Revert "pcie_sriov: Reuse SR-IOV VF device instances"

This reverts commit 139610ae67.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/pci/pci.c

@@ -2895,7 +2895,7 @@ void pci_set_enabled(PCIDevice *d, bool state)
     memory_region_set_enabled(&d->bus_master_enable_region,
                               (pci_get_word(d->config + PCI_COMMAND)
                                & PCI_COMMAND_MASTER) && d->enabled);
-    if (d->qdev.realized) {
+    if (!d->enabled) {
         pci_device_reset(d);
     }
 }

hw/pci/pcie_sriov.c

@@ -20,16 +20,9 @@
 #include "qapi/error.h"
 #include "trace.h"
 
-static void unparent_vfs(PCIDevice *dev, uint16_t total_vfs)
-{
-    for (uint16_t i = 0; i < total_vfs; i++) {
-        PCIDevice *vf = dev->exp.sriov_pf.vf[i];
-        object_unparent(OBJECT(vf));
-        object_unref(OBJECT(vf));
-    }
-    g_free(dev->exp.sriov_pf.vf);
-    dev->exp.sriov_pf.vf = NULL;
-}
+static PCIDevice *register_vf(PCIDevice *pf, int devfn,
+                              const char *name, uint16_t vf_num);
+static void unregister_vfs(PCIDevice *dev);
 
 bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
                         const char *vfname, uint16_t vf_dev_id,
@@ -37,8 +30,6 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
                         uint16_t vf_offset, uint16_t vf_stride,
                         Error **errp)
 {
-    BusState *bus = qdev_get_parent_bus(&dev->qdev);
-    int32_t devfn = dev->devfn + vf_offset;
     uint8_t *cfg = dev->config + offset;
     uint8_t *wmask;
 
@@ -58,6 +49,7 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
                         offset, PCI_EXT_CAP_SRIOV_SIZEOF);
     dev->exp.sriov_cap = offset;
     dev->exp.sriov_pf.num_vfs = 0;
+    dev->exp.sriov_pf.vfname = g_strdup(vfname);
     dev->exp.sriov_pf.vf = NULL;
 
     pci_set_word(cfg + PCI_SRIOV_VF_OFFSET, vf_offset);
@@ -91,34 +83,14 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset,
 
     qdev_prop_set_bit(&dev->qdev, "multifunction", true);
 
-    dev->exp.sriov_pf.vf = g_new(PCIDevice *, total_vfs);
-
-    for (uint16_t i = 0; i < total_vfs; i++) {
-        PCIDevice *vf = pci_new(devfn, vfname);
-        vf->exp.sriov_vf.pf = dev;
-        vf->exp.sriov_vf.vf_number = i;
-
-        if (!qdev_realize(&vf->qdev, bus, errp)) {
-            unparent_vfs(dev, i);
-            return false;
-        }
-
-        /* set vid/did according to sr/iov spec - they are not used */
-        pci_config_set_vendor_id(vf->config, 0xffff);
-        pci_config_set_device_id(vf->config, 0xffff);
-
-        dev->exp.sriov_pf.vf[i] = vf;
-        devfn += vf_stride;
-    }
-
     return true;
 }
 
 void pcie_sriov_pf_exit(PCIDevice *dev)
 {
-    uint8_t *cfg = dev->config + dev->exp.sriov_cap;
-
-    unparent_vfs(dev, pci_get_word(cfg + PCI_SRIOV_TOTAL_VF));
+    unregister_vfs(dev);
+    g_free((char *)dev->exp.sriov_pf.vfname);
+    dev->exp.sriov_pf.vfname = NULL;
 }
 
 void pcie_sriov_pf_init_vf_bar(PCIDevice *dev, int region_num,
@@ -184,11 +156,38 @@ void pcie_sriov_vf_register_bar(PCIDevice *dev, int region_num,
     }
 }
 
+static PCIDevice *register_vf(PCIDevice *pf, int devfn, const char *name,
+                              uint16_t vf_num)
+{
+    PCIDevice *dev = pci_new(devfn, name);
+    dev->exp.sriov_vf.pf = pf;
+    dev->exp.sriov_vf.vf_number = vf_num;
+    PCIBus *bus = pci_get_bus(pf);
+    Error *local_err = NULL;
+
+    qdev_realize(&dev->qdev, &bus->qbus, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+        return NULL;
+    }
+
+    /* set vid/did according to sr/iov spec - they are not used */
+    pci_config_set_vendor_id(dev->config, 0xffff);
+    pci_config_set_device_id(dev->config, 0xffff);
+
+    return dev;
+}
+
 static void register_vfs(PCIDevice *dev)
 {
     uint16_t num_vfs;
     uint16_t i;
     uint16_t sriov_cap = dev->exp.sriov_cap;
+    uint16_t vf_offset =
+        pci_get_word(dev->config + sriov_cap + PCI_SRIOV_VF_OFFSET);
+    uint16_t vf_stride =
+        pci_get_word(dev->config + sriov_cap + PCI_SRIOV_VF_STRIDE);
+    int32_t devfn = dev->devfn + vf_offset;
 
     assert(sriov_cap > 0);
     num_vfs = pci_get_word(dev->config + sriov_cap + PCI_SRIOV_NUM_VF);
@@ -196,10 +195,18 @@ static void register_vfs(PCIDevice *dev)
         return;
     }
 
+    dev->exp.sriov_pf.vf = g_new(PCIDevice *, num_vfs);
+
     trace_sriov_register_vfs(dev->name, PCI_SLOT(dev->devfn),
                              PCI_FUNC(dev->devfn), num_vfs);
     for (i = 0; i < num_vfs; i++) {
-        pci_set_enabled(dev->exp.sriov_pf.vf[i], true);
+        dev->exp.sriov_pf.vf[i] = register_vf(dev, devfn,
+                                              dev->exp.sriov_pf.vfname, i);
+        if (!dev->exp.sriov_pf.vf[i]) {
+            num_vfs = i;
+            break;
+        }
+        devfn += vf_stride;
     }
     dev->exp.sriov_pf.num_vfs = num_vfs;
 }
@@ -212,8 +219,12 @@ static void unregister_vfs(PCIDevice *dev)
     trace_sriov_unregister_vfs(dev->name, PCI_SLOT(dev->devfn),
                                PCI_FUNC(dev->devfn), num_vfs);
     for (i = 0; i < num_vfs; i++) {
-        pci_set_enabled(dev->exp.sriov_pf.vf[i], false);
+        PCIDevice *vf = dev->exp.sriov_pf.vf[i];
+        object_unparent(OBJECT(vf));
+        object_unref(OBJECT(vf));
     }
+    g_free(dev->exp.sriov_pf.vf);
+    dev->exp.sriov_pf.vf = NULL;
     dev->exp.sriov_pf.num_vfs = 0;
 }
 
@@ -235,10 +246,14 @@ void pcie_sriov_config_write(PCIDevice *dev, uint32_t address,
                              PCI_FUNC(dev->devfn), off, val, len);
 
     if (range_covers_byte(off, len, PCI_SRIOV_CTRL)) {
-        if (val & PCI_SRIOV_CTRL_VFE) {
-            register_vfs(dev);
+        if (dev->exp.sriov_pf.num_vfs) {
+            if (!(val & PCI_SRIOV_CTRL_VFE)) {
+                unregister_vfs(dev);
+            }
         } else {
-            unregister_vfs(dev);
+            if (val & PCI_SRIOV_CTRL_VFE) {
+                register_vfs(dev);
+            }
         }
     }
 }

include/hw/pci/pci.h

@@ -680,4 +680,9 @@ static inline void pci_irq_pulse(PCIDevice *pci_dev)
 MSIMessage pci_get_msi_message(PCIDevice *dev, int vector);
 void pci_set_enabled(PCIDevice *pci_dev, bool state);
 
+static inline void pci_set_power(PCIDevice *pci_dev, bool state)
+{
+    pci_set_enabled(pci_dev, state);
+}
+
 #endif

include/hw/pci/pci_device.h

@@ -212,21 +212,6 @@ static inline uint16_t pci_get_bdf(PCIDevice *dev)
     return PCI_BUILD_BDF(pci_bus_num(pci_get_bus(dev)), dev->devfn);
 }
 
-static inline void pci_set_power(PCIDevice *pci_dev, bool state)
-{
-    /*
-     * Don't change the enabled state of VFs when powering on/off the device.
-     *
-     * When powering on, VFs must not be enabled immediately but they must
-     * wait until the guest configures SR-IOV.
-     * When powering off, their corresponding PFs will be reset and disable
-     * VFs.
-     */
-    if (!pci_is_vf(pci_dev)) {
-        pci_set_enabled(pci_dev, state);
-    }
-}
-
 uint16_t pci_requester_id(PCIDevice *dev);
 
 /* DMA access functions */

include/hw/pci/pcie_sriov.h

@@ -18,6 +18,7 @@
 typedef struct PCIESriovPF {
     uint16_t num_vfs;   /* Number of virtual functions created */
     uint8_t vf_bar_type[PCI_NUM_REGIONS];   /* Store type for each VF bar */
+    const char *vfname; /* Reference to the device type used for the VFs */
     PCIDevice **vf;     /* Pointer to an array of num_vfs VF devices */
 } PCIESriovPF;