kvmtest/kvmtest-arm64.c - misc - Git at Google

 /*
  *
  * This is an Arm64 port of the x86 code accompanying "Using the KVM API"
  * (https://lwn.net/Articles/658511/).
  *
  * Original x86 code in the file kvmtest.c and https://lwn.net/Articles/658512/.
  *
  * Copyright (C) 2020 Google LLC
  * Author: Fuad Tabba <tabba@google.com>
  */

 /* Sample code for /dev/kvm API
  *
  * Copyright (c) 2015 Intel Corporation
  * Author: Josh Triplett <josh@joshtriplett.org>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
  * deal in the Software without restriction, including without limitation the
  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  * sell copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  * IN THE SOFTWARE.
  */
 #include <err.h>
 #include <fcntl.h>
 #include <linux/kvm.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/types.h>

 int main(void)
 {
     int kvm, vmfd, vcpufd, ret;

     /* Add x0 to x1 and outputs the result to MMIO at address in x2. */
     const uint8_t code[] = {
         0x20, 0x00, 0x00, 0x8b, /* add x0, x1, x0 */
         0x40, 0x00, 0x00, 0xf9, /* str x0, [x2]*/
         0x00, 0x00, 0x20, 0xd4, /* brk */
     };
     const uint64_t code_address = 0x1000;
     const uint64_t mmio_address = 0x2000;
     uint8_t *mem_code = NULL;
     size_t mmap_size;
     struct kvm_run *run = NULL;

     kvm = open("/dev/kvm", O_RDWR | O_CLOEXEC);
     if (kvm < 0)
         err(1, "/dev/kvm");

     /* Ensure this is the stable version of the KVM API (defined as 12) */
     ret = ioctl(kvm, KVM_GET_API_VERSION, NULL);
     if (ret < 0)
         err(1, "KVM_GET_API_VERSION");
     if (ret != 12)
         errx(1, "KVM_GET_API_VERSION %d, expected 12", ret);

     vmfd = ioctl(kvm, KVM_CREATE_VM, (unsigned long)0);
     if (vmfd < 0)
         err(1, "KVM_CREATE_VM");

     /* Allocate one aligned page of guest memory to hold the code. */
     mem_code = mmap(NULL, 0x1000,
         PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
     if (!mem_code)
         err(1, "allocating guest memory");
     memcpy(mem_code, code, sizeof(code));

     /* Map code memory to the second page frame. */
     struct kvm_userspace_memory_region region = {
         .slot = 0,
         .guest_phys_addr = code_address,
         .memory_size = 0x1000,
         .userspace_addr = (uint64_t)mem_code,
     };
     ret = ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &region);
     if (ret < 0)
         err(1, "KVM_SET_USER_MEMORY_REGION");

     /* Use third page frame of guest memory to simulate MMIO. */
     region.flags = KVM_MEM_READONLY; /* triggers KVM_EXIT_MEMIO on write */
     region.slot = 1;
     region.guest_phys_addr = mmio_address;
     region.userspace_addr = 0ULL;
     ret = ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &region);
     if (ret < 0)
         err(1, "KVM_SET_USER_MEMORY_REGION");

     /* Create one CPU to run in the VM. */
     vcpufd = ioctl(vmfd, KVM_CREATE_VCPU, (unsigned long)0);
     if (vcpufd < 0)
         err(1, "KVM_CREATE_VCPU");

     /* Map the shared kvm_run structure and following data. */
     ret = ioctl(kvm, KVM_GET_VCPU_MMAP_SIZE, NULL);
     if (ret < 0)
         err(1, "KVM_GET_VCPU_MMAP_SIZE");
     mmap_size = ret;
     if (mmap_size < sizeof(*run))
         errx(1, "KVM_GET_VCPU_MMAP_SIZE unexpectedly small");
     run = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, vcpufd, 0);
     if (!run)
         err(1, "mmap vcpu");

     /* Query KVM for preferred CPU target type that can be emulated. */
     struct kvm_vcpu_init vcpu_init;
     ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, &vcpu_init);
     if (ret < 0)
         err(1, "KVM_PREFERRED_TARGET");

     /* Initialize VCPU with the preferred type obtained above. */
     ret = ioctl(vcpufd, KVM_ARM_VCPU_INIT, &vcpu_init);
     if (ret < 0)
         err(1, "KVM_ARM_VCPU_INIT");

     /* Prepare the kvm_one_reg structure to use for populating registers. */
     uint64_t reg_data;
     struct kvm_one_reg reg;
     reg.addr = (__u64) &reg_data;

     // Initialize input registers (x0 and x1) to 2.
     reg_data = 2;
     reg.id = 0x6030000000100000; // x0 id
     ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
     if (ret != 0)
         err(1, "KVM_SET_ONE_REG");
     reg.id = 0x6030000000100002; // x1 id
     ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
     if (ret != 0)
         err(1, "KVM_SET_ONE_REG");

     // Initialize x3 to point to the simulated MMIO region.
     reg.id = 0x6030000000100004; // x3 id
     reg_data = mmio_address;
     ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
     if (ret != 0)
         err(1, "KVM_SET_ONE_REG");

     // Initialize the PC to point to the start of the code.
     reg.id = 0x6030000000100040; // pc id
     reg_data = code_address;
     ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
     if (ret != 0)
         err(1, "KVM_SET_ONE_REG");

     // Enable debug so that brk instruction would exit KVM_RUN (KVM_EXIT_DEBUG).
     struct kvm_guest_debug debug = {
         .control = KVM_GUESTDBG_ENABLE,
     };
     ret = ioctl(vcpufd, KVM_SET_GUEST_DEBUG, &debug);
     if (ret < 0)
         err(1, "KVM_SET_GUEST_DEBUG");

     /* Repeatedly run code and handle VM exits. */
     for (;;) {
         ret = ioctl(vcpufd, KVM_RUN, NULL);
         if (ret < 0)
             err(1, "KVM_RUN");
         switch (run->exit_reason) {
         case KVM_EXIT_DEBUG:
             puts("KVM_EXIT_DEBUG");
             return 0;
         case KVM_EXIT_MMIO:
         {
             uint64_t payload = *(uint64_t*)(run->mmio.data); /* sorry */
             printf("KVM_EXIT_MMIO: addr = 0x%llx, len = %u, is_write = %u, data = 0x%08llx\n",
                 run->mmio.phys_addr, run->mmio.len, run->mmio.is_write,
                 payload);
             break;
         }
         case KVM_EXIT_FAIL_ENTRY:
             errx(1, "KVM_EXIT_FAIL_ENTRY: hardware_entry_failure_reason = 0x%llx",
                  (unsigned long long)run->fail_entry.hardware_entry_failure_reason);
         case KVM_EXIT_INTERNAL_ERROR:
             errx(1, "KVM_EXIT_INTERNAL_ERROR: suberror = 0x%x",
                 run->internal.suberror);
         default:
             errx(1, "exit_reason = 0x%x", run->exit_reason);
         }
     }
 }
	/*
	*
	* This is an Arm64 port of the x86 code accompanying "Using the KVM API"
	* (https://lwn.net/Articles/658511/).
	*
	* Original x86 code in the file kvmtest.c and https://lwn.net/Articles/658512/.
	*
	* Copyright (C) 2020 Google LLC
	* Author: Fuad Tabba <tabba@google.com>
	*/

	/* Sample code for /dev/kvm API
	*
	* Copyright (c) 2015 Intel Corporation
	* Author: Josh Triplett <josh@joshtriplett.org>
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to
	* deal in the Software without restriction, including without limitation the
	* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
	* sell copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	* IN THE SOFTWARE.
	*/
	#include <err.h>
	#include <fcntl.h>
	#include <linux/kvm.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <sys/stat.h>
	#include <sys/types.h>

	int main(void)
	{
	int kvm, vmfd, vcpufd, ret;

	/* Add x0 to x1 and outputs the result to MMIO at address in x2. */
	const uint8_t code[] = {
	0x20, 0x00, 0x00, 0x8b, /* add x0, x1, x0 */
	0x40, 0x00, 0x00, 0xf9, /* str x0, [x2]*/
	0x00, 0x00, 0x20, 0xd4, /* brk */
	};
	const uint64_t code_address = 0x1000;
	const uint64_t mmio_address = 0x2000;
	uint8_t *mem_code = NULL;
	size_t mmap_size;
	struct kvm_run *run = NULL;

	kvm = open("/dev/kvm", O_RDWR \| O_CLOEXEC);
	if (kvm < 0)
	err(1, "/dev/kvm");

	/* Ensure this is the stable version of the KVM API (defined as 12) */
	ret = ioctl(kvm, KVM_GET_API_VERSION, NULL);
	if (ret < 0)
	err(1, "KVM_GET_API_VERSION");
	if (ret != 12)
	errx(1, "KVM_GET_API_VERSION %d, expected 12", ret);

	vmfd = ioctl(kvm, KVM_CREATE_VM, (unsigned long)0);
	if (vmfd < 0)
	err(1, "KVM_CREATE_VM");

	/* Allocate one aligned page of guest memory to hold the code. */
	mem_code = mmap(NULL, 0x1000,
	PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_ANONYMOUS, -1, 0);
	if (!mem_code)
	err(1, "allocating guest memory");
	memcpy(mem_code, code, sizeof(code));

	/* Map code memory to the second page frame. */
	struct kvm_userspace_memory_region region = {
	.slot = 0,
	.guest_phys_addr = code_address,
	.memory_size = 0x1000,
	.userspace_addr = (uint64_t)mem_code,
	};
	ret = ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &region);
	if (ret < 0)
	err(1, "KVM_SET_USER_MEMORY_REGION");

	/* Use third page frame of guest memory to simulate MMIO. */
	region.flags = KVM_MEM_READONLY; /* triggers KVM_EXIT_MEMIO on write */
	region.slot = 1;
	region.guest_phys_addr = mmio_address;
	region.userspace_addr = 0ULL;
	ret = ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &region);
	if (ret < 0)
	err(1, "KVM_SET_USER_MEMORY_REGION");

	/* Create one CPU to run in the VM. */
	vcpufd = ioctl(vmfd, KVM_CREATE_VCPU, (unsigned long)0);
	if (vcpufd < 0)
	err(1, "KVM_CREATE_VCPU");

	/* Map the shared kvm_run structure and following data. */
	ret = ioctl(kvm, KVM_GET_VCPU_MMAP_SIZE, NULL);
	if (ret < 0)
	err(1, "KVM_GET_VCPU_MMAP_SIZE");
	mmap_size = ret;
	if (mmap_size < sizeof(*run))
	errx(1, "KVM_GET_VCPU_MMAP_SIZE unexpectedly small");
	run = mmap(NULL, mmap_size, PROT_READ \| PROT_WRITE, MAP_SHARED, vcpufd, 0);
	if (!run)
	err(1, "mmap vcpu");

	/* Query KVM for preferred CPU target type that can be emulated. */
	struct kvm_vcpu_init vcpu_init;
	ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, &vcpu_init);
	if (ret < 0)
	err(1, "KVM_PREFERRED_TARGET");

	/* Initialize VCPU with the preferred type obtained above. */
	ret = ioctl(vcpufd, KVM_ARM_VCPU_INIT, &vcpu_init);
	if (ret < 0)
	err(1, "KVM_ARM_VCPU_INIT");

	/* Prepare the kvm_one_reg structure to use for populating registers. */
	uint64_t reg_data;
	struct kvm_one_reg reg;
	reg.addr = (__u64) &reg_data;

	// Initialize input registers (x0 and x1) to 2.
	reg_data = 2;
	reg.id = 0x6030000000100000; // x0 id
	ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
	if (ret != 0)
	err(1, "KVM_SET_ONE_REG");
	reg.id = 0x6030000000100002; // x1 id
	ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
	if (ret != 0)
	err(1, "KVM_SET_ONE_REG");

	// Initialize x3 to point to the simulated MMIO region.
	reg.id = 0x6030000000100004; // x3 id
	reg_data = mmio_address;
	ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
	if (ret != 0)
	err(1, "KVM_SET_ONE_REG");

	// Initialize the PC to point to the start of the code.
	reg.id = 0x6030000000100040; // pc id
	reg_data = code_address;
	ret = ioctl(vcpufd, KVM_SET_ONE_REG, &reg);
	if (ret != 0)
	err(1, "KVM_SET_ONE_REG");

	// Enable debug so that brk instruction would exit KVM_RUN (KVM_EXIT_DEBUG).
	struct kvm_guest_debug debug = {
	.control = KVM_GUESTDBG_ENABLE,
	};
	ret = ioctl(vcpufd, KVM_SET_GUEST_DEBUG, &debug);
	if (ret < 0)
	err(1, "KVM_SET_GUEST_DEBUG");

	/* Repeatedly run code and handle VM exits. */
	for (;;) {
	ret = ioctl(vcpufd, KVM_RUN, NULL);
	if (ret < 0)
	err(1, "KVM_RUN");
	switch (run->exit_reason) {
	case KVM_EXIT_DEBUG:
	puts("KVM_EXIT_DEBUG");
	return 0;
	case KVM_EXIT_MMIO:
	{
	uint64_t payload = (uint64_t)(run->mmio.data); /* sorry */
	printf("KVM_EXIT_MMIO: addr = 0x%llx, len = %u, is_write = %u, data = 0x%08llx\n",
	run->mmio.phys_addr, run->mmio.len, run->mmio.is_write,
	payload);
	break;
	}
	case KVM_EXIT_FAIL_ENTRY:
	errx(1, "KVM_EXIT_FAIL_ENTRY: hardware_entry_failure_reason = 0x%llx",
	(unsigned long long)run->fail_entry.hardware_entry_failure_reason);
	case KVM_EXIT_INTERNAL_ERROR:
	errx(1, "KVM_EXIT_INTERNAL_ERROR: suberror = 0x%x",
	run->internal.suberror);
	default:
	errx(1, "exit_reason = 0x%x", run->exit_reason);
	}
	}
	}