libqos: Change PCI accessors to take opaque BAR handle

The usual use model for the libqos PCI functions is to map a specific PCI
BAR using qpci_iomap() then pass the returned token into IO accessor
functions.  This, and the fact that iomap() returns a (void *) which
actually contains a PCI space address, kind of suggests that the return
value from iomap is supposed to be an opaque token.

..except that the callers expect to be able to add offsets to it.  Which
also assumes the compiler will support pointer arithmetic on a (void *),
and treat it as working with byte offsets.

To clarify this situation change iomap() and the IO accessors to take
a definitely opaque BAR handle (enforced with a wrapper struct) along with
an offset within the BAR.  This changes both the functions and all the
callers.

There were a number of places that checked if iomap() returned non-NULL,
and or initialized it to NULL before hand.  Since iomap() already assert()s
if it fails to map the BAR, these tests were mostly pointless and are
removed.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>

1 files changed, 53 insertions, 48 deletions

diff --git a/tests/libqos/virtio-pci.c b/tests/libqos/virtio-pci.c
index c69d09ddb2..d4bf841f23 100644
--- a/tests/libqos/virtio-pci.c
+++ b/tests/libqos/virtio-pci.c
@@ -62,13 +62,12 @@ static void qvirtio_pci_assign_device(QVirtioDevice *d, void *data)
     *vpcidev = (QVirtioPCIDevice *)d;
 }
 
-#define CONFIG_BASE(dev) \
-    ((dev)->addr + VIRTIO_PCI_CONFIG_OFF((dev)->pdev->msix_enabled))
+#define CONFIG_BASE(dev) (VIRTIO_PCI_CONFIG_OFF((dev)->pdev->msix_enabled))
 
 static uint8_t qvirtio_pci_config_readb(QVirtioDevice *d, uint64_t off)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    return qpci_io_readb(dev->pdev, CONFIG_BASE(dev) + off);
+    return qpci_io_readb(dev->pdev, dev->bar, CONFIG_BASE(dev) + off);
 }
 
 /* PCI is always read in little-endian order
@@ -84,7 +83,7 @@ static uint16_t qvirtio_pci_config_readw(QVirtioDevice *d, uint64_t off)
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
     uint16_t value;
 
-    value = qpci_io_readw(dev->pdev, CONFIG_BASE(dev) + off);
+    value = qpci_io_readw(dev->pdev, dev->bar, CONFIG_BASE(dev) + off);
     if (qvirtio_is_big_endian(d)) {
         value = bswap16(value);
     }
@@ -96,7 +95,7 @@ static uint32_t qvirtio_pci_config_readl(QVirtioDevice *d, uint64_t off)
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
     uint32_t value;
 
-    value = qpci_io_readl(dev->pdev, CONFIG_BASE(dev) + off);
+    value = qpci_io_readl(dev->pdev, dev->bar, CONFIG_BASE(dev) + off);
     if (qvirtio_is_big_endian(d)) {
         value = bswap32(value);
     }
@@ -108,7 +107,7 @@ static uint64_t qvirtio_pci_config_readq(QVirtioDevice *d, uint64_t off)
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
     uint64_t val;
 
-    val = qpci_io_readq(dev->pdev, CONFIG_BASE(dev) + off);
+    val = qpci_io_readq(dev->pdev, dev->bar, CONFIG_BASE(dev) + off);
     if (qvirtio_is_big_endian(d)) {
         val = bswap64(val);
     }
@@ -119,31 +118,31 @@ static uint64_t qvirtio_pci_config_readq(QVirtioDevice *d, uint64_t off)
 static uint32_t qvirtio_pci_get_features(QVirtioDevice *d)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    return qpci_io_readl(dev->pdev, dev->addr + VIRTIO_PCI_HOST_FEATURES);
+    return qpci_io_readl(dev->pdev, dev->bar, VIRTIO_PCI_HOST_FEATURES);
 }
 
 static void qvirtio_pci_set_features(QVirtioDevice *d, uint32_t features)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    qpci_io_writel(dev->pdev, dev->addr + VIRTIO_PCI_GUEST_FEATURES, features);
+    qpci_io_writel(dev->pdev, dev->bar, VIRTIO_PCI_GUEST_FEATURES, features);
 }
 
 static uint32_t qvirtio_pci_get_guest_features(QVirtioDevice *d)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    return qpci_io_readl(dev->pdev, dev->addr + VIRTIO_PCI_GUEST_FEATURES);
+    return qpci_io_readl(dev->pdev, dev->bar, VIRTIO_PCI_GUEST_FEATURES);
 }
 
 static uint8_t qvirtio_pci_get_status(QVirtioDevice *d)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    return qpci_io_readb(dev->pdev, dev->addr + VIRTIO_PCI_STATUS);
+    return qpci_io_readb(dev->pdev, dev->bar, VIRTIO_PCI_STATUS);
 }
 
 static void qvirtio_pci_set_status(QVirtioDevice *d, uint8_t status)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    qpci_io_writeb(dev->pdev, dev->addr + VIRTIO_PCI_STATUS, status);
+    qpci_io_writeb(dev->pdev, dev->bar, VIRTIO_PCI_STATUS, status);
 }
 
 static bool qvirtio_pci_get_queue_isr_status(QVirtioDevice *d, QVirtQueue *vq)
@@ -167,7 +166,7 @@ static bool qvirtio_pci_get_queue_isr_status(QVirtioDevice *d, QVirtQueue *vq)
             }
         }
     } else {
-        return qpci_io_readb(dev->pdev, dev->addr + VIRTIO_PCI_ISR) & 1;
+        return qpci_io_readb(dev->pdev, dev->bar, VIRTIO_PCI_ISR) & 1;
     }
 }
 
@@ -191,26 +190,26 @@ static bool qvirtio_pci_get_config_isr_status(QVirtioDevice *d)
             }
         }
     } else {
-        return qpci_io_readb(dev->pdev, dev->addr + VIRTIO_PCI_ISR) & 2;
+        return qpci_io_readb(dev->pdev, dev->bar, VIRTIO_PCI_ISR) & 2;
     }
 }
 
 static void qvirtio_pci_queue_select(QVirtioDevice *d, uint16_t index)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    qpci_io_writeb(dev->pdev, dev->addr + VIRTIO_PCI_QUEUE_SEL, index);
+    qpci_io_writeb(dev->pdev, dev->bar, VIRTIO_PCI_QUEUE_SEL, index);
 }
 
 static uint16_t qvirtio_pci_get_queue_size(QVirtioDevice *d)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    return qpci_io_readw(dev->pdev, dev->addr + VIRTIO_PCI_QUEUE_NUM);
+    return qpci_io_readw(dev->pdev, dev->bar, VIRTIO_PCI_QUEUE_NUM);
 }
 
 static void qvirtio_pci_set_queue_address(QVirtioDevice *d, uint32_t pfn)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    qpci_io_writel(dev->pdev, dev->addr + VIRTIO_PCI_QUEUE_PFN, pfn);
+    qpci_io_writel(dev->pdev, dev->bar, VIRTIO_PCI_QUEUE_PFN, pfn);
 }
 
 static QVirtQueue *qvirtio_pci_virtqueue_setup(QVirtioDevice *d,
@@ -262,7 +261,7 @@ static void qvirtio_pci_virtqueue_cleanup(QVirtQueue *vq,
 static void qvirtio_pci_virtqueue_kick(QVirtioDevice *d, QVirtQueue *vq)
 {
     QVirtioPCIDevice *dev = (QVirtioPCIDevice *)d;
-    qpci_io_writew(dev->pdev, dev->addr + VIRTIO_PCI_QUEUE_NOTIFY, vq->index);
+    qpci_io_writew(dev->pdev, dev->bar, VIRTIO_PCI_QUEUE_NOTIFY, vq->index);
 }
 
 const QVirtioBus qvirtio_pci = {
@@ -309,14 +308,12 @@ QVirtioPCIDevice *qvirtio_pci_device_find(QPCIBus *bus, uint16_t device_type)
 void qvirtio_pci_device_enable(QVirtioPCIDevice *d)
 {
     qpci_device_enable(d->pdev);
-    d->addr = qpci_iomap(d->pdev, 0, NULL);
-    g_assert(d->addr != NULL);
+    d->bar = qpci_iomap(d->pdev, 0, NULL);
 }
 
 void qvirtio_pci_device_disable(QVirtioPCIDevice *d)
 {
-    qpci_iounmap(d->pdev, d->addr);
-    d->addr = NULL;
+    qpci_iounmap(d->pdev, d->bar);
 }
 
 void qvirtqueue_pci_msix_setup(QVirtioPCIDevice *d, QVirtQueuePCI *vqpci,
@@ -324,29 +321,33 @@ void qvirtqueue_pci_msix_setup(QVirtioPCIDevice *d, QVirtQueuePCI *vqpci,
 {
     uint16_t vector;
     uint32_t control;
-    void *addr;
+    uint64_t off;
 
     g_assert(d->pdev->msix_enabled);
-    addr = d->pdev->msix_table + (entry * 16);
+    off = d->pdev->msix_table_off + (entry * 16);
 
     g_assert_cmpint(entry, >=, 0);
     g_assert_cmpint(entry, <, qpci_msix_table_size(d->pdev));
     vqpci->msix_entry = entry;
 
     vqpci->msix_addr = guest_alloc(alloc, 4);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_LOWER_ADDR,
-                                                    vqpci->msix_addr & ~0UL);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_UPPER_ADDR,
-                                            (vqpci->msix_addr >> 32) & ~0UL);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_DATA, vqpci->msix_data);
-
-    control = qpci_io_readl(d->pdev, addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_VECTOR_CTRL,
-                                        control & ~PCI_MSIX_ENTRY_CTRL_MASKBIT);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_LOWER_ADDR, vqpci->msix_addr & ~0UL);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_UPPER_ADDR,
+                   (vqpci->msix_addr >> 32) & ~0UL);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_DATA, vqpci->msix_data);
+
+    control = qpci_io_readl(d->pdev, d->pdev->msix_table_bar,
+                            off + PCI_MSIX_ENTRY_VECTOR_CTRL);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_VECTOR_CTRL,
+                   control & ~PCI_MSIX_ENTRY_CTRL_MASKBIT);
 
     qvirtio_pci_queue_select(&d->vdev, vqpci->vq.index);
-    qpci_io_writew(d->pdev, d->addr + VIRTIO_MSI_QUEUE_VECTOR, entry);
-    vector = qpci_io_readw(d->pdev, d->addr + VIRTIO_MSI_QUEUE_VECTOR);
+    qpci_io_writew(d->pdev, d->bar, VIRTIO_MSI_QUEUE_VECTOR, entry);
+    vector = qpci_io_readw(d->pdev, d->bar, VIRTIO_MSI_QUEUE_VECTOR);
     g_assert_cmphex(vector, !=, VIRTIO_MSI_NO_VECTOR);
 }
 
@@ -355,10 +356,10 @@ void qvirtio_pci_set_msix_configuration_vector(QVirtioPCIDevice *d,
 {
     uint16_t vector;
     uint32_t control;
-    void *addr;
+    uint64_t off;
 
     g_assert(d->pdev->msix_enabled);
-    addr = d->pdev->msix_table + (entry * 16);
+    off = d->pdev->msix_table_off + (entry * 16);
 
     g_assert_cmpint(entry, >=, 0);
     g_assert_cmpint(entry, <, qpci_msix_table_size(d->pdev));
@@ -367,17 +368,21 @@ void qvirtio_pci_set_msix_configuration_vector(QVirtioPCIDevice *d,
     d->config_msix_data = 0x12345678;
     d->config_msix_addr = guest_alloc(alloc, 4);
 
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_LOWER_ADDR,
-                                                    d->config_msix_addr & ~0UL);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_UPPER_ADDR,
-                                            (d->config_msix_addr >> 32) & ~0UL);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_DATA, d->config_msix_data);
-
-    control = qpci_io_readl(d->pdev, addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
-    qpci_io_writel(d->pdev, addr + PCI_MSIX_ENTRY_VECTOR_CTRL,
-                                        control & ~PCI_MSIX_ENTRY_CTRL_MASKBIT);
-
-    qpci_io_writew(d->pdev, d->addr + VIRTIO_MSI_CONFIG_VECTOR, entry);
-    vector = qpci_io_readw(d->pdev, d->addr + VIRTIO_MSI_CONFIG_VECTOR);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_LOWER_ADDR, d->config_msix_addr & ~0UL);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_UPPER_ADDR,
+                   (d->config_msix_addr >> 32) & ~0UL);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_DATA, d->config_msix_data);
+
+    control = qpci_io_readl(d->pdev, d->pdev->msix_table_bar,
+                            off + PCI_MSIX_ENTRY_VECTOR_CTRL);
+    qpci_io_writel(d->pdev, d->pdev->msix_table_bar,
+                   off + PCI_MSIX_ENTRY_VECTOR_CTRL,
+                   control & ~PCI_MSIX_ENTRY_CTRL_MASKBIT);
+
+    qpci_io_writew(d->pdev, d->bar, VIRTIO_MSI_CONFIG_VECTOR, entry);
+    vector = qpci_io_readw(d->pdev, d->bar, VIRTIO_MSI_CONFIG_VECTOR);
     g_assert_cmphex(vector, !=, VIRTIO_MSI_NO_VECTOR);
 }