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// 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)
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_vcpu *vcpu;
struct kvm_run *run;
struct kvm_vm *vm;
struct kvm_sregs sregs;
struct kvm_cpuid_entry2 *entry;
struct ucall uc;
entry = kvm_get_supported_cpuid_entry(1);
if (!(entry->ecx & X86_FEATURE_XSAVE)) {
print_skip("XSAVE feature not supported");
return 0;
}
/* Tell stdout not to buffer its content */
setbuf(stdout, NULL);
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
run = vcpu->run;
while (1) {
vcpu_run(vcpu);
TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
"Unexpected exit reason: %u (%s),\n",
run->exit_reason,
exit_reason_str(run->exit_reason));
switch (get_ucall(vcpu, &uc)) {
case UCALL_SYNC:
/* emulate hypervisor clearing CR4.OSXSAVE */
vcpu_sregs_get(vcpu, &sregs);
sregs.cr4 &= ~X86_CR4_OSXSAVE;
vcpu_sregs_set(vcpu, &sregs);
break;
case UCALL_ABORT:
TEST_FAIL("Guest CR4 bit (OSXSAVE) unsynchronized with CPUID bit.");
break;
case UCALL_DONE:
goto done;
default:
TEST_FAIL("Unknown ucall %lu", uc.cmd);
}
}
done:
kvm_vm_free(vm);
return 0;
}
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