Optimize "rep ins" by allowing emulator to write back more than one
datum at a time. Introduce new operand type OP_MEM_STR which tells
writeback() that dst contains pointer to an array that should be written
back as opposite to just one data element.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Remove unneeded segment argument. Address structure already has correct
segment which was put there during decode.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We never change emulate_ops[] at runtime so it should be r/o.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The opcode tables never change at runtime, therefor mark them const.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

As the the compiler ensures that the memory operand is always aligned
to a 16 byte memory location, use the aligned variant of MOVDQ for
read_sse_reg() and write_sse_reg().
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We want the segment selector, nor segment number.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Segment limits are verified in real mode, not just protected mode.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When loading a segment in real mode, only the base and selector must
be modified.  The limit needs to be left alone, otherwise big real mode
users will hit a #GP due to limit checking (currently this is suppressed
because we don't check limits in real mode).
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Instead of populating the entire register file, read in registers
as they are accessed, and write back only the modified ones.  This
saves a VMREAD and VMWRITE on Intel (for rsp, since it is not usually
used during emulation), and a two 128-byte copies for the registers.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The sub-register used to access the stack (sp, esp, or rsp) is not
determined by the address size attribute like other memory references,
but by the stack segment's B bit (if not in x86_64 mode).

Fix by using the existing stack_mask() to figure out the correct mask.

This long-existing bug was exposed by a combination of a27685c3
(emulate invalid guest state by default), which causes many more
instructions to be emulated, and a seabios change (possibly a bug) which
causes the high 16 bits of esp to become polluted across calls to real
mode software interrupts.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

setup_syscalls_segments() calls get_segment() and than overwrites all
but one of the structure fields and this one should also be overwritten
anyway, so we can drop call to get_segment() and avoid a couple of vmreads
on vmx. Also drop zeroing ss/cs structures since most of the fields are
set anyway. Just set those that were not set explicitly.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

No need split mmio read region into 8-bits pieces since we do it in
emulator_read_write_onepage

Changelog:
  Add a WARN_ON to check read-cache overflow
Acked-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Opcode 0F 00 /3.  Encountered during Windows XP secondary processor bringup.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Guest software doesn't actually depend on it, but vmx will refuse us
entry if we don't.  Set the bit in both the cached segment and memory,
just to be nice.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Some operations want to modify the descriptor later on, so save the
address for future use.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcode 0F 00 /2. Used by isolinux durign the protected mode transition.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcodes 0F C8 - 0F CF.

Used by the SeaBIOS cdrom code (though not in big real mode).
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcode C8.

Only ENTER with lexical nesting depth 0 is implemented, since others are
very rare.  We'll fail emulation if nonzero lexical depth is used so data
is not corrupted.
Signed-off-by: NAvi Kivity <avi@redhat.com>

This allows us to reuse the code without populating ctxt->src and
overriding ctxt->op_bytes.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Commit 2adb5ad9 removed ByteOp from MOVZX/MOVSX, replacing them by
SrcMem8, but neglected to fix the dependency in the emulation code
on ByteOp.  This caused the instruction not to have any effect in
some circumstances.

Fix by replacing the check for ByteOp with the equivalent src.op_bytes == 1.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcode 9F.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcodes 0F 01 /0 and 0F 01 /1
Signed-off-by: NAvi Kivity <avi@redhat.com>

We correctly default to SS when BP is used as a base in 16-bit address mode,
but we don't do that for 32-bit mode.

Fix by adjusting the default to SS when either ESP or EBP is used as the base
register.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcode c9; used by some variants of Windows during boot, in big real mode.
Signed-off-by: NAvi Kivity <avi@redhat.com>

The operand size for these instructions is 8 bytes in long mode, even without
a REX prefix.  Set it explicitly.

Triggered while booting Linux with emulate_invalid_guest_state=1.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Null SS is valid in long mode; allow loading it.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Opcode 0F A2.

Used by Linux during the mode change trampoline while in a state that is
not virtualizable on vmx without unrestricted_guest, so we need to emulate
it is emulate_invalid_guest_state=1.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of getting an exact leaf, follow the spec and fall back to the last
main leaf instead.  This lets us easily emulate the cpuid instruction in the
emulator.
Signed-off-by: NAvi Kivity <avi@redhat.com>

The instruction emulation for bsrw is broken in KVM because
the code always uses bsr with 32 or 64 bit operand size for
emulation. Fix that by using emulate_2op_SrcV_nobyte() macro
to use guest operand size for emulation.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Although ModRM byte is fetched for group decoding, it is soon pushed
back to make decode_modrm() fetch it later again.

Now that ModRM flag can be found in the top level opcode tables, fetch
ModRM byte before group decoding to make the code simpler.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Needed for the following patch which simplifies ModRM fetching code.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NAvi Kivity <avi@redhat.com>

'bool' wants 8-bit registers.
Reported-by: NTakuya Yoshikawa <takuya.yoshikawa@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Needed by some framebuffer drivers.  See

https://bugzilla.kernel.org/show_bug.cgi?id=42779Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

General support for the MMX instruction set.  Special care is taken
to trap pending x87 exceptions so that they are properly reflected
to the guest.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Used to write to framebuffers (by at least Icaros).
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

An Ubuntu 9.10 Karmic Koala guest is unable to boot or install due to
missing movdqa emulation:

kvm_exit: reason EXCEPTION_NMI rip 0x7fef3e025a7b info 7fef3e799000 80000b0e
kvm_page_fault: address 7fef3e799000 error_code f
kvm_emulate_insn: 0:7fef3e025a7b: 66 0f 7f 07 (prot64)

movdqa %xmm0,(%rdi)

[avi: mark it explicitly aligned]
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

x86 defines three classes of vector instructions: explicitly
aligned (#GP(0) if unaligned, explicitly unaligned, and default
(which depends on the encoding: AVX is unaligned, SSE is aligned).

Add support for marking an instruction as explicitly aligned or
unaligned, and mark MOVDQU as unaligned.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Task switches can switch between Protected Mode and VM86. The current
mode must be updated during the task switch emulation so that the new
segment selectors are interpreted correctly.

In order to let privilege checks succeed, rflags needs to be updated in
the vcpu struct as this causes a CPL update.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>