to update cpu.affinity even if it is not specified (#1182)

Signed-off-by: Pavel Boldyrev <627562+bpg@users.noreply.github.com>

.vscode/settings.json

@@ -1,4 +1,11 @@
 {
+    "editor.bracketPairColorization.enabled": true,
+    "editor.guides.bracketPairs": true,
+    "editor.guides.bracketPairsHorizontal": true,
+    "editor.guides.highlightActiveBracketPair": true,
+    "editor.rulers": [
+        100
+    ],
     "git.alwaysSignOff": true,
     "cSpell.words": [
         "aarch",

fwprovider/tests/resource_vm_test.go

@@ -87,6 +87,35 @@ func TestAccResourceVM(t *testing.T) {
 				),
 			}},
 		},
+		{
+			"update CPU block", []resource.TestStep{{
+				Config: `
+				resource "proxmox_virtual_environment_vm" "test_vm5" {
+					node_name = "pve"
+					started   = false
+					
+					cpu {
+						cores = 2
+					}
+				}`,
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("proxmox_virtual_environment_vm.test_vm5", "cpu.0.cores", "2"),
+				),
+			}, {
+				Config: `
+				resource "proxmox_virtual_environment_vm" "test_vm5" {
+					node_name = "pve"
+					started   = false
+					
+					cpu {
+						cores = 1
+					}
+				}`,
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("proxmox_virtual_environment_vm.test_vm5", "cpu.0.cores", "1"),
+				),
+			}},
+		},
 	}
 
 	accProviders := testAccMuxProviders(context.Background(), t)

proxmoxtf/resource/vm/vm.go

@@ -4823,10 +4823,15 @@ func vmUpdate(ctx context.Context, d *schema.ResourceData, m interface{}) diag.D
 		updateBody.CPUUnits = &cpuUnits
 		updateBody.NUMAEnabled = &cpuNUMA
 
-		if cpuAffinity != "" {
-			updateBody.CPUAffinity = &cpuAffinity
-		} else {
-			del = append(del, "affinity")
+		// CPU affinity is a special case, only root can change it.
+		// we can't even have it in the delete list, as PVE will return an error for non-root.
+		// Hence, checking explicitly if it has changed.
+		if d.HasChange(mkCPU + ".0." + mkCPUAffinity) {
+			if cpuAffinity != "" {
+				updateBody.CPUAffinity = &cpuAffinity
+			} else {
+				del = append(del, "affinity")
+			}
 		}
 
 		if cpuHotplugged > 0 {