[Qemu-devel] [PATCH 2/2] pseries: Properly handle allocation of multiple PCI host bridges

[David Gibson]

From: Alexey Kardashevskiy <address@hidden>

Multiple - even many - PCI host bridges (i.e. PCI domains) are very
common on real PAPR compliant hardware.  For reasons related to the
PAPR specified IOMMU interfaces, PCI device assignment with VFIO will
generally require at least two (virtual) PHBs and possibly more
depending on which devices are assigned.

At the moment the qemu PAPR PCI code will not deal with this well,
leaving several crucial parameters of PHBs other than the default one
uninitialized.  This patch reworks the code to allow this.

Every PHB needs a unique BUID (Bus Unit Identifier, the id used for
the PAPR PCI related interfaces) and a unique LIOBN (Logical IO Bus
Number, the id used for the PAPR IOMMU related interfaces).  In
addition they need windows in CPU real address space to access PCI
memory space, PCI IO space and MSIs.  Properties are added to the PCI
host bridge qdevice to allow configuration of all these.

To simplify configuration of multiple PHBs for common cases, a
convenience "index" property is also added.  This can be set instead
of the low-level properties, and will generate suitable values for the
other parameters, different for each index valu.

Signed-off-by: David Gibson <address@hidden>
---
 hw/spapr.c     |   13 +-------
 hw/spapr_pci.c |   97 +++++++++++++++++++++++++++++++++++++++++---------------
 hw/spapr_pci.h |   21 ++++++++----
 3 files changed, 87 insertions(+), 44 deletions(-)

diff --git a/hw/spapr.c b/hw/spapr.c
index d23aa9d..1609f73 100644
--- a/hw/spapr.c
+++ b/hw/spapr.c
@@ -76,12 +76,6 @@
 #define MAX_CPUS                256
 #define XICS_IRQS               1024
 
-#define SPAPR_PCI_BUID          0x800000020000001ULL
-#define SPAPR_PCI_MEM_WIN_ADDR  (0x10000000000ULL + 0xA0000000)
-#define SPAPR_PCI_MEM_WIN_SIZE  0x20000000
-#define SPAPR_PCI_IO_WIN_ADDR   (0x10000000000ULL + 0x80000000)
-#define SPAPR_PCI_MSI_WIN_ADDR  (0x10000000000ULL + 0x90000000)
-
 #define PHANDLE_XICP            0x00001111
 
 #define HTAB_SIZE(spapr)        (1ULL << ((spapr)->htab_shift))
@@ -854,12 +848,7 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
     /* Set up PCI */
     spapr_pci_rtas_init();
 
-    spapr_create_phb(spapr, "pci", SPAPR_PCI_BUID,
-                     SPAPR_PCI_MEM_WIN_ADDR,
-                     SPAPR_PCI_MEM_WIN_SIZE,
-                     SPAPR_PCI_IO_WIN_ADDR,
-                     SPAPR_PCI_MSI_WIN_ADDR);
-    phb = PCI_HOST_BRIDGE(QLIST_FIRST(&spapr->phbs));
+    phb = spapr_create_phb(spapr, 0);
 
     for (i = 0; i < nb_nics; i++) {
         NICInfo *nd = &nd_table[i];
diff --git a/hw/spapr_pci.c b/hw/spapr_pci.c
index 3c5b855..dc2ffaf 100644
--- a/hw/spapr_pci.c
+++ b/hw/spapr_pci.c
@@ -435,7 +435,7 @@ static void pci_spapr_set_irq(void *opaque, int irq_num, 
int level)
      */
     sPAPRPHBState *phb = opaque;
 
-    trace_spapr_pci_lsi_set(phb->busname, irq_num, 
phb->lsi_table[irq_num].irq);
+    trace_spapr_pci_lsi_set(phb->dtbusname, irq_num, 
phb->lsi_table[irq_num].irq);
     qemu_set_irq(spapr_phb_lsi_qirq(phb, irq_num), level);
 }
 
@@ -522,6 +522,58 @@ static int spapr_phb_init(SysBusDevice *s)
     int i;
     PCIBus *bus;
 
+    if (sphb->index != -1) {
+        hwaddr windows_base;
+
+        if ((sphb->buid != -1) || (sphb->dma_liobn != -1)
+            || (sphb->mem_win_addr != -1)
+            || (sphb->io_win_addr != -1)
+            || (sphb->msi_win_addr != -1)) {
+            fprintf(stderr, "Either \"index\" or other parameters must"
+                    " be specified for PAPR PHB, not both\n");
+            return -1;
+        }
+
+        sphb->buid = SPAPR_PCI_BASE_BUID + sphb->index;
+        sphb->dma_liobn = SPAPR_PCI_BASE_LIOBN + sphb->index;
+
+        windows_base = SPAPR_PCI_WINDOW_BASE
+            + sphb->index * SPAPR_PCI_WINDOW_SPACING;
+        sphb->mem_win_addr = windows_base + SPAPR_PCI_MMIO_WIN_OFF;
+        sphb->io_win_addr = windows_base + SPAPR_PCI_IO_WIN_OFF;
+        sphb->msi_win_addr = windows_base + SPAPR_PCI_MSI_WIN_OFF;
+    }
+
+    if (sphb->buid == -1) {
+        fprintf(stderr, "BUID not specified for PHB\n");
+        return -1;
+    }
+
+    if (sphb->dma_liobn == -1) {
+        fprintf(stderr, "LIOBN not specified for PHB\n");
+        return -1;
+    }
+
+    if (sphb->mem_win_addr == -1) {
+        fprintf(stderr, "Memory window address not specified for PHB\n");
+        return -1;
+    }
+
+    if (sphb->io_win_addr == -1) {
+        fprintf(stderr, "IO window address not specified for PHB\n");
+        return -1;
+    }
+
+    if (sphb->msi_win_addr == -1) {
+        fprintf(stderr, "MSI window address not specified for PHB\n");
+        return -1;
+    }
+
+    if (find_phb(spapr, sphb->buid)) {
+        fprintf(stderr, "PCI host bridges must have unique BUIDs\n");
+        return -1;
+    }               
+
     sphb->dtbusname = g_strdup_printf("address@hidden" PRIx64, sphb->buid);
     namebuf = alloca(strlen(sphb->dtbusname) + 32);
 
@@ -565,17 +617,19 @@ static int spapr_phb_init(SysBusDevice *s)
                                     &sphb->msiwindow);
     }
 
-    bus = pci_register_bus(DEVICE(s),
-                           sphb->busname ? sphb->busname : sphb->dtbusname,
+    bus = pci_register_bus(DEVICE(s), sphb->dtbusname,
                            pci_spapr_set_irq, pci_spapr_map_irq, sphb,
                            &sphb->memspace, &sphb->iospace,
                            PCI_DEVFN(0, 0), PCI_NUM_PINS);
     phb->bus = bus;
 
-    sphb->dma_liobn = SPAPR_PCI_BASE_LIOBN | (pci_find_domain(bus) << 16);
     sphb->dma_window_start = 0;
     sphb->dma_window_size = 0x40000000;
     sphb->dma = spapr_tce_new_dma_context(sphb->dma_liobn, 
sphb->dma_window_size);
+    if (!sphb->dma) {
+        fprintf(stderr, "Unable to create TCE table for %s\n", 
sphb->dtbusname);
+        return -1;
+    }
     pci_setup_iommu(bus, spapr_pci_dma_context_fn, sphb);
 
     QLIST_INSERT_HEAD(&spapr->phbs, sphb, list);
@@ -605,13 +659,16 @@ static void spapr_phb_reset(DeviceState *qdev)
 }
 
 static Property spapr_phb_properties[] = {
-    DEFINE_PROP_HEX64("buid", sPAPRPHBState, buid, 0),
-    DEFINE_PROP_STRING("busname", sPAPRPHBState, busname),
-    DEFINE_PROP_HEX64("mem_win_addr", sPAPRPHBState, mem_win_addr, 0),
-    DEFINE_PROP_HEX64("mem_win_size", sPAPRPHBState, mem_win_size, 0x20000000),
-    DEFINE_PROP_HEX64("io_win_addr", sPAPRPHBState, io_win_addr, 0),
-    DEFINE_PROP_HEX64("io_win_size", sPAPRPHBState, io_win_size, 0x10000),
-    DEFINE_PROP_HEX64("msi_win_addr", sPAPRPHBState, msi_win_addr, 0),
+    DEFINE_PROP_INT32("index", sPAPRPHBState, index, -1),
+    DEFINE_PROP_HEX64("buid", sPAPRPHBState, buid, -1),
+    DEFINE_PROP_HEX32("liobn", sPAPRPHBState, dma_liobn, -1),
+    DEFINE_PROP_HEX64("mem_win_addr", sPAPRPHBState, mem_win_addr, -1),
+    DEFINE_PROP_HEX64("mem_win_size", sPAPRPHBState, mem_win_size,
+                      SPAPR_PCI_MMIO_WIN_SIZE),
+    DEFINE_PROP_HEX64("io_win_addr", sPAPRPHBState, io_win_addr, -1),
+    DEFINE_PROP_HEX64("io_win_size", sPAPRPHBState, io_win_size,
+                      SPAPR_PCI_IO_WIN_SIZE),
+    DEFINE_PROP_HEX64("msi_win_addr", sPAPRPHBState, msi_win_addr, -1),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -632,25 +689,15 @@ static const TypeInfo spapr_phb_info = {
     .class_init    = spapr_phb_class_init,
 };
 
-void spapr_create_phb(sPAPREnvironment *spapr,
-                      const char *busname, uint64_t buid,
-                      uint64_t mem_win_addr, uint64_t mem_win_size,
-                      uint64_t io_win_addr, uint64_t msi_win_addr)
+PCIHostState *spapr_create_phb(sPAPREnvironment *spapr, int index)
 {
     DeviceState *dev;
 
     dev = qdev_create(NULL, TYPE_SPAPR_PCI_HOST_BRIDGE);
-
-    if (busname) {
-        qdev_prop_set_string(dev, "busname", g_strdup(busname));
-    }
-    qdev_prop_set_uint64(dev, "buid", buid);
-    qdev_prop_set_uint64(dev, "mem_win_addr", mem_win_addr);
-    qdev_prop_set_uint64(dev, "mem_win_size", mem_win_size);
-    qdev_prop_set_uint64(dev, "io_win_addr", io_win_addr);
-    qdev_prop_set_uint64(dev, "msi_win_addr", msi_win_addr);
-
+    qdev_prop_set_uint32(dev, "index", index);
     qdev_init_nofail(dev);
+
+    return PCI_HOST_BRIDGE(dev);
 }
 
 /* Macros to operate with address in OF binding to PCI */
diff --git a/hw/spapr_pci.h b/hw/spapr_pci.h
index e307ac8..76ba48a 100644
--- a/hw/spapr_pci.h
+++ b/hw/spapr_pci.h
@@ -37,8 +37,8 @@
 typedef struct sPAPRPHBState {
     PCIHostState parent_obj;
 
+    int32_t index;
     uint64_t buid;
-    char *busname;
     char *dtbusname;
 
     MemoryRegion memspace, iospace;
@@ -64,18 +64,25 @@ typedef struct sPAPRPHBState {
     QLIST_ENTRY(sPAPRPHBState) list;
 } sPAPRPHBState;
 
+#define SPAPR_PCI_BASE_BUID          0x800000020000000ULL
+
+#define SPAPR_PCI_WINDOW_BASE        0x10000000000ULL
+#define SPAPR_PCI_WINDOW_SPACING     0x1000000000ULL
+#define SPAPR_PCI_MMIO_WIN_OFF       0xA0000000
+#define SPAPR_PCI_MMIO_WIN_SIZE      0x20000000
+#define SPAPR_PCI_IO_WIN_OFF         0x80000000
+#define SPAPR_PCI_IO_WIN_SIZE        0x10000
+#define SPAPR_PCI_MSI_WIN_OFF        0x90000000
+
+#define SPAPR_PCI_MEM_WIN_BUS_OFFSET 0x80000000ULL
+
 static inline qemu_irq spapr_phb_lsi_qirq(struct sPAPRPHBState *phb, int pin)
 {
     return xics_get_qirq(spapr->icp, phb->lsi_table[pin].irq);
 }
 
-#define SPAPR_PCI_MEM_WIN_BUS_OFFSET 0x80000000ULL
-#define SPAPR_PCI_IO_WIN_SIZE        0x10000
 
-void spapr_create_phb(sPAPREnvironment *spapr,
-                      const char *busname, uint64_t buid,
-                      uint64_t mem_win_addr, uint64_t mem_win_size,
-                      uint64_t io_win_addr, uint64_t msi_win_addr);
+PCIHostState *spapr_create_phb(sPAPREnvironment *spapr, int index);
 
 int spapr_populate_pci_dt(sPAPRPHBState *phb,
                           uint32_t xics_phandle,
-- 
1.7.10.4