KVM: selftests: Test access to XMM fast hypercalls

Check that #UD is raised if bit 16 is clear in
HYPERV_CPUID_FEATURES.EDX and an 'XMM fast' hypercall is issued.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Siddharth Chandrasekaran <sidcha@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210730122625.112848-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/include/x86_64/hyperv.h b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
index 412eaee..b669107 100644 (file)
--- a/tools/testing/selftests/kvm/include/x86_64/hyperv.h
+++ b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
@@ -117,7 +117,7 @@
 #define HV_X64_GUEST_DEBUGGING_AVAILABLE               BIT(1)
 #define HV_X64_PERF_MONITOR_AVAILABLE                  BIT(2)
 #define HV_X64_CPU_DYNAMIC_PARTITIONING_AVAILABLE      BIT(3)
-#define HV_X64_HYPERCALL_PARAMS_XMM_AVAILABLE          BIT(4)
+#define HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE           BIT(4)
 #define HV_X64_GUEST_IDLE_STATE_AVAILABLE              BIT(5)
 #define HV_FEATURE_FREQUENCY_MSRS_AVAILABLE            BIT(8)
 #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE           BIT(10)
@@ -182,4 +182,7 @@
 #define HV_STATUS_INVALID_CONNECTION_ID                18
 #define HV_STATUS_INSUFFICIENT_BUFFERS         19
 
+/* hypercall options */
+#define HV_HYPERCALL_FAST_BIT          BIT(16)
+
 #endif /* !SELFTEST_KVM_HYPERV_H */

diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_features.c b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
index af27c7e..91d88aa 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
@@ -47,6 +47,7 @@ static void do_wrmsr(u32 idx, u64 val)
 }
 
 static int nr_gp;
+static int nr_ud;
 
 static inline u64 hypercall(u64 control, vm_vaddr_t input_address,
                            vm_vaddr_t output_address)
@@ -80,6 +81,12 @@ static void guest_gp_handler(struct ex_regs *regs)
                regs->rip = (uint64_t)&wrmsr_end;
 }
 
+static void guest_ud_handler(struct ex_regs *regs)
+{
+       nr_ud++;
+       regs->rip += 3;
+}
+
 struct msr_data {
        uint32_t idx;
        bool available;
@@ -90,6 +97,7 @@ struct msr_data {
 struct hcall_data {
        uint64_t control;
        uint64_t expect;
+       bool ud_expected;
 };
 
 static void guest_msr(struct msr_data *msr)
@@ -117,13 +125,26 @@ static void guest_msr(struct msr_data *msr)
 static void guest_hcall(vm_vaddr_t pgs_gpa, struct hcall_data *hcall)
 {
        int i = 0;
+       u64 res, input, output;
 
        wrmsr(HV_X64_MSR_GUEST_OS_ID, LINUX_OS_ID);
        wrmsr(HV_X64_MSR_HYPERCALL, pgs_gpa);
 
        while (hcall->control) {
-               GUEST_ASSERT(hypercall(hcall->control, pgs_gpa,
-                                      pgs_gpa + 4096) == hcall->expect);
+               nr_ud = 0;
+               if (!(hcall->control & HV_HYPERCALL_FAST_BIT)) {
+                       input = pgs_gpa;
+                       output = pgs_gpa + 4096;
+               } else {
+                       input = output = 0;
+               }
+
+               res = hypercall(hcall->control, input, output);
+               if (hcall->ud_expected)
+                       GUEST_ASSERT(nr_ud == 1);
+               else
+                       GUEST_ASSERT(res == hcall->expect);
+
                GUEST_SYNC(i++);
        }
 
@@ -552,8 +573,18 @@ static void guest_test_hcalls_access(struct kvm_vm *vm, struct hcall_data *hcall
                        recomm.ebx = 0xfff;
                        hcall->expect = HV_STATUS_SUCCESS;
                        break;
-
                case 17:
+                       /* XMM fast hypercall */
+                       hcall->control = HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT;
+                       hcall->ud_expected = true;
+                       break;
+               case 18:
+                       feat.edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
+                       hcall->ud_expected = false;
+                       hcall->expect = HV_STATUS_SUCCESS;
+                       break;
+
+               case 19:
                        /* END */
                        hcall->control = 0;
                        break;
@@ -625,6 +656,10 @@ int main(void)
        /* Test hypercalls */
        vm = vm_create_default(VCPU_ID, 0, guest_hcall);
 
+       vm_init_descriptor_tables(vm);
+       vcpu_init_descriptor_tables(vm, VCPU_ID);
+       vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler);
+
        /* Hypercall input/output */
        hcall_page = vm_vaddr_alloc_pages(vm, 2);
        memset(addr_gva2hva(vm, hcall_page), 0x0, 2 * getpagesize());