Re: [PATCH v11 14/26] samples: Add sample userspace Gunyah VM Manager

From: Alex Elder
Date: Fri Mar 31 2023 - 10:27:15 EST


On 3/3/23 7:06 PM, Elliot Berman wrote:
Add a sample Gunyah VMM capable of launching a non-proxy scheduled VM.


This example doesn't show any VM functions getting added. Is
that handled by cros_vm or something? It would be nice to
have the process of interpreting the DTS file and setting
up CPUs and interrupts be explained.

Honestly, I haven't reviewed your documentation this time
around, so maybe you've done that and I just haven't looked...

A few tiny suggestions below, but this generally looks fine.
I'll look at it once more next time.

-Alex

Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
samples/Kconfig | 10 ++
samples/Makefile | 1 +
samples/gunyah/.gitignore | 2 +
samples/gunyah/Makefile | 6 +
samples/gunyah/gunyah_vmm.c | 270 +++++++++++++++++++++++++++++++++++
samples/gunyah/sample_vm.dts | 68 +++++++++
6 files changed, 357 insertions(+)
create mode 100644 samples/gunyah/.gitignore
create mode 100644 samples/gunyah/Makefile
create mode 100644 samples/gunyah/gunyah_vmm.c
create mode 100644 samples/gunyah/sample_vm.dts

diff --git a/samples/Kconfig b/samples/Kconfig
index 30ef8bd48ba3..11070bf02bd7 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -273,6 +273,16 @@ config SAMPLE_CORESIGHT_SYSCFG
This demonstrates how a user may create their own CoreSight
configurations and easily load them into the system at runtime.
+config SAMPLE_GUNYAH
+ bool "Build example Gunyah Virtual Machine Manager"
+ depends on CC_CAN_LINK && HEADERS_INSTALL
+ depends on GUNYAH
+ help
+ Build an example Gunyah VMM userspace program capable of launching
+ a basic virtual machine under the Gunyah hypervisor.
+ This demonstrates how to create a virtual machine under the Gunyah
+ hypervisor.
+
source "samples/rust/Kconfig"
endif # SAMPLES
diff --git a/samples/Makefile b/samples/Makefile
index 7cb632ef88ee..a65555802642 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak/
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight/
obj-$(CONFIG_SAMPLE_FPROBE) += fprobe/
obj-$(CONFIG_SAMPLES_RUST) += rust/
+obj-$(CONFIG_SAMPLE_GUNYAH) += gunyah/
diff --git a/samples/gunyah/.gitignore b/samples/gunyah/.gitignore
new file mode 100644
index 000000000000..adc7d1589fde
--- /dev/null
+++ b/samples/gunyah/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+/gunyah_vmm
diff --git a/samples/gunyah/Makefile b/samples/gunyah/Makefile
new file mode 100644
index 000000000000..faf14f9bb337
--- /dev/null
+++ b/samples/gunyah/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+userprogs-always-y += gunyah_vmm
+dtb-y += sample_vm.dtb
+
+userccflags += -I usr/include
diff --git a/samples/gunyah/gunyah_vmm.c b/samples/gunyah/gunyah_vmm.c
new file mode 100644
index 000000000000..d0ba9c20cb13
--- /dev/null
+++ b/samples/gunyah/gunyah_vmm.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <getopt.h>
+#include <limits.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/sysmacros.h>
+#define __USE_GNU
+#include <sys/mman.h>
+
+#include <linux/gunyah.h>
+
+struct vm_config {
+ int image_fd;
+ int dtb_fd;
+ int ramdisk_fd;
+
+ uint64_t guest_base;
+ uint64_t guest_size;
+
+ uint64_t image_offset;
+ off_t image_size;
+ uint64_t dtb_offset;
+ off_t dtb_size;
+ uint64_t ramdisk_offset;
+ off_t ramdisk_size;
+};
+
+static struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "image", required_argument, NULL, 'i' },
+ { "dtb", required_argument, NULL, 'd' },
+ { "ramdisk", optional_argument, NULL, 'r' },
+ { "base", optional_argument, NULL, 'B' },
+ { "size", optional_argument, NULL, 'S' },
+ { "image_offset", optional_argument, NULL, 'I' },
+ { "dtb_offset", optional_argument, NULL, 'D' },
+ { "ramdisk_offset", optional_argument, NULL, 'R' },
+ { }
+};
+
+static void print_help(char *cmd)
+{
+ printf("gunyah_vmm, a sample tool to launch Gunyah VMs\n"
+ "Usage: %s <options>\n"
+ " --help, -h this menu\n"
+ " --image, -i <image> VM image file to load (e.g. a kernel Image) [Required]\n"
+ " --dtb, -d <dtb> Devicetree to load [Required]\n"

s/Devicetree/Devicetree file/

+ " --ramdisk, -r <ramdisk> Ramdisk to load\n"

s/Ramdisk/Ramdisk file/

+ " --base, -B <address> Set the base address of guest's memory [Default: 0x80000000]\n"
+ " --size, -S <number> The number of bytes large to make the guest's memory [Default: 0x6400000 (100 MB)]\n"
+ " --image_offset, -I <number> Offset into guest memory to load the VM image file [Default: 0x10000]\n"
+ " --dtb_offset, -D <number> Offset into guest memory to load the DTB [Default: 0]\n"
+ " --ramdisk_offset, -R <number> Offset into guest memory to load a ramdisk [Default: 0x4600000]\n"
+ , cmd);
+}
+
+int main(int argc, char **argv)
+{
+ int gunyah_fd, vm_fd, guest_fd;
+ struct gh_userspace_memory_region guest_mem_desc = { 0 };
+ struct gh_vm_dtb_config dtb_config = { 0 };
+ char *guest_mem;
+ struct vm_config config = {
+ /* Defaults good enough to boot static kernel and a basic ramdisk */
+ .ramdisk_fd = -1,
+ .guest_base = 0x80000000,
+ .guest_size = 0x6400000, /* 100 MB */
+ .image_offset = 0,
+ .dtb_offset = 0x45f0000,
+ .ramdisk_offset = 0x4600000, /* put at +70MB (30MB for ramdisk) */
+ };
+ struct stat st;
+ int opt, optidx, ret = 0;
+ long l;
+
+ while ((opt = getopt_long(argc, argv, "hi:d:r:B:S:I:D:R:c:", options, &optidx)) != -1) {
+ switch (opt) {
+ case 'i':
+ config.image_fd = open(optarg, O_RDONLY | O_CLOEXEC);
+ if (config.image_fd < 0) {
+ perror("Failed to open image");
+ return -1;
+ }
+ if (stat(optarg, &st) < 0) {
+ perror("Failed to stat image");
+ return -1;
+ }
+ config.image_size = st.st_size;
+ break;
+ case 'd':
+ config.dtb_fd = open(optarg, O_RDONLY | O_CLOEXEC);
+ if (config.dtb_fd < 0) {
+ perror("Failed to open dtb");
+ return -1;
+ }
+ if (stat(optarg, &st) < 0) {
+ perror("Failed to stat dtb");
+ return -1;
+ }
+ config.dtb_size = st.st_size;
+ break;
+ case 'r':
+ config.ramdisk_fd = open(optarg, O_RDONLY | O_CLOEXEC);
+ if (config.ramdisk_fd < 0) {
+ perror("Failed to open ramdisk");
+ return -1;
+ }
+ if (stat(optarg, &st) < 0) {
+ perror("Failed to stat ramdisk");
+ return -1;
+ }
+ config.ramdisk_size = st.st_size;
+ break;
+ case 'B':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse base address");
+ return -1;
+ }
+ config.guest_base = l;
+ break;
+ case 'S':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse memory size");
+ return -1;
+ }
+ config.guest_size = l;
+ break;
+ case 'I':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse image offset");
+ return -1;
+ }
+ config.image_offset = l;
+ break;
+ case 'D':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse dtb offset");
+ return -1;
+ }
+ config.dtb_offset = l;
+ break;
+ case 'R':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse ramdisk offset");
+ return -1;
+ }
+ config.ramdisk_offset = l;
+ break;
+ case 'h':
+ print_help(argv[0]);
+ return 0;
+ default:
+ print_help(argv[0]);
+ return -1;
+ }
+ }
+
+ if (!config.image_fd || !config.dtb_fd) {
+ print_help(argv[0]);
+ return -1;
+ }
+
+ if (config.image_offset + config.image_size > config.guest_size) {
+ fprintf(stderr, "Image offset and size puts it outside guest memory. Make image smaller or increase guest memory size.\n");
+ return -1;
+ }
+
+ if (config.dtb_offset + config.dtb_size > config.guest_size) {
+ fprintf(stderr, "DTB offset and size puts it outside guest memory. Make dtb smaller or increase guest memory size.\n");
+ return -1;
+ }
+
+ if (config.ramdisk_fd == -1 &&
+ config.ramdisk_offset + config.ramdisk_size > config.guest_size) {
+ fprintf(stderr, "Ramdisk offset and size puts it outside guest memory. Make ramdisk smaller or increase guest memory size.\n");
+ return -1;
+ }
+
+ gunyah_fd = open("/dev/gunyah", O_RDWR | O_CLOEXEC);
+ if (gunyah_fd < 0) {
+ perror("Failed to open /dev/gunyah");
+ return -1;
+ }
+
+ vm_fd = ioctl(gunyah_fd, GH_CREATE_VM, 0);
+ if (vm_fd < 0) {
+ perror("Failed to create vm");
+ return -1;
+ }
+
+ guest_fd = memfd_create("guest_memory", MFD_CLOEXEC);
+ if (guest_fd < 0) {
+ perror("Failed to create guest memfd");
+ return -1;
+ }
+
+ if (ftruncate(guest_fd, config.guest_size) < 0) {
+ perror("Failed to grow guest memory");
+ return -1;
+ }
+
+ guest_mem = mmap(NULL, config.guest_size, PROT_READ | PROT_WRITE, MAP_SHARED, guest_fd, 0);
+ if (guest_mem == MAP_FAILED) {
+ perror("Not enough memory");
+ return -1;
+ }
+
+ if (read(config.image_fd, guest_mem + config.image_offset, config.image_size) < 0) {
+ perror("Failed to read image into guest memory");
+ return -1;
+ }
+
+ if (read(config.dtb_fd, guest_mem + config.dtb_offset, config.dtb_size) < 0) {
+ perror("Failed to read dtb into guest memory");
+ return -1;
+ }
+
+ if (config.ramdisk_fd > 0 &&
+ read(config.ramdisk_fd, guest_mem + config.ramdisk_offset,
+ config.ramdisk_size) < 0) {
+ perror("Failed to read ramdisk into guest memory");
+ return -1;
+ }
+
+ guest_mem_desc.label = 0;
+ guest_mem_desc.flags = GH_MEM_ALLOW_READ | GH_MEM_ALLOW_WRITE | GH_MEM_ALLOW_EXEC;
+ guest_mem_desc.guest_phys_addr = config.guest_base;
+ guest_mem_desc.memory_size = config.guest_size;
+ guest_mem_desc.userspace_addr = (__u64)guest_mem;
+
+ if (ioctl(vm_fd, GH_VM_SET_USER_MEM_REGION, &guest_mem_desc) < 0) {
+ perror("Failed to register guest memory with VM");
+ return -1;
+ }
+
+ dtb_config.guest_phys_addr = config.guest_base + config.dtb_offset;
+ dtb_config.size = config.dtb_size;
+ if (ioctl(vm_fd, GH_VM_SET_DTB_CONFIG, &dtb_config) < 0) {
+ perror("Failed to set DTB configuration for VM");
+ return -1;
+ }
+
+ ret = ioctl(vm_fd, GH_VM_START);
+ if (ret) {
+ perror("GH_VM_START failed");
+ return -1;
+ }
+
+ while (1)
+ sleep(10);
+
+ return 0;
+}
diff --git a/samples/gunyah/sample_vm.dts b/samples/gunyah/sample_vm.dts
new file mode 100644
index 000000000000..293bbc0469c8
--- /dev/null
+++ b/samples/gunyah/sample_vm.dts
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+/dts-v1/;
+
+/ {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ interrupt-parent = <&intc>;
+
+ chosen {
+ bootargs = "nokaslr";
+ };
+
+ cpus {
+ #address-cells = <0x2>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ device_type = "cpu";
+ compatible = "arm,armv8";
+ reg = <0 0>;
+ };
+ };
+
+ intc: interrupt-controller@3FFF0000 {
+ compatible = "arm,gic-v3";
+ #interrupt-cells = <3>;
+ #address-cells = <2>;
+ #size-cells = <2>;
+ interrupt-controller;
+ reg = <0 0x3FFF0000 0 0x10000>,
+ <0 0x3FFD0000 0 0x20000>;
+ };
+
+ timer {
+ compatible = "arm,armv8-timer";
+ always-on;
+ interrupts = <1 13 0x108>,
+ <1 14 0x108>,
+ <1 11 0x108>,
+ <1 10 0x108>;
+ clock-frequency = <19200000>;
+ };
+
+ gunyah-vm-config {
+ image-name = "linux_vm_0";
+
+ memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ base-address = <0 0x80000000>;
+ };
+
+ interrupts {
+ config = <&intc>;
+ };
+
+ vcpus {
+ affinity-map = < 0 >;
+ sched-priority = < (-1) >;
+ sched-timeslice = < 2000 >;
+ };
+ };
+};