Re: [PATCH v2 1/2] selftests: KVM: AMD Nested test infrastructure

From: Vitaly Kuznetsov
Date: Mon Feb 03 2020 - 04:39:49 EST


Eric Auger <eric.auger@xxxxxxxxxx> writes:

> Add the basic infrastructure needed to test AMD nested SVM.
> This is largely copied from the KVM unit test infrastructure.
>
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/Makefile | 2 +-
> .../selftests/kvm/include/x86_64/processor.h | 20 +
> .../selftests/kvm/include/x86_64/svm.h | 355 ++++++++++++++++++
> tools/testing/selftests/kvm/lib/x86_64/svm.c | 211 +++++++++++
> 4 files changed, 587 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
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index 608fa835c764..2e770f554cae 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
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index aa6451b3f740..8a52ae66cf5a 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -56,6 +56,26 @@ enum x86_register {
> R15,
> };
>
> +struct regs {

Nit: I would've called it a bit more specific, like

'regs64' (to match 'desc64' below)
or 'gp_regs' (to indicate that these are only general purpose registers)

> + 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;
> +};
> +
> struct desc64 {
> uint16_t limit0;
> uint16_t base0;
> 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..4a4ebe097556
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
> @@ -0,0 +1,355 @@
> +/* 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 BIT_ULL(CPUID_SVM_BIT)
> +
> +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,
> +};

The same enum in arch/x86/include/asm/svm.h has more
(INTERCEPT_XSETBV/INTERCEPT_RDPRU).

> +
> +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];
> +};

This also doesn't match the definition in arch/x86/include/asm/svm.h

> +
> +#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 {
> + 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;
> +};
> +
> +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 */

To keep this in sync with arch/x86/include/asm/svm.h I'd suggest we
split this header into two:
1) The exact copy on arch/x86/include/asm/svm.h
2) Our testing add-ons.

It will make updating definitions much easier in the future.

> 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..b025c23e502a
> --- /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));
> +}
> +

This is not SVM specific, we seem to already have
get_gdt_base()/get_idt_base(), can these be re-used?

> +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;
> +}

We seem to have all these in include/x86_64/processor.h

> +
> +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));

Out of pure curiosity, why the clobbering is diferent for DRs?

> + asm volatile ("mov %%cr2, %0" : "=r"(save->cr2) : : "memory");

This probably can be written as a single 'asm volatile' block by
utilizing something like offsetof() (e.g. how we do in svm_vcpu_run())
but feel free to leave it for future generations :-)

> + 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;

We don't really support 32bit, do we? I'd used 'u64' then to be
explicit.

> +}
> +
> +#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] "a" (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);
> + }
> +}
> +

--
Vitaly