101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* CR4 and CPUID sync test
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*
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* Copyright 2018, Red Hat, Inc. and/or its affiliates.
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*
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* Author:
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* Wei Huang <wei@redhat.com>
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*/
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include "test_util.h"
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#include "kvm_util.h"
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#include "processor.h"
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#define MAGIC_HYPERCALL_PORT 0x80
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static void guest_code(void)
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{
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u32 regs[4] = {
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[KVM_CPUID_EAX] = X86_FEATURE_OSXSAVE.function,
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[KVM_CPUID_ECX] = X86_FEATURE_OSXSAVE.index,
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};
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/* CR4.OSXSAVE should be enabled by default (for selftests vCPUs). */
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GUEST_ASSERT(get_cr4() & X86_CR4_OSXSAVE);
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/* verify CR4.OSXSAVE == CPUID.OSXSAVE */
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GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE));
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/*
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* Notify hypervisor to clear CR4.0SXSAVE, do CPUID and save output,
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* and then restore CR4. Do this all in assembly to ensure no AVX
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* instructions are executed while OSXSAVE=0.
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*/
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asm volatile (
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"out %%al, $" __stringify(MAGIC_HYPERCALL_PORT) "\n\t"
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"cpuid\n\t"
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"mov %%rdi, %%cr4\n\t"
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: "+a" (regs[KVM_CPUID_EAX]),
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"=b" (regs[KVM_CPUID_EBX]),
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"+c" (regs[KVM_CPUID_ECX]),
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"=d" (regs[KVM_CPUID_EDX])
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: "D" (get_cr4())
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);
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/* Verify KVM cleared OSXSAVE in CPUID when it was cleared in CR4. */
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GUEST_ASSERT(!(regs[X86_FEATURE_OSXSAVE.reg] & BIT(X86_FEATURE_OSXSAVE.bit)));
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/* Verify restoring CR4 also restored OSXSAVE in CPUID. */
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GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE));
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GUEST_DONE();
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}
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int main(int argc, char *argv[])
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{
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struct kvm_vcpu *vcpu;
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struct kvm_vm *vm;
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struct kvm_sregs sregs;
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struct ucall uc;
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TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVE));
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vm = vm_create_with_one_vcpu(&vcpu, guest_code);
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while (1) {
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vcpu_run(vcpu);
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TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
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if (vcpu->run->io.port == MAGIC_HYPERCALL_PORT &&
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vcpu->run->io.direction == KVM_EXIT_IO_OUT) {
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/* emulate hypervisor clearing CR4.OSXSAVE */
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vcpu_sregs_get(vcpu, &sregs);
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sregs.cr4 &= ~X86_CR4_OSXSAVE;
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vcpu_sregs_set(vcpu, &sregs);
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continue;
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}
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switch (get_ucall(vcpu, &uc)) {
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case UCALL_ABORT:
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REPORT_GUEST_ASSERT(uc);
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break;
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case UCALL_DONE:
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goto done;
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default:
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TEST_FAIL("Unknown ucall %lu", uc.cmd);
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}
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}
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done:
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kvm_vm_free(vm);
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return 0;
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}
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