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2022-09-08KVM: VMX: Heed the 'msr' argument in msr_write_intercepted()Jim Mattson1-2/+1
[ Upstream commit 020dac4187968535f089f83f376a72beb3451311 ] Regardless of the 'msr' argument passed to the VMX version of msr_write_intercepted(), the function always checks to see if a specific MSR (IA32_SPEC_CTRL) is intercepted for write. This behavior seems unintentional and unexpected. Modify the function so that it checks to see if the provided 'msr' index is intercepted for write. Fixes: 67f4b9969c30 ("KVM: nVMX: Handle dynamic MSR intercept toggling") Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220810213050.2655000-1-jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17KVM: x86: Split kvm_is_valid_cr4() and export only the non-vendor bitsSean Christopherson1-2/+2
commit c33f6f2228fe8517e38941a508e9f905f99ecba9 upstream. Split the common x86 parts of kvm_is_valid_cr4(), i.e. the reserved bits checks, into a separate helper, __kvm_is_valid_cr4(), and export only the inner helper to vendor code in order to prevent nested VMX from calling back into vmx_is_valid_cr4() via kvm_is_valid_cr4(). On SVM, this is a nop as SVM doesn't place any additional restrictions on CR4. On VMX, this is also currently a nop, but only because nested VMX is missing checks on reserved CR4 bits for nested VM-Enter. That bug will be fixed in a future patch, and could simply use kvm_is_valid_cr4() as-is, but nVMX has _another_ bug where VMXON emulation doesn't enforce VMX's restrictions on CR0/CR4. The cleanest and most intuitive way to fix the VMXON bug is to use nested_host_cr{0,4}_valid(). If the CR4 variant routes through kvm_is_valid_cr4(), using nested_host_cr4_valid() won't do the right thing for the VMXON case as vmx_is_valid_cr4() enforces VMX's restrictions if and only if the vCPU is post-VMXON. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220607213604.3346000-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27KVM: VMX: Prevent RSB underflow before vmenterJosh Poimboeuf1-8/+0
On VMX, there are some balanced returns between the time the guest's SPEC_CTRL value is written, and the vmenter. Balanced returns (matched by a preceding call) are usually ok, but it's at least theoretically possible an NMI with a deep call stack could empty the RSB before one of the returns. For maximum paranoia, don't allow *any* returns (balanced or otherwise) between the SPEC_CTRL write and the vmenter. [ bp: Fix 32-bit build. ] Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27KVM: VMX: Fix IBRS handling after vmexitJosh Poimboeuf1-1/+6
For legacy IBRS to work, the IBRS bit needs to be always re-written after vmexit, even if it's already on. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27KVM: VMX: Prevent guest RSB poisoning attacks with eIBRSJosh Poimboeuf1-20/+28
On eIBRS systems, the returns in the vmexit return path from __vmx_vcpu_run() to vmx_vcpu_run() are exposed to RSB poisoning attacks. Fix that by moving the post-vmexit spec_ctrl handling to immediately after the vmexit. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27KVM: VMX: Convert launched argument to flagsJosh Poimboeuf1-3/+14
Convert __vmx_vcpu_run()'s 'launched' argument to 'flags', in preparation for doing SPEC_CTRL handling immediately after vmexit, which will need another flag. This is much easier than adding a fourth argument, because this code supports both 32-bit and 64-bit, and the fourth argument on 32-bit would have to be pushed on the stack. Note that __vmx_vcpu_run_flags() is called outside of the noinstr critical section because it will soon start calling potentially traceable functions. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27x86/kvm/vmx: Make noinstr cleanPeter Zijlstra1-3/+3
The recent mmio_stale_data fixes broke the noinstr constraints: vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x15b: call to wrmsrl.constprop.0() leaves .noinstr.text section vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x1bf: call to kvm_arch_has_assigned_device() leaves .noinstr.text section make it all happy again. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-14Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-1/+3
Pull kvm fixes from Paolo Bonzini: "While last week's pull request contained miscellaneous fixes for x86, this one covers other architectures, selftests changes, and a bigger series for APIC virtualization bugs that were discovered during 5.20 development. The idea is to base 5.20 development for KVM on top of this tag. ARM64: - Properly reset the SVE/SME flags on vcpu load - Fix a vgic-v2 regression regarding accessing the pending state of a HW interrupt from userspace (and make the code common with vgic-v3) - Fix access to the idreg range for protected guests - Ignore 'kvm-arm.mode=protected' when using VHE - Return an error from kvm_arch_init_vm() on allocation failure - A bunch of small cleanups (comments, annotations, indentation) RISC-V: - Typo fix in arch/riscv/kvm/vmid.c - Remove broken reference pattern from MAINTAINERS entry x86-64: - Fix error in page tables with MKTME enabled - Dirty page tracking performance test extended to running a nested guest - Disable APICv/AVIC in cases that it cannot implement correctly" [ This merge also fixes a misplaced end parenthesis bug introduced in commit 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base") pointed out by Sean Christopherson ] Link: https://lore.kernel.org/all/20220610191813.371682-1-seanjc@google.com/ * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (34 commits) KVM: selftests: Restrict test region to 48-bit physical addresses when using nested KVM: selftests: Add option to run dirty_log_perf_test vCPUs in L2 KVM: selftests: Clean up LIBKVM files in Makefile KVM: selftests: Link selftests directly with lib object files KVM: selftests: Drop unnecessary rule for STATIC_LIBS KVM: selftests: Add a helper to check EPT/VPID capabilities KVM: selftests: Move VMX_EPT_VPID_CAP_AD_BITS to vmx.h KVM: selftests: Refactor nested_map() to specify target level KVM: selftests: Drop stale function parameter comment for nested_map() KVM: selftests: Add option to create 2M and 1G EPT mappings KVM: selftests: Replace x86_page_size with PG_LEVEL_XX KVM: x86: SVM: fix nested PAUSE filtering when L0 intercepts PAUSE KVM: x86: SVM: drop preempt-safe wrappers for avic_vcpu_load/put KVM: x86: disable preemption around the call to kvm_arch_vcpu_{un|}blocking KVM: x86: disable preemption while updating apicv inhibition KVM: x86: SVM: fix avic_kick_target_vcpus_fast KVM: x86: SVM: remove avic's broken code that updated APIC ID KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base KVM: x86: document AVIC/APICv inhibit reasons KVM: x86/mmu: Set memory encryption "value", not "mask", in shadow PDPTRs ...
2022-06-14Merge tag 'x86-bugs-2022-06-01' of ↵Linus Torvalds1-0/+72
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 MMIO stale data fixes from Thomas Gleixner: "Yet another hw vulnerability with a software mitigation: Processor MMIO Stale Data. They are a class of MMIO-related weaknesses which can expose stale data by propagating it into core fill buffers. Data which can then be leaked using the usual speculative execution methods. Mitigations include this set along with microcode updates and are similar to MDS and TAA vulnerabilities: VERW now clears those buffers too" * tag 'x86-bugs-2022-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation/mmio: Print SMT warning KVM: x86/speculation: Disable Fill buffer clear within guests x86/speculation/mmio: Reuse SRBDS mitigation for SBDS x86/speculation/srbds: Update SRBDS mitigation selection x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data x86/speculation/mmio: Enable CPU Fill buffer clearing on idle x86/bugs: Group MDS, TAA & Processor MMIO Stale Data mitigations x86/speculation/mmio: Add mitigation for Processor MMIO Stale Data x86/speculation: Add a common function for MD_CLEAR mitigation update x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug Documentation: Add documentation for Processor MMIO Stale Data
2022-06-09KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC baseMaxim Levitsky1-1/+3
Neither of these settings should be changed by the guest and it is a burden to support it in the acceleration code, so just inhibit this code instead. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220606180829.102503-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-09Merge tag 'kvm-riscv-fixes-5.19-1' of https://github.com/kvm-riscv/linux ↵Paolo Bonzini1-1/+1
into HEAD KVM/riscv fixes for 5.19, take #1 - Typo fix in arch/riscv/kvm/vmid.c - Remove broken reference pattern from MAINTAINERS entry
2022-06-08Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+1
Pull KVM fixes from Paolo Bonzini: - syzkaller NULL pointer dereference - TDP MMU performance issue with disabling dirty logging - 5.14 regression with SVM TSC scaling - indefinite stall on applying live patches - unstable selftest - memory leak from wrong copy-and-paste - missed PV TLB flush when racing with emulation * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: do not report a vCPU as preempted outside instruction boundaries KVM: x86: do not set st->preempted when going back to user space KVM: SVM: fix tsc scaling cache logic KVM: selftests: Make hyperv_clock selftest more stable KVM: x86/MMU: Zap non-leaf SPTEs when disabling dirty logging x86: drop bogus "cc" clobber from __try_cmpxchg_user_asm() KVM: x86/mmu: Check every prev_roots in __kvm_mmu_free_obsolete_roots() entry/kvm: Exit to user mode when TIF_NOTIFY_SIGNAL is set KVM: Don't null dereference ops->destroy
2022-06-08KVM: x86: do not report a vCPU as preempted outside instruction boundariesPaolo Bonzini1-0/+1
If a vCPU is outside guest mode and is scheduled out, it might be in the process of making a memory access. A problem occurs if another vCPU uses the PV TLB flush feature during the period when the vCPU is scheduled out, and a virtual address has already been translated but has not yet been accessed, because this is equivalent to using a stale TLB entry. To avoid this, only report a vCPU as preempted if sure that the guest is at an instruction boundary. A rescheduling request will be delivered to the host physical CPU as an external interrupt, so for simplicity consider any vmexit *not* instruction boundary except for external interrupts. It would in principle be okay to report the vCPU as preempted also if it is sleeping in kvm_vcpu_block(): a TLB flush IPI will incur the vmentry/vmexit overhead unnecessarily, and optimistic spinning is also unlikely to succeed. However, leave it for later because right now kvm_vcpu_check_block() is doing memory accesses. Even though the TLB flush issue only applies to virtual memory address, it's very much preferrable to be conservative. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-05Merge tag 'x86-cleanups-2022-06-05' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Thomas Gleixner: "A set of small x86 cleanups: - Remove unused headers in the IDT code - Kconfig indendation and comment fixes - Fix all 'the the' typos in one go instead of waiting for bots to fix one at a time" * tag 'x86-cleanups-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Fix all occurences of the "the the" typo x86/idt: Remove unused headers x86/Kconfig: Fix indentation of arch/x86/Kconfig.debug x86/Kconfig: Fix indentation and add endif comments to arch/x86/Kconfig
2022-05-27x86: Fix all occurences of the "the the" typoBo Liu1-1/+1
Rather than waiting for the bots to fix these one-by-one, fix all occurences of "the the" throughout arch/x86. Signed-off-by: Bo Liu <liubo03@inspur.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20220527061400.5694-1-liubo03@inspur.com
2022-05-25KVM: x86: Fix the intel_pt PMI handling wrongly considered from guestYanfei Xu1-1/+1
When kernel handles the vm-exit caused by external interrupts and NMI, it always sets kvm_intr_type to tell if it's dealing an IRQ or NMI. For the PMI scenario, it could be IRQ or NMI. However, intel_pt PMIs are only generated for HARDWARE perf events, and HARDWARE events are always configured to generate NMIs. Use kvm_handling_nmi_from_guest() to precisely identify if the intel_pt PMI came from the guest; this avoids false positives if an intel_pt PMI/NMI arrives while the host is handling an unrelated IRQ VM-Exit. Fixes: db215756ae59 ("KVM: x86: More precisely identify NMI from guest when handling PMI") Signed-off-by: Yanfei Xu <yanfei.xu@intel.com> Message-Id: <20220523140821.1345605-1-yanfei.xu@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-25Merge tag 'kvm-riscv-5.19-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini1-1/+1
KVM/riscv changes for 5.19 - Added Sv57x4 support for G-stage page table - Added range based local HFENCE functions - Added remote HFENCE functions based on VCPU requests - Added ISA extension registers in ONE_REG interface - Updated KVM RISC-V maintainers entry to cover selftests support
2022-05-25Merge tag 'kvmarm-5.19' of ↵Paolo Bonzini1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 5.19 - Add support for the ARMv8.6 WFxT extension - Guard pages for the EL2 stacks - Trap and emulate AArch32 ID registers to hide unsupported features - Ability to select and save/restore the set of hypercalls exposed to the guest - Support for PSCI-initiated suspend in collaboration with userspace - GICv3 register-based LPI invalidation support - Move host PMU event merging into the vcpu data structure - GICv3 ITS save/restore fixes - The usual set of small-scale cleanups and fixes [Due to the conflict, KVM_SYSTEM_EVENT_SEV_TERM is relocated from 4 to 6. - Paolo]
2022-05-21KVM: x86/speculation: Disable Fill buffer clear within guestsPawan Gupta1-0/+69
The enumeration of MD_CLEAR in CPUID(EAX=7,ECX=0).EDX{bit 10} is not an accurate indicator on all CPUs of whether the VERW instruction will overwrite fill buffers. FB_CLEAR enumeration in IA32_ARCH_CAPABILITIES{bit 17} covers the case of CPUs that are not vulnerable to MDS/TAA, indicating that microcode does overwrite fill buffers. Guests running in VMM environments may not be aware of all the capabilities/vulnerabilities of the host CPU. Specifically, a guest may apply MDS/TAA mitigations when a virtual CPU is enumerated as vulnerable to MDS/TAA even when the physical CPU is not. On CPUs that enumerate FB_CLEAR_CTRL the VMM may set FB_CLEAR_DIS to skip overwriting of fill buffers by the VERW instruction. This is done by setting FB_CLEAR_DIS during VMENTER and resetting on VMEXIT. For guests that enumerate FB_CLEAR (explicitly asking for fill buffer clear capability) the VMM will not use FB_CLEAR_DIS. Irrespective of guest state, host overwrites CPU buffers before VMENTER to protect itself from an MMIO capable guest, as part of mitigation for MMIO Stale Data vulnerabilities. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-05-21x86/speculation/mmio: Add mitigation for Processor MMIO Stale DataPawan Gupta1-0/+3
Processor MMIO Stale Data is a class of vulnerabilities that may expose data after an MMIO operation. For details please refer to Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst. These vulnerabilities are broadly categorized as: Device Register Partial Write (DRPW): Some endpoint MMIO registers incorrectly handle writes that are smaller than the register size. Instead of aborting the write or only copying the correct subset of bytes (for example, 2 bytes for a 2-byte write), more bytes than specified by the write transaction may be written to the register. On some processors, this may expose stale data from the fill buffers of the core that created the write transaction. Shared Buffers Data Sampling (SBDS): After propagators may have moved data around the uncore and copied stale data into client core fill buffers, processors affected by MFBDS can leak data from the fill buffer. Shared Buffers Data Read (SBDR): It is similar to Shared Buffer Data Sampling (SBDS) except that the data is directly read into the architectural software-visible state. An attacker can use these vulnerabilities to extract data from CPU fill buffers using MDS and TAA methods. Mitigate it by clearing the CPU fill buffers using the VERW instruction before returning to a user or a guest. On CPUs not affected by MDS and TAA, user application cannot sample data from CPU fill buffers using MDS or TAA. A guest with MMIO access can still use DRPW or SBDR to extract data architecturally. Mitigate it with VERW instruction to clear fill buffers before VMENTER for MMIO capable guests. Add a kernel parameter mmio_stale_data={off|full|full,nosmt} to control the mitigation. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-05-12KVM: VMX: Include MKTME KeyID bits in shadow_zero_checkKai Huang1-0/+31
Intel MKTME KeyID bits (including Intel TDX private KeyID bits) should never be set to SPTE. Set shadow_me_value to 0 and shadow_me_mask to include all MKTME KeyID bits to include them to shadow_zero_check. Signed-off-by: Kai Huang <kai.huang@intel.com> Message-Id: <27bc10e97a3c0b58a4105ff9107448c190328239.1650363789.git.kai.huang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-06KVM: VMX: Exit to userspace if vCPU has injected exception and invalid stateSean Christopherson1-1/+1
Exit to userspace with an emulation error if KVM encounters an injected exception with invalid guest state, in addition to the existing check of bailing if there's a pending exception (KVM doesn't support emulating exceptions except when emulating real mode via vm86). In theory, KVM should never get to such a situation as KVM is supposed to exit to userspace before injecting an exception with invalid guest state. But in practice, userspace can intervene and manually inject an exception and/or stuff registers to force invalid guest state while a previously injected exception is awaiting reinjection. Fixes: fc4fad79fc3d ("KVM: VMX: Reject KVM_RUN if emulation is required with pending exception") Reported-by: syzbot+cfafed3bb76d3e37581b@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220502221850.131873-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-29KVM: x86/mmu: replace shadow_root_level with root_role.levelPaolo Bonzini1-1/+1
root_role.level is always the same value as shadow_level: - it's kvm_mmu_get_tdp_level(vcpu) when going through init_kvm_tdp_mmu - it's the level argument when going through kvm_init_shadow_ept_mmu - it's assigned directly from new_role.base.level when going through shadow_mmu_init_context Remove the duplication and get the level directly from the role. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21KVM: nVMX: Defer APICv updates while L2 is active until L1 is activeSean Christopherson1-0/+5
Defer APICv updates that occur while L2 is active until nested VM-Exit, i.e. until L1 regains control. vmx_refresh_apicv_exec_ctrl() assumes L1 is active and (a) stomps all over vmcs02 and (b) neglects to ever updated vmcs01. E.g. if vmcs12 doesn't enable the TPR shadow for L2 (and thus no APICv controls), L1 performs nested VM-Enter APICv inhibited, and APICv becomes unhibited while L2 is active, KVM will set various APICv controls in vmcs02 and trigger a failed VM-Entry. The kicker is that, unless running with nested_early_check=1, KVM blames L1 and chaos ensues. In all cases, ignoring vmcs02 and always deferring the inhibition change to vmcs01 is correct (or at least acceptable). The ABSENT and DISABLE inhibitions cannot truly change while L2 is active (see below). IRQ_BLOCKING can change, but it is firmly a best effort debug feature. Furthermore, only L2's APIC is accelerated/virtualized to the full extent possible, e.g. even if L1 passes through its APIC to L2, normal MMIO/MSR interception will apply to the virtual APIC managed by KVM. The exception is the SELF_IPI register when x2APIC is enabled, but that's an acceptable hole. Lastly, Hyper-V's Auto EOI can technically be toggled if L1 exposes the MSRs to L2, but for that to work in any sane capacity, L1 would need to pass through IRQs to L2 as well, and IRQs must be intercepted to enable virtual interrupt delivery. I.e. exposing Auto EOI to L2 and enabling VID for L2 are, for all intents and purposes, mutually exclusive. Lack of dynamic toggling is also why this scenario is all but impossible to encounter in KVM's current form. But a future patch will pend an APICv update request _during_ vCPU creation to plug a race where a vCPU that's being created doesn't get included in the "all vCPUs request" because it's not yet visible to other vCPUs. If userspaces restores L2 after VM creation (hello, KVM selftests), the first KVM_RUN will occur while L2 is active and thus service the APICv update request made during VM creation. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220420013732.3308816-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-13KVM: x86: Move .pmu_ops to kvm_x86_init_ops and tag as __initdataLike Xu1-1/+1
The pmu_ops should be moved to kvm_x86_init_ops and tagged as __initdata. That'll save those precious few bytes, and more importantly make the original ops unreachable, i.e. make it harder to sneak in post-init modification bugs. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Like Xu <likexu@tencent.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220329235054.3534728-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-13KVM: x86/mmu: Derive EPT violation RWX bits from EPTE RWX bitsSean Christopherson1-3/+1
Derive the mask of RWX bits reported on EPT violations from the mask of RWX bits that are shoved into EPT entries; the layout is the same, the EPT violation bits are simply shifted by three. Use the new shift and a slight copy-paste of the mask derivation instead of completely open coding the same to convert between the EPT entry bits and the exit qualification when synthesizing a nested EPT Violation. No functional change intended. Cc: SU Hang <darcy.sh@antgroup.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220329030108.97341-3-darcy.sh@antgroup.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-13kvm: vmx: remove redundant parenthesesPeng Hao1-1/+1
Remove redundant parentheses. Signed-off-by: Peng Hao <flyingpeng@tencent.com> Message-Id: <20220228030902.88465-1-flyingpeng@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: VMX: Prepare VMCS setting for posted interrupt enabling when APICv is ↵Zeng Guang1-1/+1
available Currently KVM setup posted interrupt VMCS only depending on per-vcpu APICv activation status at the vCPU creation time. However, this status can be toggled dynamically under some circumstance. So potentially, later posted interrupt enabling may be problematic without VMCS readiness. To fix this, always settle the VMCS setting for posted interrupt as long as APICv is available and lapic locates in kernel. Signed-off-by: Zeng Guang <guang.zeng@intel.com> Message-Id: <20220315145836.9910-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: x86: Remove redundant vm_entry_controls_clearbit() callZhenzhong Duan1-1/+0
When emulating exit from long mode, EFER_LMA is cleared with vmx_set_efer(). This will already unset the VM_ENTRY_IA32E_MODE control bit as requested by SDM, so there is no need to unset VM_ENTRY_IA32E_MODE again in exit_lmode() explicitly. In case EFER isn't supported by hardware, long mode isn't supported, so exit_lmode() cannot be reached. Note that, thanks to the shadow controls mechanism, this change doesn't eliminate vmread or vmwrite. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Message-Id: <20220311102643.807507-3-zhenzhong.duan@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: x86: cleanup enter_rmode()Zhenzhong Duan1-9/+5
vmx_set_efer() sets uret->data but, in fact if the value of uret->data will be used vmx_setup_uret_msrs() will have rewritten it with the value returned by update_transition_efer(). uret->data is consumed if and only if uret->load_into_hardware is true, and vmx_setup_uret_msrs() takes care of (a) updating uret->data before setting uret->load_into_hardware to true (b) setting uret->load_into_hardware to false if uret->data isn't updated. Opportunistically use "vmx" directly instead of redoing to_vmx(). Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Message-Id: <20220311102643.807507-2-zhenzhong.duan@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: x86: SVM: fix tsc scaling when the host doesn't support itMaxim Levitsky1-4/+3
It was decided that when TSC scaling is not supported, the virtual MSR_AMD64_TSC_RATIO should still have the default '1.0' value. However in this case kvm_max_tsc_scaling_ratio is not set, which breaks various assumptions. Fix this by always calculating kvm_max_tsc_scaling_ratio regardless of host support. For consistency, do the same for VMX. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220322172449.235575-8-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: x86: Make APICv inhibit reasons an enum and cleanup namingSean Christopherson1-2/+2
Use an enum for the APICv inhibit reasons, there is no meaning behind their values and they most definitely are not "unsigned longs". Rename the various params to "reason" for consistency and clarity (inhibit may be confused as a command, i.e. inhibit APICv, instead of the reason that is getting toggled/checked). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220311043517.17027-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-05Merge branch 'kvm-bugfixes' into HEADPaolo Bonzini1-11/+17
Merge bugfixes from 5.17 before merging more tricky work.
2022-03-01KVM: VMX: Handle APIC-write offset wrangling in VMX codeSean Christopherson1-2/+9
Move the vAPIC offset adjustments done in the APIC-write trap path from common x86 to VMX in anticipation of using the nodecode path for SVM's AVIC. The adjustment reflects hardware behavior, i.e. it's technically a property of VMX, no common x86. SVM's AVIC behavior is identical, so it's a bit of a moot point, the goal is purely to make it easier to understand why the adjustment is ok. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220204214205.3306634-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25KVM: x86: use struct kvm_mmu_root_info for mmu->rootPaolo Bonzini1-1/+1
The root_hpa and root_pgd fields form essentially a struct kvm_mmu_root_info. Use the struct to have more consistency between mmu->root and mmu->prev_roots. The patch is entirely search and replace except for cached_root_available, which does not need a temporary struct kvm_mmu_root_info anymore. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25KVM: VMX: Remove scratch 'cpu' variable that shadows an identical scratch varPeng Hao1-1/+0
From: Peng Hao <flyingpeng@tencent.com> Remove a redundant 'cpu' declaration from inside an if-statement that that shadows an identical declaration at function scope. Both variables are used as scratch variables in for_each_*_cpu() loops, thus there's no harm in sharing a variable. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peng Hao <flyingpeng@tencent.com> Message-Id: <20220222103954.70062-1-flyingpeng@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25kvm: vmx: Fix typos comment in __loaded_vmcs_clear()Peng Hao1-4/+4
Fix a comment documenting the memory barrier related to clearing a loaded_vmcs; loaded_vmcs tracks the host CPU the VMCS is loaded on via the field 'cpu', it doesn't have a 'vcpu' field. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peng Hao <flyingpeng@tencent.com> Message-Id: <20220222104029.70129-1-flyingpeng@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25KVM: nVMX: Make setup/unsetup under the same conditionsPeng Hao1-1/+1
Make sure nested_vmx_hardware_setup/unsetup() are called in pairs under the same conditions. Calling nested_vmx_hardware_unsetup() when nested is false "works" right now because it only calls free_page() on zero- initialized pointers, but it's possible that more code will be added to nested_vmx_hardware_unsetup() in the future. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peng Hao <flyingpeng@tencent.com> Message-Id: <20220222104054.70286-1-flyingpeng@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25Revert "KVM: VMX: Save HOST_CR3 in vmx_prepare_switch_to_guest()"Sean Christopherson1-10/+14
Revert back to refreshing vmcs.HOST_CR3 immediately prior to VM-Enter. The PCID (ASID) part of CR3 can be bumped without KVM being scheduled out, as the kernel will switch CR3 during __text_poke(), e.g. in response to a static key toggling. If switch_mm_irqs_off() chooses a new ASID for the mm associate with KVM, KVM will do VM-Enter => VM-Exit with a stale vmcs.HOST_CR3. Add a comment to explain why KVM must wait until VM-Enter is imminent to refresh vmcs.HOST_CR3. The following splat was captured by stashing vmcs.HOST_CR3 in kvm_vcpu and adding a WARN in load_new_mm_cr3() to fire if a new ASID is being loaded for the KVM-associated mm while KVM has a "running" vCPU: static void load_new_mm_cr3(pgd_t *pgdir, u16 new_asid, bool need_flush) { struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); ... WARN(vcpu && (vcpu->cr3 & GENMASK(11, 0)) != (new_mm_cr3 & GENMASK(11, 0)) && (vcpu->cr3 & PHYSICAL_PAGE_MASK) == (new_mm_cr3 & PHYSICAL_PAGE_MASK), "KVM is hosed, loading CR3 = %lx, vmcs.HOST_CR3 = %lx", new_mm_cr3, vcpu->cr3); } ------------[ cut here ]------------ KVM is hosed, loading CR3 = 8000000105393004, vmcs.HOST_CR3 = 105393003 WARNING: CPU: 4 PID: 20717 at arch/x86/mm/tlb.c:291 load_new_mm_cr3+0x82/0xe0 Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel CPU: 4 PID: 20717 Comm: stable Tainted: G W 5.17.0-rc3+ #747 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:load_new_mm_cr3+0x82/0xe0 RSP: 0018:ffffc9000489fa98 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 8000000105393004 RCX: 0000000000000027 RDX: 0000000000000027 RSI: 00000000ffffdfff RDI: ffff888277d1b788 RBP: 0000000000000004 R08: ffff888277d1b780 R09: ffffc9000489f8b8 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88810678a800 R14: 0000000000000004 R15: 0000000000000c33 FS: 00007fa9f0e72700(0000) GS:ffff888277d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001001b5003 CR4: 0000000000172ea0 Call Trace: <TASK> switch_mm_irqs_off+0x1cb/0x460 __text_poke+0x308/0x3e0 text_poke_bp_batch+0x168/0x220 text_poke_finish+0x1b/0x30 arch_jump_label_transform_apply+0x18/0x30 static_key_slow_inc_cpuslocked+0x7c/0x90 static_key_slow_inc+0x16/0x20 kvm_lapic_set_base+0x116/0x190 kvm_set_apic_base+0xa5/0xe0 kvm_set_msr_common+0x2f4/0xf60 vmx_set_msr+0x355/0xe70 [kvm_intel] kvm_set_msr_ignored_check+0x91/0x230 kvm_emulate_wrmsr+0x36/0x120 vmx_handle_exit+0x609/0x6c0 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x146f/0x1b80 kvm_vcpu_ioctl+0x279/0x690 __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK> ---[ end trace 0000000000000000 ]--- This reverts commit 15ad9762d69fd8e40a4a51828c1d6b0c1b8fbea0. Fixes: 15ad9762d69f ("KVM: VMX: Save HOST_CR3 in vmx_prepare_switch_to_guest()") Reported-by: Wanpeng Li <kernellwp@gmail.com> Cc: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Lai Jiangshan <jiangshanlai@gmail.com> Message-Id: <20220224191917.3508476-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-25Revert "KVM: VMX: Save HOST_CR3 in vmx_set_host_fs_gs()"Sean Christopherson1-9/+11
Undo a nested VMX fix as a step toward reverting the commit it fixed, 15ad9762d69f ("KVM: VMX: Save HOST_CR3 in vmx_prepare_switch_to_guest()"), as the underlying premise that "host CR3 in the vcpu thread can only be changed when scheduling" is wrong. This reverts commit a9f2705ec84449e3b8d70c804766f8e97e23080d. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220224191917.3508476-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18KVM: x86: return 1 unconditionally for availability of KVM_CAP_VAPICPaolo Bonzini1-6/+0
The two ioctls used to implement userspace-accelerated TPR, KVM_TPR_ACCESS_REPORTING and KVM_SET_VAPIC_ADDR, are available even if hardware-accelerated TPR can be used. So there is no reason not to report KVM_CAP_VAPIC. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: VMX: Use local pointer to vcpu_vmx in vmx_vcpu_after_set_cpuid()Oliver Upton1-2/+2
There is a local that contains a pointer to vcpu_vmx already. Just use that instead to get at the structure directly instead of doing pointer arithmetic. No functional change intended. Signed-off-by: Oliver Upton <oupton@google.com> Message-Id: <20220204204705.3538240-8-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: VMX: Dont' send posted IRQ if vCPU == this vCPU and vCPU is IN_GUEST_MODEWanpeng Li1-19/+21
When delivering a virtual interrupt, don't actually send a posted interrupt if the target vCPU is also the currently running vCPU and is IN_GUEST_MODE, in which case the interrupt is being sent from a VM-Exit fastpath and the core run loop in vcpu_enter_guest() will manually move the interrupt from the PIR to vmcs.GUEST_RVI. IRQs are disabled while IN_GUEST_MODE, thus there's no possibility of the virtual interrupt being sent from anything other than KVM, i.e. KVM won't suppress a wake event from an IRQ handler (see commit fdba608f15e2, "KVM: VMX: Wake vCPU when delivering posted IRQ even if vCPU == this vCPU"). Eliding the posted interrupt restores the performance provided by the combination of commits 379a3c8ee444 ("KVM: VMX: Optimize posted-interrupt delivery for timer fastpath") and 26efe2fd92e5 ("KVM: VMX: Handle preemption timer fastpath"). Thanks Sean for better comments. Suggested-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1643111979-36447-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: VMX: Rename VMX functions to conform to kvm_x86_ops namesSean Christopherson1-13/+13
Massage VMX's implementation names for kvm_x86_ops to maximize use of kvm-x86-ops.h. Leave cpu_has_vmx_wbinvd_exit() as-is to preserve the cpu_has_vmx_*() pattern used for querying VMCS capabilities. Keep pi_has_pending_interrupt() as vmx_dy_apicv_has_pending_interrupt() does a poor job of describing exactly what is being checked in VMX land. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: VMX: Call vmx_get_cpl() directly in handle_dr()Sean Christopherson1-1/+1
Use vmx_get_cpl() instead of bouncing through kvm_x86_ops.get_cpl() when performing a CPL check on MOV DR accesses. This avoids a RETPOLINE (when enabled), and more importantly removes a vendor reference to kvm_x86_ops and helps pave the way for unexporting kvm_x86_ops. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: x86: Rename kvm_x86_ops pointers to align w/ preferred vendor namesSean Christopherson1-10/+10
Rename a variety of kvm_x86_op function pointers so that preferred name for vendor implementations follows the pattern <vendor>_<function>, e.g. rename .run() to .vcpu_run() to match {svm,vmx}_vcpu_run(). This will allow vendor implementations to be wired up via the KVM_X86_OP macro. In many cases, VMX and SVM "disagree" on the preferred name, though in reality it's VMX and x86 that disagree as SVM blindly prepended _svm to the kvm_x86_ops name. Justification for using the VMX nomenclature: - set_{irq,nmi} => inject_{irq,nmi} because the helper is injecting an event that has already been "set" in e.g. the vIRR. SVM's relevant VMCB field is even named event_inj, and KVM's stat is irq_injections. - prepare_guest_switch => prepare_switch_to_guest because the former is ambiguous, e.g. it could mean switching between multiple guests, switching from the guest to host, etc... - update_pi_irte => pi_update_irte to allow for matching match the rest of VMX's posted interrupt naming scheme, which is vmx_pi_<blah>(). - start_assignment => pi_start_assignment to again follow VMX's posted interrupt naming scheme, and to provide context for what bit of code might care about an otherwise undescribed "assignment". The "tlb_flush" => "flush_tlb" creates an inconsistency with respect to Hyper-V's "tlb_remote_flush" hooks, but Hyper-V really is the one that's wrong. x86, VMX, and SVM all use flush_tlb, and even common KVM is on a variant of the bandwagon with "kvm_flush_remote_tlbs", e.g. a more appropriate name for the Hyper-V hooks would be flush_remote_tlbs. Leave that change for another time as the Hyper-V hooks always start as NULL, i.e. the name doesn't matter for using kvm-x86-ops.h, and changing all names requires an astounding amount of churn. VMX and SVM function names are intentionally left as is to minimize the diff. Both VMX and SVM will need to rename even more functions in order to fully utilize KVM_X86_OPS, i.e. an additional patch for each is inevitable. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: nSVM/nVMX: set nested_run_pending on VM entry which is a result of RSMMaxim Levitsky1-0/+1
While RSM induced VM entries are not full VM entries, they still need to be followed by actual VM entry to complete it, unlike setting the nested state. This patch fixes boot of hyperv and SMM enabled windows VM running nested on KVM, which fail due to this issue combined with lack of dirty bit setting. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Cc: stable@vger.kernel.org Message-Id: <20220207155447.840194-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-05Merge tag 'kvmarm-fixes-5.17-2' of ↵Paolo Bonzini1-1/+24
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.17, take #2 - A couple of fixes when handling an exception while a SError has been delivered - Workaround for Cortex-A510's single-step[ erratum
2022-02-01kvm/x86: rework guest entry logicMark Rutland1-2/+2
For consistency and clarity, migrate x86 over to the generic helpers for guest timing and lockdep/RCU/tracing management, and remove the x86-specific helpers. Prior to this patch, the guest timing was entered in kvm_guest_enter_irqoff() (called by svm_vcpu_enter_exit() and svm_vcpu_enter_exit()), and was exited by the call to vtime_account_guest_exit() within vcpu_enter_guest(). To minimize duplication and to more clearly balance entry and exit, both entry and exit of guest timing are placed in vcpu_enter_guest(), using the new guest_timing_{enter,exit}_irqoff() helpers. When context tracking is used a small amount of additional time will be accounted towards guests; tick-based accounting is unnaffected as IRQs are disabled at this point and not enabled until after the return from the guest. This also corrects (benign) mis-balanced context tracking accounting introduced in commits: ae95f566b3d22ade ("KVM: X86: TSCDEADLINE MSR emulation fastpath") 26efe2fd92e50822 ("KVM: VMX: Handle preemption timer fastpath") Where KVM can enter a guest multiple times, calling vtime_guest_enter() without a corresponding call to vtime_account_guest_exit(), and with vtime_account_system() called when vtime_account_guest() should be used. As account_system_time() checks PF_VCPU and calls account_guest_time(), this doesn't result in any functional problem, but is unnecessarily confusing. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Message-Id: <20220201132926.3301912-4-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01KVM: x86: Move delivery of non-APICv interrupt into vendor codeSean Christopherson1-1/+16
Handle non-APICv interrupt delivery in vendor code, even though it means VMX and SVM will temporarily have duplicate code. SVM's AVIC has a race condition that requires KVM to fall back to legacy interrupt injection _after_ the interrupt has been logged in the vIRR, i.e. to fix the race, SVM will need to open code the full flow anyways[*]. Refactor the code so that the SVM bug without introducing other issues, e.g. SVM would return "success" and thus invoke trace_kvm_apicv_accept_irq() even when delivery through the AVIC failed, and to opportunistically prepare for using KVM_X86_OP to fill each vendor's kvm_x86_ops struct, which will rely on the vendor function matching the kvm_x86_op pointer name. No functional change intended. [*] https://lore.kernel.org/all/20211213104634.199141-4-mlevitsk@redhat.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>