Enable Hyper-V Direct TLB flush and check that Hyper-V TLB flush
hypercalls from L2 don't exit to L1 unless 'TlbLockCount' is set in the
Partition assist page.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
.../selftests/kvm/x86_64/hyperv_svm_test.c | 60 +++++++++++++++++--
1 file changed, 56 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index 21f5ca9197da..e2849e58582f 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -42,11 +42,24 @@ struct hv_enlightenments {
*/
#define VMCB_HV_NESTED_ENLIGHTENMENTS (1U << 31)
+#define HV_SVM_EXITCODE_ENL 0xF0000000
+#define HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH (1)
+
static inline void vmmcall(void)
{
__asm__ __volatile__("vmmcall");
}
+static inline void hypercall(u64 control, vm_vaddr_t arg1, vm_vaddr_t arg2)
+{
+ asm volatile("mov %3, %%r8\n"
+ "vmmcall"
+ : "+c" (control), "+d" (arg1)
+ : "r" (arg2)
+ : "cc", "memory", "rax", "rbx", "r8", "r9", "r10",
+ "r11", "r12", "r13", "r14", "r15");
+}
+
void l2_guest_code(void)
{
GUEST_SYNC(3);
@@ -62,11 +75,21 @@ void l2_guest_code(void)
GUEST_SYNC(5);
+ /* Direct TLB flush tests */
+ hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT, 0x0,
+ HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES | HV_FLUSH_ALL_PROCESSORS);
+ rdmsr(MSR_FS_BASE);
+ hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT, 0x0,
+ HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES | HV_FLUSH_ALL_PROCESSORS);
+ /* Make sure we're not issuing Hyper-V TLB flush call again */
+ __asm__ __volatile__ ("mov $0xdeadbeef, %rcx");
+
/* Done, exit to L1 and never come back. */
vmmcall();
}
-static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
+static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm,
+ vm_vaddr_t pgs_gpa)
{
unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
struct vmcb *vmcb = svm->vmcb;
@@ -75,13 +98,23 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
GUEST_SYNC(1);
- wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48);
+ wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
+ wrmsr(HV_X64_MSR_HYPERCALL, pgs_gpa);
+ enable_vp_assist(svm->vp_assist_gpa, svm->vp_assist);
GUEST_ASSERT(svm->vmcb_gpa);
/* Prepare for L2 execution. */
generic_svm_setup(svm, l2_guest_code,
&l2_guest_stack[L2_GUEST_STACK_SIZE]);
+ /* Direct TLB flush setup */
+ hve->partition_assist_page = svm->partition_assist_gpa;
+ hve->hv_enlightenments_control.nested_flush_hypercall = 1;
+ hve->hv_vm_id = 1;
+ hve->hv_vp_id = 1;
+ current_vp_assist->nested_control.features.directhypercall = 1;
+ *(u32 *)(svm->partition_assist) = 0;
+
GUEST_SYNC(2);
run_guest(vmcb, svm->vmcb_gpa);
GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
@@ -116,6 +149,20 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
vmcb->save.rip += 2; /* rdmsr */
+
+ /*
+ * Direct TLB flush test. First VMCALL should be handled directly by L0,
+ * no VMCALL exit expested.
+ */
+ run_guest(vmcb, svm->vmcb_gpa);
+ GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
+ vmcb->save.rip += 2; /* rdmsr */
+ /* Enable synthetic vmexit */
+ *(u32 *)(svm->partition_assist) = 1;
+ run_guest(vmcb, svm->vmcb_gpa);
+ GUEST_ASSERT(vmcb->control.exit_code == HV_SVM_EXITCODE_ENL);
+ GUEST_ASSERT(vmcb->control.exit_info_1 == HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH);
+
run_guest(vmcb, svm->vmcb_gpa);
GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
GUEST_SYNC(6);
@@ -126,7 +173,7 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
int main(int argc, char *argv[])
{
vm_vaddr_t nested_gva = 0;
-
+ vm_vaddr_t hcall_page;
struct kvm_vm *vm;
struct kvm_run *run;
struct ucall uc;
@@ -141,7 +188,12 @@ int main(int argc, char *argv[])
vcpu_set_hv_cpuid(vm, VCPU_ID);
run = vcpu_state(vm, VCPU_ID);
vcpu_alloc_svm(vm, &nested_gva);
- vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
+
+ hcall_page = vm_vaddr_alloc_pages(vm, 1);
+ memset(addr_gva2hva(vm, hcall_page), 0x0, getpagesize());
+
+ vcpu_args_set(vm, VCPU_ID, 2, nested_gva, addr_gva2gpa(vm, hcall_page));
+ vcpu_set_msr(vm, VCPU_ID, HV_X64_MSR_VP_INDEX, VCPU_ID);
for (stage = 1;; stage++) {
_vcpu_run(vm, VCPU_ID);
--
2.35.1
