Add option to invoke QEMU with a PVM template
Add -T command line option to aarch64/run_qemu.sh which invokes QEMU
with a given file as a PVM template.
It will automatically determine the address at which the file will be
placed in memory. This is based on the fixed QEMU memory layout:
kernel | initrd | dtb | template
It will run QEMU first to dump its DTB and then overlay it with a node
specifying the address and size of the template before running QEMU
properly.
Bug: 171309087
Test: run_qemu.sh with a script:
hexdump -C /proc/device-tree/pkvm_template@*/reg
Change-Id: I82dd50f407dc45f9dc615c702e25841b607bbb61
diff --git a/aarch64/run_qemu.sh b/aarch64/run_qemu.sh
index 5fb1a37..f4f2edb 100755
--- a/aarch64/run_qemu.sh
+++ b/aarch64/run_qemu.sh
@@ -20,6 +20,7 @@
default_var ROM_DIR "${PREBUILTS_QEMU_ROM_DIR}"
default_var KERNEL "${LINUX_OUT_IMAGE}"
default_var ROOTFS "${PREBUILTS_KUT_ROOTFS}"
+default_var TEMPLATE ""
default_var CPU "max"
default_var SMP 2
default_var RAM 512
@@ -28,11 +29,15 @@
default_var VERBOSE 0
default_var TIMEOUT ""
+KiB=1024
+MiB=$((1024 * KiB))
+GiB=$((1024 * MiB))
+
function usage() {
cat <<EOF
Usage: $0 [-h] [-v]
- [-e QEMU] [-L ROM_DIR] [-k KERNEL] [-r ROOTFS] [-R DRIVE]
+ [-e QEMU] [-L ROM_DIR] [-k KERNEL] [-r ROOTFS] [-R DRIVE] [-T TEMPLATE]
[-c CPU] [-s NUM_CPUS] [-m MEM] [-g GIC] [-G]
[-t TIMEOUT]
@@ -43,6 +48,7 @@
-k kernel image
-r root filesystem image
-R additional drive image(s) to mount as read-only
+ -T VM template image
-c CPU model (defaults to "${DEFAULT_CPU}")
-s number of CPU cores (defaults to ${DEFAULT_SMP})
-m amount of memory in MB (defaults to ${DEFAULT_RAM})
@@ -52,17 +58,56 @@
EOF
}
+function file_size() {
+ stat --format=%s "$1"
+}
+
+function align_up_pow2() {
+ local val="$1"
+ local align="$2"
+ echo $(( (val + (align - 1)) & (~(align - 1)) ))
+}
+
+function hex() {
+ printf '0x%x\n' $1
+}
+
+function template_overlay() {
+ local in="$1"
+ local out="$2"
+ local addr="$3"
+ local size="$4"
+ local tmp="$(mktemp)"
+
+ # Convert input DTB back to source.
+ dtc -I dtb -O dts -o "${tmp}" "${in}"
+
+ # Append an overlay describing the template.
+ cat <<EOF >> "${tmp}"
+&{/} {
+ pkvm_template@${addr} {
+ compatible = "pkvm,arm64";
+ reg = <0x00 ${addr} 0x00 ${size}>;
+ };
+};
+EOF
+
+ # Compile back to DTB.
+ dtc -I dts -O dtb -o "${out}" "${tmp}"
+}
+
CMD=()
APPEND=()
EXTRA_RO_MOUNTS=()
-while getopts ":e:L:k:r:R:c:s:m:g:t:vGh" OPT; do
+while getopts ":e:L:k:r:R:T:c:s:m:g:t:vGh" OPT; do
case "${OPT}" in
e) QEMU="${OPTARG}" ;;
L) ROM_DIR="${OPTARG}" ;;
k) KERNEL="${OPTARG}" ;;
r) ROOTFS="${OPTARG}" ;;
R) EXTRA_RO_MOUNTS+=("${OPTARG}") ;;
+ T) TEMPLATE="${OPTARG}" ;;
c) CPU="${OPTARG}" ;;
s) SMP="${OPTARG}" ;;
m) RAM="${OPTARG}" ;;
@@ -127,6 +172,32 @@
CMD+=(-append "${APPEND[*]}")
+if [ -n "${TEMPLATE}" ]; then
+ # Dump the QEMU DTB.
+ QEMU_DTB="$(mktemp)"
+ "${CMD[@]}" -machine dumpdtb="${QEMU_DTB}" > /dev/null
+
+ # Compile the overlayed DTB with dummy values to determine its size.
+ TMP_DTB="$(mktemp)"
+ template_overlay "${QEMU_DTB}" "${TMP_DTB}" 0x0 0x0
+ TMP_DTB_SIZE=$(file_size "${TMP_DTB}")
+
+ # From QEMU's hw/arm/boot.c:
+ # RAM always starts at 1GiB PA offset. The kernel is placed there.
+ # 128MiB (or RAM/2 if RAM<256MiB) is left to the kernel to decompress.
+ # This is followed by the ramdisk and then 2MiB-aligned DTB.
+ # We place the template at the following page (assume 64KiB page size).
+ TEMPLATE_ADDR=$(( 1*GiB + 128*MiB + TMP_DTB_SIZE ))
+ TEMPLATE_ADDR=$(hex $(align_up_pow2 $TEMPLATE_ADDR 64*KiB))
+ TEMPLATE_SIZE=$(hex $(file_size "${TEMPLATE}"))
+
+ QEMU_PATCHED_DTB="$(mktemp)"
+ template_overlay "${QEMU_DTB}" "${QEMU_PATCHED_DTB}" "${TEMPLATE_ADDR}" "${TEMPLATE_SIZE}"
+
+ CMD+=(-dtb "${QEMU_PATCHED_DTB}")
+ CMD+=(-device loader,file="${TEMPLATE}",addr=${TEMPLATE_ADDR},force-raw=true)
+fi
+
if [ "${VERBOSE}" -eq 1 ]; then
set -x
fi
