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2022-04-02KVM: x86: Make APICv inhibit reasons an enum and cleanup namingSean Christopherson
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>
2022-04-02KVM: SVM: Fix kvm_cache_regs.h inclusions for is_guest_mode()Peter Gonda
Include kvm_cache_regs.h to pick up the definition of is_guest_mode(), which is referenced by nested_svm_virtualize_tpr() in svm.h. Remove include from svm_onhpyerv.c which was done only because of lack of include in svm.h. Fixes: 883b0a91f41ab ("KVM: SVM: Move Nested SVM Implementation to nested.c") Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Peter Gonda <pgonda@google.com> Message-Id: <20220304161032.2270688-1-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-08KVM: SVM: Allow AVIC support on system w/ physical APIC ID > 255Suravee Suthikulpanit
Expand KVM's mask for the AVIC host physical ID to the full 12 bits defined by the architecture. The number of bits consumed by hardware is model specific, e.g. early CPUs ignored bits 11:8, but there is no way for KVM to enumerate the "true" size. So, KVM must allow using all bits, else it risks rejecting completely legal x2APIC IDs on newer CPUs. This means KVM relies on hardware to not assign x2APIC IDs that exceed the "true" width of the field, but presumably hardware is smart enough to tie the width to the max x2APIC ID. KVM also relies on hardware to support at least 8 bits, as the legacy xAPIC ID is writable by software. But, those assumptions are unavoidable due to the lack of any way to enumerate the "true" width. Cc: stable@vger.kernel.org Cc: Maxim Levitsky <mlevitsk@redhat.com> Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Fixes: 44a95dae1d22 ("KVM: x86: Detect and Initialize AVIC support") Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Message-Id: <20220211000851.185799-1-suravee.suthikulpanit@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-01KVM: SVM: Disable preemption across AVIC load/put during APICv refreshSean Christopherson
Disable preemption when loading/putting the AVIC during an APICv refresh. If the vCPU task is preempted and migrated ot a different pCPU, the unprotected avic_vcpu_load() could set the wrong pCPU in the physical ID cache/table. Pull the necessary code out of avic_vcpu_{,un}blocking() and into a new helper to reduce the probability of introducing this exact bug a third time. Fixes: df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC") Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18KVM: x86: make several APIC virtualization callbacks optionalPaolo Bonzini
All their invocations are conditional on vcpu->arch.apicv_active, meaning that they need not be implemented by vendor code: even though at the moment both vendors implement APIC virtualization, all of them can be optional. In fact SVM does not need many of them, and their implementation can be deleted now. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18KVM: SEV: Allow SEV intra-host migration of VM with mirrorsPeter Gonda
For SEV-ES VMs with mirrors to be intra-host migrated they need to be able to migrate with the mirror. This is due to that fact that all VMSAs need to be added into the VM with LAUNCH_UPDATE_VMSA before lAUNCH_FINISH. Allowing migration with mirrors allows users of SEV-ES to keep the mirror VMs VMSAs during migration. Adds a list of mirror VMs for the original VM iterate through during its migration. During the iteration the owner pointers can be updated from the source to the destination. This fixes the ASID leaking issue which caused the blocking of migration of VMs with mirrors. Signed-off-by: Peter Gonda <pgonda@google.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Message-Id: <20220211193634.3183388-1-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-14KVM: SVM: Rename AVIC helpers to use "avic" prefix instead of "svm"Sean Christopherson
Use "avic" instead of "svm" for SVM's all of APICv hooks and make a few additional funciton name tweaks so that the AVIC functions conform to their associated kvm_x86_ops hooks. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-19-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-14Merge remote-tracking branch 'kvm/master' into HEADPaolo Bonzini
Merge bugfix patches from Linux 5.17-rc.
2022-02-11KVM: SVM: fix race between interrupt delivery and AVIC inhibitionMaxim Levitsky
If svm_deliver_avic_intr is called just after the target vcpu's AVIC got inhibited, it might read a stale value of vcpu->arch.apicv_active which can lead to the target vCPU not noticing the interrupt. To fix this use load-acquire/store-release so that, if the target vCPU is IN_GUEST_MODE, we're guaranteed to see a previous disabling of the AVIC. If AVIC has been disabled in the meanwhile, proceed with the KVM_REQ_EVENT-based delivery. Incomplete IPI vmexit has the same races as svm_deliver_avic_intr, and in fact it can be handled in exactly the same way; the only difference lies in who has set IRR, whether svm_deliver_interrupt or the processor. Therefore, svm_complete_interrupt_delivery can be used to fix incomplete IPI vmexits as well. Co-developed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: nSVM: Implement Enlightened MSR-Bitmap featureVitaly Kuznetsov
Similar to nVMX commit 502d2bf5f2fd ("KVM: nVMX: Implement Enlightened MSR Bitmap feature"), add support for the feature for nSVM (Hyper-V on KVM). Notable differences from nVMX implementation: - As the feature uses SW reserved fields in VMCB control, KVM needs to make sure it's dealing with a Hyper-V guest (kvm_hv_hypercall_enabled()). - 'msrpm_base_pa' needs to be always be overwritten in nested_svm_vmrun_msrpm(), even when the update is skipped. As an optimization, nested_vmcb02_prepare_control() copies it from VMCB01 so when MSR-Bitmap feature for L2 is disabled nothing needs to be done. - 'struct vmcb_ctrl_area_cached' needs to be extended with clean fields/sw reserved data and __nested_copy_vmcb_control_to_cache() needs to copy it so nested_svm_vmrun_msrpm() can use it later. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20220202095100.129834-5-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be rebuiltVitaly Kuznetsov
Similar to nVMX commit ed2a4800ae9d ("KVM: nVMX: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt"), introduce a flag to keep track of whether MSR bitmap for L2 needs to be rebuilt due to changes in MSR bitmap for L1 or switching to a different L2. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20220202095100.129834-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Rename hook implementations to conform to kvm_x86_ops' namesSean Christopherson
Massage SVM's implementation names that still diverge from kvm_x86_ops to allow for wiring up all SVM-defined functions via kvm-x86-ops.h. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-22-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Rename SEV implemenations to conform to kvm_x86_ops hooksSean Christopherson
Rename svm_vm_copy_asid_from() and svm_vm_migrate_from() to conform to the names used by kvm_x86_ops, and opportunistically use "sev" instead of "svm" to more precisely identify the role of the hooks. svm_vm_copy_asid_from() in particular was poorly named as the function does much more than simply copy the ASID. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-21-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: x86: Use more verbose names for mem encrypt kvm_x86_ops hooksSean Christopherson
Use slightly more verbose names for the so called "memory encrypt", a.k.a. "mem enc", kvm_x86_ops hooks to bridge the gap between the current super short kvm_x86_ops names and SVM's more verbose, but non-conforming names. This is a step toward using kvm-x86-ops.h with KVM_X86_CVM_OP() to fill svm_x86_ops. Opportunistically rename mem_enc_op() to mem_enc_ioctl() to better reflect its true nature, as it really is a full fledged ioctl() of its own. Ideally, the hook would be named confidential_vm_ioctl() or so, as the ioctl() is a gateway to more than just memory encryption, and because its underlying purpose to support Confidential VMs, which can be provided without memory encryption, e.g. if the TCB of the guest includes the host kernel but not host userspace, or by isolation in hardware without encrypting memory. But, diverging from KVM_MEMORY_ENCRYPT_OP even further is undeseriable, and short of creating alises for all related ioctl()s, which introduces a different flavor of divergence, KVM is stuck with the nomenclature. Defer renaming SVM's functions to a future commit as there are additional changes needed to make SVM fully conforming and to match reality (looking at you, svm_vm_copy_asid_from()). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-20-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Rename svm_flush_tlb() to svm_flush_tlb_current()Sean Christopherson
Rename svm_flush_tlb() to svm_flush_tlb_current() so that at least one of the flushing operations in svm_x86_ops can be filled via kvm-x86-ops.h, and to document the scope of the flush (specifically that it doesn't flush "all"). Opportunistically make svm_tlb_flush_current(), was svm_flush_tlb(), static. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-17-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: improve split between svm_prepare_guest_switch and ↵Paolo Bonzini
sev_es_prepare_guest_switch KVM performs the VMSAVE to the host save area for both regular and SEV-ES guests, so hoist it up to svm_prepare_guest_switch. And because sev_es_prepare_guest_switch does not really need to know the details of struct svm_cpu_data *, just pass it the pointer to the host save area inside the HSAVE page. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: SVM: move avic definitions from AMD's spec to svm.hMaxim Levitsky
asm/svm.h is the correct place for all values that are defined in the SVM spec, and that includes AVIC. Also add some values from the spec that were not defined before and will be soon useful. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220207155447.840194-10-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: x86: Forcibly leave nested virt when SMM state is toggledSean Christopherson
Forcibly leave nested virtualization operation if userspace toggles SMM state via KVM_SET_VCPU_EVENTS or KVM_SYNC_X86_EVENTS. If userspace forces the vCPU out of SMM while it's post-VMXON and then injects an SMI, vmx_enter_smm() will overwrite vmx->nested.smm.vmxon and end up with both vmxon=false and smm.vmxon=false, but all other nVMX state allocated. Don't attempt to gracefully handle the transition as (a) most transitions are nonsencial, e.g. forcing SMM while L2 is running, (b) there isn't sufficient information to handle all transitions, e.g. SVM wants access to the SMRAM save state, and (c) KVM_SET_VCPU_EVENTS must precede KVM_SET_NESTED_STATE during state restore as the latter disallows putting the vCPU into L2 if SMM is active, and disallows tagging the vCPU as being post-VMXON in SMM if SMM is not active. Abuse of KVM_SET_VCPU_EVENTS manifests as a WARN and memory leak in nVMX due to failure to free vmcs01's shadow VMCS, but the bug goes far beyond just a memory leak, e.g. toggling SMM on while L2 is active puts the vCPU in an architecturally impossible state. WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline] WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656 Modules linked in: CPU: 1 PID: 3606 Comm: syz-executor725 Not tainted 5.17.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline] RIP: 0010:free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656 Code: <0f> 0b eb b3 e8 8f 4d 9f 00 e9 f7 fe ff ff 48 89 df e8 92 4d 9f 00 Call Trace: <TASK> kvm_arch_vcpu_destroy+0x72/0x2f0 arch/x86/kvm/x86.c:11123 kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 [inline] kvm_destroy_vcpus+0x11f/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:460 kvm_free_vcpus arch/x86/kvm/x86.c:11564 [inline] kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:11676 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1217 [inline] kvm_put_kvm+0x4fa/0xb00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1250 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1273 __fput+0x286/0x9f0 fs/file_table.c:311 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xb29/0x2a30 kernel/exit.c:806 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 get_signal+0x4b0/0x28c0 kernel/signal.c:2862 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK> Cc: stable@vger.kernel.org Reported-by: syzbot+8112db3ab20e70d50c31@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220125220358.2091737-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: drop unnecessary code in svm_hv_vmcb_dirty_nested_enlightenments()Vitaly Kuznetsov
Commit 3fa5e8fd0a0e4 ("KVM: SVM: delay svm_vcpu_init_msrpm after svm->vmcb is initialized") re-arranged svm_vcpu_init_msrpm() call in svm_create_vcpu(), thus making the comment about vmcb being NULL obsolete. Drop it. While on it, drop superfluous vmcb_is_clean() check: vmcb_mark_dirty() is a bit flip, an extra check is unlikely to bring any performance gain. Drop now-unneeded vmcb_is_clean() helper as well. Fixes: 3fa5e8fd0a0e4 ("KVM: SVM: delay svm_vcpu_init_msrpm after svm->vmcb is initialized") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20211220152139.418372-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Nullify vcpu_(un)blocking() hooks if AVIC is disabledSean Christopherson
Nullify svm_x86_ops.vcpu_(un)blocking if AVIC/APICv is disabled as the hooks are necessary only to clear the vCPU's IsRunning entry in the Physical APIC and to update IRTE entries if the VM has a pass-through device attached. Opportunistically rename the helpers to clarify their AVIC relationship. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-24-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Use kvm_vcpu_is_blocking() in AVIC load to handle preemptionSean Christopherson
Use kvm_vcpu_is_blocking() to determine whether or not the vCPU should be marked running during avic_vcpu_load(). Drop avic_is_running, which really should have been named "vcpu_is_not_blocking", as it tracked if the vCPU was blocking, not if it was actually running, e.g. it was set during svm_create_vcpu() when the vCPU was obviously not running. This is technically a teeny tiny functional change, as the vCPU will be marked IsRunning=1 on being reloaded if the vCPU is preempted between svm_vcpu_blocking() and prepare_to_rcuwait(). But that's a benign change as the vCPU will be marked IsRunning=0 when KVM voluntarily schedules out the vCPU. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Don't bother checking for "running" AVIC when kicking for IPIsSean Christopherson
Drop the avic_vcpu_is_running() check when waking vCPUs in response to a VM-Exit due to incomplete IPI delivery. The check isn't wrong per se, but it's not 100% accurate in the sense that it doesn't guarantee that the vCPU was one of the vCPUs that didn't receive the IPI. The check isn't required for correctness as blocking == !running in this context. From a performance perspective, waking a live task is not expensive as the only moderately costly operation is a locked operation to temporarily disable preemption. And if that is indeed a performance issue, kvm_vcpu_is_blocking() would be a better check than poking into the AVIC. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20211208015236.1616697-12-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-17KVM: x86: Making the module parameter of vPMU more commonLike Xu
The new module parameter to control PMU virtualization should apply to Intel as well as AMD, for situations where userspace is not trusted. If the module parameter allows PMU virtualization, there could be a new KVM_CAP or guest CPUID bits whereby userspace can enable/disable PMU virtualization on a per-VM basis. If the module parameter does not allow PMU virtualization, there should be no userspace override, since we have no precedent for authorizing that kind of override. If it's false, other counter-based profiling features (such as LBR including the associated CPUID bits if any) will not be exposed. Change its name from "pmu" to "enable_pmu" as we have temporary variables with the same name in our code like "struct kvm_pmu *pmu". Fixes: b1d66dad65dc ("KVM: x86/svm: Add module param to control PMU virtualization") Suggested-by : Jim Mattson <jmattson@google.com> Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20220111073823.21885-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: vmx, svm: clean up mass updates to regs_avail/regs_dirty bitsPaolo Bonzini
Document the meaning of the three combinations of regs_avail and regs_dirty. Update regs_dirty just after writeback instead of doing it later after vmexit. After vmexit, instead, we clear the regs_avail bits corresponding to lazily-loaded registers. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: x86/svm: Add module param to control PMU virtualizationLike Xu
For Intel, the guest PMU can be disabled via clearing the PMU CPUID. For AMD, all hw implementations support the base set of four performance counters, with current mainstream hardware indicating the presence of two additional counters via X86_FEATURE_PERFCTR_CORE. In the virtualized world, the AMD guest driver may detect the presence of at least one counter MSR. Most hypervisor vendors would introduce a module param (like lbrv for svm) to disable PMU for all guests. Another control proposal per-VM is to pass PMU disable information via MSR_IA32_PERF_CAPABILITIES or one bit in CPUID Fn4000_00[FF:00]. Both of methods require some guest-side changes, so a module parameter may not be sufficiently granular, but practical enough. Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20211117080304.38989-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: introduce struct vmcb_ctrl_area_cachedEmanuele Giuseppe Esposito
This structure will replace vmcb_control_area in svm_nested_state, providing only the fields that are actually used by the nested state. This avoids having and copying around uninitialized fields. The cost of this, however, is that all functions (in this case vmcb_is_intercept) expect the old structure, so they need to be duplicated. In addition, in svm_get_nested_state() user space expects a vmcb_control_area struct, so we need to copy back all fields in a temporary structure before copying it to userspace. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20211103140527.752797-7-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: rename nested_load_control_from_vmcb12 in ↵Emanuele Giuseppe Esposito
nested_copy_vmcb_control_to_cache Following the same naming convention of the previous patch, rename nested_load_control_from_vmcb12. In addition, inline copy_vmcb_control_area as it is only called by this function. __nested_copy_vmcb_control_to_cache() works with vmcb_control_area parameters and it will be useful in next patches, when we use local variables instead of svm cached state. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20211103140527.752797-4-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: introduce svm->nested.save to cache save area before checksEmanuele Giuseppe Esposito
This is useful in the next patch, to keep a saved copy of vmcb12 registers and pass it around more easily. Instead of blindly copying everything, we just copy EFER, CR0, CR3, CR4, DR6 and DR7 which are needed by the VMRUN checks. If more fields will need to be checked, it will be quite obvious to see that they must be added in struct vmcb_save_area_cached and in nested_copy_vmcb_save_to_cache(). __nested_copy_vmcb_save_to_cache() takes a vmcb_save_area_cached parameter, which is useful in order to save the state to a local variable. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20211103140527.752797-3-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: SEV: Prohibit migration of a VM that has mirrorsPaolo Bonzini
VMs that mirror an encryption context rely on the owner to keep the ASID allocated. Performing a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM would cause a dangling ASID: 1. copy context from A to B (gets ref to A) 2. move context from A to L (moves ASID from A to L) 3. close L (releases ASID from L, B still references it) The right way to do the handoff instead is to create a fresh mirror VM on the destination first: 1. copy context from A to B (gets ref to A) [later] 2. close B (releases ref to A) 3. move context from A to L (moves ASID from A to L) 4. copy context from L to M So, catch the situation by adding a count of how many VMs are mirroring this one's encryption context. Fixes: 0b020f5af092 ("KVM: SEV: Add support for SEV-ES intra host migration") Message-Id: <20211123005036.2954379-11-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18Merge branch 'kvm-5.16-fixes' into kvm-masterPaolo Bonzini
* Fixes for Xen emulation * Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache * Fixes for migration of 32-bit nested guests on 64-bit hypervisor * Compilation fixes * More SEV cleanups
2021-11-18KVM: SEV: WARN if SEV-ES is marked active but SEV is notSean Christopherson
WARN if the VM is tagged as SEV-ES but not SEV. KVM relies on SEV and SEV-ES being set atomically, and guards common flows with "is SEV", i.e. observing SEV-ES without SEV means KVM has a fatal bug. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109215101.2211373-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11Merge branch 'kvm-sev-move-context' into kvm-masterPaolo Bonzini
Add support for AMD SEV and SEV-ES intra-host migration support. Intra host migration provides a low-cost mechanism for userspace VMM upgrades. In the common case for intra host migration, we can rely on the normal ioctls for passing data from one VMM to the next. SEV, SEV-ES, and other confidential compute environments make most of this information opaque, and render KVM ioctls such as "KVM_GET_REGS" irrelevant. As a result, we need the ability to pass this opaque metadata from one VMM to the next. The easiest way to do this is to leave this data in the kernel, and transfer ownership of the metadata from one KVM VM (or vCPU) to the next. In-kernel hand off makes it possible to move any data that would be unsafe/impossible for the kernel to hand directly to userspace, and cannot be reproduced using data that can be handed to userspace. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: SEV: Add support for SEV intra host migrationPeter Gonda
For SEV to work with intra host migration, contents of the SEV info struct such as the ASID (used to index the encryption key in the AMD SP) and the list of memory regions need to be transferred to the target VM. This change adds a commands for a target VMM to get a source SEV VM's sev info. Signed-off-by: Peter Gonda <pgonda@google.com> Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Message-Id: <20211021174303.385706-3-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: SEV: Refactor out sev_es_state structPeter Gonda
Move SEV-ES vCPU metadata into new sev_es_state struct from vcpu_svm. Signed-off-by: Peter Gonda <pgonda@google.com> Suggested-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Message-Id: <20211021174303.385706-2-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - More progress on the protected VM front, now with the full fixed feature set as well as the limitation of some hypercalls after initialisation. - Cleanup of the RAZ/WI sysreg handling, which was pointlessly complicated - Fixes for the vgic placement in the IPA space, together with a bunch of selftests - More memcg accounting of the memory allocated on behalf of a guest - Timer and vgic selftests - Workarounds for the Apple M1 broken vgic implementation - KConfig cleanups - New kvmarm.mode=none option, for those who really dislike us RISC-V: - New KVM port. x86: - New API to control TSC offset from userspace - TSC scaling for nested hypervisors on SVM - Switch masterclock protection from raw_spin_lock to seqcount - Clean up function prototypes in the page fault code and avoid repeated memslot lookups - Convey the exit reason to userspace on emulation failure - Configure time between NX page recovery iterations - Expose Predictive Store Forwarding Disable CPUID leaf - Allocate page tracking data structures lazily (if the i915 KVM-GT functionality is not compiled in) - Cleanups, fixes and optimizations for the shadow MMU code s390: - SIGP Fixes - initial preparations for lazy destroy of secure VMs - storage key improvements/fixes - Log the guest CPNC Starting from this release, KVM-PPC patches will come from Michael Ellerman's PPC tree" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits) RISC-V: KVM: fix boolreturn.cocci warnings RISC-V: KVM: remove unneeded semicolon RISC-V: KVM: Fix GPA passed to __kvm_riscv_hfence_gvma_xyz() functions RISC-V: KVM: Factor-out FP virtualization into separate sources KVM: s390: add debug statement for diag 318 CPNC data KVM: s390: pv: properly handle page flags for protected guests KVM: s390: Fix handle_sske page fault handling KVM: x86: SGX must obey the KVM_INTERNAL_ERROR_EMULATION protocol KVM: x86: On emulation failure, convey the exit reason, etc. to userspace KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info KVM: x86: Clarify the kvm_run.emulation_failure structure layout KVM: s390: Add a routine for setting userspace CPU state KVM: s390: Simplify SIGP Set Arch handling KVM: s390: pv: avoid stalls when making pages secure KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm KVM: s390: pv: avoid double free of sida page KVM: s390: pv: add macros for UVC CC values s390/mm: optimize reset_guest_reference_bit() s390/mm: optimize set_guest_storage_key() s390/mm: no need for pte_alloc_map_lock() if we know the pmd is present ...
2021-11-01Merge tag 'objtool-core-2021-10-31' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Thomas Gleixner: - Improve retpoline code patching by separating it from alternatives which reduces memory footprint and allows to do better optimizations in the actual runtime patching. - Add proper retpoline support for x86/BPF - Address noinstr warnings in x86/kvm, lockdep and paravirtualization code - Add support to handle pv_opsindirect calls in the noinstr analysis - Classify symbols upfront and cache the result to avoid redundant str*cmp() invocations. - Add a CFI hash to reduce memory consumption which also reduces runtime on a allyesconfig by ~50% - Adjust XEN code to make objtool handling more robust and as a side effect to prevent text fragmentation due to placement of the hypercall page. * tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) bpf,x86: Respect X86_FEATURE_RETPOLINE* bpf,x86: Simplify computing label offsets x86,bugs: Unconditionally allow spectre_v2=retpoline,amd x86/alternative: Add debug prints to apply_retpolines() x86/alternative: Try inline spectre_v2=retpoline,amd x86/alternative: Handle Jcc __x86_indirect_thunk_\reg x86/alternative: Implement .retpoline_sites support x86/retpoline: Create a retpoline thunk array x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h x86/asm: Fixup odd GEN-for-each-reg.h usage x86/asm: Fix register order x86/retpoline: Remove unused replacement symbols objtool,x86: Replace alternatives with .retpoline_sites objtool: Shrink struct instruction objtool: Explicitly avoid self modifying code in .altinstr_replacement objtool: Classify symbols objtool: Support pv_opsindirect calls for noinstr x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays x86/xen: Mark xen_force_evtchn_callback() noinstr x86/xen: Make irq_disable() noinstr ...
2021-10-18KVM: SEV-ES: reduce ghcb_sa_len to 32 bitsPaolo Bonzini
The size of the GHCB scratch area is limited to 16 KiB (GHCB_SCRATCH_AREA_LIMIT), so there is no need for it to be a u64. This fixes a build error on 32-bit systems: i686-linux-gnu-ld: arch/x86/kvm/svm/sev.o: in function `sev_es_string_io: sev.c:(.text+0x110f): undefined reference to `__udivdi3' Cc: stable@vger.kernel.org Fixes: 019057bd73d1 ("KVM: SEV-ES: fix length of string I/O") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-07Merge branch 'objtool/urgent'Peter Zijlstra
Fixup conflicts. # Conflicts: # tools/objtool/check.c
2021-10-01KVM: x86: nSVM: implement nested TSC scalingMaxim Levitsky
This was tested by booting a nested guest with TSC=1Ghz, observing the clocks, and doing about 100 cycles of migration. Note that qemu patch is needed to support migration because of a new MSR that needs to be placed in the migration state. The patch will be sent to the qemu mailing list soon. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210914154825.104886-14-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: SVM: Move RESET emulation to svm_vcpu_reset()Sean Christopherson
Move RESET emulation for SVM vCPUs to svm_vcpu_reset(), and drop an extra init_vmcb() from svm_create_vcpu() in the process. Hopefully KVM will someday expose a dedicated RESET ioctl(), and in the meantime separating "create" from "RESET" is a nice cleanup. Keep the call to svm_switch_vmcb() so that misuse of svm->vmcb at worst breaks the guest, e.g. premature accesses doesn't cause a NULL pointer dereference. Cc: Reiji Watanabe <reijiw@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210921000303.400537-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: SVM: call KVM_REQ_GET_NESTED_STATE_PAGES on exit from SMM modeMaxim Levitsky
Currently the KVM_REQ_GET_NESTED_STATE_PAGES on SVM only reloads PDPTRs, and MSR bitmap, with former not really needed for SMM as SMM exit code reloads them again from SMRAM'S CR3, and later happens to work since MSR bitmap isn't modified while in SMM. Still it is better to be consistient with VMX. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-15x86/kvm: Always inline to_svm()Peter Zijlstra
vmlinux.o: warning: objtool: svm_vcpu_enter_exit()+0x13: call to to_svm() leaves .noinstr.text section Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210624095148.066347165@infradead.org
2021-09-15x86/kvm: Always inline sev_*guest()Peter Zijlstra
vmlinux.o: warning: objtool: svm_vcpu_enter_exit()+0x4d: call to sev_es_guest() leaves .noinstr.text section vmlinux.o: warning: objtool: svm_vcpu_enter_exit()+0x50: call to sev_guest() leaves .noinstr.text section Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210624095147.880513802@infradead.org
2021-08-20KVM: SVM: AVIC: drop unsupported AVIC base relocation codeMaxim Levitsky
APIC base relocation is not supported anyway and won't work correctly so just drop the code that handles it and keep AVIC MMIO bar at the default APIC base. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210810205251.424103-17-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20KVM: SVM: remove svm_toggle_avic_for_irq_windowMaxim Levitsky
Now that kvm_request_apicv_update doesn't need to drop the kvm->srcu lock, we can call kvm_request_apicv_update directly. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210810205251.424103-13-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-20KVM: x86: don't disable APICv memslot when inhibitedMaxim Levitsky
Thanks to the former patches, it is now possible to keep the APICv memslot always enabled, and it will be invisible to the guest when it is inhibited This code is based on a suggestion from Sean Christopherson: https://lkml.org/lkml/2021/7/19/2970 Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210810205251.424103-9-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-26KVM: nSVM: Swap the parameter order for ↵Vitaly Kuznetsov
svm_copy_vmrun_state()/svm_copy_vmloadsave_state() Make svm_copy_vmrun_state()/svm_copy_vmloadsave_state() interface match 'memcpy(dest, src)' to avoid any confusion. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210719090322.625277-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-26KVM: nSVM: Rename nested_svm_vmloadsave() to svm_copy_vmloadsave_state()Vitaly Kuznetsov
To match svm_copy_vmrun_state(), rename nested_svm_vmloadsave() to svm_copy_vmloadsave_state(). Opportunistically add missing braces to 'else' branch in vmload_vmsave_interception(). No functional change intended. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210716144104.465269-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-15KVM: nSVM: Restore nested control upon leaving SMMVitaly Kuznetsov
If the VM was migrated while in SMM, no nested state was saved/restored, and therefore svm_leave_smm has to load both save and control area of the vmcb12. Save area is already loaded from HSAVE area, so now load the control area as well from the vmcb12. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210628104425.391276-6-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-15KVM: nSVM: Introduce svm_copy_vmrun_state()Vitaly Kuznetsov
Separate the code setting non-VMLOAD-VMSAVE state from svm_set_nested_state() into its own function. This is going to be re-used from svm_enter_smm()/svm_leave_smm(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210628104425.391276-4-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>