diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c')
| -rw-r--r-- | tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c b/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c new file mode 100644 index 000000000000..fa512d033205 --- /dev/null +++ b/tools/testing/selftests/kvm/x86/vmx_dirty_log_test.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KVM dirty page logging test + * + * Copyright (C) 2018, Red Hat, Inc. + */ +#include <stdio.h> +#include <stdlib.h> +#include <linux/bitmap.h> +#include <linux/bitops.h> + +#include "test_util.h" +#include "kvm_util.h" +#include "processor.h" +#include "vmx.h" + +/* The memory slot index to track dirty pages */ +#define TEST_MEM_SLOT_INDEX 1 +#define TEST_MEM_PAGES 3 + +/* L1 guest test virtual memory offset */ +#define GUEST_TEST_MEM 0xc0000000 + +/* L2 guest test virtual memory offset */ +#define NESTED_TEST_MEM1 0xc0001000 +#define NESTED_TEST_MEM2 0xc0002000 + +static void l2_guest_code(u64 *a, u64 *b) +{ + READ_ONCE(*a); + WRITE_ONCE(*a, 1); + GUEST_SYNC(true); + GUEST_SYNC(false); + + WRITE_ONCE(*b, 1); + GUEST_SYNC(true); + WRITE_ONCE(*b, 1); + GUEST_SYNC(true); + GUEST_SYNC(false); + + /* Exit to L1 and never come back. */ + vmcall(); +} + +static void l2_guest_code_ept_enabled(void) +{ + l2_guest_code((u64 *)NESTED_TEST_MEM1, (u64 *)NESTED_TEST_MEM2); +} + +static void l2_guest_code_ept_disabled(void) +{ + /* Access the same L1 GPAs as l2_guest_code_ept_enabled() */ + l2_guest_code((u64 *)GUEST_TEST_MEM, (u64 *)GUEST_TEST_MEM); +} + +void l1_guest_code(struct vmx_pages *vmx) +{ +#define L2_GUEST_STACK_SIZE 64 + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + void *l2_rip; + + GUEST_ASSERT(vmx->vmcs_gpa); + GUEST_ASSERT(prepare_for_vmx_operation(vmx)); + GUEST_ASSERT(load_vmcs(vmx)); + + if (vmx->eptp_gpa) + l2_rip = l2_guest_code_ept_enabled; + else + l2_rip = l2_guest_code_ept_disabled; + + prepare_vmcs(vmx, l2_rip, &l2_guest_stack[L2_GUEST_STACK_SIZE]); + + GUEST_SYNC(false); + GUEST_ASSERT(!vmlaunch()); + GUEST_SYNC(false); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); + GUEST_DONE(); +} + +static void test_vmx_dirty_log(bool enable_ept) +{ + vm_vaddr_t vmx_pages_gva = 0; + struct vmx_pages *vmx; + unsigned long *bmap; + uint64_t *host_test_mem; + + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + bool done = false; + + pr_info("Nested EPT: %s\n", enable_ept ? "enabled" : "disabled"); + + /* Create VM */ + vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code); + vmx = vcpu_alloc_vmx(vm, &vmx_pages_gva); + vcpu_args_set(vcpu, 1, vmx_pages_gva); + + /* Add an extra memory slot for testing dirty logging */ + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + GUEST_TEST_MEM, + TEST_MEM_SLOT_INDEX, + TEST_MEM_PAGES, + KVM_MEM_LOG_DIRTY_PAGES); + + /* + * Add an identity map for GVA range [0xc0000000, 0xc0002000). This + * affects both L1 and L2. However... + */ + virt_map(vm, GUEST_TEST_MEM, GUEST_TEST_MEM, TEST_MEM_PAGES); + + /* + * ... pages in the L2 GPA range [0xc0001000, 0xc0003000) will map to + * 0xc0000000. + * + * Note that prepare_eptp should be called only L1's GPA map is done, + * meaning after the last call to virt_map. + * + * When EPT is disabled, the L2 guest code will still access the same L1 + * GPAs as the EPT enabled case. + */ + if (enable_ept) { + prepare_eptp(vmx, vm, 0); + nested_map_memslot(vmx, vm, 0); + nested_map(vmx, vm, NESTED_TEST_MEM1, GUEST_TEST_MEM, 4096); + nested_map(vmx, vm, NESTED_TEST_MEM2, GUEST_TEST_MEM, 4096); + } + + bmap = bitmap_zalloc(TEST_MEM_PAGES); + host_test_mem = addr_gpa2hva(vm, GUEST_TEST_MEM); + + while (!done) { + memset(host_test_mem, 0xaa, TEST_MEM_PAGES * 4096); + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + /* NOT REACHED */ + case UCALL_SYNC: + /* + * The nested guest wrote at offset 0x1000 in the memslot, but the + * dirty bitmap must be filled in according to L1 GPA, not L2. + */ + kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap); + if (uc.args[1]) { + TEST_ASSERT(test_bit(0, bmap), "Page 0 incorrectly reported clean"); + TEST_ASSERT(host_test_mem[0] == 1, "Page 0 not written by guest"); + } else { + TEST_ASSERT(!test_bit(0, bmap), "Page 0 incorrectly reported dirty"); + TEST_ASSERT(host_test_mem[0] == 0xaaaaaaaaaaaaaaaaULL, "Page 0 written by guest"); + } + + TEST_ASSERT(!test_bit(1, bmap), "Page 1 incorrectly reported dirty"); + TEST_ASSERT(host_test_mem[4096 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 1 written by guest"); + TEST_ASSERT(!test_bit(2, bmap), "Page 2 incorrectly reported dirty"); + TEST_ASSERT(host_test_mem[8192 / 8] == 0xaaaaaaaaaaaaaaaaULL, "Page 2 written by guest"); + break; + case UCALL_DONE: + done = true; + break; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + } +} + +int main(int argc, char *argv[]) +{ + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX)); + + test_vmx_dirty_log(/*enable_ept=*/false); + + if (kvm_cpu_has_ept()) + test_vmx_dirty_log(/*enable_ept=*/true); + + return 0; +} |