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>
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>
emulate_2op_SrcV(), and its siblings, emulate_2op_SrcV_nobyte()
and emulate_2op_SrcB(), all use the same calling conventions
and all get passed exactly the same parameters. Simplify them
by passing just the emulation context.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Return EMULATION_OK/FAILED consistently. Also treat instruction fetch
errors, not restricted to X86EMUL_UNHANDLEABLE, as EMULATION_FAILED;
although this cannot happen in practice, the current logic will continue
the emulation even if the decoder fails to fetch the instruction.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Fetching the instruction which was to be executed by the guest cannot
fail normally. So compiler should always predict that it will succeed.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of passing ctxt->_eip from insn_fetch() call sites, get it from
ctxt in do_insn_fetch_byte(). This is done by replacing the argument
_eip of insn_fetch() with _ctxt, which should be better than letting the
macro use ctxt silently in its body.
Though this changes the place where ctxt->_eip is incremented from
insn_fetch() to do_insn_fetch_byte(), this does not have any real
effect.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Src2CL decode (used for double width shifts) erronously decodes only bit 3
of %rcx, instead of bits 7:0.
Fix by decoding %cl in its entirety.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This saves a lot of pointless casts x86_emulate_ctxt and decode_cache.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The name eip conflicts with a field of the same name in x86_emulate_ctxt,
which we plan to fold decode_cache into.
The name _eip is unfortunate, but what's really needed is a refactoring
here, not a better name.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Different functions for those which take segment register operands.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In addition, replace one "goto xchg" with an em_xchg() call.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The next patch will change these to be called by opcode::execute.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We should use the local variables ctxt and c when the emulate_ctxt and
decode appears many times. At least, we need to be consistent about
how we use these in a function.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Fix:
warning: ‘cs_sel’ may be used uninitialized in this function
warning: ‘ss_sel’ may be used uninitialized in this function
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Dereference it in the actual users.
This not only cleans up the emulator but also makes it easy to convert
the old emulation functions to the new em_xxx() form later.
Note: Remove some inline keywords to let the compiler decide inlining.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Dereference it in the actual users: only do_insn_fetch_byte().
This is consistent with the way __linearize() dereferences it.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The two macros need special care to use:
Assume rc, ctxt, ops and done exist outside of them.
Can goto outside.
Considering the fact that these are used only in decode functions,
moving these right after do_insn_fetch() seems to be a right thing
to improve the readability.
We also rename do_fetch_insn_byte() to do_insn_fetch_byte() to be
consistent.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
%rip-relative addressing is relative to the first byte of the next instruction,
so we need to add %rip only after we've fetched any immediate bytes.
Based on original patch by Li Xin <xin.li@intel.com>.
Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Li Xin <xin.li@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Commit f6511935f4 moved the permission check for io instructions
to the ->check_perm callback. It failed to copy the port value from RDX
register for string and "in,out ax,dx" instructions.
Fix it by reading RDX register at decode stage when appropriate.
Fixes FC8.32 installation.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We introduce em_jmp_far().
We also call this from em_grp45() to stop treating modrm_reg == 5 case
separately in the group 5 emulation.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
The prototypes are changed appropriately.
We also replaces "goto grp45;" with simple em_grp45() call.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
The opt of emulate_grp1a() is also removed.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
In addition, one comma at the end of a statement is replaced with a
semicolon.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of separate accessors for the segment selector and cached descriptor,
use one accessor for both. This simplifies the code somewhat.
Signed-off-by: Avi Kivity <avi@redhat.com>
Move all groups into a single field and handle them in a single place. This
saves bits when we add more group types (3 bits -> 7 groups types).
Signed-off-by: Avi Kivity <avi@redhat.com>
For this, emulate_pusha/popa() are converted to em_pusha/popa().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
In addition, the RET emulation is changed to call em_pop() to remove
the pop_instruction label.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
The following instructions are changed to use opcode::execute.
Group 1 (80-83)
ADD (00-05), OR (08-0D), ADC (10-15), SBB (18-1D), AND (20-25),
SUB (28-2D), XOR (30-35), CMP (38-3D)
CMPS (A6-A7), SCAS (AE-AF)
The last two do the same as CMP in the emulator, so em_cmp() is used.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
While it isn't defined, no need to force a #UD. If it becomes defined
in the future this can cause wierd problems for the guest.
Signed-off-by: Avi Kivity <avi@redhat.com>
arch/x86/kvm/emulate.c:2598: warning: integer constant is too large for 'long' type
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit 0b56652e33c72092956c651ab6ceb9f0ad081153 fails to build:
CC [M] arch/x86/kvm/emulate.o
arch/x86/kvm/emulate.c: In function 'x86_emulate_insn':
arch/x86/kvm/emulate.c:4095:25: error: macro "wbinvd" passed 1 arguments, but takes just 0
arch/x86/kvm/emulate.c:4095:3: warning: statement with no effect
make[2]: *** [arch/x86/kvm/emulate.o] Error 1
make[1]: *** [arch/x86/kvm] Error 2
make: *** [arch/x86] Error 2
Work around this for now.
Signed-off-by: Clemens Noss <cnoss@gmx.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Avoid using ctxt->vcpu; we can do everything with ->get_cr() and ->set_cr().
A side effect is that we no longer activate the fpu on emulated CLTS; but that
should be very rare.
Signed-off-by: Avi Kivity <avi@redhat.com>
Making the emulator caller agnostic.
[Takuya Yoshikawa: fix typo leading to LDT failures]
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Since segments need to be handled slightly differently when fetching
instructions, we add a __linearize helper that accepts a new 'fetch' boolean.
[avi: fix oops caused by wrong segmented_address initialization order]
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, setting a large (i.e. negative) base address for %cs does not work on
a 64-bit host. The "JOS" teaching operating system, used by MIT and other
universities, relies on such segments while bootstrapping its way to full
virtual memory management.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
em_push() is a simple wrapper of emulate_push(). So this patch replaces
emulate_push() with em_push() and removes the unnecessary former.
In addition, the unused ops arguments are removed from emulate_pusha()
and emulate_grp45().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
PUSH emulation stores the value by calling writeback() after setting
the dst operand appropriately in emulate_push().
This writeback() using dst is not needed at all because we know the
target is the stack. So this patch makes emulate_push() call, newly
introduced, segmented_write() directly.
By this, many inlined writeback()'s are removed.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
This stops "CMP r/m, reg" to write back the data into memory.
Pointed out by Avi.
The writeback suppression now covers CMP, CMPS, SCAS.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
VMMCALL needs the VendorSpecific tag so that #UD emulation
(called if a guest running on AMD was migrated to an Intel host)
is allowed to process the instruction.
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds code to check for IOIO intercepts on
instructions decoded by the KVM instruction emulator.
[avi: fix build error due to missing #define D2bvIP]
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch add intercept checks for emulated one-byte
instructions to the KVM instruction emulation path.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds intercepts checks for the remaining twobyte
instructions to the KVM instruction emulator.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements the emulator intercept checks for the
RDTSCP, MONITOR, and MWAIT instructions.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the necessary code changes in the
instruction emulator and the extensions to svm.c to
implement intercept checks for the svm instructions.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch add intercept checks into the KVM instruction
emulator to check for the 8 instructions that access the
descriptor table addresses.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the intercept checks for instruction
accessing the debug registers.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds all necessary intercept checks for
instructions that access the crX registers.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a callback into kvm_x86_ops so that svm and
vmx code can do intercept checks on emulated instructions.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a flag for the opcoded to tag instruction
which are only recognized in protected mode. The necessary
check is added too.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a check_perm callback for each opcode into
the instruction emulator. This will be used to do all
necessary permission checks on instructions before checking
whether they are intercepted or not.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch prevents the changed CPU state to be written back
when the emulator detected that the instruction was
intercepted by the guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add intercept codes for instructions defined by SVM as
interceptable.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When running in guest mode, certain instructions can be intercepted by
hardware. This also holds for nested guests running on emulated
virtualization hardware, in particular instructions emulated by kvm
itself.
This patch adds a framework for intercepting instructions. If an
instruction is marked for interception, and if we're running in guest
mode, a callback is called to check whether an intercept is needed or
not. The callback is called at three points in time: immediately after
beginning execution, after checking privilge exceptions, and after
checking memory exception. This suits the different interception points
defined for different instructions and for the various virtualization
instruction sets.
In addition, a new X86EMUL_INTERCEPT is defined, which any callback or
memory access may define, allowing the more complicated intercepts to be
implemented in existing callbacks.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Most SIMD instructions use the 66/f2/f3 prefixes to distinguish between
different variants of the same instruction. Usually the encoding is quite
regular, but in some cases (including non-SIMD instructions) the prefixes
generate very different instructions. Examples include XCHG/PAUSE,
MOVQ/MOVDQA/MOVDQU, and MOVBE/CRC32.
Allow the emulator to handle these special cases by splitting such opcodes
into groups, with different decode flags and execution functions for different
prefixes.
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently we store a rep prefix as 1 or 2 depending on whether it is a REPE or
REPNE. Since sse instructions depend on the prefix value, store it as the
original opcode to simplify things further on.
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently if io port + len crosses 8bit boundary in io permission bitmap the
check may allow IO that otherwise should not be allowed. The patch fixes that.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Current implementation truncates upper 32bit of TR base address during IO
permission bitmap check. The patch fixes this.
Reported-and-tested-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Mark some instructions as vendor specific, and allow the caller to request
emulation only of vendor specific instructions. This is useful in some
circumstances (responding to a #UD fault).
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In case of a nested page fault or an intercepted #PF newer SVM
implementations provide a copy of the faulting instruction bytes
in the VMCB.
Use these bytes to feed the instruction emulator and avoid the costly
guest instruction fetch in this case.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Immediately after we generate an exception, we want a X86EMUL_PROPAGATE_FAULT
constant, so return it from the generation functions.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Instead of checking for X86EMUL_PROPAGATE_FAULT, check for any error,
making the callers more reliable.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If rc == X86EMUL_PROPAGATE_FAULT, we would have returned earlier.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Introduce a structure that can contain an exception to be passed back
to main kvm code.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Linear addresses are supposed to already have segment checks performed on them;
if we play with these addresses the checks become invalid.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently the x86 emulator converts the segment register associated with
an operand into a segment base which is added into the operand address.
This loss of information results in us not doing segment limit checks properly.
Replace struct operand's addr.mem field by a segmented_address structure
which holds both the effetive address and segment. This will allow us to
do the limit check at the point of access.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Failed emulation is reported via a tracepoint; the cmps printk is pointless.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Eliminate:
arch/x86/kvm/emulate.c:801: warning: ‘sv’ may be used uninitialized in this
function
on gcc 4.1.2
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM currently ignores fetch faults in the instruction
emulator. With nested-npt we could have such faults. This
patch adds the code to handle these.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces a struct with two new fields in
vcpu_arch for x86:
* fault.address
* fault.error_code
This will be used to correctly propagate page faults back
into the guest when we could have either an ordinary page
fault or a nested page fault. In the case of a nested page
fault the fault-address is different from the original
address that should be walked. So we need to keep track
about the real fault-address.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
x86_emulate_insn() is full of things like
if (rc != X86EMUL_CONTINUE)
goto done;
break;
consolidate all of those at the end of the switch statement.
Signed-off-by: Avi Kivity <avi@redhat.com>
The ALU opcode block is very regular; introduce D6ALU() to define decode
flags for 6 instructions at a time.
Suggested by Paolo Bonzini.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Many x86 instructions come in byte and word variants distinguished with bit
0 of the opcode. Add macros to aid in defining them.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
SrcMemFAddr is not defined with the modrm operand designating a register
instead of a memory address.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
x86_emulate_insn() will return 1 if instruction can be restarted
without re-entering a guest.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Most x86 two operand instructions allow the destination to be a memory operand,
but IMUL (for example) requires that the destination be a register. Change
____emulate_2op() to take a register for both source and destination so we
can invoke IMUL.
Signed-off-by: Avi Kivity <avi@redhat.com>
