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selftests: kvm: Add exception handling to selftests

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Add the infrastructure needed to enable exception handling in selftests.
This allows any of the exception and interrupt vectors to be overridden
in the guest.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Message-Id: <20201012194716.3950330-4-aaronlewis@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Aaron Lewis 2020-10-12 12:47:15 -07:00 committed by Paolo Bonzini
parent 85f2a4320e
commit 29faeb9632
9 changed files with 244 additions and 9 deletions
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19
tools/testing/selftests/kvm/Makefile
View File

@ -34,7 +34,7 @@ ifeq ($(ARCH),s390)
endif
LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.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_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S
LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c
@ -111,14 +111,21 @@ LDFLAGS += -pthread $(no-pie-option) $(pgste-option)
include ../lib.mk
STATIC_LIBS := $(OUTPUT)/libkvm.a
LIBKVM_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM))
EXTRA_CLEAN += $(LIBKVM_OBJ) $(STATIC_LIBS) cscope.*
LIBKVM_C := $(filter %.c,$(LIBKVM))
LIBKVM_S := $(filter %.S,$(LIBKVM))
LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C))
LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S))
EXTRA_CLEAN += $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(STATIC_LIBS) cscope.*
x := $(shell mkdir -p $(sort $(dir $(LIBKVM_OBJ))))
$(LIBKVM_OBJ): $(OUTPUT)/%.o: %.c
x := $(shell mkdir -p $(sort $(dir $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ))))
$(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c
$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
$(OUTPUT)/libkvm.a: $(LIBKVM_OBJ)
$(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S
$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ)
$(OUTPUT)/libkvm.a: $(LIBKVM_OBJS)
$(AR) crs $@ $^
x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))

2
tools/testing/selftests/kvm/include/kvm_util.h
View File

@ -294,6 +294,8 @@ int vm_create_device(struct kvm_vm *vm, struct kvm_create_device *cd);
memcpy(&(g), _p, sizeof(g)); \
})
void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid);
/* Common ucalls */
enum {
UCALL_NONE,

24
tools/testing/selftests/kvm/include/x86_64/processor.h
View File

@ -36,6 +36,8 @@
#define X86_CR4_SMAP (1ul << 21)
#define X86_CR4_PKE (1ul << 22)
#define UNEXPECTED_VECTOR_PORT 0xfff0u
/* General Registers in 64-Bit Mode */
struct gpr64_regs {
u64 rax;
@ -239,6 +241,11 @@ static inline struct desc_ptr get_idt(void)
return idt;
}
static inline void outl(uint16_t port, uint32_t value)
{
__asm__ __volatile__("outl %%eax, %%dx" : : "d"(port), "a"(value));
}
#define SET_XMM(__var, __xmm) \
asm volatile("movq %0, %%"#__xmm : : "r"(__var) : #__xmm)
@ -338,6 +345,23 @@ uint32_t kvm_get_cpuid_max_basic(void);
uint32_t kvm_get_cpuid_max_extended(void);
void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits);
struct ex_regs {
uint64_t rax, rcx, rdx, rbx;
uint64_t rbp, rsi, rdi;
uint64_t r8, r9, r10, r11;
uint64_t r12, r13, r14, r15;
uint64_t vector;
uint64_t error_code;
uint64_t rip;
uint64_t cs;
uint64_t rflags;
};
void vm_init_descriptor_tables(struct kvm_vm *vm);
void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid);
void vm_handle_exception(struct kvm_vm *vm, int vector,
void (*handler)(struct ex_regs *));
/*
* Basic CPU control in CR0
*/

4
tools/testing/selftests/kvm/lib/aarch64/processor.c
View File

@ -350,3 +350,7 @@ void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...)
va_end(ap);
}
void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid)
{
}

3
tools/testing/selftests/kvm/lib/kvm_util.c
View File

@ -1204,6 +1204,9 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
do {
rc = ioctl(vcpu->fd, KVM_RUN, NULL);
} while (rc == -1 && errno == EINTR);
assert_on_unhandled_exception(vm, vcpuid);
return rc;
}

2
tools/testing/selftests/kvm/lib/kvm_util_internal.h
View File

@ -50,6 +50,8 @@ struct kvm_vm {
vm_paddr_t pgd;
vm_vaddr_t gdt;
vm_vaddr_t tss;
vm_vaddr_t idt;
vm_vaddr_t handlers;
};
struct vcpu *vcpu_find(struct kvm_vm *vm, uint32_t vcpuid);

4
tools/testing/selftests/kvm/lib/s390x/processor.c
View File

@ -241,3 +241,7 @@ void vcpu_dump(FILE *stream, struct kvm_vm *vm, uint32_t vcpuid, uint8_t indent)
fprintf(stream, "%*spstate: psw: 0x%.16llx:0x%.16llx\n",
indent, "", vcpu->state->psw_mask, vcpu->state->psw_addr);
}
void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid)
{
}

81
tools/testing/selftests/kvm/lib/x86_64/handlers.S Normal file
View File

@ -0,0 +1,81 @@
handle_exception:
push %r15
push %r14
push %r13
push %r12
push %r11
push %r10
push %r9
push %r8
push %rdi
push %rsi
push %rbp
push %rbx
push %rdx
push %rcx
push %rax
mov %rsp, %rdi
call route_exception
pop %rax
pop %rcx
pop %rdx
pop %rbx
pop %rbp
pop %rsi
pop %rdi
pop %r8
pop %r9
pop %r10
pop %r11
pop %r12
pop %r13
pop %r14
pop %r15
/* Discard vector and error code. */
add $16, %rsp
iretq
/*
* Build the handle_exception wrappers which push the vector/error code on the
* stack and an array of pointers to those wrappers.
*/
.pushsection .rodata
.globl idt_handlers
idt_handlers:
.popsection
.macro HANDLERS has_error from to
vector = \from
.rept \to - \from + 1
.align 8
/* Fetch current address and append it to idt_handlers. */
current_handler = .
.pushsection .rodata
.quad current_handler
.popsection
.if ! \has_error
pushq $0
.endif
pushq $vector
jmp handle_exception
vector = vector + 1
.endr
.endm
.global idt_handler_code
idt_handler_code:
HANDLERS has_error=0 from=0 to=7
HANDLERS has_error=1 from=8 to=8
HANDLERS has_error=0 from=9 to=9
HANDLERS has_error=1 from=10 to=14
HANDLERS has_error=0 from=15 to=16
HANDLERS has_error=1 from=17 to=17
HANDLERS has_error=0 from=18 to=255
.section .note.GNU-stack, "", %progbits

114
tools/testing/selftests/kvm/lib/x86_64/processor.c
View File

@ -12,9 +12,18 @@
#include "../kvm_util_internal.h"
#include "processor.h"
#ifndef NUM_INTERRUPTS
#define NUM_INTERRUPTS 256
#endif
#define DEFAULT_CODE_SELECTOR 0x8
#define DEFAULT_DATA_SELECTOR 0x10
/* Minimum physical address used for virtual translation tables. */
#define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000
vm_vaddr_t exception_handlers;
/* Virtual translation table structure declarations */
struct pageMapL4Entry {
uint64_t present:1;
@ -557,9 +566,9 @@ static void vcpu_setup(struct kvm_vm *vm, int vcpuid, int pgd_memslot, int gdt_m
sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
kvm_seg_set_unusable(&sregs.ldt);
kvm_seg_set_kernel_code_64bit(vm, 0x8, &sregs.cs);
kvm_seg_set_kernel_data_64bit(vm, 0x10, &sregs.ds);
kvm_seg_set_kernel_data_64bit(vm, 0x10, &sregs.es);
kvm_seg_set_kernel_code_64bit(vm, DEFAULT_CODE_SELECTOR, &sregs.cs);
kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.ds);
kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.es);
kvm_setup_tss_64bit(vm, &sregs.tr, 0x18, gdt_memslot, pgd_memslot);
break;
@ -1119,3 +1128,102 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
*va_bits = (entry->eax >> 8) & 0xff;
}
}
struct idt_entry {
uint16_t offset0;
uint16_t selector;
uint16_t ist : 3;
uint16_t : 5;
uint16_t type : 4;
uint16_t : 1;
uint16_t dpl : 2;
uint16_t p : 1;
uint16_t offset1;
uint32_t offset2; uint32_t reserved;
};
static void set_idt_entry(struct kvm_vm *vm, int vector, unsigned long addr,
int dpl, unsigned short selector)
{
struct idt_entry *base =
(struct idt_entry *)addr_gva2hva(vm, vm->idt);
struct idt_entry *e = &base[vector];
memset(e, 0, sizeof(*e));
e->offset0 = addr;
e->selector = selector;
e->ist = 0;
e->type = 14;
e->dpl = dpl;
e->p = 1;
e->offset1 = addr >> 16;
e->offset2 = addr >> 32;
}
void kvm_exit_unexpected_vector(uint32_t value)
{
outl(UNEXPECTED_VECTOR_PORT, value);
}
void route_exception(struct ex_regs *regs)
{
typedef void(*handler)(struct ex_regs *);
handler *handlers = (handler *)exception_handlers;
if (handlers && handlers[regs->vector]) {
handlers[regs->vector](regs);
return;
}
kvm_exit_unexpected_vector(regs->vector);
}
void vm_init_descriptor_tables(struct kvm_vm *vm)
{
extern void *idt_handlers;
int i;
vm->idt = vm_vaddr_alloc(vm, getpagesize(), 0x2000, 0, 0);
vm->handlers = vm_vaddr_alloc(vm, 256 * sizeof(void *), 0x2000, 0, 0);
/* Handlers have the same address in both address spaces.*/
for (i = 0; i < NUM_INTERRUPTS; i++)
set_idt_entry(vm, i, (unsigned long)(&idt_handlers)[i], 0,
DEFAULT_CODE_SELECTOR);
}
void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid)
{
struct kvm_sregs sregs;
vcpu_sregs_get(vm, vcpuid, &sregs);
sregs.idt.base = vm->idt;
sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
sregs.gdt.base = vm->gdt;
sregs.gdt.limit = getpagesize() - 1;
kvm_seg_set_kernel_data_64bit(NULL, DEFAULT_DATA_SELECTOR, &sregs.gs);
vcpu_sregs_set(vm, vcpuid, &sregs);
*(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers;
}
void vm_handle_exception(struct kvm_vm *vm, int vector,
void (*handler)(struct ex_regs *))
{
vm_vaddr_t *handlers = (vm_vaddr_t *)addr_gva2hva(vm, vm->handlers);
handlers[vector] = (vm_vaddr_t)handler;
}
void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid)
{
if (vcpu_state(vm, vcpuid)->exit_reason == KVM_EXIT_IO
&& vcpu_state(vm, vcpuid)->io.port == UNEXPECTED_VECTOR_PORT
&& vcpu_state(vm, vcpuid)->io.size == 4) {
/* Grab pointer to io data */
uint32_t *data = (void *)vcpu_state(vm, vcpuid)
+ vcpu_state(vm, vcpuid)->io.data_offset;
TEST_ASSERT(false,
"Unexpected vectored event in guest (vector:0x%x)",
*data);
}
}