ohhhhhhhhhhh (exclude linux-extra-rootfs.img build artifact)

ISO/run_qemu_kvm.sh

@@ -25,10 +25,10 @@
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-IMG="$SCRIPT_DIR/deshab-dev.img"
-SATA_IMG="$SCRIPT_DIR/../.build_tmp/sata_fat32_dsk.img"
-NVME_IMG="$SCRIPT_DIR/../.build_tmp/nvme_test.img"
-USB_IMG="$SCRIPT_DIR/../.build_tmp/usb_test.img"
+IMG="${IMG_OVERRIDE:-$SCRIPT_DIR/deshab-dev.img}"
+SATA_IMG="${SATA_IMG_OVERRIDE:-$SCRIPT_DIR/../.build_tmp/sata_fat32_dsk.img}"
+NVME_IMG="${NVME_IMG_OVERRIDE:-$SCRIPT_DIR/../.build_tmp/nvme_test.img}"
+USB_IMG="${USB_IMG_OVERRIDE:-$SCRIPT_DIR/../.build_tmp/usb_test.img}"
 
 if [[ ! -f "$IMG" ]]; then
     echo "[qemu] Image not found: $IMG"
@@ -54,6 +54,7 @@ fi
 # Locate OVMF firmware
 OVMF=""
 for p in \
+    /usr/share/OVMF/OVMF_CODE_4M.fd \
     /usr/share/OVMF/OVMF_CODE.fd \
     /usr/share/edk2/ovmf/OVMF_CODE.fd \
     /usr/share/ovmf/OVMF.fd \
@@ -67,11 +68,22 @@ if [[ -z "$OVMF" ]]; then
     exit 1
 fi
 
+# 4M OVMF requires a writable NVRAM vars file; derive it from the CODE image
+# name and copy to a scratch location so the pristine firmware image is untouched.
+OVMF_VARS_SRC="$(dirname "$OVMF")/$(basename "$OVMF" | sed 's/CODE/VARS/')"
+OVMF_VARS=""
+if [[ -f "$OVMF_VARS_SRC" ]]; then
+    OVMF_VARS="${SCRIPT_DIR}/../.build_tmp/ovmf_vars.fd"
+    cp -f "$OVMF_VARS_SRC" "$OVMF_VARS"
+fi
+
 # Accelerator selection: KVM preferred for nested VMX (Linux guest).
 # Override with QEMU_ACCEL=tcg to fall back to TCG (no nested VMX, Linux guest
 # will skip VMX init gracefully).
 ACCEL="${QEMU_ACCEL:-kvm}"
-CPU="host"
+# Hide CET from L1 CPUID. Hardware CET can still leak into L2 when nested
+# KVM skips CET VMCS; qemu_disable_cet.c then tries KVM_SET_MSRS U_CET=0.
+CPU="${QEMU_CPU:-host}"
 if [[ "$ACCEL" == "kvm" ]]; then
     if [[ ! -e /dev/kvm ]]; then
         echo "[qemu] WARNING: /dev/kvm not found, KVM acceleration unavailable."
@@ -80,14 +92,55 @@ if [[ "$ACCEL" == "kvm" ]]; then
         echo "[qemu]   - On Linux: ensure kvm module is loaded and /dev/kvm permissions OK."
         echo "[qemu] Falling back to TCG (Linux guest will NOT run without nested VMX)."
         ACCEL="tcg"
+    else
+        # Prefer hiding IBT/SHSTK from L1 CPUID. Nested KVM still may leak
+        # L0 U_CET into L2; qemu_disable_cet.so tries KVM_SET_MSRS next.
+        if [[ "$CPU" == "host" ]]; then
+            if "$QEMU" -cpu help 2>/dev/null | grep -qE '(^|[[:space:]])ibt([[:space:]]|$)' && \
+               "$QEMU" -cpu help 2>/dev/null | grep -qE '(^|[[:space:]])shstk([[:space:]]|$)'; then
+                CPU="host,-ibt,-shstk"
+            fi
+        fi
     fi
 fi
 if [[ "$ACCEL" == "tcg" ]]; then
     CPU="qemu64,-vmx"   # disable VMX CPUID under TCG (no nested virt support)
 fi
 
-# Memory and CPU topology: VSCode + Electron + GUI stack needs >= 4GB.
-MEM="${QEMU_MEM:-4G}"
+# Nested KVM leaks this process's U_CET into L2. Disable SHSTK/IBT for
+# QEMU only (arch_prctl), never a host-wide wrmsr of IA32_U_CET.
+CET_SRC="${SCRIPT_DIR}/../CODE/linux/qemu_disable_cet.c"
+CET_SO="${SCRIPT_DIR}/../CODE/linux/.cache/disable_cet.so"
+if [[ -f "$CET_SRC" ]]; then
+    mkdir -p "$(dirname "$CET_SO")"
+    if [[ ! -f "$CET_SO" || "$CET_SRC" -nt "$CET_SO" ]]; then
+        gcc -shared -fPIC -O2 -o "$CET_SO" "$CET_SRC" -ldl 2>/dev/null || true
+    fi
+fi
+if [[ -f "$CET_SO" ]]; then
+    export LD_PRELOAD="$CET_SO${LD_PRELOAD:+:$LD_PRELOAD}"
+    export GLIBC_TUNABLES="glibc.cpu.hwcaps=-IBT,-SHSTK${GLIBC_TUNABLES:+:}${GLIBC_TUNABLES:-}"
+    echo "[qemu] QEMU-process CET disabled (LD_PRELOAD + glibc tunables)"
+fi
+
+# Memory: Limine loads SYSTEM/boot modules into RAM. linux-rootfs (~768MB)
+# plus linux-extra-rootfs (<4GiB) need a larger default than the old 4G.
+# Cap to host RAM so WSL/8G boxes do not fail with "Cannot allocate memory".
+if [[ -z "${QEMU_MEM:-}" ]]; then
+    host_mib="$(awk '/MemAvailable:/ {print int($2/1024)}' /proc/meminfo 2>/dev/null || echo 0)"
+    if [[ "$host_mib" -gt 14000 ]]; then
+        MEM="12G"
+    elif [[ "$host_mib" -gt 9000 ]]; then
+        MEM="8G"
+    elif [[ "$host_mib" -gt 6500 ]]; then
+        MEM="6G"
+    else
+        MEM="4G"
+        echo "[qemu] WARNING: only ${host_mib} MiB available; 6G+ preferred for extra-rootfs"
+    fi
+else
+    MEM="$QEMU_MEM"
+fi
 SMP="${QEMU_SMP:-2}"
 
 # Detect whether Linux compat layer is enabled (bzImage module present in IMG).
@@ -120,7 +173,7 @@ else
     echo "[qemu] Linux compat: disabled (build via CODE/linux/build.sh to enable)"
 fi
 
-# Optional NVMe test disk
+# Optional NVMe test disk (disabled when the file is missing).
 NVME_OPTS=""
 if [[ -f "$NVME_IMG" ]]; then
     echo "[qemu] NVMe:  $NVME_IMG"
@@ -134,24 +187,73 @@ if [[ -f "$USB_IMG" ]]; then
     USB_OPTS="-device qemu-xhci,id=xhci0 -drive id=usb0,if=none,file=$USB_IMG,format=raw -device usb-storage,bus=xhci0.0,drive=usb0"
 fi
 
-# Optional SATA FAT32 disk (AHCI test)
-if [[ -f "$SATA_IMG" ]]; then
-    echo "[qemu] SATA:  $SATA_IMG"
-    SATA_OPTS="-drive id=sata0,format=raw,file=$SATA_IMG,if=none -device ide-hd,drive=sata0,bus=ide.0"
+# Optional SATA FAT32 sidecar (AHCI test). Never attach it on the same
+# ide.0 port as the boot disk. The boot image itself is AHCI (see below)
+# so UTSM/DSK can parse the GPT ESP; the old sata_fat32_dsk.img sideca
+# hid ESP DSK when it was the first FAT32 block device.
+if [[ -f "$SATA_IMG" && "$(readlink -f "$SATA_IMG" 2>/dev/null || echo "$SATA_IMG")" != "$(readlink -f "$IMG" 2>/dev/null || echo "$IMG")" ]]; then
+    echo "[qemu] SATA sidecar: $SATA_IMG (ide.1)"
+    SATA_OPTS="-drive id=sata0,format=raw,file=$SATA_IMG,if=none -device ide-hd,drive=sata0,bus=ide.1"
 else
-    echo "[qemu] SATA image not found, booting without block device"
+    echo "[qemu] no extra SATA sidecar (boot disk is AHCI)"
     SATA_OPTS=""
 fi
 
+# Serial: default stdio; QEMU_SERIAL_LOG=path redirects to a file
+# (required for Phase 0 Linux guest log capture in headless runs).
+# QEMU_SERIAL_TCP=127.0.0.1:45455 makes COM1 a socket so the host can
+# send '1'/'2' for the DSK session chooser while still logging output.
+SERIAL="stdio"
+SERIAL_ARGS=()
+if [[ -n "${QEMU_SERIAL_TCP:-}" ]]; then
+    tcp="${QEMU_SERIAL_TCP}"
+    host="${tcp%%:*}"
+    port="${tcp##*:}"
+    logopt=""
+    if [[ -n "${QEMU_SERIAL_LOG:-}" ]]; then
+        logopt=",logfile=${QEMU_SERIAL_LOG},logappend=on"
+    fi
+    SERIAL_ARGS=(-chardev "socket,id=com1,host=${host},port=${port},server=on,wait=off${logopt}" -serial chardev:com1)
+    echo "[qemu] Serial: tcp:${tcp} log=${QEMU_SERIAL_LOG:-none}"
+elif [[ -n "${QEMU_SERIAL_LOG:-}" ]]; then
+    SERIAL="file:$QEMU_SERIAL_LOG"
+    SERIAL_ARGS=(-serial "$SERIAL")
+    echo "[qemu] Serial: $SERIAL"
+else
+    SERIAL_ARGS=(-serial "$SERIAL")
+    echo "[qemu] Serial: $SERIAL"
+fi
+
+DISPLAY_OPTS=()
+if [[ -n "${QEMU_DISPLAY:-}" ]]; then
+    DISPLAY_OPTS=(-display "$QEMU_DISPLAY")
+    echo "[qemu] Display: $QEMU_DISPLAY"
+fi
+
+MONITOR_OPTS=()
+if [[ -n "${QEMU_MONITOR:-}" ]]; then
+    MONITOR_OPTS=(-monitor "$QEMU_MONITOR")
+    echo "[qemu] Monitor: $QEMU_MONITOR"
+fi
+
+PFLASH_VARS=()
+if [[ -n "$OVMF_VARS" ]]; then
+    PFLASH_VARS=(-drive if=pflash,format=raw,file="$OVMF_VARS")
+fi
+
 exec "$QEMU" \
     -accel "$ACCEL" \
     -machine q35 \
     -m "$MEM" \
     -smp "$SMP" \
     -cpu "$CPU" \
-    -serial stdio \
+    "${DISPLAY_OPTS[@]}" \
+    "${MONITOR_OPTS[@]}" \
+    "${SERIAL_ARGS[@]}" \
     -drive if=pflash,format=raw,readonly=on,file="$OVMF" \
-    -drive format=raw,file="$IMG",if=virtio \
+    "${PFLASH_VARS[@]}" \
+    -drive if=none,id=osdisk,format=raw,file="$IMG" \
+    -device ide-hd,drive=osdisk,bus=ide.0,bootindex=1 \
     $SATA_OPTS \
     $NVME_OPTS \
     $USB_OPTS \