Commit graph

64 commits

Author SHA1 Message Date
Avi Kivity
a77ab5ead5 KVM: x86 emulator: implement 'ret far' instruction (opcode 0xcb)
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:01 +02:00
Avi Kivity
350f69dcd1 KVM: x86 emulator: Make emulate_pop() a little more generic
Allow emulate_pop() to read into arbitrary memory rather than just the
source operand.  Needed for complicated instructions like far returns.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:03:00 +02:00
Avi Kivity
2b3d2a2060 KVM: Fix vmload and friends misinterpreted as lidt
The AMD SVM instruction family all overload the 0f 01 /3 opcode, further
multiplexing on the three r/m bits.  But the code decided that anything that
isn't a vmmcall must be an lidt (which shares the 0f 01 /3 opcode, for the
case that mod = 3).

Fix by aborting emulation if this isn't a vmmcall.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24 11:02:51 +02:00
Amit Shah
fbce554e94 KVM: x86 emulator: Fix handling of VMMCALL instruction
The VMMCALL instruction doesn't get recognised and isn't processed
by the emulator.

This is seen on an Intel host that tries to execute the VMMCALL
instruction after a guest live migrates from an AMD host.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:43 +02:00
Guillaume Thouvenin
9bf8ea42fe KVM: x86 emulator: add the emulation of shld and shrd instructions
Add emulation of shld and shrd instructions

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:43 +02:00
Guillaume Thouvenin
d175226a5f KVM: x86 emulator: add the assembler code for three operands
Add the assembler code for instruction with three operands and one
operand is stored in ECX register

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:42 +02:00
Guillaume Thouvenin
bfcadf83ec KVM: x86 emulator: add a new "implied 1" Src decode type
Add SrcOne operand type when we need to decode an implied '1' like with
regular shift instruction

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:42 +02:00
Guillaume Thouvenin
0dc8d10f7d KVM: x86 emulator: add Src2 decode set
Instruction like shld has three operands, so we need to add a Src2
decode set. We start with Src2None, Src2CL, and Src2ImmByte, Src2One to
support shld/shrd and we will expand it later.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:42 +02:00
Guillaume Thouvenin
45ed60b371 KVM: x86 emulator: Extend the opcode descriptor
Extend the opcode descriptor to 32 bits. This is needed by the
introduction of a new Src2 operand type.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:41 +02:00
Avi Kivity
f3fd92fbdb KVM: Remove extraneous semicolon after do/while
Notices by Guillaume Thouvenin.

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:05 +02:00
Avi Kivity
2b48cc75b2 KVM: x86 emulator: fix popf emulation
Set operand type and size to get correct writeback behavior.

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:05 +02:00
Avi Kivity
cf5de4f886 KVM: x86 emulator: fix ret emulation
'ret' did not set the operand type or size for the destination, so
writeback ignored it.

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:05 +02:00
Avi Kivity
8a09b6877f KVM: x86 emulator: switch 'pop reg' instruction to emulate_pop()
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:04 +02:00
Avi Kivity
781d0edc5f KVM: x86 emulator: allow pop from mmio
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:04 +02:00
Avi Kivity
faa5a3ae39 KVM: x86 emulator: Extract 'pop' sequence into a function
Switch 'pop r/m' instruction to use the new function.

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:04 +02:00
Avi Kivity
6b7ad61ffb KVM: x86 emulator: consolidate emulation of two operand instructions
No need to repeat the same assembly block over and over.

Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:03 +02:00
Avi Kivity
dda96d8f1b KVM: x86 emulator: reduce duplication in one operand emulation thunks
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:03 +02:00
Guillaume Thouvenin
e93f36bcfa KVM: allow emulator to adjust rip for emulated pio instructions
If we call the emulator we shouldn't call skip_emulated_instruction()
in the first place, since the emulator already computes the next rip
for us. Thus we move ->skip_emulated_instruction() out of
kvm_emulate_pio() and into handle_io() (and the svm equivalent). We
also replaced "return 0" by "break" in the "do_io:" case because now
the shadow register state needs to be committed. Otherwise eip will never
be updated.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:48 +02:00
Guillaume Thouvenin
291fd39bfc KVM: x86 emulator: Add decode entries for 0x04 and 0x05 opcodes (add acc, imm)
Add decode entries for 0x04 and 0x05 (ADD) opcodes, execution is already
implemented.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:46 +02:00
Guillaume Thouvenin
2786b014ec KVM: x86 emulator: consolidate push reg
This patch consolidate the emulation of push reg instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:51:39 +02:00
Guillaume Thouvenin
aa3a816b6d KVM: x86 emulator: Use DstAcc for 'and'
For instruction 'and al,imm' we use DstAcc instead of doing
the emulation directly into the instruction's opcode.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:16:14 +02:00
Guillaume Thouvenin
8a9fee67fb KVM: x86 emulator: Add cmp al, imm and cmp ax, imm instructions (ocodes 3c, 3d)
Add decode entries for these opcodes; execution is already implemented.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:16:14 +02:00
Guillaume Thouvenin
9c9fddd0e7 KVM: x86 emulator: Add DstAcc operand type
Add DstAcc operand type. That means that there are 4 bits now for
DstMask.

"In the good old days cpus would have only one register that was able to
 fully participate in arithmetic operations, typically called A for
 Accumulator.  The x86 retains this tradition by having special, shorter
 encodings for the A register (like the cmp opcode), and even some
 instructions that only operate on A (like mul).

 SrcAcc and DstAcc would accommodate these instructions by decoding A
 into the corresponding 'struct operand'."
  -- Avi Kivity

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:16:14 +02:00
Avi Kivity
ef46f18ea0 KVM: x86 emulator: fix jmp r/m64 instruction
jmp r/m64 doesn't require the rex.w prefix to indicate the operand size
is 64 bits.  Set the Stack attribute (even though it doesn't involve the
stack, really) to indicate this.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:27 +02:00
Mohammed Gamal
d19292e457 KVM: x86 emulator: Add call near absolute instruction (opcode 0xff/2)
Add call near absolute instruction.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:26 +02:00
Mohammed Gamal
a6a3034cb9 KVM: x86 emulator: Add in/out instructions (opcodes 0xe4-0xe7, 0xec-0xef)
The patch adds in/out instructions to the x86 emulator.

The instruction was encountered while running the BIOS while using
the invalid guest state emulation patch.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:25 +02:00
Mohammed Gamal
fb4616f431 KVM: x86 emulator: Add std and cld instructions (opcodes 0xfc-0xfd)
This adds the std and cld instructions to the emulator.

Encountered while running the BIOS with invalid guest
state emulation enabled.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:25 +02:00
Mohammed Gamal
a5e2e82b8b KVM: x86 emulator: Add mov r, imm instructions (opcodes 0xb0-0xbf)
The emulator only supported one instance of mov r, imm instruction
(opcode 0xb8), this adds the rest of these instructions.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:23 +02:00
Avi Kivity
6eb06cb286 KVM: x86 emulator: remove bad ByteOp specifier from NEG descriptor
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:22 +02:00
roel kluin
41afa02587 KVM: x86 emulator: remove duplicate SrcImm
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:15:21 +02:00
Marcelo Tosatti
5fdbf9765b KVM: x86: accessors for guest registers
As suggested by Avi, introduce accessors to read/write guest registers.
This simplifies the ->cache_regs/->decache_regs interface, and improves
register caching which is important for VMX, where the cost of
vmcs_read/vmcs_write is significant.

[avi: fix warnings]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-10-15 10:13:57 +02:00
Glauber Costa
2a7c5b8b55 KVM: x86 emulator: emulate clflush
If the guest issues a clflush in a mmio address, the instruction
can trap into the hypervisor. Currently, we do not decode clflush
properly, causing the guest to hang. This patch fixes this emulating
clflush (opcode 0f ae).

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:40 +03:00
Mohammed Gamal
19fdfa0d13 KVM: x86 emulator: Fix HLT instruction
This patch fixes issue encountered with HLT instruction
under FreeDOS's HIMEM XMS Driver.

The HLT instruction jumped directly to the done label and
skips updating the EIP value, therefore causing the guest
to spin endlessly on the same instruction.

The patch changes the instruction so that it writes back
the updated EIP value.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:38 +03:00
Avi Kivity
7a5b56dfd3 KVM: x86 emulator: lazily evaluate segment registers
Instead of prefetching all segment bases before emulation, read them at the
last moment.  Since most of them are unneeded, we save some cycles on
Intel machines where this is a bit expensive.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:35 +03:00
Avi Kivity
0adc8675d6 KVM: x86 emulator: avoid segment base adjust for lea
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:34 +03:00
Avi Kivity
f5b4edcd52 KVM: x86 emulator: simplify rip relative decoding
rip relative decoding is relative to the instruction pointer of the next
instruction; by moving address adjustment until after decoding is complete,
we remove the need to determine the instruction size.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:34 +03:00
Avi Kivity
84411d85da KVM: x86 emulator: simplify r/m decoding
Consolidate the duplicated code when not in any special case.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity
dc71d0f162 KVM: x86 emulator: simplify sib decoding
Instead of using sparse switches, use simpler if/else sequences.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity
8684c0af0b KVM: x86 emulator: handle undecoded rex.b with r/m = 5 in certain cases
x86_64 does not decode rex.b in certain cases, where the r/m field = 5.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Mohammed Gamal
b13354f8f0 KVM: x86 emulator: emulate nop and xchg reg, acc (opcodes 0x90 - 0x97)
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:33 +03:00
Avi Kivity
91ed7a0e15 KVM: x86 emulator: implement 'push imm' (opcode 0x68)
Encountered in FC6 boot sequence, now that we don't force ss.rpl = 0 during
the protected mode transition.  Not really necessary, but nice to have.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:29 +03:00
Avi Kivity
19e43636b5 KVM: x86 emulator: simplify push imm8 emulation
Instead of fetching the data explicitly, use SrcImmByte.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:29 +03:00
Guillaume Thouvenin
38d5bc6d50 KVM: x86 emulator: Add support for mov r, sreg (0x8c) instruction
Add support for mov r, sreg (0x8c) instruction

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin
4257198ae2 KVM: x86 emulator: Add support for mov seg, r (0x8e) instruction
Add support for mov r, sreg (0x8c) instruction.

[avi: drop the sreg decoding table in favor of 1:1 encoding]

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:28 +03:00
Guillaume Thouvenin
615ac12561 KVM: x86 emulator: adds support to mov r,imm (opcode 0xb8) instruction
Add support to mov r, imm (0xb8) instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin
954cd36f76 KVM: x86 emulator: add support for jmp far 0xea
Add support for jmp far (opcode 0xea) instruction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Guillaume Thouvenin
89c696383d KVM: x86 emulator: Update c->dst.bytes in decode instruction
Update c->dst.bytes in decode instruction instead of instruction
itself.  It's needed because if c->dst.bytes is equal to 0, the
instruction is not emulated.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Laurent Vivier <laurent.vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20 12:42:27 +03:00
Avi Kivity
33e3885de2 KVM: x86 emulator: fix hypercall return value on AMD
The hypercall instructions on Intel and AMD are different.  KVM allows the
guest to choose one or the other (the default is Intel), and if the guest
chooses incorrectly, KVM will patch it at runtime to select the correct
instruction.  This allows live migration between Intel and AMD machines.

This patching occurs in the x86 emulator.  The current code also executes
the hypercall.  Unfortunately, the tail end of the x86 emulator code also
executes, overwriting the return value of the hypercall with the original
contents of rax (which happens to be the hypercall number).

Fix not by executing the hypercall in the emulator context; instead let the
guest reissue the patched instruction and execute the hypercall via the
normal path.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-06 21:08:25 +03:00
Avi Kivity
107d6d2efa KVM: x86 emulator: fix writes to registers with modrm encodings
A register destination encoded with a mod=3 encoding left dst.ptr NULL.
Normally we don't trap writes to registers, but in the case of smsw, we do.

Fix by pointing dst.ptr at the destination register.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-18 14:34:14 +03:00
Avi Kivity
dc7457ea52 KVM: x86 emulator: disable writeback on lmsw
The recent changes allowing memory operands with lmsw and smsw left
lmsw with writeback enabled.  Since lmsw has no oridinary destination
operand, the dst pointer was not initialized, resulting in an oops.

Close the hole by disabling writeback for lmsw.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-04 14:44:45 +03:00