[PATCH 4.16 06/43] KVM: x86: introduce linear_{read,write}_system

Greg Kroah-Hartman
2018-06-14T14:08:55Z

From: Paolo Bonzini <pbonzini@redhat.com>

commit 79367a65743975e5cac8d24d08eccc7fdae832b0 upstream.

Wrap the common invocation of ctxt->ops->read_std and ctxt->ops->write_std, so
as to have a smaller patch when the functions grow another argument.

Fixes: 129a72a0d3c8 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kvm/emulate.c | 64 ++++++++++++++++++++++++-------------------------
1 file changed, 32 insertions(+), 32 deletions(-)

--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -811,6 +811,19 @@ static inline int jmp_rel(struct x86_emu
return assign_eip_near(ctxt, ctxt->_eip + rel);
}

+static int linear_read_system(struct x86_emulate_ctxt *ctxt, ulong linear,
+ void *data, unsigned size)
+{
+ return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
+}
+
+static int linear_write_system(struct x86_emulate_ctxt *ctxt,
+ ulong linear, void *data,
+ unsigned int size)
+{
+ return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception);
+}
+
static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
struct segmented_address addr,
void *data,
@@ -1495,8 +1508,7 @@ static int read_interrupt_descriptor(str
return emulate_gp(ctxt, index << 3 | 0x2);

addr = dt.address + index * 8;
- return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
- &ctxt->exception);
+ return linear_read_system(ctxt, addr, desc, sizeof *desc);
}

static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
@@ -1559,8 +1571,7 @@ static int read_segment_descriptor(struc
if (rc != X86EMUL_CONTINUE)
return rc;

- return ctxt->ops->read_std(ctxt, *desc_addr_p, desc, sizeof(*desc),
- &ctxt->exception);
+ return linear_read_system(ctxt, *desc_addr_p, desc, sizeof(*desc));
}

/* allowed just for 8 bytes segments */
@@ -1574,8 +1585,7 @@ static int write_segment_descriptor(stru
if (rc != X86EMUL_CONTINUE)
return rc;

- return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,
- &ctxt->exception);
+ return linear_write_system(ctxt, addr, desc, sizeof *desc);
}

static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
@@ -1736,8 +1746,7 @@ static int __load_segment_descriptor(str
return ret;
}
} else if (ctxt->mode == X86EMUL_MODE_PROT64) {
- ret = ctxt->ops->read_std(ctxt, desc_addr+8, &base3,
- sizeof(base3), &ctxt->exception);
+ ret = linear_read_system(ctxt, desc_addr+8, &base3, sizeof(base3));
if (ret != X86EMUL_CONTINUE)
return ret;
if (emul_is_noncanonical_address(get_desc_base(&seg_desc) |
@@ -2050,11 +2059,11 @@ static int __emulate_int_real(struct x86
eip_addr = dt.address + (irq << 2);
cs_addr = dt.address + (irq << 2) + 2;

- rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);
+ rc = linear_read_system(ctxt, cs_addr, &cs, 2);
if (rc != X86EMUL_CONTINUE)
return rc;

- rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);
+ rc = linear_read_system(ctxt, eip_addr, &eip, 2);
if (rc != X86EMUL_CONTINUE)
return rc;

@@ -3041,35 +3050,30 @@ static int task_switch_16(struct x86_emu
u16 tss_selector, u16 old_tss_sel,
ulong old_tss_base, struct desc_struct *new_desc)
{
- const struct x86_emulate_ops *ops = ctxt->ops;
struct tss_segment_16 tss_seg;
int ret;
u32 new_tss_base = get_desc_base(new_desc);

- ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
- &ctxt->exception);
+ ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg);
if (ret != X86EMUL_CONTINUE)
return ret;

save_state_to_tss16(ctxt, &tss_seg);

- ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
- &ctxt->exception);
+ ret = linear_write_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg);
if (ret != X86EMUL_CONTINUE)
return ret;

- ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
- &ctxt->exception);
+ ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof tss_seg);
if (ret != X86EMUL_CONTINUE)
return ret;

if (old_tss_sel != 0xffff) {
tss_seg.prev_task_link = old_tss_sel;

- ret = ops->write_std(ctxt, new_tss_base,
- &tss_seg.prev_task_link,
- sizeof tss_seg.prev_task_link,
- &ctxt->exception);
+ ret = linear_write_system(ctxt, new_tss_base,
+ &tss_seg.prev_task_link,
+ sizeof tss_seg.prev_task_link);
if (ret != X86EMUL_CONTINUE)
return ret;
}
@@ -3185,38 +3189,34 @@ static int task_switch_32(struct x86_emu
u16 tss_selector, u16 old_tss_sel,
ulong old_tss_base, struct desc_struct *new_desc)
{
- const struct x86_emulate_ops *ops = ctxt->ops;
struct tss_segment_32 tss_seg;
int ret;
u32 new_tss_base = get_desc_base(new_desc);
u32 eip_offset = offsetof(struct tss_segment_32, eip);
u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector);

- ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
- &ctxt->exception);
+ ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg);
if (ret != X86EMUL_CONTINUE)
return ret;

save_state_to_tss32(ctxt, &tss_seg);

/* Only GP registers and segment selectors are saved */
- ret = ops->write_std(ctxt, old_tss_base + eip_offset, &tss_seg.eip,
- ldt_sel_offset - eip_offset, &ctxt->exception);
+ ret = linear_write_system(ctxt, old_tss_base + eip_offset, &tss_seg.eip,
+ ldt_sel_offset - eip_offset);
if (ret != X86EMUL_CONTINUE)
return ret;

- ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
- &ctxt->exception);
+ ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof tss_seg);
if (ret != X86EMUL_CONTINUE)
return ret;

if (old_tss_sel != 0xffff) {
tss_seg.prev_task_link = old_tss_sel;

- ret = ops->write_std(ctxt, new_tss_base,
- &tss_seg.prev_task_link,
- sizeof tss_seg.prev_task_link,
- &ctxt->exception);
+ ret = linear_write_system(ctxt, new_tss_base,
+ &tss_seg.prev_task_link,
+ sizeof tss_seg.prev_task_link);
if (ret != X86EMUL_CONTINUE)
return ret;
}