Hi,
On 24/09/2024 17:23, Edgar E. Iglesias wrote:
From: Stewart Hildebrand <stewart.hildebr...@amd.com>
When virtio-pci is specified in the dom0less domU properties, create a
virtio-pci node in the guest's device tree. Set up an mmio handler with
a register for the guest to poll when the backend has connected and
virtio-pci bus is ready to be probed. Grant tables may be used by
specifying virtio-pci = "grants";.
[Edgar: Use GPEX PCI INTX interrupt swizzling (from PCI specs).
Make grants iommu-map cover the entire PCI bus.
Add virtio-pci-ranges to specify memory-map for direct-mapped guests.
Document virtio-pci dom0less fdt bindings.]
Signed-off-by: Stewart Hildebrand <stewart.hildebr...@amd.com>
Signed-off-by: Edgar E. Iglesias <edgar.igles...@amd.com>
---
docs/misc/arm/device-tree/booting.txt | 21 +++
xen/arch/arm/dom0less-build.c | 238 ++++++++++++++++++++++++++
xen/arch/arm/include/asm/kernel.h | 15 ++
3 files changed, 274 insertions(+)
diff --git a/docs/misc/arm/device-tree/booting.txt
b/docs/misc/arm/device-tree/booting.txt
index 3a04f5c57f..82f3bd7026 100644
--- a/docs/misc/arm/device-tree/booting.txt
+++ b/docs/misc/arm/device-tree/booting.txt
@@ -276,6 +276,27 @@ with the following properties:
passed through. This option is the default if this property is missing
and the user does not provide the device partial device tree for the
domain.
+- virtio-pci
Similar question to the other patches, why is this specific to virtio
PCI? QEMU (or another device module) is free to emulate whatever it
wants behind the PCI hosbtridge.
+
+ A string property specifying whether virtio-pci is enabled for the
+ domain and if grant table mappings should be used. If no value is set
+ this property is treated as a boolean and the same way as if set to
+ "enabled".
+ Possible property values are:
+
+ - "enabled"
+ Virtio-pci is enabled for the domain.
+
+ - "grants"
+ Virtio-pci is enabled for the domain and an grants IOMMU node will be
+ generated in the domains device-tree.
+
+- virtio-pci-ranges
+
+ An optional array of 6 u32 values specifying the 2 cells base addresses of
+ the ECAM, Memory and Prefetchable-Memory regions for virtio-pci. This is
+ useful to avoid memory-map collisions when using direct-mapped guests.
+
Under the "xen,domain" compatible node, one or more sub-nodes are present
for the DomU kernel and ramdisk.
diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index 09b65e44ae..dab24fa9e2 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -586,6 +586,189 @@ static int __init domain_handle_dtb_bootmodule(struct
domain *d,
return res;
}
+static int __init make_virtio_pci_domU_node(const struct kernel_info *kinfo)
+{
+ void *fdt = kinfo->fdt;
+ /* reg is sized to be used for all the needed properties below */
+ __be32 reg[(1 + (GUEST_ROOT_ADDRESS_CELLS * 2) + GUEST_ROOT_SIZE_CELLS)
+ * 2];
+ __be32 irq_map[4 * 4 * 8];
+ __be32 *cells;
+ char buf[22]; /* pcie@ + max 16 char address + '\0' */
+ int res;
+ int devfn, intx_pin;
+ static const char compat[] = "pci-host-ecam-generic";
+ static const char reg_names[] = "ecam";
+
+ if ( p2m_ipa_bits <= 40 ) {
+ printk("PA bits %d is too small!\nvirtio-pci is only supported "
+ "on platforms with PA bits > 40\n", p2m_ipa_bits);
+ return -EINVAL;
+ }
Please add a comment explaining where does this requires come from. If
this is the Address layout, then probably be to avoid relying on
hardcoded number of bits.
Cheers,
--
Julien Grall
