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Emulate "POP r/m".

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This is needed to boot OpenBSD/i386 MP kernel in bhyve.

Reported by:	grehan
MFC after:	1 week
This commit is contained in:
neel 2014-10-14 21:02:33 +00:00
parent 11a43062e8
commit 268d74c73a
1 changed files with 78 additions and 21 deletions
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99
sys/amd64/vmm/vmm_instruction_emul.c
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@ -69,6 +69,7 @@ enum {
VIE_OP_TYPE_TWO_BYTE,
VIE_OP_TYPE_PUSH,
VIE_OP_TYPE_CMP,
VIE_OP_TYPE_POP,
VIE_OP_TYPE_LAST
};
@ -159,6 +160,11 @@ static const struct vie_op one_byte_opcodes[256] = {
.op_type = VIE_OP_TYPE_OR,
.op_flags = VIE_OP_F_IMM8,
},
[0x8F] = {
/* XXX Group 1A extended opcode - not just POP */
.op_byte = 0x8F,
.op_type = VIE_OP_TYPE_POP,
},
[0xFF] = {
/* XXX Group 5 extended opcode - not just PUSH */
.op_byte = 0xFF,
@ -821,7 +827,7 @@ emulate_sub(void *vm, int vcpuid, uint64_t gpa, struct vie *vie,
}
static int
emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
emulate_stack_op(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
struct vm_guest_paging *paging, mem_region_read_t memread,
mem_region_write_t memwrite, void *arg)
{
@ -832,18 +838,12 @@ emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
#endif
struct seg_desc ss_desc;
uint64_t cr0, rflags, rsp, stack_gla, val;
int error, size, stackaddrsize;
/*
* Table A-6, "Opcode Extensions", Intel SDM, Vol 2.
*
* PUSH is part of the group 5 extended opcodes and is identified
* by ModRM:reg = b110.
*/
if ((vie->reg & 7) != 6)
return (EINVAL);
int error, size, stackaddrsize, pushop;
val = 0;
size = vie->opsize;
pushop = (vie->op.op_type == VIE_OP_TYPE_PUSH) ? 1 : 0;
/*
* From "Address-Size Attributes for Stack Accesses", Intel SDL, Vol 1
*/
@ -882,10 +882,13 @@ emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
error = vie_read_register(vm, vcpuid, VM_REG_GUEST_RSP, &rsp);
KASSERT(error == 0, ("%s: error %d getting rsp", __func__, error));
if (pushop) {
rsp -= size;
}
rsp -= size;
if (vie_calculate_gla(paging->cpu_mode, VM_REG_GUEST_SS, &ss_desc,
rsp, size, stackaddrsize, PROT_WRITE, &stack_gla)) {
rsp, size, stackaddrsize, pushop ? PROT_WRITE : PROT_READ,
&stack_gla)) {
vm_inject_ss(vm, vcpuid, 0);
return (0);
}
@ -900,8 +903,8 @@ emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
return (0);
}
error = vm_copy_setup(vm, vcpuid, paging, stack_gla, size, PROT_WRITE,
copyinfo, nitems(copyinfo));
error = vm_copy_setup(vm, vcpuid, paging, stack_gla, size,
pushop ? PROT_WRITE : PROT_READ, copyinfo, nitems(copyinfo));
if (error == -1) {
/*
* XXX cannot return a negative error value here because it
@ -914,16 +917,66 @@ emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
return (0);
}
error = memread(vm, vcpuid, mmio_gpa, &val, size, arg);
if (error == 0) {
vm_copyout(vm, vcpuid, &val, copyinfo, size);
error = vie_update_register(vm, vcpuid, VM_REG_GUEST_RSP, rsp,
stackaddrsize);
KASSERT(error == 0, ("error %d updating rsp", error));
if (pushop) {
error = memread(vm, vcpuid, mmio_gpa, &val, size, arg);
if (error == 0)
vm_copyout(vm, vcpuid, &val, copyinfo, size);
} else {
vm_copyin(vm, vcpuid, copyinfo, &val, size);
error = memwrite(vm, vcpuid, mmio_gpa, val, size, arg);
rsp += size;
}
#ifdef _KERNEL
vm_copy_teardown(vm, vcpuid, copyinfo, nitems(copyinfo));
#endif
if (error == 0) {
error = vie_update_register(vm, vcpuid, VM_REG_GUEST_RSP, rsp,
stackaddrsize);
KASSERT(error == 0, ("error %d updating rsp", error));
}
return (error);
}
static int
emulate_push(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
struct vm_guest_paging *paging, mem_region_read_t memread,
mem_region_write_t memwrite, void *arg)
{
int error;
/*
* Table A-6, "Opcode Extensions", Intel SDM, Vol 2.
*
* PUSH is part of the group 5 extended opcodes and is identified
* by ModRM:reg = b110.
*/
if ((vie->reg & 7) != 6)
return (EINVAL);
error = emulate_stack_op(vm, vcpuid, mmio_gpa, vie, paging, memread,
memwrite, arg);
return (error);
}
static int
emulate_pop(void *vm, int vcpuid, uint64_t mmio_gpa, struct vie *vie,
struct vm_guest_paging *paging, mem_region_read_t memread,
mem_region_write_t memwrite, void *arg)
{
int error;
/*
* Table A-6, "Opcode Extensions", Intel SDM, Vol 2.
*
* POP is part of the group 1A extended opcodes and is identified
* by ModRM:reg = b000.
*/
if ((vie->reg & 7) != 0)
return (EINVAL);
error = emulate_stack_op(vm, vcpuid, mmio_gpa, vie, paging, memread,
memwrite, arg);
return (error);
}
@ -938,6 +991,10 @@ vmm_emulate_instruction(void *vm, int vcpuid, uint64_t gpa, struct vie *vie,
return (EINVAL);
switch (vie->op.op_type) {
case VIE_OP_TYPE_POP:
error = emulate_pop(vm, vcpuid, gpa, vie, paging, memread,
memwrite, memarg);
break;
case VIE_OP_TYPE_PUSH:
error = emulate_push(vm, vcpuid, gpa, vie, paging, memread,
memwrite, memarg);