[PATCH] selftests: KVM: AMD Nested SVM test infrastructure

[Eric Auger <eric.auger@redhat.com>]

Add the basic infrastructure needed to test AMD nested SVM.
This is largely copied from the KVM unit test infrastructure.
Three very basic tests come along, executed in sequence.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

Given the amount of code taken from KVM unit test, I would be
more than happy to transfer any authorship. Please let me know.
---
 tools/testing/selftests/kvm/Makefile          |   3 +-
 .../selftests/kvm/include/x86_64/svm.h        | 390 ++++++++++++++++++
 tools/testing/selftests/kvm/lib/x86_64/svm.c  | 211 ++++++++++
 tools/testing/selftests/kvm/x86_64/svm_test.c | 127 ++++++
 4 files changed, 730 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/kvm/include/x86_64/svm.h
 create mode 100644 tools/testing/selftests/kvm/lib/x86_64/svm.c
 create mode 100644 tools/testing/selftests/kvm/x86_64/svm_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 3138a916574a..ea2f8bcf729e 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -8,7 +8,7 @@ KSFT_KHDR_INSTALL := 1
 UNAME_M := $(shell uname -m)
 
 LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c
-LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/ucall.c
+LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c
 LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
 LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c
 
@@ -26,6 +26,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
 TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
+TEST_GEN_PROGS_x86_64 += x86_64/svm_test
 TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
 TEST_GEN_PROGS_x86_64 += dirty_log_test
 TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
new file mode 100644
index 000000000000..12c23961f73a
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
@@ -0,0 +1,390 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * tools/testing/selftests/kvm/include/x86_64/svm.h
+ * Header for nested SVM testing
+ * Largely copied from KVM unit test svm.h
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+
+#ifndef SELFTEST_KVM_SVM_H
+#define SELFTEST_KVM_SVM_H
+
+#include <stdint.h>
+#include "processor.h"
+
+#define CPUID_SVM_BIT		2
+#define CPUID_SVM		(1 << 2)
+
+enum {
+	INTERCEPT_INTR,
+	INTERCEPT_NMI,
+	INTERCEPT_SMI,
+	INTERCEPT_INIT,
+	INTERCEPT_VINTR,
+	INTERCEPT_SELECTIVE_CR0,
+	INTERCEPT_STORE_IDTR,
+	INTERCEPT_STORE_GDTR,
+	INTERCEPT_STORE_LDTR,
+	INTERCEPT_STORE_TR,
+	INTERCEPT_LOAD_IDTR,
+	INTERCEPT_LOAD_GDTR,
+	INTERCEPT_LOAD_LDTR,
+	INTERCEPT_LOAD_TR,
+	INTERCEPT_RDTSC,
+	INTERCEPT_RDPMC,
+	INTERCEPT_PUSHF,
+	INTERCEPT_POPF,
+	INTERCEPT_CPUID,
+	INTERCEPT_RSM,
+	INTERCEPT_IRET,
+	INTERCEPT_INTn,
+	INTERCEPT_INVD,
+	INTERCEPT_PAUSE,
+	INTERCEPT_HLT,
+	INTERCEPT_INVLPG,
+	INTERCEPT_INVLPGA,
+	INTERCEPT_IOIO_PROT,
+	INTERCEPT_MSR_PROT,
+	INTERCEPT_TASK_SWITCH,
+	INTERCEPT_FERR_FREEZE,
+	INTERCEPT_SHUTDOWN,
+	INTERCEPT_VMRUN,
+	INTERCEPT_VMMCALL,
+	INTERCEPT_VMLOAD,
+	INTERCEPT_VMSAVE,
+	INTERCEPT_STGI,
+	INTERCEPT_CLGI,
+	INTERCEPT_SKINIT,
+	INTERCEPT_RDTSCP,
+	INTERCEPT_ICEBP,
+	INTERCEPT_WBINVD,
+	INTERCEPT_MONITOR,
+	INTERCEPT_MWAIT,
+	INTERCEPT_MWAIT_COND,
+};
+
+struct __attribute__ ((__packed__)) vmcb_control_area {
+	u16 intercept_cr_read;
+	u16 intercept_cr_write;
+	u16 intercept_dr_read;
+	u16 intercept_dr_write;
+	u32 intercept_exceptions;
+	u64 intercept;
+	u8 reserved_1[42];
+	u16 pause_filter_count;
+	u64 iopm_base_pa;
+	u64 msrpm_base_pa;
+	u64 tsc_offset;
+	u32 asid;
+	u8 tlb_ctl;
+	u8 reserved_2[3];
+	u32 int_ctl;
+	u32 int_vector;
+	u32 int_state;
+	u8 reserved_3[4];
+	u32 exit_code;
+	u32 exit_code_hi;
+	u64 exit_info_1;
+	u64 exit_info_2;
+	u32 exit_int_info;
+	u32 exit_int_info_err;
+	u64 nested_ctl;
+	u8 reserved_4[16];
+	u32 event_inj;
+	u32 event_inj_err;
+	u64 nested_cr3;
+	u64 lbr_ctl;
+	u64 reserved_5;
+	u64 next_rip;
+	u8 reserved_6[816];
+};
+
+struct regs {
+	u64 rax;
+	u64 rbx;
+	u64 rcx;
+	u64 rdx;
+	u64 cr2;
+	u64 rbp;
+	u64 rsi;
+	u64 rdi;
+	u64 r8;
+	u64 r9;
+	u64 r10;
+	u64 r11;
+	u64 r12;
+	u64 r13;
+	u64 r14;
+	u64 r15;
+	u64 rflags;
+};
+
+#define TLB_CONTROL_DO_NOTHING 0
+#define TLB_CONTROL_FLUSH_ALL_ASID 1
+
+#define V_TPR_MASK 0x0f
+
+#define V_IRQ_SHIFT 8
+#define V_IRQ_MASK (1 << V_IRQ_SHIFT)
+
+#define V_INTR_PRIO_SHIFT 16
+#define V_INTR_PRIO_MASK (0x0f << V_INTR_PRIO_SHIFT)
+
+#define V_IGN_TPR_SHIFT 20
+#define V_IGN_TPR_MASK (1 << V_IGN_TPR_SHIFT)
+
+#define V_INTR_MASKING_SHIFT 24
+#define V_INTR_MASKING_MASK (1 << V_INTR_MASKING_SHIFT)
+
+#define SVM_INTERRUPT_SHADOW_MASK 1
+
+#define SVM_IOIO_STR_SHIFT 2
+#define SVM_IOIO_REP_SHIFT 3
+#define SVM_IOIO_SIZE_SHIFT 4
+#define SVM_IOIO_ASIZE_SHIFT 7
+
+#define SVM_IOIO_TYPE_MASK 1
+#define SVM_IOIO_STR_MASK (1 << SVM_IOIO_STR_SHIFT)
+#define SVM_IOIO_REP_MASK (1 << SVM_IOIO_REP_SHIFT)
+#define SVM_IOIO_SIZE_MASK (7 << SVM_IOIO_SIZE_SHIFT)
+#define SVM_IOIO_ASIZE_MASK (7 << SVM_IOIO_ASIZE_SHIFT)
+
+#define SVM_VM_CR_VALID_MASK	0x001fULL
+#define SVM_VM_CR_SVM_LOCK_MASK 0x0008ULL
+#define SVM_VM_CR_SVM_DIS_MASK  0x0010ULL
+
+struct __attribute__ ((__packed__)) vmcb_seg {
+	u16 selector;
+	u16 attrib;
+	u32 limit;
+	u64 base;
+};
+
+struct __attribute__ ((__packed__)) vmcb_save_area {
+	struct vmcb_seg es;
+	struct vmcb_seg cs;
+	struct vmcb_seg ss;
+	struct vmcb_seg ds;
+	struct vmcb_seg fs;
+	struct vmcb_seg gs;
+	struct vmcb_seg gdtr;
+	struct vmcb_seg ldtr;
+	struct vmcb_seg idtr;
+	struct vmcb_seg tr;
+	u8 reserved_1[43];
+	u8 cpl;
+	u8 reserved_2[4];
+	u64 efer;
+	u8 reserved_3[112];
+	u64 cr4;
+	u64 cr3;
+	u64 cr0;
+	u64 dr7;
+	u64 dr6;
+	u64 rflags;
+	u64 rip;
+	u8 reserved_4[88];
+	u64 rsp;
+	u8 reserved_5[24];
+	u64 rax;
+	u64 star;
+	u64 lstar;
+	u64 cstar;
+	u64 sfmask;
+	u64 kernel_gs_base;
+	u64 sysenter_cs;
+	u64 sysenter_esp;
+	u64 sysenter_eip;
+	u64 cr2;
+	u8 reserved_6[32];
+	u64 g_pat;
+	u64 dbgctl;
+	u64 br_from;
+	u64 br_to;
+	u64 last_excp_from;
+	u64 last_excp_to;
+};
+
+struct __attribute__ ((__packed__)) vmcb {
+	struct vmcb_control_area control;
+	struct vmcb_save_area save;
+};
+
+#define SVM_CPUID_FEATURE_SHIFT 2
+#define SVM_CPUID_FUNC 0x8000000a
+
+#define SVM_VM_CR_SVM_DISABLE 4
+
+#define SVM_SELECTOR_S_SHIFT 4
+#define SVM_SELECTOR_DPL_SHIFT 5
+#define SVM_SELECTOR_P_SHIFT 7
+#define SVM_SELECTOR_AVL_SHIFT 8
+#define SVM_SELECTOR_L_SHIFT 9
+#define SVM_SELECTOR_DB_SHIFT 10
+#define SVM_SELECTOR_G_SHIFT 11
+
+#define SVM_SELECTOR_TYPE_MASK (0xf)
+#define SVM_SELECTOR_S_MASK (1 << SVM_SELECTOR_S_SHIFT)
+#define SVM_SELECTOR_DPL_MASK (3 << SVM_SELECTOR_DPL_SHIFT)
+#define SVM_SELECTOR_P_MASK (1 << SVM_SELECTOR_P_SHIFT)
+#define SVM_SELECTOR_AVL_MASK (1 << SVM_SELECTOR_AVL_SHIFT)
+#define SVM_SELECTOR_L_MASK (1 << SVM_SELECTOR_L_SHIFT)
+#define SVM_SELECTOR_DB_MASK (1 << SVM_SELECTOR_DB_SHIFT)
+#define SVM_SELECTOR_G_MASK (1 << SVM_SELECTOR_G_SHIFT)
+
+#define SVM_SELECTOR_WRITE_MASK (1 << 1)
+#define SVM_SELECTOR_READ_MASK SVM_SELECTOR_WRITE_MASK
+#define SVM_SELECTOR_CODE_MASK (1 << 3)
+
+#define INTERCEPT_CR0_MASK 1
+#define INTERCEPT_CR3_MASK (1 << 3)
+#define INTERCEPT_CR4_MASK (1 << 4)
+#define INTERCEPT_CR8_MASK (1 << 8)
+
+#define INTERCEPT_DR0_MASK 1
+#define INTERCEPT_DR1_MASK (1 << 1)
+#define INTERCEPT_DR2_MASK (1 << 2)
+#define INTERCEPT_DR3_MASK (1 << 3)
+#define INTERCEPT_DR4_MASK (1 << 4)
+#define INTERCEPT_DR5_MASK (1 << 5)
+#define INTERCEPT_DR6_MASK (1 << 6)
+#define INTERCEPT_DR7_MASK (1 << 7)
+
+#define SVM_EVTINJ_VEC_MASK 0xff
+
+#define SVM_EVTINJ_TYPE_SHIFT 8
+#define SVM_EVTINJ_TYPE_MASK (7 << SVM_EVTINJ_TYPE_SHIFT)
+
+#define SVM_EVTINJ_TYPE_INTR (0 << SVM_EVTINJ_TYPE_SHIFT)
+#define SVM_EVTINJ_TYPE_NMI (2 << SVM_EVTINJ_TYPE_SHIFT)
+#define SVM_EVTINJ_TYPE_EXEPT (3 << SVM_EVTINJ_TYPE_SHIFT)
+#define SVM_EVTINJ_TYPE_SOFT (4 << SVM_EVTINJ_TYPE_SHIFT)
+
+#define SVM_EVTINJ_VALID (1 << 31)
+#define SVM_EVTINJ_VALID_ERR (1 << 11)
+
+#define SVM_EXITINTINFO_VEC_MASK SVM_EVTINJ_VEC_MASK
+#define SVM_EXITINTINFO_TYPE_MASK SVM_EVTINJ_TYPE_MASK
+
+#define	SVM_EXITINTINFO_TYPE_INTR SVM_EVTINJ_TYPE_INTR
+#define	SVM_EXITINTINFO_TYPE_NMI SVM_EVTINJ_TYPE_NMI
+#define	SVM_EXITINTINFO_TYPE_EXEPT SVM_EVTINJ_TYPE_EXEPT
+#define	SVM_EXITINTINFO_TYPE_SOFT SVM_EVTINJ_TYPE_SOFT
+
+#define SVM_EXITINTINFO_VALID SVM_EVTINJ_VALID
+#define SVM_EXITINTINFO_VALID_ERR SVM_EVTINJ_VALID_ERR
+
+#define SVM_EXITINFOSHIFT_TS_REASON_IRET 36
+#define SVM_EXITINFOSHIFT_TS_REASON_JMP 38
+#define SVM_EXITINFOSHIFT_TS_HAS_ERROR_CODE 44
+
+#define	SVM_EXIT_READ_CR0	0x000
+#define	SVM_EXIT_READ_CR3	0x003
+#define	SVM_EXIT_READ_CR4	0x004
+#define	SVM_EXIT_READ_CR8	0x008
+#define	SVM_EXIT_WRITE_CR0	0x010
+#define	SVM_EXIT_WRITE_CR3	0x013
+#define	SVM_EXIT_WRITE_CR4	0x014
+#define	SVM_EXIT_WRITE_CR8	0x018
+#define	SVM_EXIT_READ_DR0	0x020
+#define	SVM_EXIT_READ_DR1	0x021
+#define	SVM_EXIT_READ_DR2	0x022
+#define	SVM_EXIT_READ_DR3	0x023
+#define	SVM_EXIT_READ_DR4	0x024
+#define	SVM_EXIT_READ_DR5	0x025
+#define	SVM_EXIT_READ_DR6	0x026
+#define	SVM_EXIT_READ_DR7	0x027
+#define	SVM_EXIT_WRITE_DR0	0x030
+#define	SVM_EXIT_WRITE_DR1	0x031
+#define	SVM_EXIT_WRITE_DR2	0x032
+#define	SVM_EXIT_WRITE_DR3	0x033
+#define	SVM_EXIT_WRITE_DR4	0x034
+#define	SVM_EXIT_WRITE_DR5	0x035
+#define	SVM_EXIT_WRITE_DR6	0x036
+#define	SVM_EXIT_WRITE_DR7	0x037
+#define SVM_EXIT_EXCP_BASE      0x040
+#define SVM_EXIT_INTR		0x060
+#define SVM_EXIT_NMI		0x061
+#define SVM_EXIT_SMI		0x062
+#define SVM_EXIT_INIT		0x063
+#define SVM_EXIT_VINTR		0x064
+#define SVM_EXIT_CR0_SEL_WRITE	0x065
+#define SVM_EXIT_IDTR_READ	0x066
+#define SVM_EXIT_GDTR_READ	0x067
+#define SVM_EXIT_LDTR_READ	0x068
+#define SVM_EXIT_TR_READ	0x069
+#define SVM_EXIT_IDTR_WRITE	0x06a
+#define SVM_EXIT_GDTR_WRITE	0x06b
+#define SVM_EXIT_LDTR_WRITE	0x06c
+#define SVM_EXIT_TR_WRITE	0x06d
+#define SVM_EXIT_RDTSC		0x06e
+#define SVM_EXIT_RDPMC		0x06f
+#define SVM_EXIT_PUSHF		0x070
+#define SVM_EXIT_POPF		0x071
+#define SVM_EXIT_CPUID		0x072
+#define SVM_EXIT_RSM		0x073
+#define SVM_EXIT_IRET		0x074
+#define SVM_EXIT_SWINT		0x075
+#define SVM_EXIT_INVD		0x076
+#define SVM_EXIT_PAUSE		0x077
+#define SVM_EXIT_HLT		0x078
+#define SVM_EXIT_INVLPG		0x079
+#define SVM_EXIT_INVLPGA	0x07a
+#define SVM_EXIT_IOIO		0x07b
+#define SVM_EXIT_MSR		0x07c
+#define SVM_EXIT_TASK_SWITCH	0x07d
+#define SVM_EXIT_FERR_FREEZE	0x07e
+#define SVM_EXIT_SHUTDOWN	0x07f
+#define SVM_EXIT_VMRUN		0x080
+#define SVM_EXIT_VMMCALL	0x081
+#define SVM_EXIT_VMLOAD		0x082
+#define SVM_EXIT_VMSAVE		0x083
+#define SVM_EXIT_STGI		0x084
+#define SVM_EXIT_CLGI		0x085
+#define SVM_EXIT_SKINIT		0x086
+#define SVM_EXIT_RDTSCP		0x087
+#define SVM_EXIT_ICEBP		0x088
+#define SVM_EXIT_WBINVD		0x089
+#define SVM_EXIT_MONITOR	0x08a
+#define SVM_EXIT_MWAIT		0x08b
+#define SVM_EXIT_MWAIT_COND	0x08c
+#define SVM_EXIT_NPF		0x400
+
+#define SVM_EXIT_ERR		-1
+
+#define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)
+
+struct svm_test_data;
+
+struct test {
+	const char *name;
+	bool (*supported)(void);
+	void (*l1_custom_setup)(struct svm_test_data *svm);
+	void (*l2_guest_code)(struct svm_test_data *svm);
+	int expected_exit_code;
+	bool (*l1_check_result)(struct svm_test_data *svm);
+	bool (*finished)(struct svm_test_data *svm);
+	ulong scratch;
+};
+
+struct svm_test_data {
+	void *vmcb_hva;
+	uint64_t vmcb_gpa;
+	struct vmcb *vmcb;
+
+	void *save_area_hva;
+	uint64_t save_area_gpa;
+	struct vmcb_save_area *save_area;
+
+	struct test *test;
+};
+
+extern struct regs regs;
+
+struct svm_test_data *vcpu_alloc_svm(struct kvm_vm *vm, vm_vaddr_t *p_svm_gva);
+void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp);
+void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa);
+void nested_svm_check_supported(void);
+
+#endif /* SELFTEST_KVM_SVM_H */
diff --git a/tools/testing/selftests/kvm/lib/x86_64/svm.c b/tools/testing/selftests/kvm/lib/x86_64/svm.c
new file mode 100644
index 000000000000..acb04ca4e757
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86_64/svm.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * tools/testing/selftests/kvm/lib/x86_64/svm.c
+ * Helpers used for nested SVM testing
+ * Largely inspired from KVM unit test svm.c
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "../kvm_util_internal.h"
+#include "processor.h"
+#include "svm.h"
+
+struct regs regs;
+
+/* Allocate memory regions for nested SVM tests.
+ *
+ * Input Args:
+ *   vm - The VM to allocate guest-virtual addresses in.
+ *
+ * Output Args:
+ *   p_svm_gva - The guest virtual address for the struct svm_test_data.
+ *
+ * Return:
+ *   Pointer to structure with the addresses of the SVM areas.
+ */
+struct svm_test_data *
+vcpu_alloc_svm(struct kvm_vm *vm, vm_vaddr_t *p_svm_gva)
+{
+	vm_vaddr_t svm_gva = vm_vaddr_alloc(vm, getpagesize(),
+					    0x10000, 0, 0);
+	struct svm_test_data *svm = addr_gva2hva(vm, svm_gva);
+
+	svm->vmcb = (void *)vm_vaddr_alloc(vm, getpagesize(),
+					   0x10000, 0, 0);
+	svm->vmcb_hva = addr_gva2hva(vm, (uintptr_t)svm->vmcb);
+	svm->vmcb_gpa = addr_gva2gpa(vm, (uintptr_t)svm->vmcb);
+
+	svm->save_area = (void *)vm_vaddr_alloc(vm, getpagesize(),
+						0x10000, 0, 0);
+	svm->save_area_hva = addr_gva2hva(vm, (uintptr_t)svm->save_area);
+	svm->save_area_gpa = addr_gva2gpa(vm, (uintptr_t)svm->save_area);
+
+	*p_svm_gva = svm_gva;
+	return svm;
+}
+
+struct descriptor_table_ptr {
+	u16 limit;
+	ulong base;
+} __attribute__((packed));
+
+static inline void sgdt(struct descriptor_table_ptr *ptr)
+{
+	asm volatile ("sgdt %0" : "=m"(*ptr));
+}
+
+static inline void sidt(struct descriptor_table_ptr *ptr)
+{
+	asm volatile ("sidt %0" : "=m"(*ptr));
+}
+
+static void vmcb_set_seg(struct vmcb_seg *seg, u16 selector,
+			 u64 base, u32 limit, u32 attr)
+{
+	seg->selector = selector;
+	seg->attrib = attr;
+	seg->limit = limit;
+	seg->base = base;
+}
+
+static inline u16 read_cs(void)
+{
+	u16 val;
+
+	asm volatile ("mov %%cs, %0" : "=mr"(val));
+	return val;
+}
+
+static inline u16 read_ds(void)
+{
+	u16 val;
+
+	asm volatile ("mov %%ds, %0" : "=mr"(val));
+	return val;
+}
+
+static inline u16 read_es(void)
+{
+	u16 val;
+
+	asm volatile ("mov %%es, %0" : "=mr"(val));
+	return val;
+}
+
+static inline u16 read_ss(void)
+{
+	unsigned int val;
+
+	asm volatile ("mov %%ss, %0" : "=mr"(val));
+	return val;
+}
+
+void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp)
+{
+	struct vmcb *vmcb = svm->vmcb;
+	uint64_t vmcb_gpa = svm->vmcb_gpa;
+	struct vmcb_save_area *save = &vmcb->save;
+	struct vmcb_control_area *ctrl = &vmcb->control;
+	u32 data_seg_attr = 3 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK
+	      | SVM_SELECTOR_DB_MASK | SVM_SELECTOR_G_MASK;
+	u32 code_seg_attr = 9 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK
+		| SVM_SELECTOR_L_MASK | SVM_SELECTOR_G_MASK;
+	struct descriptor_table_ptr desc_table_ptr;
+	uint64_t efer;
+
+	efer = rdmsr(MSR_EFER);
+	wrmsr(MSR_EFER, efer | EFER_SVME);
+	wrmsr(MSR_VM_HSAVE_PA, svm->save_area_gpa);
+
+	memset(vmcb, 0, sizeof(*vmcb));
+	asm volatile ("vmsave %0" : : "a" (vmcb_gpa) : "memory");
+	vmcb_set_seg(&save->es, read_es(), 0, -1U, data_seg_attr);
+	vmcb_set_seg(&save->cs, read_cs(), 0, -1U, code_seg_attr);
+	vmcb_set_seg(&save->ss, read_ss(), 0, -1U, data_seg_attr);
+	vmcb_set_seg(&save->ds, read_ds(), 0, -1U, data_seg_attr);
+	sgdt(&desc_table_ptr);
+	vmcb_set_seg(&save->gdtr, 0,
+		     desc_table_ptr.base, desc_table_ptr.limit, 0);
+	sidt(&desc_table_ptr);
+	vmcb_set_seg(&save->idtr, 0,
+		     desc_table_ptr.base, desc_table_ptr.limit, 0);
+
+	ctrl->asid = 1;
+	save->cpl = 0;
+	save->efer = rdmsr(MSR_EFER);
+	asm volatile ("mov %%cr4, %0" : "=r"(save->cr4) : : "memory");
+	asm volatile ("mov %%cr3, %0" : "=r"(save->cr3) : : "memory");
+	asm volatile ("mov %%cr0, %0" : "=r"(save->cr0) : : "memory");
+	asm volatile ("mov %%dr7, %0" : "=r"(save->dr7));
+	asm volatile ("mov %%dr6, %0" : "=r"(save->dr6));
+	asm volatile ("mov %%cr2, %0" : "=r"(save->cr2) : : "memory");
+	save->g_pat = rdmsr(MSR_IA32_CR_PAT);
+	save->dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
+	ctrl->intercept = (1ULL << INTERCEPT_VMRUN) |
+				(1ULL << INTERCEPT_VMMCALL);
+
+	vmcb->save.rip = (ulong)guest_rip;
+	vmcb->save.rsp = (ulong)guest_rsp;
+	regs.rdi = (ulong)svm;
+}
+
+#define SAVE_GPR_C                              \
+	"xchg %%rbx, regs+0x8\n\t"              \
+	"xchg %%rcx, regs+0x10\n\t"             \
+	"xchg %%rdx, regs+0x18\n\t"             \
+	"xchg %%rbp, regs+0x28\n\t"             \
+	"xchg %%rsi, regs+0x30\n\t"             \
+	"xchg %%rdi, regs+0x38\n\t"             \
+	"xchg %%r8, regs+0x40\n\t"              \
+	"xchg %%r9, regs+0x48\n\t"              \
+	"xchg %%r10, regs+0x50\n\t"             \
+	"xchg %%r11, regs+0x58\n\t"             \
+	"xchg %%r12, regs+0x60\n\t"             \
+	"xchg %%r13, regs+0x68\n\t"             \
+	"xchg %%r14, regs+0x70\n\t"             \
+	"xchg %%r15, regs+0x78\n\t"
+
+#define LOAD_GPR_C      SAVE_GPR_C
+
+/*
+ * selftests do not use interrupts so we dropped clgi/sti/cli/stgi
+ * for now
+ */
+void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa)
+{
+	asm volatile (
+		"vmload\n\t"
+		"vmload %[vmcb_gpa]\n\t"
+		"mov regs+0x80, %%r15\n\t"  // rflags
+		"mov %%r15, 0x170(%[vmcb])\n\t"
+		"mov regs, %%r15\n\t"       // rax
+		"mov %%r15, 0x1f8(%[vmcb])\n\t"
+		LOAD_GPR_C
+		"vmrun %[vmcb_gpa]\n\t"
+		SAVE_GPR_C
+		"mov 0x170(%[vmcb]), %%r15\n\t"  // rflags
+		"mov %%r15, regs+0x80\n\t"
+		"mov 0x1f8(%[vmcb]), %%r15\n\t"  // rax
+		"mov %%r15, regs\n\t"
+		"vmsave %[vmcb_gpa]\n\t"
+		: : [vmcb] "r" (vmcb), [vmcb_gpa] "r" (vmcb_gpa)
+		: "rbx", "rcx", "rdx", "rsi",
+		  "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
+		  "memory");
+
+}
+
+void nested_svm_check_supported(void)
+{
+	struct kvm_cpuid_entry2 *entry =
+		kvm_get_supported_cpuid_entry(0x80000001);
+
+	if (!(entry->ecx & CPUID_SVM)) {
+		fprintf(stderr, "nested SVM not enabled, skipping test\n");
+		exit(KSFT_SKIP);
+	}
+}
+
diff --git a/tools/testing/selftests/kvm/x86_64/svm_test.c b/tools/testing/selftests/kvm/x86_64/svm_test.c
new file mode 100644
index 000000000000..d46af36d5aae
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/svm_test.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * svm_test
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ *
+ * Nested SVM testing
+ *
+ * The main executes several nested SVM tests
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "svm.h"
+
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "kselftest.h"
+#include <linux/kernel.h>
+
+#define VCPU_ID		5
+
+/* The virtual machine object. */
+static struct kvm_vm *vm;
+
+static void l2_vmcall(struct svm_test_data *svm)
+{
+	__asm__ __volatile__("vmcall");
+}
+
+static void l2_vmrun(struct svm_test_data *svm)
+{
+	__asm__ __volatile__("vmrun");
+}
+
+static void l2_cr3_read(struct svm_test_data *svm)
+{
+	asm volatile ("mov %%cr3, %0" : "=r"(svm->test->scratch) : : "memory");
+}
+static void prepare_cr3_intercept(struct svm_test_data *svm)
+{
+	svm->vmcb->control.intercept_cr_read |= 1 << 3;
+}
+
+static struct test tests[] = {
+	/* name, supported, custom setup, l2 code, exit code, custom check, finished */
+	{"vmmcall", NULL, NULL, l2_vmcall, SVM_EXIT_VMMCALL},
+	{"vmrun", NULL, NULL, l2_vmrun, SVM_EXIT_VMRUN},
+	{"CR3 read intercept", NULL, prepare_cr3_intercept, l2_cr3_read, SVM_EXIT_READ_CR3},
+};
+
+static void l1_guest_code(struct svm_test_data *svm)
+{
+	#define L2_GUEST_STACK_SIZE 64
+	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+	struct vmcb *vmcb = svm->vmcb;
+
+	/* Prepare for L2 execution. */
+	generic_svm_setup(svm, svm->test->l2_guest_code,
+			  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+	if (svm->test->l1_custom_setup)
+		svm->test->l1_custom_setup(svm);
+
+	run_guest(vmcb, svm->vmcb_gpa);
+	do {
+		run_guest(vmcb, svm->vmcb_gpa);
+		if (!svm->test->finished)
+			break;
+	} while (!svm->test->finished(svm));
+
+	GUEST_ASSERT(vmcb->control.exit_code ==
+			svm->test->expected_exit_code);
+	GUEST_DONE();
+}
+
+int main(int argc, char *argv[])
+{
+	vm_vaddr_t svm_gva;
+	int i;
+
+	nested_svm_check_supported();
+
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		struct svm_test_data *svm;
+
+		vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code);
+		vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+		/* Allocate VMX pages and shared descriptors (svm_pages). */
+		svm = vcpu_alloc_svm(vm, &svm_gva);
+		svm->test = &tests[i];
+		vcpu_args_set(vm, VCPU_ID, 1, svm_gva);
+
+		printf("Execute test %s\n", svm->test->name);
+
+		for (;;) {
+			volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+			struct ucall uc;
+
+			vcpu_run(vm, VCPU_ID);
+			TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+				    "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
+				    run->exit_reason,
+				    exit_reason_str(run->exit_reason));
+
+			switch (get_ucall(vm, VCPU_ID, &uc)) {
+			case UCALL_ABORT:
+				TEST_ASSERT(false, "%s",
+					    (const char *)uc.args[0]);
+				/* NOT REACHED */
+			case UCALL_SYNC:
+				break;
+			case UCALL_DONE:
+				goto done;
+			default:
+				TEST_ASSERT(false,
+					    "Unknown ucall 0x%x.", uc.cmd);
+			}
+		}
+done:
+		kvm_vm_free(vm);
+	}
+	return 0;
+}
-- 
2.20.1