// SPDX-License-Identifier: GPL-2.0 /* * CR4 and CPUID sync test * * Copyright 2018, Red Hat, Inc. and/or its affiliates. * * Author: * Wei Huang <wei@redhat.com> */ #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include "test_util.h" #include "kvm_util.h" #include "processor.h" #define X86_FEATURE_XSAVE (1<<26) #define X86_FEATURE_OSXSAVE (1<<27) #define VCPU_ID 1 static inline bool cr4_cpuid_is_sync(void) { int func, subfunc; uint32_t eax, ebx, ecx, edx; uint64_t cr4; func = 0x1; subfunc = 0x0; __asm__ __volatile__("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(func), "c"(subfunc)); cr4 = get_cr4(); return (!!(ecx & X86_FEATURE_OSXSAVE)) == (!!(cr4 & X86_CR4_OSXSAVE)); } static void guest_code(void) { uint64_t cr4; /* turn on CR4.OSXSAVE */ cr4 = get_cr4(); cr4 |= X86_CR4_OSXSAVE; set_cr4(cr4); /* verify CR4.OSXSAVE == CPUID.OSXSAVE */ GUEST_ASSERT(cr4_cpuid_is_sync()); /* notify hypervisor to change CR4 */ GUEST_SYNC(0); /* check again */ GUEST_ASSERT(cr4_cpuid_is_sync()); GUEST_DONE(); } int main(int argc, char *argv[]) { struct kvm_run *run; struct kvm_vm *vm; struct kvm_sregs sregs; struct kvm_cpuid_entry2 *entry; struct ucall uc; int rc; entry = kvm_get_supported_cpuid_entry(1); if (!(entry->ecx & X86_FEATURE_XSAVE)) { printf("XSAVE feature not supported, skipping test\n"); return 0; } /* Tell stdout not to buffer its content */ setbuf(stdout, NULL); /* Create VM */ vm = vm_create_default(VCPU_ID, 0, guest_code); vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); run = vcpu_state(vm, VCPU_ID); while (1) { rc = _vcpu_run(vm, VCPU_ID); if (run->exit_reason == KVM_EXIT_IO) { switch (get_ucall(vm, VCPU_ID, &uc)) { case UCALL_SYNC: /* emulate hypervisor clearing CR4.OSXSAVE */ vcpu_sregs_get(vm, VCPU_ID, &sregs); sregs.cr4 &= ~X86_CR4_OSXSAVE; vcpu_sregs_set(vm, VCPU_ID, &sregs); break; case UCALL_ABORT: TEST_ASSERT(false, "Guest CR4 bit (OSXSAVE) unsynchronized with CPUID bit."); break; case UCALL_DONE: goto done; default: TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd); } } } kvm_vm_free(vm); done: return 0; }