[V5,5/6] libxl: Allocate MMIO params for I2c device and update DT

Commit Message

Viresh Kumar Aug. 22, 2022, 9:15 a.m. UTC

This patch allocates Virtio MMIO params (IRQ and memory region) and pass
them to the backend, also update Guest device-tree based on Virtio I2C
DT bindings [1].

This also relocates the code responsible to call make_xen_iommu_node()
towards the end of the routine, so we create the node only once.

[1] https://www.kernel.org/doc/Documentation/devicetree/bindings/i2c/i2c-virtio.yaml

Reviewed-by: Oleksandr Tyshchenko <[e-mail]>
Signed-off-by: Viresh Kumar <[e-mail]>
---
 tools/libs/light/libxl_arm.c | 57 +++++++++++++++++++++++++++++++-----
 1 file changed, 50 insertions(+), 7 deletions(-)

Comments

Anthony PERARD Sept. 6, 2022, 4:38 p.m. UTC | #1

On Mon, Aug 22, 2022 at 02:45:17PM +0530, Viresh Kumar wrote:
> This also relocates the code responsible to call make_xen_iommu_node()
> towards the end of the routine, so we create the node only once.

Could you do this part in a separate patch? Then, I believe the rest of
the patch could be squashed into the patch that adds i2c support into
libxl.

Thanks,

Patch

diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index 4d0469f8166a..4c1012e56893 100644
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -112,6 +112,15 @@  int libxl__arch_domain_prepare_config(libxl__gc *gc,
         }
     }
 
+    for (i = 0; i < d_config->num_i2cs; i++) {
+        libxl_device_i2c *i2c = &d_config->i2cs[i];
+        int rc = alloc_virtio_mmio_params(gc, &i2c->base, &i2c->irq,
+                                          &virtio_mmio_base, &virtio_mmio_irq);
+
+        if (rc)
+            return rc;
+    }
+
     /*
      * Every virtio-mmio device uses one emulated SPI. If Virtio devices are
      * present, make sure that we allocate enough SPIs for them.
@@ -955,6 +964,26 @@  static int make_virtio_mmio_node_simple(libxl__gc *gc, void *fdt, uint64_t base,
     return fdt_end_node(fdt);
 }
 
+static int make_virtio_mmio_node_i2c(libxl__gc *gc, void *fdt, uint64_t base,
+                                     uint32_t irq, uint32_t backend_domid)
+{
+    int res;
+
+    res = make_virtio_mmio_node_common(gc, fdt, base, irq, backend_domid);
+    if (res) return res;
+
+    res = fdt_begin_node(fdt, "i2c");
+    if (res) return res;
+
+    res = fdt_property_compat(gc, fdt, 1, "virtio,device22");
+    if (res) return res;
+
+    res = fdt_end_node(fdt);
+    if (res) return res;
+
+    return fdt_end_node(fdt);
+}
+
 static const struct arch_info *get_arch_info(libxl__gc *gc,
                                              const struct xc_dom_image *dom)
 {
@@ -1156,7 +1185,7 @@  static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_config *d_config,
     size_t fdt_size = 0;
     int pfdt_size = 0;
     libxl_domain_build_info *const info = &d_config->b_info;
-    bool iommu_created;
+    bool iommu_needed;
     unsigned int i;
 
     const libxl_version_info *vers;
@@ -1264,16 +1293,13 @@  static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_config *d_config,
         if (d_config->num_pcidevs)
             FDT( make_vpci_node(gc, fdt, ainfo, dom) );
 
-        iommu_created = false;
+        iommu_needed = false;
         for (i = 0; i < d_config->num_disks; i++) {
             libxl_device_disk *disk = &d_config->disks[i];
 
             if (disk->specification == LIBXL_DISK_SPECIFICATION_VIRTIO) {
-                if (disk->backend_domid != LIBXL_TOOLSTACK_DOMID &&
-                    !iommu_created) {
-                    FDT( make_xen_iommu_node(gc, fdt) );
-                    iommu_created = true;
-                }
+                if (disk->backend_domid != LIBXL_TOOLSTACK_DOMID)
+                    iommu_needed = true;
 
                 FDT( make_virtio_mmio_node_simple(gc, fdt, disk->base,
                                                   disk->irq,
@@ -1281,6 +1307,23 @@  static int libxl__prepare_dtb(libxl__gc *gc, libxl_domain_config *d_config,
             }
         }
 
+        for (i = 0; i < d_config->num_i2cs; i++) {
+            libxl_device_i2c *i2c = &d_config->i2cs[i];
+
+            if (i2c->backend_domid != LIBXL_TOOLSTACK_DOMID)
+                iommu_needed = true;
+
+            FDT( make_virtio_mmio_node_i2c(gc, fdt, i2c->base, i2c->irq,
+                                           i2c->backend_domid) );
+        }
+
+        /*
+         * Note, this should be only called after creating all virtio-mmio
+         * device nodes
+         */
+        if (iommu_needed)
+            FDT( make_xen_iommu_node(gc, fdt) );
+
         if (pfdt)
             FDT( copy_partial_fdt(gc, fdt, pfdt) );