diff options
authorMichal Orzel <michal.orzel@arm.com>2022-06-09 11:57:47 +0200
committerBruce Ashfield <bruce.ashfield@gmail.com>2022-06-20 12:08:58 -0400
commit15ed3e5294ca67705476880765139accccac0690 (patch)
parent42c308c7ad8dfd167454d965c806b110d24a66d9 (diff)
Revert "xen: Disable PCI on qemuarm with Xen"
This reverts commit fb0a7b97db4f419b82309f98a4944ae3330d1e2e. Justification: Commit fb0a7b97db4f removed the PCI node from the qemu device tree due to the issue when trying to access PCI configuration space that was causing Linux running on top of Xen to end up in an infinite loop. The investigation showed that the problem occurs due to qemu placing ECAM space at 256GiB mark. Even though Xen officially supports on arm32 up to 12GiB of physical address space, it is able to map it correctly for dom0. However, when Linux tries to access the ECAM space and the stage2 translation fault occurs, HPFAR register contains incorrect IPA. We can say it is incorrect because using hardware AT instruction or software lookup, we can obtain the correct IPA from the same VA. This can suggest that the problem is related to QEMU fault handling. Instead of removing the PCI node the follow-up commit will disable highmem option in qemu which will cause placing ECAM space in the 32-bit space. Signed-off-by: Michal Orzel <michal.orzel@arm.com> Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com> Reviewed-by: Christopher Clark <christopher.w.clark@gmail.com> Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
1 files changed, 0 insertions, 22 deletions
diff --git a/classes/qemuboot-xen-dtb.bbclass b/classes/qemuboot-xen-dtb.bbclass
index 1f17a86..d43d23a 100644
--- a/classes/qemuboot-xen-dtb.bbclass
+++ b/classes/qemuboot-xen-dtb.bbclass
@@ -63,21 +63,6 @@ write_lops_xen_section() {
-write_lop_rm_pci() {
- cat <<EOF >"$1"
-/ {
- compatible = "system-device-tree-v1";
- lops {
- lop_1 {
- compatible = "system-device-tree-v1,lop,modify";
- modify = "/pcie@10000000::";
- };
- };
write_lop_add_to_xen_cmdline() {
cat <<EOF >"$1"
@@ -150,13 +135,6 @@ generate_xen_qemuboot_dtb() {
write_lop_add_to_xen_cmdline "${B}/lop-xen-cmdline.dts" \
- # On Qemu Arm32, Dom0 accessing PCI config space ends up in an
- # infinite loop. Remove pci node from the device tree
- if [ "${MACHINE}" = "qemuarm" ]; then
- write_lop_rm_pci "${B}/lop-rm-pci.dts"
- LOP_MODULE_ARGS="${LOP_MODULE_ARGS} -i ${B}/lop-rm-pci.dts"
- fi
if [ -z "${QB_XEN_DOMAIN_MODULES}" ]; then
bbwarn "No domain modules: please set QB_XEN_DOMAIN_MODULES"