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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c b/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c new file mode 100644 index 000000000..fbe8417cb --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vmx_tsc_adjust_test + * + * Copyright (C) 2018, Google LLC. + * + * IA32_TSC_ADJUST test + * + * According to the SDM, "if an execution of WRMSR to the + * IA32_TIME_STAMP_COUNTER MSR adds (or subtracts) value X from the TSC, + * the logical processor also adds (or subtracts) value X from the + * IA32_TSC_ADJUST MSR. + * + * Note that when L1 doesn't intercept writes to IA32_TSC, a + * WRMSR(IA32_TSC) from L2 sets L1's TSC value, not L2's perceived TSC + * value. + * + * This test verifies that this unusual case is handled correctly. + */ + +#include "test_util.h" +#include "kvm_util.h" +#include "processor.h" +#include "vmx.h" + +#include <string.h> +#include <sys/ioctl.h> + +#include "kselftest.h" + +#ifndef MSR_IA32_TSC_ADJUST +#define MSR_IA32_TSC_ADJUST 0x3b +#endif + +#define PAGE_SIZE 4096 +#define VCPU_ID 5 + +#define TSC_ADJUST_VALUE (1ll << 32) +#define TSC_OFFSET_VALUE -(1ll << 48) + +enum { + PORT_ABORT = 0x1000, + PORT_REPORT, + PORT_DONE, +}; + +enum { + VMXON_PAGE = 0, + VMCS_PAGE, + MSR_BITMAP_PAGE, + + NUM_VMX_PAGES, +}; + +struct kvm_single_msr { + struct kvm_msrs header; + struct kvm_msr_entry entry; +} __attribute__((packed)); + +/* The virtual machine object. */ +static struct kvm_vm *vm; + +static void check_ia32_tsc_adjust(int64_t max) +{ + int64_t adjust; + + adjust = rdmsr(MSR_IA32_TSC_ADJUST); + GUEST_SYNC(adjust); + GUEST_ASSERT(adjust <= max); +} + +static void l2_guest_code(void) +{ + uint64_t l1_tsc = rdtsc() - TSC_OFFSET_VALUE; + + wrmsr(MSR_IA32_TSC, l1_tsc - TSC_ADJUST_VALUE); + check_ia32_tsc_adjust(-2 * TSC_ADJUST_VALUE); + + /* Exit to L1 */ + __asm__ __volatile__("vmcall"); +} + +static void l1_guest_code(struct vmx_pages *vmx_pages) +{ +#define L2_GUEST_STACK_SIZE 64 + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + uint32_t control; + uintptr_t save_cr3; + + GUEST_ASSERT(rdtsc() < TSC_ADJUST_VALUE); + wrmsr(MSR_IA32_TSC, rdtsc() - TSC_ADJUST_VALUE); + check_ia32_tsc_adjust(-1 * TSC_ADJUST_VALUE); + + GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); + GUEST_ASSERT(load_vmcs(vmx_pages)); + + /* Prepare the VMCS for L2 execution. */ + prepare_vmcs(vmx_pages, l2_guest_code, + &l2_guest_stack[L2_GUEST_STACK_SIZE]); + control = vmreadz(CPU_BASED_VM_EXEC_CONTROL); + control |= CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_USE_TSC_OFFSETTING; + vmwrite(CPU_BASED_VM_EXEC_CONTROL, control); + vmwrite(TSC_OFFSET, TSC_OFFSET_VALUE); + + /* Jump into L2. First, test failure to load guest CR3. */ + save_cr3 = vmreadz(GUEST_CR3); + vmwrite(GUEST_CR3, -1ull); + GUEST_ASSERT(!vmlaunch()); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == + (EXIT_REASON_FAILED_VMENTRY | EXIT_REASON_INVALID_STATE)); + check_ia32_tsc_adjust(-1 * TSC_ADJUST_VALUE); + vmwrite(GUEST_CR3, save_cr3); + + GUEST_ASSERT(!vmlaunch()); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); + + check_ia32_tsc_adjust(-2 * TSC_ADJUST_VALUE); + + GUEST_DONE(); +} + +static void report(int64_t val) +{ + pr_info("IA32_TSC_ADJUST is %ld (%lld * TSC_ADJUST_VALUE + %lld).\n", + val, val / TSC_ADJUST_VALUE, val % TSC_ADJUST_VALUE); +} + +int main(int argc, char *argv[]) +{ + vm_vaddr_t vmx_pages_gva; + + nested_vmx_check_supported(); + + vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code); + vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); + + /* Allocate VMX pages and shared descriptors (vmx_pages). */ + vcpu_alloc_vmx(vm, &vmx_pages_gva); + vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva); + + for (;;) { + volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID); + struct ucall uc; + + vcpu_run(vm, VCPU_ID); + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, + "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n", + run->exit_reason, + exit_reason_str(run->exit_reason)); + + switch (get_ucall(vm, VCPU_ID, &uc)) { + case UCALL_ABORT: + TEST_FAIL("%s", (const char *)uc.args[0]); + /* NOT REACHED */ + case UCALL_SYNC: + report(uc.args[1]); + break; + case UCALL_DONE: + goto done; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + } + + kvm_vm_free(vm); +done: + return 0; +} |