hw/block/nvme: move msix table and pba to BAR 0

In the interest of supporting both CMB and PMR to be enabled on the same
device, move the MSI-X table and pending bit array out of BAR 4 and into
BAR 0.

This is a simplified version of the patch contributed by Andrzej
Jakowski (see [1]). Leaving the CMB at offset 0 removes the need for
changes to CMB address mapping code.

  [1]: https://lore.kernel.org/qemu-devel/20200729220107.37758-3-andrzej.jakowski@linux.intel.com/

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Tested-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

hw/block/nvme.c

@@ -4268,6 +4268,8 @@ static void nvme_init_pmr(NvmeCtrl *n, PCIDevice *pci_dev)
 static int nvme_init_pci(NvmeCtrl *n, PCIDevice *pci_dev, Error **errp)
 {
     uint8_t *pci_conf = pci_dev->config;
+    uint64_t bar_size, msix_table_size, msix_pba_size;
+    unsigned msix_table_offset, msix_pba_offset;
     int ret;
 
     Error *err = NULL;
@@ -4286,11 +4288,28 @@ static int nvme_init_pci(NvmeCtrl *n, PCIDevice *pci_dev, Error **errp)
     pci_config_set_class(pci_conf, PCI_CLASS_STORAGE_EXPRESS);
     pcie_endpoint_cap_init(pci_dev, 0x80);
 
+    bar_size = QEMU_ALIGN_UP(n->reg_size, 4 * KiB);
+    msix_table_offset = bar_size;
+    msix_table_size = PCI_MSIX_ENTRY_SIZE * n->params.msix_qsize;
+
+    bar_size += msix_table_size;
+    bar_size = QEMU_ALIGN_UP(bar_size, 4 * KiB);
+    msix_pba_offset = bar_size;
+    msix_pba_size = QEMU_ALIGN_UP(n->params.msix_qsize, 64) / 8;
+
+    bar_size += msix_pba_size;
+    bar_size = pow2ceil(bar_size);
+
+    memory_region_init(&n->bar0, OBJECT(n), "nvme-bar0", bar_size);
     memory_region_init_io(&n->iomem, OBJECT(n), &nvme_mmio_ops, n, "nvme",
                           n->reg_size);
+    memory_region_add_subregion(&n->bar0, 0, &n->iomem);
+
     pci_register_bar(pci_dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY |
-                     PCI_BASE_ADDRESS_MEM_TYPE_64, &n->iomem);
-    ret = msix_init_exclusive_bar(pci_dev, n->params.msix_qsize, 4, &err);
+                     PCI_BASE_ADDRESS_MEM_TYPE_64, &n->bar0);
+    ret = msix_init(pci_dev, n->params.msix_qsize,
+                    &n->bar0, 0, msix_table_offset,
+                    &n->bar0, 0, msix_pba_offset, 0, &err);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
             warn_report_err(err);

hw/block/nvme.h

@@ -125,6 +125,7 @@ typedef struct NvmeFeatureVal {
 
 typedef struct NvmeCtrl {
     PCIDevice    parent_obj;
+    MemoryRegion bar0;
     MemoryRegion iomem;
     MemoryRegion ctrl_mem;
     NvmeBar      bar;