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2018-12-21KVM: x86: Add CPUID support for new instruction WBNOINVDRobert Hoo
Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: VMX: Move VM-Enter + VM-Exit handling to non-inline sub-routinesSean Christopherson
Transitioning to/from a VMX guest requires KVM to manually save/load the bulk of CPU state that the guest is allowed to direclty access, e.g. XSAVE state, CR2, GPRs, etc... For obvious reasons, loading the guest's GPR snapshot prior to VM-Enter and saving the snapshot after VM-Exit is done via handcoded assembly. The assembly blob is written as inline asm so that it can easily access KVM-defined structs that are used to hold guest state, e.g. moving the blob to a standalone assembly file would require generating defines for struct offsets. The other relevant aspect of VMX transitions in KVM is the handling of VM-Exits. KVM doesn't employ a separate VM-Exit handler per se, but rather treats the VMX transition as a mega instruction (with many side effects), i.e. sets the VMCS.HOST_RIP to a label immediately following VMLAUNCH/VMRESUME. The label is then exposed to C code via a global variable definition in the inline assembly. Because of the global variable, KVM takes steps to (attempt to) ensure only a single instance of the owning C function, e.g. vmx_vcpu_run, is generated by the compiler. The earliest approach placed the inline assembly in a separate noinline function[1]. Later, the assembly was folded back into vmx_vcpu_run() and tagged with __noclone[2][3], which is still used today. After moving to __noclone, an edge case was encountered where GCC's -ftracer optimization resulted in the inline assembly blob being duplicated. This was "fixed" by explicitly disabling -ftracer in the __noclone definition[4]. Recently, it was found that disabling -ftracer causes build warnings for unsuspecting users of __noclone[5], and more importantly for KVM, prevents the compiler for properly optimizing vmx_vcpu_run()[6]. And perhaps most importantly of all, it was pointed out that there is no way to prevent duplication of a function with 100% reliability[7], i.e. more edge cases may be encountered in the future. So to summarize, the only way to prevent the compiler from duplicating the global variable definition is to move the variable out of inline assembly, which has been suggested several times over[1][7][8]. Resolve the aforementioned issues by moving the VMLAUNCH+VRESUME and VM-Exit "handler" to standalone assembly sub-routines. Moving only the core VMX transition codes allows the struct indexing to remain as inline assembly and also allows the sub-routines to be used by nested_vmx_check_vmentry_hw(). Reusing the sub-routines has a happy side-effect of eliminating two VMWRITEs in the nested_early_check path as there is no longer a need to dynamically change VMCS.HOST_RIP. Note that callers to vmx_vmenter() must account for the CALL modifying RSP, e.g. must subtract op-size from RSP when synchronizing RSP with VMCS.HOST_RSP and "restore" RSP prior to the CALL. There are no great alternatives to fudging RSP. Saving RSP in vmx_enter() is difficult because doing so requires a second register (VMWRITE does not provide an immediate encoding for the VMCS field and KVM supports Hyper-V's memory-based eVMCS ABI). The other more drastic alternative would be to use eschew VMCS.HOST_RSP and manually save/load RSP using a per-cpu variable (which can be encoded as e.g. gs:[imm]). But because a valid stack is needed at the time of VM-Exit (NMIs aren't blocked and a user could theoretically insert INT3/INT1ICEBRK at the VM-Exit handler), a dedicated per-cpu VM-Exit stack would be required. A dedicated stack isn't difficult to implement, but it would require at least one page per CPU and knowledge of the stack in the dumpstack routines. And in most cases there is essentially zero overhead in dynamically updating VMCS.HOST_RSP, e.g. the VMWRITE can be avoided for all but the first VMLAUNCH unless nested_early_check=1, which is not a fast path. In other words, avoiding the VMCS.HOST_RSP by using a dedicated stack would only make the code marginally less ugly while requiring at least one page per CPU and forcing the kernel to be aware (and approve) of the VM-Exit stack shenanigans. [1] cea15c24ca39 ("KVM: Move KVM context switch into own function") [2] a3b5ba49a8c5 ("KVM: VMX: add the __noclone attribute to vmx_vcpu_run") [3] 104f226bfd0a ("KVM: VMX: Fold __vmx_vcpu_run() into vmx_vcpu_run()") [4] 95272c29378e ("compiler-gcc: disable -ftracer for __noclone functions") [5] https://lkml.kernel.org/r/20181218140105.ajuiglkpvstt3qxs@treble [6] https://patchwork.kernel.org/patch/8707981/#21817015 [7] https://lkml.kernel.org/r/ri6y38lo23g.fsf@suse.cz [8] https://lkml.kernel.org/r/20181218212042.GE25620@tassilo.jf.intel.com Suggested-by: Andi Kleen <ak@linux.intel.com> Suggested-by: Martin Jambor <mjambor@suse.cz> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Nadav Amit <namit@vmware.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Martin Jambor <mjambor@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm blobsSean Christopherson
Use '%% " _ASM_CX"' instead of '%0' to dereference RCX, i.e. the 'struct vcpu_vmx' pointer, in the VM-Enter asm blobs of vmx_vcpu_run() and nested_vmx_check_vmentry_hw(). Using the symbolic name means that adding/removing an output parameter(s) requires "rewriting" almost all of the asm blob, which makes it nearly impossible to understand what's being changed in even the most minor patches. Opportunistically improve the code comments. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Use jmp to invoke kvm_spurious_fault() from .fixupSean Christopherson
____kvm_handle_fault_on_reboot() provides a generic exception fixup handler that is used to cleanly handle faults on VMX/SVM instructions during reboot (or at least try to). If there isn't a reboot in progress, ____kvm_handle_fault_on_reboot() treats any exception as fatal to KVM and invokes kvm_spurious_fault(), which in turn generates a BUG() to get a stack trace and die. When it was originally added by commit 4ecac3fd6dc2 ("KVM: Handle virtualization instruction #UD faults during reboot"), the "call" to kvm_spurious_fault() was handcoded as PUSH+JMP, where the PUSH'd value is the RIP of the faulting instructing. The PUSH+JMP trickery is necessary because the exception fixup handler code lies outside of its associated function, e.g. right after the function. An actual CALL from the .fixup code would show a slightly bogus stack trace, e.g. an extra "random" function would be inserted into the trace, as the return RIP on the stack would point to no known function (and the unwinder will likely try to guess who owns the RIP). Unfortunately, the JMP was replaced with a CALL when the macro was reworked to not spin indefinitely during reboot (commit b7c4145ba2eb "KVM: Don't spin on virt instruction faults during reboot"). This causes the aforementioned behavior where a bogus function is inserted into the stack trace, e.g. my builds like to blame free_kvm_area(). Revert the CALL back to a JMP. The changelog for commit b7c4145ba2eb ("KVM: Don't spin on virt instruction faults during reboot") contains nothing that indicates the switch to CALL was deliberate. This is backed up by the fact that the PUSH <insn RIP> was left intact. Note that an alternative to the PUSH+JMP magic would be to JMP back to the "real" code and CALL from there, but that would require adding a JMP in the non-faulting path to avoid calling kvm_spurious_fault() and would add no value, i.e. the stack trace would be the same. Using CALL: ------------[ cut here ]------------ kernel BUG at /home/sean/go/src/kernel.org/linux/arch/x86/kvm/x86.c:356! invalid opcode: 0000 [#1] SMP CPU: 4 PID: 1057 Comm: qemu-system-x86 Not tainted 4.20.0-rc6+ #75 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_spurious_fault+0x5/0x10 [kvm] Code: <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41 RSP: 0018:ffffc900004bbcc8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888273fd8000 R08: 00000000000003e8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000784 R12: ffffc90000371fb0 R13: 0000000000000000 R14: 000000026d763cf4 R15: ffff888273fd8000 FS: 00007f3d69691700(0000) GS:ffff888277800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f89bc56fe0 CR3: 0000000271a5a001 CR4: 0000000000362ee0 Call Trace: free_kvm_area+0x1044/0x43ea [kvm_intel] ? vmx_vcpu_run+0x156/0x630 [kvm_intel] ? kvm_arch_vcpu_ioctl_run+0x447/0x1a40 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? __set_task_blocked+0x38/0x90 ? __set_current_blocked+0x50/0x60 ? __fpu__restore_sig+0x97/0x490 ? do_vfs_ioctl+0xa1/0x620 ? __x64_sys_futex+0x89/0x180 ? ksys_ioctl+0x66/0x70 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x4f/0x100 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Modules linked in: vhost_net vhost tap kvm_intel kvm irqbypass bridge stp llc ---[ end trace 9775b14b123b1713 ]--- Using JMP: ------------[ cut here ]------------ kernel BUG at /home/sean/go/src/kernel.org/linux/arch/x86/kvm/x86.c:356! invalid opcode: 0000 [#1] SMP CPU: 6 PID: 1067 Comm: qemu-system-x86 Not tainted 4.20.0-rc6+ #75 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_spurious_fault+0x5/0x10 [kvm] Code: <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41 RSP: 0018:ffffc90000497cd0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88827058bd40 R08: 00000000000003e8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000784 R12: ffffc90000369fb0 R13: 0000000000000000 R14: 00000003c8fc6642 R15: ffff88827058bd40 FS: 00007f3d7219e700(0000) GS:ffff888277900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3d64001000 CR3: 0000000271c6b004 CR4: 0000000000362ee0 Call Trace: vmx_vcpu_run+0x156/0x630 [kvm_intel] ? kvm_arch_vcpu_ioctl_run+0x447/0x1a40 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? kvm_vcpu_ioctl+0x368/0x5c0 [kvm] ? __set_task_blocked+0x38/0x90 ? __set_current_blocked+0x50/0x60 ? __fpu__restore_sig+0x97/0x490 ? do_vfs_ioctl+0xa1/0x620 ? __x64_sys_futex+0x89/0x180 ? ksys_ioctl+0x66/0x70 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x4f/0x100 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Modules linked in: vhost_net vhost tap kvm_intel kvm irqbypass bridge stp llc ---[ end trace f9daedb85ab3ddba ]--- Fixes: b7c4145ba2eb ("KVM: Don't spin on virt instruction faults during reboot") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM/x86: Use SVM assembly instruction mnemonics instead of .byte streamsUros Bizjak
Recently the minimum required version of binutils was changed to 2.20, which supports all SVM instruction mnemonics. The patch removes all .byte #defines and uses real instruction mnemonics instead. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()Lan Tianyu
Originally, flush tlb is done by slot_handle_level_range(). This patch moves the flush directly to kvm_zap_gfn_range() when range flush is available, so that only the requested range can be flushed. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM/MMU: Flush tlb directly in kvm_set_pte_rmapp()Lan Tianyu
This patch is to flush tlb directly in kvm_set_pte_rmapp() function when Hyper-V remote TLB flush is available, returning 0 so that kvm_mmu_notifier_change_pte() does not flush again. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte()Lan Tianyu
This patch is to move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte() in order to avoid redundant tlb flush. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: Make kvm_set_spte_hva() return intLan Tianyu
The patch is to make kvm_set_spte_hva() return int and caller can check return value to determine flush tlb or not. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: Replace old tlb flush function with new one to flush a specified range.Lan Tianyu
This patch is to replace kvm_flush_remote_tlbs() with kvm_flush_ remote_tlbs_with_address() in some functions without logic change. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM/MMU: Add tlb flush with range helper functionLan Tianyu
This patch is to add wrapper functions for tlb_remote_flush_with_range callback and flush tlb directly in kvm_mmu_zap_collapsible_spte(). kvm_mmu_zap_collapsible_spte() returns flush request to the slot_handle_leaf() and the latter does flush on demand. When range flush is available, make kvm_mmu_zap_collapsible_spte() to flush tlb with range directly to avoid returning range back to slot_handle_leaf(). Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM/VMX: Add hv tlb range flush supportLan Tianyu
This patch is to register tlb_remote_flush_with_range callback with hv tlb range flush interface. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21x86/hyper-v: Add HvFlushGuestAddressList hypercall supportLan Tianyu
Hyper-V provides HvFlushGuestAddressList() hypercall to flush EPT tlb with specified ranges. This patch is to add the hypercall support. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: Add tlb_remote_flush_with_range callback in kvm_x86_opsLan Tianyu
Add flush range call back in the kvm_x86_ops and platform can use it to register its associated function. The parameter "kvm_tlb_range" accepts a single range and flush list which contains a list of ranges. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Disable Intel PT when VMXON in L1 guestLuwei Kang
Currently, Intel Processor Trace do not support tracing in L1 guest VMX operation(IA32_VMX_MISC[bit 14] is 0). As mentioned in SDM, on these type of processors, execution of the VMXON instruction will clears IA32_RTIT_CTL.TraceEn and any attempt to write IA32_RTIT_CTL causes a general-protection exception (#GP). Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Set intercept for Intel PT MSRs read/writeChao Peng
To save performance overhead, disable intercept Intel PT MSRs read/write when Intel PT is enabled in guest. MSR_IA32_RTIT_CTL is an exception that will always be intercepted. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Implement Intel PT MSRs read/write emulationChao Peng
This patch implement Intel Processor Trace MSRs read/write emulation. Intel PT MSRs read/write need to be emulated when Intel PT MSRs is intercepted in guest and during live migration. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Introduce a function to initialize the PT configurationLuwei Kang
Initialize the Intel PT configuration when cpuid update. Include cpuid inforamtion, rtit_ctl bit mask and the number of address ranges. Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Add Intel PT context switch for each vcpuChao Peng
Load/Store Intel Processor Trace register in context switch. MSR IA32_RTIT_CTL is loaded/stored automatically from VMCS. In Host-Guest mode, we need load/resore PT MSRs only when PT is enabled in guest. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Add Intel Processor Trace cpuid emulationChao Peng
Expose Intel Processor Trace to guest only when the PT works in Host-Guest mode. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: x86: Add Intel PT virtualization work modeChao Peng
Intel Processor Trace virtualization can be work in one of 2 possible modes: a. System-Wide mode (default): When the host configures Intel PT to collect trace packets of the entire system, it can leave the relevant VMX controls clear to allow VMX-specific packets to provide information across VMX transitions. KVM guest will not aware this feature in this mode and both host and KVM guest trace will output to host buffer. b. Host-Guest mode: Host can configure trace-packet generation while in VMX non-root operation for guests and root operation for native executing normally. Intel PT will be exposed to KVM guest in this mode, and the trace output to respective buffer of host and guest. In this mode, tht status of PT will be saved and disabled before VM-entry and restored after VM-exit if trace a virtual machine. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21perf/x86/intel/pt: add new capability for Intel PTLuwei Kang
This adds support for "output to Trace Transport subsystem" capability of Intel PT. It means that PT can output its trace to an MMIO address range rather than system memory buffer. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21perf/x86/intel/pt: Add new bit definitions for PT MSRsLuwei Kang
Add bit definitions for Intel PT MSRs to support trace output directed to the memeory subsystem and holds a count if packet bytes that have been sent out. These are required by the upcoming PT support in KVM guests for MSRs read/write emulation. Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21perf/x86/intel/pt: Introduce intel_pt_validate_cap()Luwei Kang
intel_pt_validate_hw_cap() validates whether a given PT capability is supported by the hardware. It checks the PT capability array which reflects the capabilities of the hardware on which the code is executed. For setting up PT for KVM guests this is not correct as the capability array for the guest can be different from the host array. Provide a new function to check against a given capability array. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21perf/x86/intel/pt: Export pt_cap_get()Chao Peng
pt_cap_get() is required by the upcoming PT support in KVM guests. Export it and move the capabilites enum to a global header. As a global functions, "pt_*" is already used for ptrace and other things, so it makes sense to use "intel_pt_*" as a prefix. Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21perf/x86/intel/pt: Move Intel PT MSRs bit defines to global headerChao Peng
The Intel Processor Trace (PT) MSR bit defines are in a private header. The upcoming support for PT virtualization requires these defines to be accessible from KVM code. Move them to the global MSR header file. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-21KVM: fix some typosWei Yang
Signed-off-by: Wei Yang <richard.weiyang@gmail.com> [Preserved the iff and a probably intentional weird bracket notation. Also dropped the style change to make a single-purpose patch. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21x86/kvmclock: convert to SPDX identifiersPeng Hao
Update the verbose license text with the matching SPDX license identifier. Signed-off-by: Peng Hao <peng.hao2@zte.com.cn> [Changed deprecated GPL-2.0+ to GPL-2.0-or-later. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21KVM: x86: Remove KF() macro placeholderSean Christopherson
Although well-intentioned, keeping the KF() definition as a hint for handling scattered CPUID features may be counter-productive. Simply redefining the bit position only works for directly manipulating the guest's CPUID leafs, e.g. it doesn't make guest_cpuid_has() magically work. Taking an alternative approach, e.g. ensuring the bit position is identical between the Linux-defined and hardware-defined features, may be a simpler and/or more effective method of exposing scattered features to the guest. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21kvm: vmx: Allow guest read access to IA32_TSCJim Mattson
Let the guest read the IA32_TSC MSR with the generic RDMSR instruction as well as the specific RDTSC(P) instructions. Note that the hardware applies the TSC multiplier and offset (when applicable) to the result of RDMSR(IA32_TSC), just as it does to the result of RDTSC(P). Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21kvm: nVMX: NMI-window and interrupt-window exiting should wake L2 from HLTJim Mattson
According to the SDM, "NMI-window exiting" VM-exits wake a logical processor from the same inactive states as would an NMI and "interrupt-window exiting" VM-exits wake a logical processor from the same inactive states as would an external interrupt. Specifically, they wake a logical processor from the shutdown state and from the states entered using the HLT and MWAIT instructions. Fixes: 6dfacadd5858 ("KVM: nVMX: Add support for activity state HLT") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Peter Shier <pshier@google.com> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com> [Squashed comments of two Jim's patches and used the simplified code hunk provided by Sean. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21KVM: nSVM: Fix nested guest support for PAUSE filtering.Tambe, William
Currently, the nested guest's PAUSE intercept intentions are not being honored. Instead, since the L0 hypervisor's pause_filter_count and pause_filter_thresh values are still in place, these values are used instead of those programmed in the VMCB by the L1 hypervisor. To honor the desired PAUSE intercept support of the L1 hypervisor, the L0 hypervisor must use the PAUSE filtering fields of the L1 hypervisor. This requires saving and restoring of both the L0 and L1 hypervisor's PAUSE filtering fields. Signed-off-by: William Tambe <william.tambe@amd.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21KVM: VMX: Remove duplicated include from vmx.cYueHaibing
Remove duplicated include. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21KVM: x86: svm: report MSR_IA32_MCG_EXT_CTL as unsupportedVitaly Kuznetsov
AMD doesn't seem to implement MSR_IA32_MCG_EXT_CTL and svm code in kvm knows nothing about it, however, this MSR is among emulated_msrs and thus returned with KVM_GET_MSR_INDEX_LIST. The consequent KVM_GET_MSRS, of course, fails. Report the MSR as unsupported to not confuse userspace. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-12-21KVM: x86: fix size of x86_fpu_cache objectsPaolo Bonzini
The memory allocation in b666a4b69739 ("kvm: x86: Dynamically allocate guest_fpu", 2018-11-06) is wrong, there are other members in struct fpu before the fpregs_state union and the patch should be doing something similar to the code in fpu__init_task_struct_size. It's enough to run a guest and then rmmod kvm to see slub errors which are actually caused by memory corruption. For now let's revert it to sizeof(struct fpu), which is conservative. I have plans to move fsave/fxsave/xsave directly in KVM, without using the kernel FPU helpers, and once it's done, the size of the object in the cache will be something like kvm_xstate_size. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: x86: Dynamically allocate guest_fpuMarc Orr
Previously, the guest_fpu field was embedded in the kvm_vcpu_arch struct. Unfortunately, the field is quite large, (e.g., 4352 bytes on my current setup). This bloats the kvm_vcpu_arch struct for x86 into an order 3 memory allocation, which can become a problem on overcommitted machines. Thus, this patch moves the fpu state outside of the kvm_vcpu_arch struct. With this patch applied, the kvm_vcpu_arch struct is reduced to 15168 bytes for vmx on my setup when building the kernel with kvmconfig. Suggested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Marc Orr <marcorr@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: x86: Use task structs fpu field for userMarc Orr
Previously, x86's instantiation of 'struct kvm_vcpu_arch' added an fpu field to save/restore fpu-related architectural state, which will differ from kvm's fpu state. However, this is redundant to the 'struct fpu' field, called fpu, embedded in the task struct, via the thread field. Thus, this patch removes the user_fpu field from the kvm_vcpu_arch struct and replaces it with the task struct's fpu field. This change is significant because the fpu struct is actually quite large. For example, on the system used to develop this patch, this change reduces the size of the vcpu_vmx struct from 23680 bytes down to 19520 bytes, when building the kernel with kvmconfig. This reduction in the size of the vcpu_vmx struct moves us closer to being able to allocate the struct at order 2, rather than order 3. Suggested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Marc Orr <marcorr@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Move the checks for Guest Non-Register States to a separate ↵Krish Sadhukhan
helper function .. to improve readability and maintainability, and to align the code as per the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Move the checks for Host Control Registers and MSRs to a separate ↵Krish Sadhukhan
helper function .. to improve readability and maintainability, and to align the code as per the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Move the checks for VM-Entry Control Fields to a separate helper ↵Krish Sadhukhan
function .. to improve readability and maintainability, and to align the code as per the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Move the checks for VM-Exit Control Fields to a separate helper ↵Krish Sadhukhan
function .. to improve readability and maintainability, and to align the code as per the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Remove param indirection from nested_vmx_check_msr_switch()Sean Christopherson
Passing the enum and doing an indirect lookup is silly when we can simply pass the field directly. Remove the "fast path" code in nested_vmx_check_msr_switch_controls() as it's now nothing more than a redundant check. Remove the debug message rather than continue passing the enum for the address field. Having debug messages for the MSRs themselves is useful as MSR legality is a huge space, whereas messing up a physical address means the VMM is fundamentally broken. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Move the checks for VM-Execution Control Fields to a separate ↵Krish Sadhukhan
helper function .. to improve readability and maintainability, and to align the code as per the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: nVMX: Prepend "nested_vmx_" to check_vmentry_{pre,post}reqs()Krish Sadhukhan
.. as they are used only in nested vmx context. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM/VMX: Check ept_pointer before flushing ept tlbLan Tianyu
This patch is to initialize ept_pointer to INVALID_PAGE and check it before flushing ept tlb. If ept_pointer is invalid, bypass the flush request. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM nVMX: MSRs should not be stored if VM-entry fails during or after ↵Krish Sadhukhan
loading guest state According to section "VM-entry Failures During or After Loading Guest State" in Intel SDM vol 3C, "No MSRs are saved into the VM-exit MSR-store area." when bit 31 of the exit reason is set. Reported-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: x86: Don't modify MSR_PLATFORM_INFO on vCPU resetJim Mattson
If userspace has provided a different value for this MSR (e.g with the turbo bits set), the userspace-provided value should survive a vCPU reset. For backwards compatibility, MSR_PLATFORM_INFO is initialized in kvm_arch_vcpu_setup. Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Drew Schmitt <dasch@google.com> Cc: Abhiroop Dabral <adabral@paloaltonetworks.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: vmx: add cpu into VMX preemption timer bug listWei Huang
This patch adds Intel "Xeon CPU E3-1220 V2", with CPUID.01H.EAX=0x000306A8, into the list of known broken CPUs which fail to support VMX preemption timer. This bug was found while running the APIC timer test of kvm-unit-test on this specific CPU, even though the errata info can't be located in the public domain for this CPU. Signed-off-by: Wei Huang <wei@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14kvm: x86: Report STIBP on GET_SUPPORTED_CPUIDEduardo Habkost
Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL to the guest, which makes STIBP available to guests. This was implemented by commits d28b387fb74d ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL") and b2ac58f90540 ("KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL"). However, we never updated GET_SUPPORTED_CPUID to let userspace know that STIBP can be enabled in CPUID. Fix that by updating kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14x86/hyper-v: Stop caring about EOI for direct stimersVitaly Kuznetsov
Turns out we over-engineered Direct Mode for stimers a bit: unlike traditional stimers where we may want to try to re-inject the message upon EOI, Direct Mode stimers just set the irq in APIC and kvm_apic_set_irq() fails only when APIC is disabled (see APIC_DM_FIXED case in __apic_accept_irq()). Remove the redundant part. Suggested-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>