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: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi 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: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Needed for the following patch which simplifies ModRM fetching code.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@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: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo 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: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo 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: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo 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: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Setting the segment DPL to 0 for at least the VM86 code segment makes
the VM entry fail on VMX.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, all task switches check privileges against the DPL of the
TSS. This is only correct for jmp/call to a TSS. If a task gate is used,
the DPL of this take gate is used for the check instead. Exceptions,
external interrupts and iret shouldn't perform any check.
[avi: kill kvm-kmod remnants]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the guest thinks it's an AMD, it will not have prepared the SYSENTER MSRs,
and if the guest executes SYSENTER in compatibility mode, it will fails.
Detect this condition and #UD instead, like the spec says.
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently we treat MOVSX/MOVZX with a byte source as a byte instruction,
and change the destination operand size with a hack. Change it to be
a word instruction, so the destination receives its natural size, and
change the source to be SrcMem8.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
On hosts without this patch, 32bit guests will crash (and 64bit guests
may behave in a wrong way) for example by simply executing following
nasm-demo-application:
[bits 32]
global _start
SECTION .text
_start: syscall
(I tested it with winxp and linux - both always crashed)
Disassembly of section .text:
00000000 <_start>:
0: 0f 05 syscall
The reason seems a missing "invalid opcode"-trap (int6) for the
syscall opcode "0f05", which is not available on Intel CPUs
within non-longmodes, as also on some AMD CPUs within legacy-mode.
(depending on CPU vendor, MSR_EFER and cpuid)
Because previous mentioned OSs may not engage corresponding
syscall target-registers (STAR, LSTAR, CSTAR), they remain
NULL and (non trapping) syscalls are leading to multiple
faults and finally crashs.
Depending on the architecture (AMD or Intel) pretended by
guests, various checks according to vendor's documentation
are implemented to overcome the current issue and behave
like the CPUs physical counterparts.
[mtosatti: cleanup/beautify code]
Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
RDPMC is only privileged if CR4.PCE=0. check_rdpmc() already implements this,
so all we need to do is drop the Priv flag.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Group 9: 0F C7
Rename em_grp9() to em_cmpxchg8b() and register it.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
This was probably copy&pasted from the cr0 case, but it's unneeded here.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
INSB : 6C
INSW/INSD : 6D
OUTSB : 6E
OUTSW/OUTSD: 6F
The I/O port address is read from the DX register when we decode the
operand because we see the SrcDX/DstDX flag is set.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the emulation is caused by #PF and it is non-page_table writing instruction,
it means the VM-EXIT is caused by shadow page protected, we can zap the shadow
page and retry this instruction directly
The idea is from Avi
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The idea is from Avi:
| tag instructions that are typically used to modify the page tables, and
| drop shadow if any other instruction is used.
| The list would include, I'd guess, and, or, bts, btc, mov, xchg, cmpxchg,
| and cmpxchg8b.
This patch is used to tag the instructions and in the later path, shadow page
is dropped if it is written by other instructions
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The opcodes
push %seg
pop %seg
l%seg, %mem, %reg (e.g. lds/les/lss/lfs/lgs)
all have an segment register encoded in the instruction. To allow reuse,
decode the segment number into src2 during the decode stage instead of the
execution stage.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Use the same technique as the other OpMem variants, and goto mem_common.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
OpReg decoding has a hack that inhibits byte registers for movsx and movzx
instructions. It should be replaced by something better, but meanwhile,
qualify that the hack is only active for the destination operand.
Note these instructions only use OpReg for the destination, but better to
be explicit about it.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Op fields are going to grow by a bit, we need two free bits.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Unifiying the operands means not taking advantage of the fact that some
operand types can only go into certain operands (for example, DI can only
be used by the destination), so we need more bits to hold the operand type.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Instead of decoding each operand using its own code, use a generic
function. Start with the destination operand.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The TEST instruction doesn't write its destination operand. This
could cause problems if an MMIO register was accessed using the TEST
instruction. Recently Windows XP was observed to use TEST against
the APIC ICR; this can cause spurious IPIs.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
emulate_1op_rax_rdx() is always called with the same parameters. Simplify
by passing just the emulation context.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We have two emulate-with-extended-accumulator implementations: once
which expect traps (_ex) and one which doesn't (plain). Drop the
plain implementation and always use the one which expects traps;
it will simply return 0 in the _ex argument and we can happily ignore
it.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
emulate_1op() is always called with the same parameters. Simplify
by passing just the emulation context.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
emulate_2op_cl() is always called with the same parameters. Simplify
by passing just the emulation context.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
