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KVM: x86: introduce linear_{read,write}_system
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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: 129a72a ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Paolo Bonzini committed Jun 12, 2018
1 parent 727ba74 commit 79367a6
Showing 1 changed file with 32 additions and 32 deletions.
64 changes: 32 additions & 32 deletions arch/x86/kvm/emulate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -812,6 +812,19 @@ static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
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,
Expand Down Expand Up @@ -1496,8 +1509,7 @@ static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt,
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,
Expand Down Expand Up @@ -1560,8 +1572,7 @@ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
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 */
Expand All @@ -1575,8 +1586,7 @@ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
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,
Expand Down Expand Up @@ -1737,8 +1747,7 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
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) |
Expand Down Expand Up @@ -2051,11 +2060,11 @@ static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
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;

Expand Down Expand Up @@ -3053,35 +3062,30 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt,
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;
}
Expand Down Expand Up @@ -3197,38 +3201,34 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt,
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;
}
Expand Down

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