Support mapping of empty pages during TVM's execution (#85)

* enabled mapping of an empty page during TVM runtime
* improved broadcasting of remote commands
* optimize TAP decoding and verification
* make sure we use same endianness for serializing and deserializing TAP
* update Linux kernel patches
* add Qemu patches

---------

Signed-off-by: Wojciech Ozga <[email protected]>

Author: wojciechozga

confidential-vms/linux_vm/Makefile

@@ -70,6 +70,7 @@ dev:
 	$(MAKE) -s -C $(LINUX_VM_BUILDROOT_SOURCE_DIR) RISCV=$(RISCV_GNU_TOOLCHAIN_WORK_DIR) PATH=$(PATH) O=$(LINUX_VM_BUILDROOT_WORK_DIR) CROSS_COMPILE=$(CROSS_COMPILE) BR2_JLEVEL=0 linux-rebuild all
 
 overlay: setup
+	echo "Rebuilding overloay"; \
 	mkdir -p $(LINUX_VM_OVERLAY_WORK_DIR) ;\
 	mkdir -p $(LINUX_VM_OVERLAY_WORK_ROOT_DIR); \
 	cp -r $(LINUX_VM_OVERLAY_SOURCE_DIR)/* $(LINUX_VM_OVERLAY_WORK_DIR)/ ;\
@@ -78,9 +79,8 @@ overlay: setup
 	cp $(LINUX_VM_ROOTFS_SOURCE_DIR)/*.sh $(HYPERVISOR_OVERLAY_ROOT_DIR)/ ;\
 	rm -rf $(HYPERVISOR_OVERLAY_LINUX_VM_DIR) && mkdir -p $(HYPERVISOR_OVERLAY_LINUX_VM_DIR) ;\
 	rm -f $(LINUX_VM_COVE_TAP_QEMU) ;\
-	$(eval $@_TMP = $(shell $(TOOLS_WORK_DIR)/cove-tap-tool measure  --embedded-tap --kernel-file=$(LINUX_VM_IMAGE) | cut -d' ' -f2-;) )
+	$(eval $@_TMP = $(shell $(TOOLS_WORK_DIR)/cove-tap-tool measure --base-address=0x80000000 --kernel-file=$(LINUX_VM_IMAGE) | cut -d' ' -f2-;) )
 	$(TOOLS_WORK_DIR)/cove-tap-tool generate --pcrs 4=$($@_TMP) --secrets 0=0xc0ffee --output-file=$(LINUX_VM_COVE_TAP_QEMU)
-	$(TOOLS_WORK_DIR)/cove-tap-tool attach --tap-file=$(LINUX_VM_COVE_TAP_QEMU) --kernel-file=$(LINUX_VM_IMAGE)
 	cp $(LINUX_VM_COVE_TAP_QEMU) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)/
 	cp $(LINUX_VM_IMAGE) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)/
 	cp $(LINUX_VM_BUILDROOT_ROOTFS) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)

confidential-vms/linux_vm/hypervisor_rootfs/run_linux_vm_qemu.sh

@@ -7,6 +7,7 @@ QEMU_CMD=qemu-system-riscv64
 KERNEL=/root/linux_vm/Image
 DRIVE=/root/linux_vm/rootfs.ext2
 INITRAMFS=/root/linux_vm/rootfs.cpio
+TAP=/root/linux_vm/cove_tap_qemu
 
 HOST_PORT="$((3000 + RANDOM % 3000))"
 INTERACTIVE="-nographic"
@@ -52,7 +53,7 @@ echo "Number of cores assigned to the guest: ${SMP}"
 ${QEMU_CMD} ${DEBUG_OPTIONS} \
     ${INTERACTIVE} \
     --enable-kvm \
-    -machine virt -cpu rv64,f=true -smp ${SMP} -m ${MEMORY} \
+    -machine virt,cove=true,cove-tap-filename=${TAP} -cpu rv64,f=true -smp ${SMP} -m ${MEMORY} \
     -kernel ${KERNEL} \
     -seed 0 \
     -global virtio-mmio.force-legacy=false \

hypervisor/Makefile

@@ -45,7 +45,7 @@ buildroot: setup
 		sed "s@^BR2_ROOTFS_OVERLAY=.*@BR2_ROOTFS_OVERLAY=\"$(HYPERVISOR_OVERLAY_DIR)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
 		sed "s@^BR2_TARGET_ROOTFS_EXT2_SIZE=.*@BR2_TARGET_ROOTFS_EXT2_SIZE=\"$(HYPERVISOR_ROOTFS_SIZE)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
 		sed "s@^BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE=.*@BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE=\"$(HYPERVISOR_LINUX_CONFIG)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
-		sed "s@^BR2_LINUX_KERNEL_PATCH=.*@BR2_LINUX_KERNEL_PATCH=\"$(HYPERVISOR_LINUX_PATCH)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
+		sed "s@^BR2_GLOBAL_PATCH_DIR=.*@BR2_GLOBAL_PATCH_DIR=\"$(HYPERVISOR_PATCHES_DIR)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
 		if [ ! -f "$(BUILDROOT_SOURCE_DIR)/Makefile" ]; then \
 			echo "Buildroot repository not initialized. Did you forget to run: git submodule update --init --recursive?" ;\
 			exit 1 ;\
@@ -64,7 +64,8 @@ overlay: kvmtool
 dev:
 	sed "s@^BR2_PACKAGE_OVERRIDE_FILE=.*@BR2_PACKAGE_OVERRIDE_FILE=\"$(HYPERVISOR_BUILDROOT_OVERRIDE_DIR)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
 	sed "s@^BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE=.*@BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE=\"$(HYPERVISOR_LINUX_CONFIG)\"@g" -i $(BUILDROOT_WORK_DIR)/.config; \
-	$(MAKE) -s -C $(BUILDROOT_SOURCE_DIR) RISCV=$(RISCV_GNU_TOOLCHAIN_WORK_DIR) PATH=$(PATH) O=$(BUILDROOT_WORK_DIR) BR2_JLEVEL=0 linux-rebuild all
+	$(MAKE) -s -C $(BUILDROOT_SOURCE_DIR) RISCV=$(RISCV_GNU_TOOLCHAIN_WORK_DIR) PATH=$(PATH) O=$(BUILDROOT_WORK_DIR) BR2_JLEVEL=0 linux-rebuild all; \
+	#$(MAKE) -s -C $(BUILDROOT_SOURCE_DIR) RISCV=$(RISCV_GNU_TOOLCHAIN_WORK_DIR) PATH=$(PATH) O=$(BUILDROOT_WORK_DIR) BR2_JLEVEL=0 qemu-rebuild all
 
 rootfs: overlay
 	echo "Generating hypervisor's root filesystem" ;\

hypervisor/configurations/qemu_riscv64_virt_defconfig

@@ -52,6 +52,8 @@ BR2_LINUX_KERNEL_PATCH=""
 # development with custom Linux kernel sources
 BR2_PACKAGE_OVERRIDE_FILE=""
 
+BR2_GLOBAL_PATCH_DIR=""
+
 # Packages
 BR2_PACKAGE_DROPBEAR=y
 
@@ -62,17 +64,6 @@ BR2_PACKAGE_QEMU_SYSTEM=y
 # build just QEMU for riscv64
 BR2_PACKAGE_QEMU_CHOOSE_TARGETS=y
 BR2_PACKAGE_QEMU_TARGET_RISCV64=y
-#
-BR2_PACKAGE_QEMU_HAS_EMULS=y
-BR2_PACKAGE_QEMU_FDT=y
-BR2_PACKAGE_QEMU_TOOLS=y
-BR2_PACKAGE_HOST_QEMU=y
-BR2_PACKAGE_HOST_QEMU_SYSTEM_MODE=y
-BR2_PACKAGE_QEMU_BLOBS=y
-
-# below not needed?
-BR2_TARGET_OPENSBI=y
-BR2_TARGET_OPENSBI_PLAT="generic"
 
 BR2_PER_PACKAGE_DIRECTORIES=y
 BR2_VERBOSE=0