- 11 7月, 2014 12 次提交
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由 Paolo Bonzini 提交于
do_insn_fetch_bytes will only be called once in a given insn_fetch and insn_fetch_arr, because in fact it will only be called at most twice for any instruction and the first call is explicit in x86_decode_insn. This observation lets us hoist the call out of the memory copying loop. It does not buy performance, because most fetches are one byte long anyway, but it prepares for the next patch. The overflow check is tricky, but correct. Because do_insn_fetch_bytes has already been called once, we know that fc->end is at least 15. So it is okay to subtract the number of bytes we want to read. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
Hoist the common case up from do_insn_fetch_byte to do_insn_fetch, and prime the fetch_cache in x86_decode_insn. This helps a bit the compiler and the branch predictor, but above all it lays the ground for further changes in the next few patches. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Bandan Das 提交于
rip_relative is only set if decode_modrm runs, and if you have ModRM you will also have a memopp. We can then access memopp unconditionally. Note that rip_relative cannot be hoisted up to decode_modrm, or you break "mov $0, xyz(%rip)". Also, move typecast on "out of range value" of mem.ea to decode_modrm. Together, all these optimizations save about 50 cycles on each emulated instructions (4-6%). Signed-off-by: NBandan Das <bsd@redhat.com> [Fix immediate operands with rip-relative addressing. - Paolo] Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Bandan Das 提交于
x86_decode_insn already sets a default for seg_override, so remove it from the zeroed area. Also replace set/get functions with direct access to the field. Signed-off-by: NBandan Das <bsd@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Bandan Das 提交于
A lot of initializations are unnecessary as they get set to appropriate values before actually being used. Optimize placement of fields in x86_emulate_ctxt Signed-off-by: NBandan Das <bsd@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Bandan Das 提交于
Remove the if conditional - that will help us avoid an "else initialize to 0" Also, rearrange operators for slightly better code. Signed-off-by: NBandan Das <bsd@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Bandan Das 提交于
The same information can be gleaned from ctxt->d and avoids having to zero/NULL initialize intercept and check_perm Signed-off-by: NBandan Das <bsd@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Bandan Das 提交于
Core emulator functions all belong in emulator.c, x86 should have no knowledge of emulator internals Signed-off-by: NBandan Das <bsd@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
The "if/return" checks are useless, because we return X86EMUL_CONTINUE anyway if we do not return. Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
We can just blindly move all 16 bytes of ctxt->src's value to ctxt->dst. write_register_operand will take care of writing only the lower bytes. Avoiding a call to memcpy (the compiler optimizes it out) gains about 200 cycles on kvm-unit-tests for register-to-register moves, and makes them about as fast as arithmetic instructions. We could perhaps get a larger speedup by moving all instructions _except_ moves out of x86_emulate_insn, removing opcode_len, and replacing the switch statement with an inlined em_mov. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
There are several checks for "peculiar" aspects of instructions in both x86_decode_insn and x86_emulate_insn. Group them together, and guard them with a single "if" that lets the processor quickly skip them all. Make this more effective by adding two more flag bits that say whether the .intercept and .check_perm fields are valid. We will reuse these flags later to avoid initializing fields of the emulate_ctxt struct. This skims about 30 cycles for each emulated instructions, which is approximately a 3% improvement. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
The only purpose of this patch is to make the next patch simpler to review. No semantic change. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 10 7月, 2014 1 次提交
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由 Jan Kiszka 提交于
Obtaining the port number from DX is bogus as a) there are immediate port accesses and b) user space may have changed the register content while processing the PIO access. Forward the correct value from the instruction emulator instead. Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 19 6月, 2014 7 次提交
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由 Nadav Amit 提交于
On long-mode the current NOP (0x90) emulation still writes back to RAX. As a result, EAX is zero-extended and the high 32-bits of RAX are cleared. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
Even if the condition of cmov is not satisfied, bits[63:32] should be cleared. This is clearly stated in Intel's CMOVcc documentation. The solution is to reassign the destination onto itself if the condition is unsatisfied. For that matter the original destination value needs to be read. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
Return unhandlable error on inter-privilege level ret instruction. This is since the current emulation does not check the privilege level correctly when loading the CS, and does not pop RSP/SS as needed. Cc: stable@vger.kernel.org Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The emulator does not emulate the xadd instruction correctly if the two operands are the same. In this (unlikely) situation the result should be the sum of X and X (2X) when it is currently X. The solution is to first perform writeback to the source, before writing to the destination. The only instruction which should be affected is xadd, as the other instructions that perform writeback to the source use the extended accumlator (e.g., RAX:RDX). Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The current emulation of bit operations ignores the offset from the destination on 64-bit target memory operands. This patch fixes this behavior. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
It was using the wrong member of the union. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
Memory is always the destination for BitOp instructions. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 18 6月, 2014 10 次提交
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由 Paolo Bonzini 提交于
We did not do that when interruptibility was added to the emulator, because at the time pop to segment was not implemented. Now it is, add it. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
In 64-bit mode, when the destination is a register, the assignment is done according to the operand size. Otherwise (memory operand or no 64-bit mode), a 16-bit assignment is performed. Currently, 16-bit assignment is always done to the destination. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
cmpxchg16b is currently unimplemented in the emulator. The least we can do is return error upon the emulation of this instruction. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The rdpmc emulation checks that the counter (ECX) is not higher than 2, without taking into considerations bits 30:31 role (e.g., bit 30 marks whether the counter is fixed). The fix uses the pmu information for checking the validity of the pmu counter. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
If the operand-size prefix (0x66) is used in 64-bit mode, the emulator would assume the destination operand is 64-bit, when it should be 32-bit. Reminder: movnti does not support 16-bit operands and its default operand size is 32-bit. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The current implementation of cmpxchg does not update the flags correctly, since the accumulator should be compared with the destination and not the other way around. The current implementation does not update the flags correctly. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The SGDT and SIDT instructions are not privilaged, i.e. they can be executed with CPL>0. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The current emulator implementation ignores the high 32 bits of the base in long-mode. During segment load from the LDT, the base of the LDT is calculated incorrectly and may cause the wrong segment to be loaded. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
The current implementation ignores the LDTR/TR base high 32-bits on long-mode. As a result the loaded segment descriptor may be incorrect. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Nadav Amit 提交于
Currently the emulator does not recognize vex-prefix instructions. However, it may incorrectly decode lgdt/lidt instructions and try to execute them. This patch returns unhandlable error on their emulation. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 27 5月, 2014 1 次提交
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由 Nadav Amit 提交于
MOV CR/DR instructions ignore the mod field (in the ModR/M byte). As the SDM states: "The 2 bits in the mod field are ignored". Accordingly, the second operand of these instructions is always a general purpose register. The current emulator implementation does not do so. If the mod bits do not equal 3, it expects the second operand to be in memory. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 22 5月, 2014 2 次提交
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由 Paolo Bonzini 提交于
Table 7-1 of the SDM mentions a check that the code segment's DPL must match the selector's RPL. This was not done by KVM, fix it. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Paolo Bonzini 提交于
During task switch, all of CS.DPL, CS.RPL, SS.DPL must match (in addition to all the other requirements) and will be the new CPL. So far this worked by carefully setting the CS selector and flag before doing the task switch; setting CS.selector will already change the CPL. However, this will not work once we get the CPL from SS.DPL, because then you will have to set the full segment descriptor cache to change the CPL. ctxt->ops->cpl(ctxt) will then return the old CPL during the task switch, and the check that SS.DPL == CPL will fail. Temporarily assume that the CPL comes from CS.RPL during task switch to a protected-mode task. This is the same approach used in QEMU's emulation code, which (until version 2.0) manually tracks the CPL. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 24 4月, 2014 2 次提交
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由 Nadav Amit 提交于
The IN instruction is not be affected by REP-prefix as INS is. Therefore, the emulation should ignore the REP prefix as well. The current emulator implementation tries to perform writeback when IN instruction with REP-prefix is emulated. This causes it to perform wrong memory write or spurious #GP exception to be injected to the guest. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
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由 Nadav Amit 提交于
According to Intel specifications, PAE and non-PAE does not have any reserved bits. In long-mode, regardless to PCIDE, only the high bits (above the physical address) are reserved. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
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- 22 4月, 2014 1 次提交
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由 Nadav Amit 提交于
According to Intel specifications, only general purpose registers and segment selectors should be saved in the old TSS during 32-bit task-switch. Signed-off-by: NNadav Amit <namit@cs.technion.ac.il> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
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- 17 3月, 2014 2 次提交
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由 Igor Mammedov 提交于
Add emulation for 0x66 prefixed instruction of 0f 28 opcode that has been added earlier. Signed-off-by: NIgor Mammedov <imammedo@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Igor Mammedov 提交于
HCK memory driver test fails when testing 32-bit Windows 8.1 with baloon driver. tracing KVM shows error: reason EXIT_ERR rip 0x81c18326 info 0 0 x/10i 0x81c18326-20 0x0000000081c18312: add %al,(%eax) 0x0000000081c18314: add %cl,-0x7127711d(%esi) 0x0000000081c1831a: rolb $0x0,0x80ec(%ecx) 0x0000000081c18321: and $0xfffffff0,%esp 0x0000000081c18324: mov %esp,%esi 0x0000000081c18326: movaps %xmm0,(%esi) 0x0000000081c18329: movaps %xmm1,0x10(%esi) 0x0000000081c1832d: movaps %xmm2,0x20(%esi) 0x0000000081c18331: movaps %xmm3,0x30(%esi) 0x0000000081c18335: movaps %xmm4,0x40(%esi) which points to MOVAPS instruction currently no emulated by KVM. Fix it by adding appropriate entries to opcode table in KVM's emulator. Signed-off-by: NIgor Mammedov <imammedo@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 05 11月, 2013 2 次提交
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由 Gleb Natapov 提交于
Make code shorter. Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGleb Natapov <gleb@redhat.com>
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由 Gleb Natapov 提交于
All decode_register() callers check if instruction has rex prefix to properly decode one byte operand. It make sense to move the check inside. Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGleb Natapov <gleb@redhat.com>
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