Commit 4b5d8b22 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
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KVM: selftests: evmcs_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: <20221101145426.251680-47-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 75ee7505

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

+2 −0
Original line number Diff line number Diff line
@@ -237,6 +237,8 @@ struct hv_enlightened_vmcs { 
#define HV_VMX_ENLIGHTENED_CLEAN_FIELD_ENLIGHTENMENTSCONTROL    BIT(15)

#define HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL                      0xFFFF



#define HV_VMX_SYNTHETIC_EXIT_REASON_TRAP_AFTER_FLUSH 0x10000031



extern struct hv_enlightened_vmcs *current_evmcs;



int vcpu_enable_evmcs(struct kvm_vcpu *vcpu);

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

+48 −2
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 


#include "kvm_util.h"



#include "hyperv.h"

#include "vmx.h"



static int ud_count;
@@ -41,6 +42,8 @@ static inline void rdmsr_from_l2(uint32_t msr) 
/* Exit to L1 from L2 with RDMSR instruction */

void l2_guest_code(void)

{

	u64 unused;



	GUEST_SYNC(7);



	GUEST_SYNC(8);
@@ -57,15 +60,31 @@ void l2_guest_code(void) 
	vmcall();

	rdmsr_from_l2(MSR_GS_BASE); /* intercepted */



	/* 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.  */

	vmcall();

}



void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages)

void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages,

		vm_vaddr_t hv_hcall_page_gpa)

{

#define L2_GUEST_STACK_SIZE 64

	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];



	wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);

	wrmsr(HV_X64_MSR_HYPERCALL, hv_hcall_page_gpa);



	x2apic_enable();



	GUEST_SYNC(1);
@@ -95,7 +114,17 @@ void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages) 
	vmwrite(PIN_BASED_VM_EXEC_CONTROL, vmreadz(PIN_BASED_VM_EXEC_CONTROL) |

		PIN_BASED_NMI_EXITING);



	/* L2 TLB flush setup */

	current_evmcs->partition_assist_page = hv_pages->partition_assist_gpa;

	current_evmcs->hv_enlightenments_control.nested_flush_hypercall = 1;

	current_evmcs->hv_vm_id = 1;

	current_evmcs->hv_vp_id = 1;

	current_vp_assist->nested_control.features.directhypercall = 1;

	*(u32 *)(hv_pages->partition_assist) = 0;



	GUEST_ASSERT(!vmlaunch());

	GUEST_ASSERT_EQ(vmreadz(VM_EXIT_REASON), EXIT_REASON_EXCEPTION_NMI);

	GUEST_ASSERT_EQ((vmreadz(VM_EXIT_INTR_INFO) & 0xff), NMI_VECTOR);

	GUEST_ASSERT(vmptrstz() == hv_pages->enlightened_vmcs_gpa);



	/*
@@ -139,6 +168,18 @@ void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages) 
	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_MSR_READ);

	current_evmcs->guest_rip += 2; /* rdmsr */



	/*

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

	 * no VMCALL exit expected.

	 */

	GUEST_ASSERT(!vmresume());

	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_MSR_READ);

	current_evmcs->guest_rip += 2; /* rdmsr */

	/* Enable synthetic vmexit */

	*(u32 *)(hv_pages->partition_assist) = 1;

	GUEST_ASSERT(!vmresume());

	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == HV_VMX_SYNTHETIC_EXIT_REASON_TRAP_AFTER_FLUSH);



	GUEST_ASSERT(!vmresume());

	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

	GUEST_SYNC(11);
@@ -192,6 +233,7 @@ static struct kvm_vcpu *save_restore_vm(struct kvm_vm *vm, 
int main(int argc, char *argv[])

{

	vm_vaddr_t vmx_pages_gva = 0, hv_pages_gva = 0;

	vm_vaddr_t hcall_page;



	struct kvm_vcpu *vcpu;

	struct kvm_vm *vm;
@@ -205,12 +247,16 @@ int main(int argc, char *argv[]) 
	TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE));

	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS));



	hcall_page = vm_vaddr_alloc_pages(vm, 1);

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



	vcpu_set_hv_cpuid(vcpu);

	vcpu_enable_evmcs(vcpu);



	vcpu_alloc_vmx(vm, &vmx_pages_gva);

	vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);

	vcpu_args_set(vcpu, 2, vmx_pages_gva, hv_pages_gva);

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

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



	vm_init_descriptor_tables(vm);

	vcpu_init_descriptor_tables(vcpu);