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* i387: move TS_USEDFPU flag from thread_info to task_structLinus Torvalds2012-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This moves the bit that indicates whether a thread has ownership of the FPU from the TS_USEDFPU bit in thread_info->status to a word of its own (called 'has_fpu') in task_struct->thread.has_fpu. This fixes two independent bugs at the same time: - changing 'thread_info->status' from the scheduler causes nasty problems for the other users of that variable, since it is defined to be thread-synchronous (that's what the "TS_" part of the naming was supposed to indicate). So perfectly valid code could (and did) do ti->status |= TS_RESTORE_SIGMASK; and the compiler was free to do that as separate load, or and store instructions. Which can cause problems with preemption, since a task switch could happen in between, and change the TS_USEDFPU bit. The change to TS_USEDFPU would be overwritten by the final store. In practice, this seldom happened, though, because the 'status' field was seldom used more than once, so gcc would generally tend to generate code that used a read-modify-write instruction and thus happened to avoid this problem - RMW instructions are naturally low fat and preemption-safe. - On x86-32, the current_thread_info() pointer would, during interrupts and softirqs, point to a *copy* of the real thread_info, because x86-32 uses %esp to calculate the thread_info address, and thus the separate irq (and softirq) stacks would cause these kinds of odd thread_info copy aliases. This is normally not a problem, since interrupts aren't supposed to look at thread information anyway (what thread is running at interrupt time really isn't very well-defined), but it confused the heck out of irq_fpu_usable() and the code that tried to squirrel away the FPU state. (It also caused untold confusion for us poor kernel developers). It also turns out that using 'task_struct' is actually much more natural for most of the call sites that care about the FPU state, since they tend to work with the task struct for other reasons anyway (ie scheduling). And the FPU data that we are going to save/restore is found there too. Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to the %esp issue. Cc: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: Raphael Prevost <raphael@buro.asia> Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* i387: don't ever touch TS_USEDFPU directly, use helper functionsLinus Torvalds2012-02-16
| | | | | | | | | | | | | | | | | | | | | This creates three helper functions that do the TS_USEDFPU accesses, and makes everybody that used to do it by hand use those helpers instead. In addition, there's a couple of helper functions for the "change both CR0.TS and TS_USEDFPU at the same time" case, and the places that do that together have been changed to use those. That means that we have fewer random places that open-code this situation. The intent is partly to clarify the code without actually changing any semantics yet (since we clearly still have some hard to reproduce bug in this area), but also to make it much easier to use another approach entirely to caching the CR0.TS bit for software accesses. Right now we use a bit in the thread-info 'status' variable (this patch does not change that), but we might want to make it a full field of its own or even make it a per-cpu variable. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* KVM: do not #GP on perf MSR writes when vPMU is disabledGleb Natapov2012-02-01
| | | | | | | | | Return to behaviour perf MSR had before introducing vPMU in case vPMU is disabled. Some guests access those registers unconditionally and do not expect it to fail. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: fix missing checks in syscall emulationStephan Bärwolf2012-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid"Stephan Bärwolf2012-02-01
| | | | | | | | | | | | In order to be able to proceed checks on CPU-specific properties within the emulator, function "get_cpuid" is introduced. With "get_cpuid" it is possible to virtually call the guests "cpuid"-opcode without changing the VM's context. [mtosatti: cleanup/beautify code] Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* module_param: make bool parameters really bool (arch)Rusty Russell2012-01-12
| | | | | | | | | | | module_param(bool) used to counter-intuitively take an int. In fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy trick. It's time to remove the int/unsigned int option. For this version it'll simply give a warning, but it'll break next kernel version. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* KVM: x86 emulator: implement RDPMC (0F 33)Avi Kivity2011-12-27
| | | | | | Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86 emulator: fix RDPMC privilege checkAvi Kivity2011-12-27
| | | | | | | | | 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>
* KVM: Expose the architectural performance monitoring CPUID leafGleb Natapov2011-12-27
| | | | | | | Provide a CPUID leaf that describes the emulated PMU. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: VMX: Intercept RDPMCAvi Kivity2011-12-27
| | | | | | | | Intercept RDPMC and forward it to the PMU emulation code. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: SVM: Intercept RDPMCAvi Kivity2011-12-27
| | | | | | | | Intercept RDPMC and forward it to the PMU emulation code. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Add generic RDPMC supportAvi Kivity2011-12-27
| | | | | | | | Add a helper function that emulates the RDPMC instruction operation. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Expose a version 2 architectural PMU to a guestsGleb Natapov2011-12-27
| | | | | | | | | | | | | Use perf_events to emulate an architectural PMU, version 2. Based on PMU version 1 emulation by Avi Kivity. [avi: adjust for cpuid.c] [jan: fix anonymous field initialization for older gcc] Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Expose kvm_lapic_local_deliver()Avi Kivity2011-12-27
| | | | | | | | Needed to deliver performance monitoring interrupts. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86 emulator: Use opcode::execute for Group 9 instructionTakuya Yoshikawa2011-12-27
| | | | | | | | | 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>
* KVM: x86 emulator: Use opcode::execute for Group 4/5 instructionsTakuya Yoshikawa2011-12-27
| | | | | | | | Group 4: FE Group 5: FF Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86 emulator: Use opcode::execute for Group 1A instructionTakuya Yoshikawa2011-12-27
| | | | | | | | | Group 1A: 8F Register em_pop() directly and remove em_grp1a(). Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: drop bsp_vcpu pointer from kvm structGleb Natapov2011-12-27
| | | | | | | | Drop bsp_vcpu pointer from kvm struct since its only use is incorrect anyway. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: Consolidate PIT legacy testJan Kiszka2011-12-27
| | | | | | | | Move the test for KVM_PIT_FLAGS_HPET_LEGACY into create_pit_timer instead of replicating it on the caller site. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: Do not rely on implicit inclusionsJan Kiszka2011-12-27
| | | | | | | Works so far by change, but it is not guaranteed to stay like this. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Make KVM_INTEL depend on CPU_SUP_INTELAvi Kivity2011-12-27
| | | | | | | | | | | | | | | PMU virtualization needs to talk to Intel-specific bits of perf; these are only available when CPU_SUP_INTEL=y. Fixes arch/x86/built-in.o: In function `atomic_switch_perf_msrs': vmx.c:(.text+0x6b1d4): undefined reference to `perf_guest_get_msrs' Reported-by: Ingo Molnar <mingo@elte.hu> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Use memdup_user instead of kmalloc/copy_from_userSasha Levin2011-12-27
| | | | | | | | Switch to using memdup_user when possible. This makes code more smaller and compact, and prevents errors. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Use kmemdup() instead of kmalloc/memcpySasha Levin2011-12-27
| | | | | | | Switch to kmemdup() in two places to shorten the code and avoid possible bugs. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86 emulator: Remove set-but-unused cr4 from check_cr_writeJan Kiszka2011-12-27
| | | | | | | 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>
* KVM: MMU: Drop unused return value of kvm_mmu_remove_some_alloc_mmu_pagesJan Kiszka2011-12-27
| | | | | | | | freed_pages is never evaluated, so remove it as well as the return code kvm_mmu_remove_some_alloc_mmu_pages so far delivered to its only user. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: use this_cpu_xxx replace percpu_xxx funcsAlex,Shi2011-12-27
| | | | | | | | | | | percpu_xxx funcs are duplicated with this_cpu_xxx funcs, so replace them for further code clean up. And in preempt safe scenario, __this_cpu_xxx funcs has a bit better performance since __this_cpu_xxx has no redundant preempt_disable() Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: audit: inline audit functionXiao Guangrong2011-12-27
| | | | | | | inline audit function and little cleanup Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: remove oos_shadow parameterXiao Guangrong2011-12-27
| | | | | | | | The unsync code should be stable now, maybe it is the time to remove this parameter to cleanup the code a little bit Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: move the relevant mmu code to mmu.cXiao Guangrong2011-12-27
| | | | | | | Move the mmu code in kvm_arch_vcpu_init() to kvm_mmu_create() Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: remove the dead code of KVM_EXIT_HYPERCALLXiao Guangrong2011-12-27
| | | | | | | KVM_EXIT_HYPERCALL is not used anymore, so remove the code Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: audit: replace mmu audit tracepoint with jump-labelXiao Guangrong2011-12-27
| | | | | | | | The tracepoint is only used to audit mmu code, it should not be exposed to user, let us replace it with jump-label. Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Refactor and simplify kvm_dev_ioctl_get_supported_cpuidSasha Levin2011-12-27
| | | | | | | | | | | This patch cleans and simplifies kvm_dev_ioctl_get_supported_cpuid by using a table instead of duplicating code as Avi suggested. This patch also fixes a bug where kvm_dev_ioctl_get_supported_cpuid would return -E2BIG when amount of entries passed was just right. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: expose latest Intel cpu new features (BMI1/BMI2/FMA/AVX2) to guestLiu, Jinsong2011-12-27
| | | | | | | | | | | | | | | | | | | | | Intel latest cpu add 6 new features, refer http://software.intel.com/file/36945 The new feature cpuid listed as below: 1. FMA CPUID.EAX=01H:ECX.FMA[bit 12] 2. MOVBE CPUID.EAX=01H:ECX.MOVBE[bit 22] 3. BMI1 CPUID.EAX=07H,ECX=0H:EBX.BMI1[bit 3] 4. AVX2 CPUID.EAX=07H,ECX=0H:EBX.AVX2[bit 5] 5. BMI2 CPUID.EAX=07H,ECX=0H:EBX.BMI2[bit 8] 6. LZCNT CPUID.EAX=80000001H:ECX.LZCNT[bit 5] This patch expose these features to guest. Among them, FMA/MOVBE/LZCNT has already been defined, MOVBE/LZCNT has already been exposed. This patch defines BMI1/AVX2/BMI2, and exposes FMA/BMI1/AVX2/BMI2 to guest. Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Move cpuid code to new fileAvi Kivity2011-12-27
| | | | | | The cpuid code has grown; put it into a separate file. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86 emulator: Use opcode::execute for INS/OUTS from/to port in DXTakuya Yoshikawa2011-12-27
| | | | | | | | | | | | | 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>
* KVM: introduce id_to_memslot functionXiao Guangrong2011-12-27
| | | | | | | Introduce id_to_memslot to get memslot by slot id Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: introduce kvm_for_each_memslot macroXiao Guangrong2011-12-27
| | | | | | | Introduce kvm_for_each_memslot to walk all valid memslot Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: introduce update_memslots functionXiao Guangrong2011-12-27
| | | | | | | | Introduce update_memslots to update slot which will be update to kvm->memslots Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: introduce KVM_MEM_SLOTS_NUM macroXiao Guangrong2011-12-27
| | | | | | | | Introduce KVM_MEM_SLOTS_NUM macro to instead of KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86 emulator: Use opcode::execute for BSF/BSRTakuya Yoshikawa2011-12-27
| | | | | | | | BSF: 0F BC BSR: 0F BD Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86 emulator: Use opcode::execute for CMPXCHGTakuya Yoshikawa2011-12-27
| | | | | | | CMPXCHG: 0F B0, 0F B1 Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86 emulator: Use opcode::execute for WRMSR/RDMSRTakuya Yoshikawa2011-12-27
| | | | | | | | WRMSR: 0F 30 RDMSR: 0F 32 Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86 emulator: Use opcode::execute for MOV to cr/drTakuya Yoshikawa2011-12-27
| | | | | | | | MOV: 0F 22 (move to control registers) MOV: 0F 23 (move to debug registers) Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86 emulator: Use opcode::execute for CALLTakuya Yoshikawa2011-12-27
| | | | | | | CALL: E8 Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86 emulator: Use opcode::execute for BT familyTakuya Yoshikawa2011-12-27
| | | | | | | | | | | | BT : 0F A3 BTS: 0F AB BTR: 0F B3 BTC: 0F BB Group 8: 0F BA Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86 emulator: Use opcode::execute for IN/OUTTakuya Yoshikawa2011-12-27
| | | | | | | | IN : E4, E5, EC, ED OUT: E6, E7, EE, EF Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: VMX: remove unneeded vmx_load_host_state() calls.Gleb Natapov2011-12-27
| | | | | | | | | vmx_load_host_state() does not handle msrs switching (except MSR_KERNEL_GS_BASE) since commit 26bb0981b3f. Remove call to it where it is no longer make sense. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Optimize dirty logging by rmap_write_protect()Takuya Yoshikawa2011-12-27
| | | | | | | | | | | | | | | | | | | | | | | Currently, write protecting a slot needs to walk all the shadow pages and checks ones which have a pte mapping a page in it. The walk is overly heavy when dirty pages in that slot are not so many and checking the shadow pages would result in unwanted cache pollution. To mitigate this problem, we use rmap_write_protect() and check only the sptes which can be reached from gfns marked in the dirty bitmap when the number of dirty pages are less than that of shadow pages. This criterion is reasonable in its meaning and worked well in our test: write protection became some times faster than before when the ratio of dirty pages are low and was not worse even when the ratio was near the criterion. Note that the locking for this write protection becomes fine grained. The reason why this is safe is descripted in the comments. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Count the number of dirty pages for dirty loggingTakuya Yoshikawa2011-12-27
| | | | | | | | Needed for the next patch which uses this number to decide how to write protect a slot. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: Split gfn_to_rmap() into two functionsTakuya Yoshikawa2011-12-27
| | | | | | | | | | | | | rmap_write_protect() calls gfn_to_rmap() for each level with gfn fixed. This results in calling gfn_to_memslot() repeatedly with that gfn. This patch introduces __gfn_to_rmap() which takes the slot as an argument to avoid this. This is also needed for the following dirty logging optimization. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>