From 20694b60d7df6b38ed786809600fb4c9d8f41a96 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 14 Jun 2022 20:06:43 +0000 Subject: [PATCH] KVM: selftests: Cache CPUID in struct kvm_vcpu Cache a vCPU's CPUID information in "struct kvm_vcpu" to allow fixing the mess where tests, often unknowingly, modify the global/static "cpuid" allocated by kvm_get_supported_cpuid(). Add vcpu_init_cpuid() to handle stuffing an entirely different CPUID model, e.g. during vCPU creation or when switching to the Hyper-V enabled CPUID model. Automatically refresh the cache on vcpu_set_cpuid() so that any adjustments made by KVM are always reflected in the cache. Drop vcpu_get_cpuid() entirely to force tests to use the cache, and to allow adding e.g. vcpu_get_cpuid_entry() in the future without creating a conflicting set of APIs where vcpu_get_cpuid() does KVM_GET_CPUID2, but vcpu_get_cpuid_entry() does not. Opportunistically convert the VMX nested state test and KVM PV test to manipulating the vCPU's CPUID (because it's easy), but use vcpu_init_cpuid() for the Hyper-V features test and "emulator error" test to effectively retain their current behavior as they're less trivial to convert. Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20220614200707.3315957-19-seanjc@google.com --- .../selftests/kvm/include/kvm_util_base.h | 5 +++ .../selftests/kvm/include/x86_64/processor.h | 25 +++++++---- tools/testing/selftests/kvm/lib/kvm_util.c | 7 ++++ .../selftests/kvm/lib/x86_64/processor.c | 42 +++++++++---------- .../testing/selftests/kvm/x86_64/cpuid_test.c | 18 ++++---- .../kvm/x86_64/emulator_error_test.c | 2 +- .../selftests/kvm/x86_64/hyperv_features.c | 2 +- .../selftests/kvm/x86_64/kvm_pv_test.c | 6 +-- .../selftests/kvm/x86_64/monitor_mwait_test.c | 2 +- .../kvm/x86_64/vmx_set_nested_state_test.c | 6 +-- .../selftests/kvm/x86_64/xapic_state_test.c | 4 +- 11 files changed, 69 insertions(+), 50 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index 19f7b33a1e581..24fde97f61211 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -50,6 +50,9 @@ struct kvm_vcpu { int fd; struct kvm_vm *vm; struct kvm_run *run; +#ifdef __x86_64__ + struct kvm_cpuid2 *cpuid; +#endif struct kvm_dirty_gfn *dirty_gfns; uint32_t fetch_index; uint32_t dirty_gfns_count; @@ -748,6 +751,8 @@ static inline struct kvm_vcpu *vm_vcpu_recreate(struct kvm_vm *vm, return vm_arch_vcpu_recreate(vm, vcpu_id); } +void vcpu_arch_free(struct kvm_vcpu *vcpu); + void virt_arch_pgd_alloc(struct kvm_vm *vm); static inline void virt_pgd_alloc(struct kvm_vm *vm) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 1326377f72b79..c61b3aa4950ff 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -618,18 +618,29 @@ static inline struct kvm_cpuid2 *allocate_kvm_cpuid2(int nr_entries) return cpuid; } -struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vcpu *vcpu); +void vcpu_init_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid); -static inline int __vcpu_set_cpuid(struct kvm_vcpu *vcpu, - struct kvm_cpuid2 *cpuid) +static inline int __vcpu_set_cpuid(struct kvm_vcpu *vcpu) { - return __vcpu_ioctl(vcpu, KVM_SET_CPUID2, cpuid); + int r; + + TEST_ASSERT(vcpu->cpuid, "Must do vcpu_init_cpuid() first"); + r = __vcpu_ioctl(vcpu, KVM_SET_CPUID2, vcpu->cpuid); + if (r) + return r; + + /* On success, refresh the cache to pick up adjustments made by KVM. */ + vcpu_ioctl(vcpu, KVM_GET_CPUID2, vcpu->cpuid); + return 0; } -static inline void vcpu_set_cpuid(struct kvm_vcpu *vcpu, - struct kvm_cpuid2 *cpuid) +static inline void vcpu_set_cpuid(struct kvm_vcpu *vcpu) { - vcpu_ioctl(vcpu, KVM_SET_CPUID2, cpuid); + TEST_ASSERT(vcpu->cpuid, "Must do vcpu_init_cpuid() first"); + vcpu_ioctl(vcpu, KVM_SET_CPUID2, vcpu->cpuid); + + /* Refresh the cache to pick up adjustments made by KVM. */ + vcpu_ioctl(vcpu, KVM_GET_CPUID2, vcpu->cpuid); } struct kvm_cpuid_entry2 * diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 49c189878af31..9889fe0d8919c 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -472,6 +472,11 @@ kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start, return ®ion->region; } +__weak void vcpu_arch_free(struct kvm_vcpu *vcpu) +{ + +} + /* * VM VCPU Remove * @@ -501,6 +506,8 @@ static void vm_vcpu_rm(struct kvm_vm *vm, struct kvm_vcpu *vcpu) TEST_ASSERT(!ret, __KVM_SYSCALL_ERROR("close()", ret)); list_del(&vcpu->list); + + vcpu_arch_free(vcpu); free(vcpu); } diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 4d383dee30b7d..4cbcc333bba07 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -648,7 +648,7 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id, DEFAULT_GUEST_STACK_VADDR_MIN); vcpu = __vm_vcpu_add(vm, vcpu_id); - vcpu_set_cpuid(vcpu, kvm_get_supported_cpuid()); + vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid()); vcpu_setup(vm, vcpu); /* Setup guest general purpose registers */ @@ -669,11 +669,17 @@ struct kvm_vcpu *vm_arch_vcpu_recreate(struct kvm_vm *vm, uint32_t vcpu_id) { struct kvm_vcpu *vcpu = __vm_vcpu_add(vm, vcpu_id); - vcpu_set_cpuid(vcpu, kvm_get_supported_cpuid()); + vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid()); return vcpu; } +void vcpu_arch_free(struct kvm_vcpu *vcpu) +{ + if (vcpu->cpuid) + free(vcpu->cpuid); +} + /* * KVM Supported CPUID Get * @@ -743,30 +749,22 @@ uint64_t kvm_get_feature_msr(uint64_t msr_index) return buffer.entry.data; } -struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vcpu *vcpu) +void vcpu_init_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid) { - struct kvm_cpuid2 *cpuid; - int max_ent; - int rc = -1; - - cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES); - max_ent = cpuid->nent; + TEST_ASSERT(cpuid != vcpu->cpuid, "@cpuid can't be the vCPU's CPUID"); - for (cpuid->nent = 1; cpuid->nent <= max_ent; cpuid->nent++) { - rc = __vcpu_ioctl(vcpu, KVM_GET_CPUID2, cpuid); - if (!rc) - break; - - TEST_ASSERT(rc == -1 && errno == E2BIG, - "KVM_GET_CPUID2 should either succeed or give E2BIG: %d %d", - rc, errno); + /* Allow overriding the default CPUID. */ + if (vcpu->cpuid && vcpu->cpuid->nent < cpuid->nent) { + free(vcpu->cpuid); + vcpu->cpuid = NULL; } - TEST_ASSERT(!rc, KVM_IOCTL_ERROR(KVM_GET_CPUID2, rc)); - return cpuid; -} - + if (!vcpu->cpuid) + vcpu->cpuid = allocate_kvm_cpuid2(cpuid->nent); + memcpy(vcpu->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent)); + vcpu_set_cpuid(vcpu); +} /* * Locate a cpuid entry. @@ -1302,7 +1300,7 @@ void vcpu_set_hv_cpuid(struct kvm_vcpu *vcpu) cpuid_full->nent = nent + cpuid_hv->nent; } - vcpu_set_cpuid(vcpu, cpuid_full); + vcpu_init_cpuid(vcpu, cpuid_full); } struct kvm_cpuid2 *vcpu_get_supported_hv_cpuid(struct kvm_vcpu *vcpu) diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c b/tools/testing/selftests/kvm/x86_64/cpuid_test.c index 59dcdf5a12200..96f141a758ca0 100644 --- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c +++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c @@ -144,21 +144,22 @@ struct kvm_cpuid2 *vcpu_alloc_cpuid(struct kvm_vm *vm, vm_vaddr_t *p_gva, struct return guest_cpuids; } -static void set_cpuid_after_run(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid) +static void set_cpuid_after_run(struct kvm_vcpu *vcpu) { + struct kvm_cpuid2 *cpuid = vcpu->cpuid; struct kvm_cpuid_entry2 *ent; int rc; u32 eax, ebx, x; /* Setting unmodified CPUID is allowed */ - rc = __vcpu_set_cpuid(vcpu, cpuid); + rc = __vcpu_set_cpuid(vcpu); TEST_ASSERT(!rc, "Setting unmodified CPUID after KVM_RUN failed: %d", rc); /* Changing CPU features is forbidden */ ent = get_cpuid(cpuid, 0x7, 0); ebx = ent->ebx; ent->ebx--; - rc = __vcpu_set_cpuid(vcpu, cpuid); + rc = __vcpu_set_cpuid(vcpu); TEST_ASSERT(rc, "Changing CPU features should fail"); ent->ebx = ebx; @@ -167,14 +168,14 @@ static void set_cpuid_after_run(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid) eax = ent->eax; x = eax & 0xff; ent->eax = (eax & ~0xffu) | (x - 1); - rc = __vcpu_set_cpuid(vcpu, cpuid); + rc = __vcpu_set_cpuid(vcpu); TEST_ASSERT(rc, "Changing MAXPHYADDR should fail"); ent->eax = eax; } int main(void) { - struct kvm_cpuid2 *supp_cpuid, *cpuid2; + struct kvm_cpuid2 *supp_cpuid; struct kvm_vcpu *vcpu; vm_vaddr_t cpuid_gva; struct kvm_vm *vm; @@ -183,18 +184,17 @@ int main(void) vm = vm_create_with_one_vcpu(&vcpu, guest_main); supp_cpuid = kvm_get_supported_cpuid(); - cpuid2 = vcpu_get_cpuid(vcpu); - compare_cpuids(supp_cpuid, cpuid2); + compare_cpuids(supp_cpuid, vcpu->cpuid); - vcpu_alloc_cpuid(vm, &cpuid_gva, cpuid2); + vcpu_alloc_cpuid(vm, &cpuid_gva, vcpu->cpuid); vcpu_args_set(vcpu, 1, cpuid_gva); for (stage = 0; stage < 3; stage++) run_vcpu(vcpu, stage); - set_cpuid_after_run(vcpu, cpuid2); + set_cpuid_after_run(vcpu); kvm_vm_free(vm); } diff --git a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c index 3aa3d17f230f3..d8dbed4196381 100644 --- a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c +++ b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c @@ -171,7 +171,7 @@ int main(int argc, char *argv[]) entry->eax = (entry->eax & 0xffffff00) | MAXPHYADDR; set_cpuid(cpuid, entry); - vcpu_set_cpuid(vcpu, cpuid); + vcpu_init_cpuid(vcpu, cpuid); rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE); TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable"); diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_features.c b/tools/testing/selftests/kvm/x86_64/hyperv_features.c index 2070ba0d63926..86ce1f1e98ee5 100644 --- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c +++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c @@ -102,7 +102,7 @@ static void hv_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, "failed to set HYPERV_CPUID_ENLIGHTMENT_INFO leaf"); TEST_ASSERT(set_cpuid(cpuid, dbg), "failed to set HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES leaf"); - vcpu_set_cpuid(vcpu, cpuid); + vcpu_init_cpuid(vcpu, cpuid); } static void guest_test_msrs_access(void) diff --git a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c index ea452444f4af9..986ca7282a092 100644 --- a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c @@ -147,7 +147,6 @@ static void enter_guest(struct kvm_vcpu *vcpu) int main(void) { - struct kvm_cpuid2 *best; struct kvm_vcpu *vcpu; struct kvm_vm *vm; @@ -157,9 +156,8 @@ int main(void) vcpu_enable_cap(vcpu, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, 1); - best = kvm_get_supported_cpuid(); - clear_kvm_cpuid_features(best); - vcpu_set_cpuid(vcpu, best); + clear_kvm_cpuid_features(vcpu->cpuid); + vcpu_set_cpuid(vcpu); vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vcpu); diff --git a/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c b/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c index c804f6f041342..0ac5bec1e3b76 100644 --- a/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c +++ b/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c @@ -80,7 +80,7 @@ int main(int argc, char *argv[]) set_cpuid(cpuid, entry); vm = vm_create_with_one_vcpu(&vcpu, guest_code); - vcpu_set_cpuid(vcpu, cpuid); + vcpu_set_cpuid(vcpu); run = vcpu->run; diff --git a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c index 66cb2d0054e64..1cf78ec007f2c 100644 --- a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c +++ b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c @@ -121,7 +121,7 @@ void test_vmx_nested_state(struct kvm_vcpu *vcpu) test_nested_state(vcpu, state); /* Enable VMX in the guest CPUID. */ - vcpu_set_cpuid(vcpu, kvm_get_supported_cpuid()); + vcpu_set_cpuid(vcpu); /* * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without @@ -245,7 +245,7 @@ void test_vmx_nested_state(struct kvm_vcpu *vcpu) void disable_vmx(struct kvm_vcpu *vcpu) { - struct kvm_cpuid2 *cpuid = kvm_get_supported_cpuid(); + struct kvm_cpuid2 *cpuid = vcpu->cpuid; int i; for (i = 0; i < cpuid->nent; ++i) @@ -255,7 +255,7 @@ void disable_vmx(struct kvm_vcpu *vcpu) TEST_ASSERT(i != cpuid->nent, "CPUID function 1 not found"); cpuid->entries[i].ecx &= ~CPUID_VMX; - vcpu_set_cpuid(vcpu, cpuid); + vcpu_set_cpuid(vcpu); cpuid->entries[i].ecx |= CPUID_VMX; } diff --git a/tools/testing/selftests/kvm/x86_64/xapic_state_test.c b/tools/testing/selftests/kvm/x86_64/xapic_state_test.c index 87531623064f7..52133bb4d85a4 100644 --- a/tools/testing/selftests/kvm/x86_64/xapic_state_test.c +++ b/tools/testing/selftests/kvm/x86_64/xapic_state_test.c @@ -152,13 +152,13 @@ int main(int argc, char *argv[]) vm = vm_create_with_one_vcpu(&x.vcpu, xapic_guest_code); x.is_x2apic = false; - cpuid = vcpu_get_cpuid(x.vcpu); + cpuid = x.vcpu->cpuid; for (i = 0; i < cpuid->nent; i++) { if (cpuid->entries[i].function == 1) break; } cpuid->entries[i].ecx &= ~BIT(21); - vcpu_set_cpuid(x.vcpu, cpuid); + vcpu_set_cpuid(x.vcpu); virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA); test_icr(&x); -- 2.39.5