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path: root/arch/x86/kvm/emulate.c
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2015-03-30KVM: remove useless check of "ret" variable prior to returning the same valueEugene Korenevsky
A trivial code cleanup. This `if` is redundant. Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com> Message-Id: <20150328222717.GA6508@gnote> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-30KVM: x86: Remove redundant definitionsNadav Amit
Some constants are redfined in emulate.c. Avoid it. s/SELECTOR_RPL_MASK/SEGMENT_RPL_MASK s/SELECTOR_TI_MASK/SEGMENT_TI_MASK No functional change. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427635984-8113-3-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-30KVM: x86: removing redundant eflags bits definitionsNadav Amit
The eflags are redefined (using other defines) in emulate.c. Use the definition from processor-flags.h as some mess already started. No functional change. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427635984-8113-2-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-30KVM: x86: BSF and BSR emulation change register unnecassarilyNadav Amit
If the source of BSF and BSR is zero, the destination register should not change. That is how real hardware behaves. If we set the destination even with the same value that we had before, we may clear bits [63:32] unnecassarily. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427719163-5429-4-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-30KVM: x86: POPA emulation may not clear bits [63:32]Nadav Amit
POPA should assign the values to the registers as usual registers are assigned. In other words, 32-bits register assignments should clear bits [63:32] of the register. Split the code of register assignments that will be used by future changes as well. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427719163-5429-3-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-30KVM: x86: CMOV emulation on legacy mode is wrongNadav Amit
On legacy mode CMOV emulation should still clear bits [63:32] even if the assignment is not done. The previous fix 140bad89fd ("KVM: x86: emulation of dword cmov on long-mode should clear [63:32]") was incomplete. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Message-Id: <1427719163-5429-2-git-send-email-namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-13KVM: x86: Fix re-execution of patched vmmcallJan Kiszka
For a very long time (since 2b3d2a20), the path handling a vmmcall instruction of the guest on an Intel host only applied the patch but no longer handled the hypercall. The reverse case, vmcall on AMD hosts, is fine. As both em_vmcall and em_vmmcall actually have to do the same, we can fix the issue by consolidating both into the same handler. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-02-23KVM: emulate: fix CMPXCHG8B on 32-bit hostsPaolo Bonzini
This has been broken for a long time: it broke first in 2.6.35, then was almost fixed in 2.6.36 but this one-liner slipped through the cracks. The bug shows up as an infinite loop in Windows 7 (and newer) boot on 32-bit hosts without EPT. Windows uses CMPXCHG8B to write to page tables, which causes a page fault if running without EPT; the emulator is then called from kvm_mmu_page_fault. The loop then happens if the higher 4 bytes are not 0; the common case for this is that the NX bit (bit 63) is 1. Fixes: 6550e1f165f384f3a46b60a1be9aba4bc3c2adad Fixes: 16518d5ada690643453eb0aef3cc7841d3623c2d Cc: stable@vger.kernel.org # 2.6.35+ Reported-by: Erik Rull <erik.rull@rdsoftware.de> Tested-by: Erik Rull <erik.rull@rdsoftware.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM update from Paolo Bonzini: "Fairly small update, but there are some interesting new features. Common: Optional support for adding a small amount of polling on each HLT instruction executed in the guest (or equivalent for other architectures). This can improve latency up to 50% on some scenarios (e.g. O_DSYNC writes or TCP_RR netperf tests). This also has to be enabled manually for now, but the plan is to auto-tune this in the future. ARM/ARM64: The highlights are support for GICv3 emulation and dirty page tracking s390: Several optimizations and bugfixes. Also a first: a feature exposed by KVM (UUID and long guest name in /proc/sysinfo) before it is available in IBM's hypervisor! :) MIPS: Bugfixes. x86: Support for PML (page modification logging, a new feature in Broadwell Xeons that speeds up dirty page tracking), nested virtualization improvements (nested APICv---a nice optimization), usual round of emulation fixes. There is also a new option to reduce latency of the TSC deadline timer in the guest; this needs to be tuned manually. Some commits are common between this pull and Catalin's; I see you have already included his tree. Powerpc: Nothing yet. The KVM/PPC changes will come in through the PPC maintainers, because I haven't received them yet and I might end up being offline for some part of next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits) KVM: ia64: drop kvm.h from installed user headers KVM: x86: fix build with !CONFIG_SMP KVM: x86: emulate: correct page fault error code for NoWrite instructions KVM: Disable compat ioctl for s390 KVM: s390: add cpu model support KVM: s390: use facilities and cpu_id per KVM KVM: s390/CPACF: Choose crypto control block format s390/kernel: Update /proc/sysinfo file with Extended Name and UUID KVM: s390: reenable LPP facility KVM: s390: floating irqs: fix user triggerable endless loop kvm: add halt_poll_ns module parameter kvm: remove KVM_MMIO_SIZE KVM: MIPS: Don't leak FPU/DSP to guest KVM: MIPS: Disable HTW while in guest KVM: nVMX: Enable nested posted interrupt processing KVM: nVMX: Enable nested virtual interrupt delivery KVM: nVMX: Enable nested apic register virtualization KVM: nVMX: Make nested control MSRs per-cpu KVM: nVMX: Enable nested virtualize x2apic mode KVM: nVMX: Prepare for using hardware MSR bitmap ...
2015-02-09KVM: x86: emulate: correct page fault error code for NoWrite instructionsPaolo Bonzini
NoWrite instructions (e.g. cmp or test) never set the "write access" bit in the error code, even if one of the operands is treated as a destination. Fixes: c205fb7d7d4f81e46fc577b707ceb9e356af1456 Cc: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: Emulation of call may use incorrect stack sizeNadav Amit
On long-mode, when far call that changes cs.l takes place, the stack size is determined by the new mode. For instance, if we go from 32-bit mode to 64-bit mode, the stack-size if 64. KVM uses the old stack size. Fix it. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: 32-bit wraparound read/write not emulated correctlyNadav Amit
If we got a wraparound of 32-bit operand, and the limit is 0xffffffff, read and writes should be successful. It just needs to be done in two segments. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: Fix defines in emulator.cNadav Amit
Unnecassary define was left after commit 7d882ffa81d5 ("KVM: x86: Revert NoBigReal patch in the emulator"). Commit 39f062ff51b2 ("KVM: x86: Generate #UD when memory operand is required") was missing undef. Fix it. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: ARPL emulation can cause spurious exceptionsNadav Amit
ARPL and MOVSXD are encoded the same and their execution depends on the execution mode. The operand sizes of each instruction are different. Currently, ARPL is detected too late, after the decoding was already done, and therefore may result in spurious exception (instead of failed emulation). Introduce a group to the emulator to handle instructions according to execution mode (32/64 bits). Note: in order not to make changes that may affect performance, the new ModeDual can only be applied to instructions with ModRM. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: IRET emulation does not clear NMI maskingNadav Amit
The IRET instruction should clear NMI masking, but the current implementation does not do so. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: Wrong operand size for far retNadav Amit
Indeed, Intel SDM specifically states that for the RET instruction "In 64-bit mode, the default operation size of this instruction is the stack-address size, i.e. 64 bits." However, experiments show this is not the case. Here is for example objdump of small 64-bit asm: 4004f1: ca 14 00 lret $0x14 4004f4: 48 cb lretq 4004f6: 48 ca 14 00 lretq $0x14 Therefore, remove the Stack flag from far-ret instructions. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-26KVM: x86: Dirty the dest op page on cmpxchg emulationNadav Amit
Intel SDM says for CMPXCHG: "To simplify the interface to the processor’s bus, the destination operand receives a write cycle without regard to the result of the comparison.". This means the destination page should be dirtied. Fix it to by writing back the original value if cmpxchg failed. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-23KVM: x86: SYSENTER emulation is brokenNadav Amit
SYSENTER emulation is broken in several ways: 1. It misses the case of 16-bit code segments completely (CVE-2015-0239). 2. MSR_IA32_SYSENTER_CS is checked in 64-bit mode incorrectly (bits 0 and 1 can still be set without causing #GP). 3. MSR_IA32_SYSENTER_EIP and MSR_IA32_SYSENTER_ESP are not masked in legacy-mode. 4. There is some unneeded code. Fix it. Cc: stable@vger.linux.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-23KVM: x86: Fix of previously incomplete fix for CVE-2014-8480Nadav Amit
STR and SLDT with rip-relative operand can cause a host kernel oops. Mark them as DstMem as well. Cc: stable@vger.linux.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-09KVM: x86: #PF error-code on R/W operations is wrongNadav Amit
When emulating an instruction that reads the destination memory operand (i.e., instructions without the Mov flag in the emulator), the operand is first read. If a page-fault is detected in this phase, the error-code which would be delivered to the VM does not indicate that the access that caused the exception is a write one. This does not conform with real hardware, and may cause the VM to enter the page-fault handler twice for no reason (once for read, once for write). Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: Access to LDT/GDT that wraparound is incorrectNadav Amit
When access to descriptor in LDT/GDT wraparound outside long-mode, the address of the descriptor should be truncated to 32-bit. Citing Intel SDM 2.1.1.1 "Global and Local Descriptor Tables in IA-32e Mode": "GDTR and LDTR registers are expanded to 64-bits wide in both IA-32e sub-modes (64-bit mode and compatibility mode)." So in other cases, we need to truncate. Creating new function to return a pointer to descriptor table to avoid too much code duplication. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> [Wrap 64-bit check with #ifdef CONFIG_X86_64, to avoid a "right shift count >= width of type" warning and consequent undefined behavior. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: Do not set access bit on accessed segmentsNadav Amit
When segment is loaded, the segment access bit is set unconditionally. In fact, it should be set conditionally, based on whether the segment had the accessed bit set before. In addition, it can improve performance. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: POP [ESP] is not emulated correctlyNadav Amit
According to Intel SDM: "If the ESP register is used as a base register for addressing a destination operand in memory, the POP instruction computes the effective address of the operand after it increments the ESP register." The current emulation does not behave so. The fix required to waste another of the precious instruction flags and to check the flag in decode_modrm. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: em_call_far should return failure resultNadav Amit
Currently, if em_call_far fails it returns success instead of the resulting error-code. Fix it. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: JMP/CALL using call- or task-gate causes exceptionNadav Amit
The KVM emulator does not emulate JMP and CALL that target a call gate or a task gate. This patch does not try to implement these scenario as they are presumably rare; yet it returns X86EMUL_UNHANDLEABLE error in such cases instead of generating an exception. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: fnstcw and fnstsw may cause spurious exceptionNadav Amit
Since the operand size of fnstcw and fnstsw is updated during the execution, the emulation may cause spurious exceptions as it reads the memory beforehand. Marking these instructions as Mov (since the previous value is ignored) and DstMem16 to simplify the setting of operand size. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: pop sreg accesses only 2 bytesNadav Amit
Although pop sreg updates RSP according to the operand size, only 2 bytes are read. The current behavior may result in incorrect #GP or #PF exceptions. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08KVM: x86: Remove FIXMEs in emulate.c for the function,task_switch_32Nicholas Krause
Remove FIXME comments about needing fault addresses to be returned. These are propaagated from walk_addr_generic to gva_to_gpa and from there to ops->read_std and ops->write_std. Signed-off-by: Nicholas Krause <xerofoify@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-18Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM update from Paolo Bonzini: "3.19 changes for KVM: - spring cleaning: removed support for IA64, and for hardware- assisted virtualization on the PPC970 - ARM, PPC, s390 all had only small fixes For x86: - small performance improvements (though only on weird guests) - usual round of hardware-compliancy fixes from Nadav - APICv fixes - XSAVES support for hosts and guests. XSAVES hosts were broken because the (non-KVM) XSAVES patches inadvertently changed the KVM userspace ABI whenever XSAVES was enabled; hence, this part is going to stable. Guest support is just a matter of exposing the feature and CPUID leaves support" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (179 commits) KVM: move APIC types to arch/x86/ KVM: PPC: Book3S: Enable in-kernel XICS emulation by default KVM: PPC: Book3S HV: Improve H_CONFER implementation KVM: PPC: Book3S HV: Fix endianness of instruction obtained from HEIR register KVM: PPC: Book3S HV: Remove code for PPC970 processors KVM: PPC: Book3S HV: Tracepoints for KVM HV guest interactions KVM: PPC: Book3S HV: Simplify locking around stolen time calculations arch: powerpc: kvm: book3s_paired_singles.c: Remove unused function arch: powerpc: kvm: book3s_pr.c: Remove unused function arch: powerpc: kvm: book3s.c: Remove some unused functions arch: powerpc: kvm: book3s_32_mmu.c: Remove unused function KVM: PPC: Book3S HV: Check wait conditions before sleeping in kvmppc_vcore_blocked KVM: PPC: Book3S HV: ptes are big endian KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI KVM: PPC: Book3S HV: Fix KSM memory corruption KVM: PPC: Book3S HV: Fix an issue where guest is paused on receiving HMI KVM: PPC: Book3S HV: Fix computation of tlbie operand KVM: PPC: Book3S HV: Add missing HPTE unlock KVM: PPC: BookE: Improve irq inject tracepoint arm/arm64: KVM: Require in-kernel vgic for the arch timers ...
2014-12-11KVM: x86: em_ret_far overrides cplNadav Amit
commit d50eaa18039b ("KVM: x86: Perform limit checks when assigning EIP") mistakenly used zero as cpl on em_ret_far. Use the actual one. Fixes: d50eaa18039b8b848c2285478d0775335ad5e930 Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10KVM: x86: Emulate should check #UD before #GPNadav Amit
Intel SDM table 6-2 ("Priority Among Simultaneous Exceptions and Interrupts") shows that faults from decoding the next instruction got higher priority than general protection. Moving the protected-mode check before the CPL check to avoid wrong exception on vm86 mode. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10KVM: x86: Do not push eflags.vm on pushfNadav Amit
The pushf instruction does not push eflags.VM, so emulation should not do so as well. Although eflags.RF should not be pushed as well, it is already cleared by the time pushf is executed. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-10KVM: x86: Remove prefix flag when GP macro is usedNadav Amit
The macro GP already sets the flag Prefix. Remove the redundant flag for 0f_38_f0 and 0f_38_f1 opcodes. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-04KVM: x86: Generate #UD when memory operand is requiredNadav Amit
Certain x86 instructions that use modrm operands only allow memory operand (i.e., mod012), and cause a #UD exception otherwise. KVM ignores this fact. Currently, the instructions that are such and are emulated by KVM are MOVBE, MOVNTPS, MOVNTPD and MOVNTI. MOVBE is the most blunt example, since it may be emulated by the host regardless of MMIO. The fix introduces a new group for handling such instructions, marking mod3 as illegal instruction. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Remove FIXMEs in emulate.cNicholas Krause
Remove FIXME comments about needing fault addresses to be returned. These are propaagated from walk_addr_generic to gva_to_gpa and from there to ops->read_std and ops->write_std. Signed-off-by: Nicholas Krause <xerofoify@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: emulator: remove duplicated limit checkPaolo Bonzini
The check on the higher limit of the segment, and the check on the maximum accessible size, is the same for both expand-up and expand-down segments. Only the computation of "lim" varies. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: emulator: remove code duplication in register_address{,_increment}Paolo Bonzini
register_address has been a duplicate of address_mask ever since the ancestor of __linearize was born in 90de84f50b42 (KVM: x86 emulator: preserve an operand's segment identity, 2010-11-17). However, we can put it to a better use by including the call to reg_read in register_address. Similarly, the call to reg_rmw can be moved to register_address_increment. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Move __linearize masking of la into switchNadav Amit
In __linearize there is check of the condition whether to check if masking of the linear address is needed. It occurs immediately after switch that evaluates the same condition. Merge them. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Non-canonical access using SS should cause #SSNadav Amit
When SS is used using a non-canonical address, an #SS exception is generated on real hardware. KVM emulator causes a #GP instead. Fix it to behave as real x86 CPU. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Perform limit checks when assigning EIPNadav Amit
If branch (e.g., jmp, ret) causes limit violations, since the target IP > limit, the #GP exception occurs before the branch. In other words, the RIP pushed on the stack should be that of the branch and not that of the target. To do so, we can call __linearize, with new EIP, which also saves us the code which performs the canonical address checks. On the case of assigning an EIP >= 2^32 (when switching cs.l), we also safe, as __linearize will check the new EIP does not exceed the limit and would trigger #GP(0) otherwise. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Emulator performs privilege checks on __linearizeNadav Amit
When segment is accessed, real hardware does not perform any privilege level checks. In contrast, KVM emulator does. This causes some discrepencies from real hardware. For instance, reading from readable code segment may fail due to incorrect segment checks. In addition, it introduces unnecassary overhead. To reference Intel SDM 5.5 ("Privilege Levels"): "Privilege levels are checked when the segment selector of a segment descriptor is loaded into a segment register." The SDM never mentions privilege level checks during memory access, except for loading far pointers in section 5.10 ("Pointer Validation"). Those are actually segment selector loads and are emulated in the similarily (i.e., regardless to __linearize checks). This behavior was also checked using sysexit. A data-segment whose DPL=0 was loaded, and after sysexit (CPL=3) it is still accessible. Therefore, all the privilege level checks in __linearize are removed. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Stack size is overridden by __linearizeNadav Amit
When performing segmented-read/write in the emulator for stack operations, it ignores the stack size, and uses the ad_bytes as indication for the pointer size. As a result, a wrong address may be accessed. To fix this behavior, we can remove the masking of address in __linearize and perform it beforehand. It is already done for the operands (so currently it is inefficiently done twice). It is missing in two cases: 1. When using rip_relative 2. On fetch_bit_operand that changes the address. This patch masks the address on these two occassions, and removes the masking from __linearize. Note that it does not mask EIP during fetch. In protected/legacy mode code fetch when RIP >= 2^32 should result in #GP and not wrap-around. Since we make limit checks within __linearize, this is the expected behavior. Partial revert of commit 518547b32ab4 (KVM: x86: Emulator does not calculate address correctly, 2014-09-30). Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-19KVM: x86: Revert NoBigReal patch in the emulatorNadav Amit
Commit 10e38fc7cab6 ("KVM: x86: Emulator flag for instruction that only support 16-bit addresses in real mode") introduced NoBigReal for instructions such as MONITOR. Apparetnly, the Intel SDM description that led to this patch is misleading. Since no instruction is using NoBigReal, it is safe to remove it, we fully understand what the SDM means. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-08KVM: x86: MOVNTI emulation min opsize is not respectedNadav Amit
Commit 3b32004a66e9 ("KVM: x86: movnti minimum op size of 32-bit is not kept") did not fully fix the minimum operand size of MONTI emulation. Still, MOVNTI may be mistakenly performed using 16-bit opsize. This patch add No16 flag to mark an instruction does not support 16-bits operand size. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-08KVM: x86: Return UNHANDLABLE on unsupported SYSENTERNadav Amit
Now that KVM injects #UD on "unhandlable" error, it makes better sense to return such error on sysenter instead of directly injecting #UD to the guest. This allows to track more easily the unhandlable cases the emulator does not support. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-08KVM: x86: Emulator mis-decodes VEX instructions on real-modeNadav Amit
Commit 7fe864dc942c (KVM: x86: Mark VEX-prefix instructions emulation as unimplemented, 2014-06-02) marked VEX instructions as such in protected mode. VEX-prefix instructions are not supported relevant on real-mode and VM86, but should cause #UD instead of being decoded as LES/LDS. Fix this behaviour to be consistent with real hardware. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> [Check for mod == 3, rather than 2 or 3. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07KVM: x86: Remove redundant and incorrect cpl check on task-switchNadav Amit
Task-switch emulation checks the privilege level prior to performing the task-switch. This check is incorrect in the case of task-gates, in which the tss.dpl is ignored, and can cause superfluous exceptions. Moreover this check is unnecassary, since the CPU checks the privilege levels prior to exiting. Intel SDM 25.4.2 says "If CALL or JMP accesses a TSS descriptor directly outside IA-32e mode, privilege levels are checked on the TSS descriptor" prior to exiting. AMD 15.14.1 says "The intercept is checked before the task switch takes place but after the incoming TSS and task gate (if one was involved) have been checked for correctness." This patch removes the CPL checks for CALL and JMP. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07KVM: x86: Inject #GP when loading system segments with non-canonical baseNadav Amit
When emulating LTR/LDTR/LGDT/LIDT, #GP should be injected if the base is non-canonical. Otherwise, VM-entry will fail. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07KVM: x86: Combine the lgdt and lidt emulation logicNadav Amit
LGDT and LIDT emulation logic is almost identical. Merge the logic into a single point to avoid redundancy. This will be used by the next patch that will ensure the bases of the loaded GDTR and IDTR are canonical. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07KVM: x86: MOV to CR3 can set bit 63Nadav Amit
Although Intel SDM mentions bit 63 is reserved, MOV to CR3 can have bit 63 set. As Intel SDM states in section 4.10.4 "Invalidation of TLBs and Paging-Structure Caches": " MOV to CR3. ... If CR4.PCIDE = 1 and bit 63 of the instruction’s source operand is 0 ..." In other words, bit 63 is not reserved. KVM emulator currently consider bit 63 as reserved. Fix it. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>