[PATCH 26/42] KVM: selftests: Use vCPU's CPUID directly in Hyper-V test

From: Sean Christopherson
Date: Fri Jun 03 2022 - 21:24:02 EST


Use the vCPU's persistent CPUID array directly when manipulating the set
of exposed Hyper-V CPUID features. Drop set_cpuid() to route all future
modification through the vCPU helpers; the Hyper-V features test was the
last user.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
.../selftests/kvm/include/x86_64/processor.h | 9 --
.../selftests/kvm/lib/x86_64/processor.c | 18 ---
.../selftests/kvm/x86_64/hyperv_features.c | 126 +++++++++---------
3 files changed, 64 insertions(+), 89 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 22e2eaf42360..b9b3a19895aa 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -727,15 +727,6 @@ uint64_t vm_get_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
void vm_set_page_table_entry(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
uint64_t vaddr, uint64_t pte);

-/*
- * set_cpuid() - overwrites a matching cpuid entry with the provided value.
- * matches based on ent->function && ent->index. returns true
- * if a match was found and successfully overwritten.
- * @cpuid: the kvm cpuid list to modify.
- * @ent: cpuid entry to insert
- */
-bool set_cpuid(struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 *ent);
-
uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
uint64_t a3);

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 69239b3613f7..1812b14de3dd 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1208,24 +1208,6 @@ struct kvm_cpuid_entry2 *get_cpuid_entry(struct kvm_cpuid2 *cpuid,
return NULL;
}

-bool set_cpuid(struct kvm_cpuid2 *cpuid,
- struct kvm_cpuid_entry2 *ent)
-{
- int i;
-
- for (i = 0; i < cpuid->nent; i++) {
- struct kvm_cpuid_entry2 *cur = &cpuid->entries[i];
-
- if (cur->function != ent->function || cur->index != ent->index)
- continue;
-
- memcpy(cur, ent, sizeof(struct kvm_cpuid_entry2));
- return true;
- }
-
- return false;
-}
-
uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
uint64_t a3)
{
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_features.c b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
index f08f51bad68b..3d0df079496b 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
@@ -150,37 +150,28 @@ static void guest_hcall(vm_vaddr_t pgs_gpa, struct hcall_data *hcall)
GUEST_DONE();
}

-static void hv_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
- struct kvm_cpuid_entry2 *feat,
- struct kvm_cpuid_entry2 *recomm,
- struct kvm_cpuid_entry2 *dbg)
+static void vcpu_reset_hv_cpuid(struct kvm_vcpu *vcpu)
{
- TEST_ASSERT(set_cpuid(cpuid, feat),
- "failed to set KVM_CPUID_FEATURES leaf");
- TEST_ASSERT(set_cpuid(cpuid, recomm),
- "failed to set HYPERV_CPUID_ENLIGHTMENT_INFO leaf");
- TEST_ASSERT(set_cpuid(cpuid, dbg),
- "failed to set HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES leaf");
- vcpu_init_cpuid(vcpu, cpuid);
+ /*
+ * Enable all supported Hyper-V features, then clear the leafs holding
+ * the features that will be tested one by one.
+ */
+ vcpu_set_hv_cpuid(vcpu);
+
+ vcpu_clear_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
+ vcpu_clear_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO);
+ vcpu_clear_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);
}

static void guest_test_msrs_access(void)
{
+ struct kvm_cpuid2 *prev_cpuid = NULL;
+ struct kvm_cpuid_entry2 *feat, *dbg;
struct kvm_vcpu *vcpu;
struct kvm_run *run;
struct kvm_vm *vm;
struct ucall uc;
int stage = 0;
- struct kvm_cpuid_entry2 feat = {
- .function = HYPERV_CPUID_FEATURES
- };
- struct kvm_cpuid_entry2 recomm = {
- .function = HYPERV_CPUID_ENLIGHTMENT_INFO
- };
- struct kvm_cpuid_entry2 dbg = {
- .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
- };
- struct kvm_cpuid2 *best;
vm_vaddr_t msr_gva;
struct msr_data *msr;

@@ -194,9 +185,16 @@ static void guest_test_msrs_access(void)
vcpu_args_set(vcpu, 1, msr_gva);
vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_ENFORCE_CPUID, 1);

- vcpu_set_hv_cpuid(vcpu);
+ if (!prev_cpuid) {
+ vcpu_reset_hv_cpuid(vcpu);

- best = kvm_get_supported_hv_cpuid();
+ prev_cpuid = allocate_kvm_cpuid2(vcpu->cpuid->nent);
+ } else {
+ vcpu_init_cpuid(vcpu, prev_cpuid);
+ }
+
+ feat = vcpu_get_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
+ dbg = vcpu_get_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);

vm_init_descriptor_tables(vm);
vcpu_init_descriptor_tables(vcpu);
@@ -219,7 +217,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 2:
- feat.eax |= HV_MSR_HYPERCALL_AVAILABLE;
+ feat->eax |= HV_MSR_HYPERCALL_AVAILABLE;
/*
* HV_X64_MSR_GUEST_OS_ID has to be written first to make
* HV_X64_MSR_HYPERCALL available.
@@ -246,7 +244,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 6:
- feat.eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
+ feat->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -263,7 +261,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 9:
- feat.eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
+ feat->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -280,7 +278,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 12:
- feat.eax |= HV_MSR_VP_INDEX_AVAILABLE;
+ feat->eax |= HV_MSR_VP_INDEX_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -297,7 +295,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 15:
- feat.eax |= HV_MSR_RESET_AVAILABLE;
+ feat->eax |= HV_MSR_RESET_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -313,7 +311,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 18:
- feat.eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
+ feat->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -336,7 +334,7 @@ static void guest_test_msrs_access(void)
vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_SYNIC2, 0);
break;
case 22:
- feat.eax |= HV_MSR_SYNIC_AVAILABLE;
+ feat->eax |= HV_MSR_SYNIC_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -352,7 +350,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 25:
- feat.eax |= HV_MSR_SYNTIMER_AVAILABLE;
+ feat->eax |= HV_MSR_SYNTIMER_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -368,7 +366,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 28:
- feat.edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
+ feat->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
msr->available = 1;
break;

@@ -378,7 +376,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 30:
- feat.eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
+ feat->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
msr->write = 1;
msr->write_val = 1;
msr->available = 1;
@@ -390,7 +388,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 32:
- feat.eax |= HV_ACCESS_FREQUENCY_MSRS;
+ feat->eax |= HV_ACCESS_FREQUENCY_MSRS;
msr->write = 0;
msr->available = 1;
break;
@@ -407,7 +405,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 35:
- feat.eax |= HV_ACCESS_REENLIGHTENMENT;
+ feat->eax |= HV_ACCESS_REENLIGHTENMENT;
msr->write = 0;
msr->available = 1;
break;
@@ -430,7 +428,7 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 39:
- feat.edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
+ feat->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
msr->write = 0;
msr->available = 1;
break;
@@ -446,8 +444,8 @@ static void guest_test_msrs_access(void)
msr->available = 0;
break;
case 42:
- feat.edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
- dbg.eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
+ feat->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
+ dbg->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
msr->write = 0;
msr->available = 1;
break;
@@ -463,7 +461,9 @@ static void guest_test_msrs_access(void)
break;
}

- hv_set_cpuid(vcpu, best, &feat, &recomm, &dbg);
+ vcpu_set_cpuid(vcpu);
+
+ memcpy(prev_cpuid, vcpu->cpuid, kvm_cpuid2_size(vcpu->cpuid->nent));

if (msr->idx)
pr_debug("Stage %d: testing msr: 0x%x for %s\n", stage,
@@ -497,24 +497,15 @@ static void guest_test_msrs_access(void)

static void guest_test_hcalls_access(void)
{
+ struct kvm_cpuid_entry2 *feat, *recomm, *dbg;
+ struct kvm_cpuid2 *prev_cpuid = NULL;
struct kvm_vcpu *vcpu;
struct kvm_run *run;
struct kvm_vm *vm;
struct ucall uc;
int stage = 0;
- struct kvm_cpuid_entry2 feat = {
- .function = HYPERV_CPUID_FEATURES,
- .eax = HV_MSR_HYPERCALL_AVAILABLE
- };
- struct kvm_cpuid_entry2 recomm = {
- .function = HYPERV_CPUID_ENLIGHTMENT_INFO
- };
- struct kvm_cpuid_entry2 dbg = {
- .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
- };
vm_vaddr_t hcall_page, hcall_params;
struct hcall_data *hcall;
- struct kvm_cpuid2 *best;

while (true) {
vm = vm_create_with_one_vcpu(&vcpu, guest_hcall);
@@ -534,14 +525,23 @@ static void guest_test_hcalls_access(void)
vcpu_args_set(vcpu, 2, addr_gva2gpa(vm, hcall_page), hcall_params);
vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_ENFORCE_CPUID, 1);

- vcpu_set_hv_cpuid(vcpu);
+ if (!prev_cpuid) {
+ vcpu_reset_hv_cpuid(vcpu);

- best = kvm_get_supported_hv_cpuid();
+ prev_cpuid = allocate_kvm_cpuid2(vcpu->cpuid->nent);
+ } else {
+ vcpu_init_cpuid(vcpu, prev_cpuid);
+ }
+
+ feat = vcpu_get_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
+ recomm = vcpu_get_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO);
+ dbg = vcpu_get_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);

run = vcpu->run;

switch (stage) {
case 0:
+ feat->eax |= HV_MSR_HYPERCALL_AVAILABLE;
hcall->control = 0xdeadbeef;
hcall->expect = HV_STATUS_INVALID_HYPERCALL_CODE;
break;
@@ -551,7 +551,7 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 2:
- feat.ebx |= HV_POST_MESSAGES;
+ feat->ebx |= HV_POST_MESSAGES;
hcall->expect = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;

@@ -560,7 +560,7 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 4:
- feat.ebx |= HV_SIGNAL_EVENTS;
+ feat->ebx |= HV_SIGNAL_EVENTS;
hcall->expect = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;

@@ -569,11 +569,11 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_INVALID_HYPERCALL_CODE;
break;
case 6:
- dbg.eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
+ dbg->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 7:
- feat.ebx |= HV_DEBUGGING;
+ feat->ebx |= HV_DEBUGGING;
hcall->expect = HV_STATUS_OPERATION_DENIED;
break;

@@ -582,7 +582,7 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 9:
- recomm.eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
+ recomm->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
hcall->expect = HV_STATUS_SUCCESS;
break;
case 10:
@@ -590,7 +590,7 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 11:
- recomm.eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
+ recomm->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
hcall->expect = HV_STATUS_SUCCESS;
break;

@@ -599,7 +599,7 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 13:
- recomm.eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
+ recomm->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
hcall->expect = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
case 14:
@@ -613,7 +613,7 @@ static void guest_test_hcalls_access(void)
hcall->expect = HV_STATUS_ACCESS_DENIED;
break;
case 16:
- recomm.ebx = 0xfff;
+ recomm->ebx = 0xfff;
hcall->expect = HV_STATUS_SUCCESS;
break;
case 17:
@@ -622,7 +622,7 @@ static void guest_test_hcalls_access(void)
hcall->ud_expected = true;
break;
case 18:
- feat.edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
+ feat->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
hcall->ud_expected = false;
hcall->expect = HV_STATUS_SUCCESS;
break;
@@ -633,7 +633,9 @@ static void guest_test_hcalls_access(void)
break;
}

- hv_set_cpuid(vcpu, best, &feat, &recomm, &dbg);
+ vcpu_set_cpuid(vcpu);
+
+ memcpy(prev_cpuid, vcpu->cpuid, kvm_cpuid2_size(vcpu->cpuid->nent));

if (hcall->control)
pr_debug("Stage %d: testing hcall: 0x%lx\n", stage,
--
2.36.1.255.ge46751e96f-goog