[RFC v3 13/19] vfio-user: pci_user_realize PCI setup

From: John Johnson <john.g.johnson@oracle.com>
To: qemu-devel@nongnu.org
Subject: [RFC v3 13/19] vfio-user: pci_user_realize PCI setup
Date: Mon,  8 Nov 2021 16:46:41 -0800	[thread overview]
Message-ID: <faab1fd983815a5563b246849d68d57884d3fb41.1636057885.git.john.g.johnson@oracle.com> (raw)
In-Reply-To: <cover.1636057885.git.john.g.johnson@oracle.com>

PCI BARs read from remote device
PCI config reads/writes sent to remote server

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
 hw/vfio/pci.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 88 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index d5f9987..f8729b2 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3551,8 +3551,93 @@ static void vfio_user_pci_realize(PCIDevice *pdev, Error **errp)
         goto error;
     }
 
+    /* Get a copy of config space */
+    ret = VDEV_REGION_READ(vbasedev, VFIO_PCI_CONFIG_REGION_INDEX, 0,
+                           MIN(pci_config_size(pdev), vdev->config_size),
+                           pdev->config);
+    if (ret < (int)MIN(pci_config_size(&vdev->pdev), vdev->config_size)) {
+        error_setg_errno(errp, -ret, "failed to read device config space");
+        goto error;
+    }
+
+    /* vfio emulates a lot for us, but some bits need extra love */
+    vdev->emulated_config_bits = g_malloc0(vdev->config_size);
+
+    /* QEMU can choose to expose the ROM or not */
+    memset(vdev->emulated_config_bits + PCI_ROM_ADDRESS, 0xff, 4);
+    /* QEMU can also add or extend BARs */
+    memset(vdev->emulated_config_bits + PCI_BASE_ADDRESS_0, 0xff, 6 * 4);
+    vdev->vendor_id = pci_get_word(pdev->config + PCI_VENDOR_ID);
+    vdev->device_id = pci_get_word(pdev->config + PCI_DEVICE_ID);
+
+    /* QEMU can change multi-function devices to single function, or reverse */
+    vdev->emulated_config_bits[PCI_HEADER_TYPE] =
+                                              PCI_HEADER_TYPE_MULTI_FUNCTION;
+
+    /* Restore or clear multifunction, this is always controlled by QEMU */
+    if (vdev->pdev.cap_present & QEMU_PCI_CAP_MULTIFUNCTION) {
+        vdev->pdev.config[PCI_HEADER_TYPE] |= PCI_HEADER_TYPE_MULTI_FUNCTION;
+    } else {
+        vdev->pdev.config[PCI_HEADER_TYPE] &= ~PCI_HEADER_TYPE_MULTI_FUNCTION;
+    }
+
+    /*
+     * Clear host resource mapping info.  If we choose not to register a
+     * BAR, such as might be the case with the option ROM, we can get
+     * confusing, unwritable, residual addresses from the host here.
+     */
+    memset(&vdev->pdev.config[PCI_BASE_ADDRESS_0], 0, 24);
+    memset(&vdev->pdev.config[PCI_ROM_ADDRESS], 0, 4);
+
+    vfio_pci_size_rom(vdev);
+
+    vfio_bars_prepare(vdev);
+
+    vfio_msix_early_setup(vdev, &err);
+    if (err) {
+        error_propagate(errp, err);
+        goto error;
+    }
+
+    vfio_bars_register(vdev);
+
+    ret = vfio_add_capabilities(vdev, errp);
+    if (ret) {
+        goto out_teardown;
+    }
+
+    /* QEMU emulates all of MSI & MSIX */
+    if (pdev->cap_present & QEMU_PCI_CAP_MSIX) {
+        memset(vdev->emulated_config_bits + pdev->msix_cap, 0xff,
+               MSIX_CAP_LENGTH);
+    }
+
+    if (pdev->cap_present & QEMU_PCI_CAP_MSI) {
+        memset(vdev->emulated_config_bits + pdev->msi_cap, 0xff,
+               vdev->msi_cap_size);
+    }
+
+    if (vdev->pdev.config[PCI_INTERRUPT_PIN] != 0) {
+        vdev->intx.mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
+                                             vfio_intx_mmap_enable, vdev);
+        pci_device_set_intx_routing_notifier(&vdev->pdev,
+                                             vfio_intx_routing_notifier);
+        vdev->irqchip_change_notifier.notify = vfio_irqchip_change;
+        kvm_irqchip_add_change_notifier(&vdev->irqchip_change_notifier);
+        ret = vfio_intx_enable(vdev, errp);
+        if (ret) {
+            goto out_deregister;
+        }
+    }
+
     return;
 
+out_deregister:
+    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
+    kvm_irqchip_remove_change_notifier(&vdev->irqchip_change_notifier);
+out_teardown:
+    vfio_teardown_msi(vdev);
+    vfio_bars_exit(vdev);
 error:
     vfio_user_disconnect(proxy);
     error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.name);
@@ -3565,7 +3650,9 @@ static void vfio_user_instance_finalize(Object *obj)
 
     vfio_put_device(vdev);
 
-    vfio_user_disconnect(vbasedev->proxy);
+    if (vbasedev->proxy != NULL) {
+        vfio_user_disconnect(vbasedev->proxy);
+    }
 }
 
 static Property vfio_user_pci_dev_properties[] = {
-- 
1.8.3.1


