Commit 9dba988e authored by Aaron Lewis's avatar Aaron Lewis Committed by Paolo Bonzini

tests: kvm: Check for a kernel warning

When running with /sys/module/kvm_intel/parameters/unrestricted_guest=N,
test that a kernel warning does not occur informing us that
vcpu->mmio_needed=1.  This can happen when KVM_RUN is called after a
triple fault.
This test was made to detect a bug that was reported by Syzkaller
(https://groups.google.com/forum/#!topic/syzkaller/lHfau8E3SOE) and
fixed with commit bbeac283 ("KVM: X86: Fix residual mmio emulation
request to userspace").
Signed-off-by: default avatarAaron Lewis <aaronlewis@google.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Reviewed-by: default avatarPeter Shier <pshier@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 61cfcd54
...@@ -2,6 +2,7 @@ ...@@ -2,6 +2,7 @@
/x86_64/evmcs_test /x86_64/evmcs_test
/x86_64/hyperv_cpuid /x86_64/hyperv_cpuid
/x86_64/kvm_create_max_vcpus /x86_64/kvm_create_max_vcpus
/x86_64/mmio_warning_test
/x86_64/platform_info_test /x86_64/platform_info_test
/x86_64/set_sregs_test /x86_64/set_sregs_test
/x86_64/smm_test /x86_64/smm_test
......
...@@ -15,6 +15,7 @@ TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test ...@@ -15,6 +15,7 @@ TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
TEST_GEN_PROGS_x86_64 += x86_64/kvm_create_max_vcpus TEST_GEN_PROGS_x86_64 += x86_64/kvm_create_max_vcpus
TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
TEST_GEN_PROGS_x86_64 += x86_64/smm_test TEST_GEN_PROGS_x86_64 += x86_64/smm_test
......
...@@ -139,6 +139,8 @@ struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_size, ...@@ -139,6 +139,8 @@ struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_size,
void *guest_code); void *guest_code);
void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code); void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code);
bool vm_is_unrestricted_guest(struct kvm_vm *vm);
struct kvm_userspace_memory_region * struct kvm_userspace_memory_region *
kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start, kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start,
uint64_t end); uint64_t end);
......
...@@ -303,6 +303,8 @@ static inline unsigned long get_xmm(int n) ...@@ -303,6 +303,8 @@ static inline unsigned long get_xmm(int n)
return 0; return 0;
} }
bool is_intel_cpu(void);
struct kvm_x86_state; struct kvm_x86_state;
struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid); struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid,
......
...@@ -1583,3 +1583,39 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva) ...@@ -1583,3 +1583,39 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva)
{ {
return addr_gpa2hva(vm, addr_gva2gpa(vm, gva)); return addr_gpa2hva(vm, addr_gva2gpa(vm, gva));
} }
/*
* Is Unrestricted Guest
*
* Input Args:
* vm - Virtual Machine
*
* Output Args: None
*
* Return: True if the unrestricted guest is set to 'Y', otherwise return false.
*
* Check if the unrestricted guest flag is enabled.
*/
bool vm_is_unrestricted_guest(struct kvm_vm *vm)
{
char val = 'N';
size_t count;
FILE *f;
if (vm == NULL) {
/* Ensure that the KVM vendor-specific module is loaded. */
f = fopen(KVM_DEV_PATH, "r");
TEST_ASSERT(f != NULL, "Error in opening KVM dev file: %d",
errno);
fclose(f);
}
f = fopen("/sys/module/kvm_intel/parameters/unrestricted_guest", "r");
if (f) {
count = fread(&val, sizeof(char), 1, f);
TEST_ASSERT(count == 1, "Unable to read from param file.");
fclose(f);
}
return val == 'Y';
}
...@@ -1137,3 +1137,19 @@ void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_x86_state *s ...@@ -1137,3 +1137,19 @@ void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_x86_state *s
r); r);
} }
} }
bool is_intel_cpu(void)
{
int eax, ebx, ecx, edx;
const uint32_t *chunk;
const int leaf = 0;
__asm__ __volatile__(
"cpuid"
: /* output */ "=a"(eax), "=b"(ebx),
"=c"(ecx), "=d"(edx)
: /* input */ "0"(leaf), "2"(0));
chunk = (const uint32_t *)("GenuineIntel");
return (ebx == chunk[0] && edx == chunk[1] && ecx == chunk[2]);
}
/*
* mmio_warning_test
*
* Copyright (C) 2019, Google LLC.
*
* This work is licensed under the terms of the GNU GPL, version 2.
*
* Test that we don't get a kernel warning when we call KVM_RUN after a
* triple fault occurs. To get the triple fault to occur we call KVM_RUN
* on a VCPU that hasn't been properly setup.
*
*/
#define _GNU_SOURCE
#include <fcntl.h>
#include <kvm_util.h>
#include <linux/kvm.h>
#include <processor.h>
#include <pthread.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>
#include <sys/wait.h>
#include <test_util.h>
#include <unistd.h>
#define NTHREAD 4
#define NPROCESS 5
struct thread_context {
int kvmcpu;
struct kvm_run *run;
};
void *thr(void *arg)
{
struct thread_context *tc = (struct thread_context *)arg;
int res;
int kvmcpu = tc->kvmcpu;
struct kvm_run *run = tc->run;
res = ioctl(kvmcpu, KVM_RUN, 0);
printf("ret1=%d exit_reason=%d suberror=%d\n",
res, run->exit_reason, run->internal.suberror);
return 0;
}
void test(void)
{
int i, kvm, kvmvm, kvmcpu;
pthread_t th[NTHREAD];
struct kvm_run *run;
struct thread_context tc;
kvm = open("/dev/kvm", O_RDWR);
TEST_ASSERT(kvm != -1, "failed to open /dev/kvm");
kvmvm = ioctl(kvm, KVM_CREATE_VM, 0);
TEST_ASSERT(kvmvm != -1, "KVM_CREATE_VM failed");
kvmcpu = ioctl(kvmvm, KVM_CREATE_VCPU, 0);
TEST_ASSERT(kvmcpu != -1, "KVM_CREATE_VCPU failed");
run = (struct kvm_run *)mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_SHARED,
kvmcpu, 0);
tc.kvmcpu = kvmcpu;
tc.run = run;
srand(getpid());
for (i = 0; i < NTHREAD; i++) {
pthread_create(&th[i], NULL, thr, (void *)(uintptr_t)&tc);
usleep(rand() % 10000);
}
for (i = 0; i < NTHREAD; i++)
pthread_join(th[i], NULL);
}
int get_warnings_count(void)
{
int warnings;
FILE *f;
f = popen("dmesg | grep \"WARNING:\" | wc -l", "r");
fscanf(f, "%d", &warnings);
fclose(f);
return warnings;
}
int main(void)
{
int warnings_before, warnings_after;
if (!is_intel_cpu()) {
printf("Must be run on an Intel CPU, skipping test\n");
exit(KSFT_SKIP);
}
if (vm_is_unrestricted_guest(NULL)) {
printf("Unrestricted guest must be disabled, skipping test\n");
exit(KSFT_SKIP);
}
warnings_before = get_warnings_count();
for (int i = 0; i < NPROCESS; ++i) {
int status;
int pid = fork();
if (pid < 0)
exit(1);
if (pid == 0) {
test();
exit(0);
}
while (waitpid(pid, &status, __WALL) != pid)
;
}
warnings_after = get_warnings_count();
TEST_ASSERT(warnings_before == warnings_after,
"Warnings found in kernel. Run 'dmesg' to inspect them.");
return 0;
}
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