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path: root/arch/x86/kvm/vmx/evmcs.h
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2020-02-05x86/kvm/hyper-v: don't allow to turn on unsupported VMX controls for nested ↵Vitaly Kuznetsov
guests Sane L1 hypervisors are not supposed to turn any of the unsupported VMX controls on for its guests and nested_vmx_check_controls() checks for that. This is, however, not the case for the controls which are supported on the host but are missing in enlightened VMCS and when eVMCS is in use. It would certainly be possible to add these missing checks to nested_check_vm_execution_controls()/_vm_exit_controls()/.. but it seems preferable to keep eVMCS-specific stuff in eVMCS and reduce the impact on non-eVMCS guests by doing less unrelated checks. Create a separate nested_evmcs_check_controls() for this purpose. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-05x86/kvm/hyper-v: move VMX controls sanitization out of nested_enable_evmcs()Vitaly Kuznetsov
With fine grained VMX feature enablement QEMU>=4.2 tries to do KVM_SET_MSRS with default (matching CPU model) values and in case eVMCS is also enabled, fails. It would be possible to drop VMX feature filtering completely and make this a guest's responsibility: if it decides to use eVMCS it should know which fields are available and which are not. Hyper-V mostly complies to this, however, there are some problematic controls: SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES VM_{ENTRY,EXIT}_LOAD_IA32_PERF_GLOBAL_CTRL which Hyper-V enables. As there are no corresponding fields in eVMCS, we can't handle this properly in KVM. This is a Hyper-V issue. Move VMX controls sanitization from nested_enable_evmcs() to vmx_get_msr(), and do the bare minimum (only clear controls which are known to cause issues). This allows userspace to keep setting controls it wants and at the same time hides them from the guest. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-24KVM/Hyper-V/VMX: Add direct tlb flush supportVitaly Kuznetsov
Hyper-V provides direct tlb flush function which helps L1 Hypervisor to handle Hyper-V tlb flush request from L2 guest. Add the function support for VMX. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-02x86/kvm/nVMX: fix VMCLEAR when Enlightened VMCS is in useVitaly Kuznetsov
When Enlightened VMCS is in use, it is valid to do VMCLEAR and, according to TLFS, this should "transition an enlightened VMCS from the active to the non-active state". It is, however, wrong to assume that it is only valid to do VMCLEAR for the eVMCS which is currently active on the vCPU performing VMCLEAR. Currently, the logic in handle_vmclear() is broken: in case, there is no active eVMCS on the vCPU doing VMCLEAR we treat the argument as a 'normal' VMCS and kvm_vcpu_write_guest() to the 'launch_state' field irreversibly corrupts the memory area. So, in case the VMCLEAR argument is not the current active eVMCS on the vCPU, how can we know if the area it is pointing to is a normal or an enlightened VMCS? Thanks to the bug in Hyper-V (see commit 72aeb60c52bf7 ("KVM: nVMX: Verify eVMCS revision id match supported eVMCS version on eVMCS VMPTRLD")) we can not, the revision can't be used to distinguish between them. So let's assume it is always enlightened in case enlightened vmentry is enabled in the assist page. Also, check if vmx->nested.enlightened_vmcs_enabled to minimize the impact for 'unenlightened' workloads. Fixes: b8bbab928fb1 ("KVM: nVMX: implement enlightened VMPTRLD and VMCLEAR") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helperVitaly Kuznetsov
The upcoming KVM_GET_SUPPORTED_HV_CPUID ioctl will need to return Enlightened VMCS version in HYPERV_CPUID_NESTED_FEATURES.EAX when it was enabled. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: VMX: Move eVMCS code to dedicated filesSean Christopherson
The header, evmcs.h, already exists and contains a fair amount of code, but there are a few pieces in vmx.c that can be moved verbatim. In addition, move an array definition to evmcs.c to prepare for multiple consumers of evmcs.h. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: VMX: Drop the "vmx" prefix from vmx_evmcs.hSean Christopherson
VMX specific files now reside in a dedicated subdirectory, i.e. the file name prefix is redundant. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>