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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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67730e6c53
Use the kernel's canonical $(ARCH) paths instead of the raw target triple for KVM selftests directories. KVM selftests are quite nearly the only place in the entire kernel that using the target triple for directories, tools/testing/selftests/drivers/s390x being the lone holdout. Using the kernel's preferred nomenclature eliminates the minor, but annoying, friction of having to translate to KVM's selftests directories, e.g. for pattern matching, opening files, running selftests, etc. Opportunsitically delete file comments that reference the full path of the file, as they are obviously prone to becoming stale, and serve no known purpose. Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20241128005547.4077116-16-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
142 lines
3.4 KiB
C
142 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2020, Google LLC.
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*
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* Tests for KVM paravirtual feature disablement
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*/
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#include <asm/kvm_para.h>
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#include <linux/kvm_para.h>
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#include <linux/stringify.h>
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#include <stdint.h>
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#include "kvm_test_harness.h"
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#include "apic.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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/* VMCALL and VMMCALL are both 3-byte opcodes. */
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#define HYPERCALL_INSN_SIZE 3
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static bool quirk_disabled;
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static void guest_ud_handler(struct ex_regs *regs)
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{
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regs->rax = -EFAULT;
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regs->rip += HYPERCALL_INSN_SIZE;
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}
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static const uint8_t vmx_vmcall[HYPERCALL_INSN_SIZE] = { 0x0f, 0x01, 0xc1 };
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static const uint8_t svm_vmmcall[HYPERCALL_INSN_SIZE] = { 0x0f, 0x01, 0xd9 };
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extern uint8_t hypercall_insn[HYPERCALL_INSN_SIZE];
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static uint64_t do_sched_yield(uint8_t apic_id)
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{
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uint64_t ret;
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asm volatile("hypercall_insn:\n\t"
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".byte 0xcc,0xcc,0xcc\n\t"
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: "=a"(ret)
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: "a"((uint64_t)KVM_HC_SCHED_YIELD), "b"((uint64_t)apic_id)
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: "memory");
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return ret;
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}
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static void guest_main(void)
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{
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const uint8_t *native_hypercall_insn;
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const uint8_t *other_hypercall_insn;
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uint64_t ret;
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if (host_cpu_is_intel) {
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native_hypercall_insn = vmx_vmcall;
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other_hypercall_insn = svm_vmmcall;
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} else if (host_cpu_is_amd) {
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native_hypercall_insn = svm_vmmcall;
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other_hypercall_insn = vmx_vmcall;
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} else {
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GUEST_ASSERT(0);
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/* unreachable */
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return;
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}
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memcpy(hypercall_insn, other_hypercall_insn, HYPERCALL_INSN_SIZE);
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ret = do_sched_yield(GET_APIC_ID_FIELD(xapic_read_reg(APIC_ID)));
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/*
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* If the quirk is disabled, verify that guest_ud_handler() "returned"
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* -EFAULT and that KVM did NOT patch the hypercall. If the quirk is
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* enabled, verify that the hypercall succeeded and that KVM patched in
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* the "right" hypercall.
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*/
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if (quirk_disabled) {
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GUEST_ASSERT(ret == (uint64_t)-EFAULT);
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GUEST_ASSERT(!memcmp(other_hypercall_insn, hypercall_insn,
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HYPERCALL_INSN_SIZE));
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} else {
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GUEST_ASSERT(!ret);
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GUEST_ASSERT(!memcmp(native_hypercall_insn, hypercall_insn,
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HYPERCALL_INSN_SIZE));
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}
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GUEST_DONE();
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}
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KVM_ONE_VCPU_TEST_SUITE(fix_hypercall);
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static void enter_guest(struct kvm_vcpu *vcpu)
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{
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struct kvm_run *run = vcpu->run;
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struct ucall uc;
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vcpu_run(vcpu);
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switch (get_ucall(vcpu, &uc)) {
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case UCALL_SYNC:
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pr_info("%s: %016lx\n", (const char *)uc.args[2], uc.args[3]);
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break;
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case UCALL_DONE:
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return;
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case UCALL_ABORT:
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REPORT_GUEST_ASSERT(uc);
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default:
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TEST_FAIL("Unhandled ucall: %ld\nexit_reason: %u (%s)",
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uc.cmd, run->exit_reason, exit_reason_str(run->exit_reason));
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}
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}
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static void test_fix_hypercall(struct kvm_vcpu *vcpu, bool disable_quirk)
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{
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struct kvm_vm *vm = vcpu->vm;
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vm_install_exception_handler(vcpu->vm, UD_VECTOR, guest_ud_handler);
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if (disable_quirk)
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vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2,
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KVM_X86_QUIRK_FIX_HYPERCALL_INSN);
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quirk_disabled = disable_quirk;
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sync_global_to_guest(vm, quirk_disabled);
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virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA);
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enter_guest(vcpu);
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}
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KVM_ONE_VCPU_TEST(fix_hypercall, enable_quirk, guest_main)
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{
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test_fix_hypercall(vcpu, false);
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}
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KVM_ONE_VCPU_TEST(fix_hypercall, disable_quirk, guest_main)
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{
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test_fix_hypercall(vcpu, true);
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}
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int main(int argc, char *argv[])
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{
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TEST_REQUIRE(kvm_check_cap(KVM_CAP_DISABLE_QUIRKS2) & KVM_X86_QUIRK_FIX_HYPERCALL_INSN);
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return test_harness_run(argc, argv);
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}
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