Commit 9c2e8819 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

KVM: selftests: hyperv_svm_test: Introduce L2 TLB flush test 



Enable Hyper-V L2 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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-48-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4b5d8b22

tools/testing/selftests/kvm/include/x86_64/svm.h

+4 −0
Original line number Diff line number Diff line
@@ -76,6 +76,10 @@ struct hv_vmcb_enlightenments { 
 */

#define HV_VMCB_NESTED_ENLIGHTENMENTS (1U << 31)



/* Synthetic VM-Exit */

#define HV_SVM_EXITCODE_ENL			0xf0000000

#define HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH	(1)



struct __attribute__ ((__packed__)) vmcb_control_area {

	u32 intercept_cr;

	u32 intercept_dr;

tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c

+54 −5
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ static inline void rdmsr_from_l2(uint32_t msr) 


void l2_guest_code(void)

{

	u64 unused;



	GUEST_SYNC(3);

	/* Exit to L1 */

	vmmcall();
@@ -47,11 +49,28 @@ void l2_guest_code(void) 


	GUEST_SYNC(5);



	/* L2 TLB flush tests */

	hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |

			 HV_HYPERCALL_FAST_BIT, 0x0,

			 HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |

			 HV_FLUSH_ALL_PROCESSORS);

	rdmsr_from_l2(MSR_FS_BASE);

	/*

	 * Note: hypercall status (RAX) is not preserved correctly by L1 after

	 * synthetic vmexit, use unchecked version.

	 */

	__hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |

			   HV_HYPERCALL_FAST_BIT, 0x0,

			   HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |

			   HV_FLUSH_ALL_PROCESSORS, &unused);



	/* 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,

						    struct hyperv_test_pages *hv_pages,

						    vm_vaddr_t pgs_gpa)

{

	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

	struct vmcb *vmcb = svm->vmcb;
@@ -59,13 +78,23 @@ 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(hv_pages->vp_assist_gpa, hv_pages->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]);



	/* L2 TLB flush setup */

	hve->partition_assist_page = hv_pages->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 *)(hv_pages->partition_assist) = 0;



	GUEST_SYNC(2);

	run_guest(vmcb, svm->vmcb_gpa);

	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
@@ -100,6 +129,20 @@ 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 */





	/*

	 * L2 TLB flush test. First VMCALL should be handled directly by L0,

	 * no VMCALL exit expected.

	 */

	run_guest(vmcb, svm->vmcb_gpa);

	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);

	vmcb->save.rip += 2; /* rdmsr */

	/* Enable synthetic vmexit */

	*(u32 *)(hv_pages->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);
@@ -109,8 +152,8 @@ 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 nested_gva = 0, hv_pages_gva = 0;

	vm_vaddr_t hcall_page;

	struct kvm_vcpu *vcpu;

	struct kvm_vm *vm;

	struct kvm_run *run;
@@ -124,7 +167,13 @@ int main(int argc, char *argv[]) 
	vcpu_set_hv_cpuid(vcpu);

	run = vcpu->run;

	vcpu_alloc_svm(vm, &nested_gva);

	vcpu_args_set(vcpu, 1, nested_gva);

	vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);



	hcall_page = vm_vaddr_alloc_pages(vm, 1);

	memset(addr_gva2hva(vm, hcall_page), 0x0,  getpagesize());



	vcpu_args_set(vcpu, 3, nested_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));

	vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);



	for (stage = 1;; stage++) {

		vcpu_run(vcpu);