kvm: selftests: add test for nested state save/restore (cb547637) · Commits · EulixOS / Software / Kernel

tools/testing/selftests/kvm/include/vmx.h

+33 −0

Original line number	Diff line number	Diff line
		@@ -380,6 +380,30 @@ static inline int vmptrld(uint64_t vmcs_pa)
		return ret;
		}

		static inline int vmptrst(uint64_t *value)
		{
		uint64_t tmp;
		uint8_t ret;

		__asm__ __volatile__("vmptrst %[value]; setna %[ret]"
		: [value]"=m"(tmp), [ret]"=rm"(ret)
		: : "cc", "memory");

		*value = tmp;
		return ret;
		}

		/*
		* A wrapper around vmptrst that ignores errors and returns zero if the
		* vmptrst instruction fails.
		*/
		static inline uint64_t vmptrstz(void)
		{
		uint64_t value = 0;
		vmptrst(&value);
		return value;
		}

		/*
		* No guest state (e.g. GPRs) is established by this vmlaunch.
		*/
		@@ -444,6 +468,15 @@ static inline int vmresume(void)
		return ret;
		}

		static inline void vmcall(void)
		{
		/* Currently, L1 destroys our GPRs during vmexits. */
		__asm__ __volatile__("push %%rbp; vmcall; pop %%rbp" : : :
		"rax", "rbx", "rcx", "rdx",
		"rsi", "rdi", "r8", "r9", "r10", "r11", "r12",
		"r13", "r14", "r15");
		}

		static inline int vmread(uint64_t encoding, uint64_t *value)
		{
		uint64_t tmp;

tools/testing/selftests/kvm/lib/x86.c

+29 −0

Original line number	Diff line number	Diff line
		@@ -736,6 +736,10 @@ struct kvm_x86_state {
		struct kvm_xcrs xcrs;
		struct kvm_sregs sregs;
		struct kvm_debugregs debugregs;
		union {
		struct kvm_nested_state nested;
		char nested_[16384];
		};
		struct kvm_msrs msrs;
		};

		@@ -758,6 +762,14 @@ struct kvm_x86_state vcpu_save_state(struct kvm_vm vm, uint32_t vcpuid)
		struct kvm_msr_list *list;
		struct kvm_x86_state *state;
		int nmsrs, r, i;
		static int nested_size = -1;

		if (nested_size == -1) {
		nested_size = kvm_check_cap(KVM_CAP_NESTED_STATE);
		TEST_ASSERT(nested_size <= sizeof(state->nested_),
		"Nested state size too big, %i > %zi",
		nested_size, sizeof(state->nested_));
		}

		nmsrs = kvm_get_num_msrs(vm);
		list = malloc(sizeof(list) + nmsrs sizeof(list->indices[0]));
		@@ -791,6 +803,17 @@ struct kvm_x86_state vcpu_save_state(struct kvm_vm vm, uint32_t vcpuid)
		TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_SREGS, r: %i",
		r);

		if (nested_size) {
		state->nested.size = sizeof(state->nested_);
		r = ioctl(vcpu->fd, KVM_GET_NESTED_STATE, &state->nested);
		TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_NESTED_STATE, r: %i",
		r);
		TEST_ASSERT(state->nested.size <= nested_size,
		"Nested state size too big, %i (KVM_CHECK_CAP gave %i)",
		state->nested.size, nested_size);
		} else
		state->nested.size = 0;

		state->msrs.nmsrs = nmsrs;
		for (i = 0; i < nmsrs; i++)
		state->msrs.entries[i].index = list->indices[i];
		@@ -811,6 +834,12 @@ void vcpu_load_state(struct kvm_vm vm, uint32_t vcpuid, struct kvm_x86_state s
		struct vcpu *vcpu = vcpu_find(vm, vcpuid);
		int r;

		if (state->nested.size) {
		r = ioctl(vcpu->fd, KVM_SET_NESTED_STATE, &state->nested);
		TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_NESTED_STATE, r: %i",
		r);
		}

		r = ioctl(vcpu->fd, KVM_SET_XSAVE, &state->xsave);
		TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_XSAVE, r: %i",
		r);

tools/testing/selftests/kvm/state_test.c

+70 −1

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@

		#include "kvm_util.h"
		#include "x86.h"
		#include "vmx.h"

		#define VCPU_ID 5
		#define PORT_SYNC 0x1000
		@@ -45,16 +46,75 @@ static inline void __exit_to_l0(uint16_t port, uint64_t arg0, uint64_t arg1)

		static bool have_nested_state;

		void guest_code(void)
		void l2_guest_code(void)
		{
		GUEST_SYNC(5);

		/* Exit to L1 */
		vmcall();

		GUEST_SYNC(7);

		/* Done, exit to L1 and never come back. */
		vmcall();
		}

		void l1_guest_code(struct vmx_pages *vmx_pages)
		{
		#define L2_GUEST_STACK_SIZE 64
		unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

		GUEST_ASSERT(vmx_pages->vmcs_gpa);
		GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
		GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);

		GUEST_SYNC(3);
		GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);

		prepare_vmcs(vmx_pages, l2_guest_code,
		&l2_guest_stack[L2_GUEST_STACK_SIZE]);

		GUEST_SYNC(4);
		GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
		GUEST_ASSERT(!vmlaunch());
		GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
		GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

		/* Check that the launched state is preserved. */
		GUEST_ASSERT(vmlaunch());

		GUEST_ASSERT(!vmresume());
		GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

		GUEST_SYNC(6);
		GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

		GUEST_ASSERT(!vmresume());
		GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

		vmwrite(GUEST_RIP, vmreadz(GUEST_RIP) + 3);

		GUEST_ASSERT(!vmresume());
		GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
		GUEST_SYNC(8);
		}

		void guest_code(struct vmx_pages *vmx_pages)
		{
		GUEST_SYNC(1);
		GUEST_SYNC(2);

		if (vmx_pages)
		l1_guest_code(vmx_pages);

		exit_to_l0(PORT_DONE, 0, 0);
		}

		int main(int argc, char *argv[])
		{
		struct vmx_pages *vmx_pages = NULL;
		vm_vaddr_t vmx_pages_gva = 0;

		struct kvm_regs regs1, regs2;
		struct kvm_vm *vm;
		struct kvm_run *run;
		@@ -69,6 +129,15 @@ int main(int argc, char *argv[])
		run = vcpu_state(vm, VCPU_ID);

		vcpu_regs_get(vm, VCPU_ID, &regs1);

		if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
		vmx_pages = vcpu_alloc_vmx(vm, &vmx_pages_gva);
		vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
		} else {
		printf("will skip nested state checks\n");
		vcpu_args_set(vm, VCPU_ID, 1, 0);
		}

		for (stage = 1;; stage++) {
		_vcpu_run(vm, VCPU_ID);
		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,