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2022-12-29KVM: x86: Hyper-V invariant TSC controlVitaly Kuznetsov1-0/+27
Normally, genuine Hyper-V doesn't expose architectural invariant TSC (CPUID.80000007H:EDX[8]) to its guests by default. A special PV MSR (HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x40000118) and corresponding CPUID feature bit (CPUID.0x40000003.EAX[15]) were introduced. When bit 0 of the PV MSR is set, invariant TSC bit starts to show up in CPUID. When the feature is exposed to Hyper-V guests, reenlightenment becomes unneeded. Add the feature to KVM. Keep CPUID output intact when the feature wasn't exposed to L1 and implement the required logic for hiding invariant TSC when the feature was exposed and invariant TSC control MSR wasn't written to. Copy genuine Hyper-V behavior and forbid to disable the feature once it was enabled. For the reference, for linux guests, support for the feature was added in commit dce7cd62754b ("x86/hyperv: Allow guests to enable InvariantTSC"). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221013095849.705943-4-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: nSVM: hyper-v: Enable L2 TLB flushVitaly Kuznetsov1-0/+11
Implement Hyper-V L2 TLB flush for nSVM. The feature needs to be enabled both in extended 'nested controls' in VMCB and VP assist page. According to Hyper-V TLFS, synthetic vmexit to L1 is performed with - HV_SVM_EXITCODE_ENL exit_code. - HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH exit_info_1. Note: VP assist page is cached in 'struct kvm_vcpu_hv' so recalc_intercepts() doesn't need to read from guest's memory. KVM needs to update the case upon each VMRUN and after svm_set_nested_state (svm_get_nested_state_pages()) to handle the case when the guest got migrated while L2 was running. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-29-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: Make kvm_hv_get_assist_page() return 0/-errnoVitaly Kuznetsov1-1/+1
Convert kvm_hv_get_assist_page() to return 'int' and propagate possible errors from kvm_read_guest_cached(). Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-28-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: nVMX: hyper-v: Cache VP assist page in 'struct kvm_vcpu_hv'Vitaly Kuznetsov1-2/+1
In preparation to enabling L2 TLB flush, cache VP assist page in 'struct kvm_vcpu_hv'. While on it, rename nested_enlightened_vmentry() to nested_get_evmptr() and make it return eVMCS GPA directly. No functional change intended. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-26-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: hyper-v: Introduce fast guest_hv_cpuid_has_l2_tlb_flush() checkVitaly Kuznetsov1-0/+8
Introduce a helper to quickly check if KVM needs to handle VMCALL/VMMCALL from L2 in L0 to process L2 TLB flush requests. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-25-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: hyper-v: L2 TLB flushVitaly Kuznetsov1-3/+0
Handle L2 TLB flush requests by going through all vCPUs and checking whether there are vCPUs running the same VM_ID with a VP_ID specified in the requests. Perform synthetic exit to L2 upon finish. Note, while checking VM_ID/VP_ID of running vCPUs seem to be a bit racy, we count on the fact that KVM flushes the whole L2 VPID upon transition. Also, KVM_REQ_HV_TLB_FLUSH request needs to be done upon transition between L1 and L2 to make sure all pending requests are always processed. For the reference, Hyper-V TLFS refers to the feature as "Direct Virtual Flush". Note, nVMX/nSVM code does not handle VMCALL/VMMCALL from L2 yet. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-24-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: hyper-v: Introduce kvm_hv_is_tlb_flush_hcall()Vitaly Kuznetsov1-0/+17
The newly introduced helper checks whether vCPU is performing a Hyper-V TLB flush hypercall. This is required to filter out L2 TLB flush hypercalls for processing. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-23-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: hyper-v: Create a separate fifo for L2 TLB flushVitaly Kuznetsov1-3/+16
To handle L2 TLB flush requests, KVM needs to use a separate fifo from regular (L1) Hyper-V TLB flush requests: e.g. when a request to flush something in L2 is made, the target vCPU can transition from L2 to L1, receive a request to flush a GVA for L1 and then try to enter L2 back. The first request needs to be processed at this point. Similarly, requests to flush GVAs in L1 must wait until L2 exits to L1. No functional change as KVM doesn't handle L2 TLB flush requests from L2 yet. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-18-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-18KVM: x86: hyper-v: Introduce TLB flush fifoVitaly Kuznetsov1-0/+15
To allow flushing individual GVAs instead of always flushing the whole VPID a per-vCPU structure to pass the requests is needed. Use standard 'kfifo' to queue two types of entries: individual GVA (GFN + up to 4095 following GFNs in the lower 12 bits) and 'flush all'. The size of the fifo is arbitrarily set to '16'. Note, kvm_hv_flush_tlb() only queues 'flush all' entries for now and kvm_hv_vcpu_flush_tlb() doesn't actually read the fifo just resets the queue before returning -EOPNOTSUPP (which triggers full TLB flush) so the functional change is very small but the infrastructure is prepared to handle individual GVA flush requests. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221101145426.251680-10-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-26KVM: x86: Report error when setting CPUID if Hyper-V allocation failsSean Christopherson1-1/+5
Return -ENOMEM back to userspace if allocating the Hyper-V vCPU struct fails when enabling Hyper-V in guest CPUID. Silently ignoring failure means that KVM will not have an up-to-date CPUID cache if allocating the struct succeeds later on, e.g. when activating SynIC. Rejecting the CPUID operation also guarantess that vcpu->arch.hyperv is non-NULL if hyperv_enabled is true, which will allow for additional cleanup, e.g. in the eVMCS code. Note, the initialization needs to be done before CPUID is set, and more subtly before kvm_check_cpuid(), which potentially enables dynamic XFEATURES. Sadly, there's no easy way to avoid exposing Hyper-V details to CPUID or vice versa. Expose kvm_hv_vcpu_init() and the Hyper-V CPUID signature to CPUID instead of exposing cpuid_entry2_find() outside of CPUID code. It's hard to envision kvm_hv_vcpu_init() being misused, whereas cpuid_entry2_find() absolutely shouldn't be used outside of core CPUID code. Fixes: 10d7bf1e46dc ("KVM: x86: hyper-v: Cache guest CPUID leaves determining features availability") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20220830133737.1539624-6-vkuznets@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-11KVM: x86: hyper-v: Avoid writing to TSC page without an active vCPUVitaly Kuznetsov1-1/+1
The following WARN is triggered from kvm_vm_ioctl_set_clock(): WARNING: CPU: 10 PID: 579353 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:3161 mark_page_dirty_in_slot+0x6c/0x80 [kvm] ... CPU: 10 PID: 579353 Comm: qemu-system-x86 Tainted: G W O 5.16.0.stable #20 Hardware name: LENOVO 20UF001CUS/20UF001CUS, BIOS R1CET65W(1.34 ) 06/17/2021 RIP: 0010:mark_page_dirty_in_slot+0x6c/0x80 [kvm] ... Call Trace: <TASK> ? kvm_write_guest+0x114/0x120 [kvm] kvm_hv_invalidate_tsc_page+0x9e/0xf0 [kvm] kvm_arch_vm_ioctl+0xa26/0xc50 [kvm] ? schedule+0x4e/0xc0 ? __cond_resched+0x1a/0x50 ? futex_wait+0x166/0x250 ? __send_signal+0x1f1/0x3d0 kvm_vm_ioctl+0x747/0xda0 [kvm] ... The WARN was introduced by commit 03c0304a86bc ("KVM: Warn if mark_page_dirty() is called without an active vCPU") but the change seems to be correct (unlike Hyper-V TSC page update mechanism). In fact, there's no real need to actually write to guest memory to invalidate TSC page, this can be done by the first vCPU which goes through kvm_guest_time_update(). Reported-by: Maxim Levitsky <mlevitsk@redhat.com> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20220407201013.963226-1-vkuznets@redhat.com>
2022-02-10KVM: x86: Make kvm_hv_hypercall_enabled() static inlineVitaly Kuznetsov1-1/+5
In preparation for using kvm_hv_hypercall_enabled() from SVM code, make it static inline to avoid the need to export it. The function is a simple check with only two call sites currently. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20220202095100.129834-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: Query vcpu->vcpu_idx directly and drop its accessorSean Christopherson1-1/+1
Read vcpu->vcpu_idx directly instead of bouncing through the one-line wrapper, kvm_vcpu_get_idx(), and drop the wrapper. The wrapper is a remnant of the original implementation and serves no purpose; remove it before it gains more users. Back when kvm_vcpu_get_idx() was added by commit 497d72d80a78 ("KVM: Add kvm_vcpu_get_idx to get vcpu index in kvm->vcpus"), the implementation was more than just a simple wrapper as vcpu->vcpu_idx did not exist and retrieving the index meant walking over the vCPU array to find the given vCPU. When vcpu_idx was introduced by commit 8750e72a79dd ("KVM: remember position in kvm->vcpus array"), the helper was left behind, likely to avoid extra thrash (but even then there were only two users, the original arm usage having been removed at some point in the past). No functional change intended. Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210910183220.2397812-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17KVM: x86: hyper-v: Introduce KVM_CAP_HYPERV_ENFORCE_CPUIDVitaly Kuznetsov1-0/+1
Modeled after KVM_CAP_ENFORCE_PV_FEATURE_CPUID, the new capability allows for limiting Hyper-V features to those exposed to the guest in Hyper-V CPUIDs (0x40000003, 0x40000004, ...). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210521095204.2161214-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-17KVM: x86: hyper-v: Prevent using not-yet-updated TSC page by secondary CPUsVitaly Kuznetsov1-0/+1
When KVM_REQ_MASTERCLOCK_UPDATE request is issued (e.g. after migration) we need to make sure no vCPU sees stale values in PV clock structures and thus all vCPUs are kicked with KVM_REQ_CLOCK_UPDATE. Hyper-V TSC page clocksource is global and kvm_guest_time_update() only updates in on vCPU0 but this is not entirely correct: nothing blocks some other vCPU from entering the guest before we finish the update on CPU0 and it can read stale values from the page. Invalidate TSC page in kvm_gen_update_masterclock() to switch all vCPUs to using MSR based clocksource (HV_X64_MSR_TIME_REF_COUNT). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210316143736.964151-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Drop hv_vcpu_to_vcpu() helperVitaly Kuznetsov1-7/+4
hv_vcpu_to_vcpu() helper is only used by other helpers and is not very complex, we can drop it without much regret. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-16-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Allocate Hyper-V context lazilyVitaly Kuznetsov1-2/+0
Hyper-V context is only needed for guests which use Hyper-V emulation in KVM (e.g. Windows/Hyper-V guests) so we don't actually need to allocate it in kvm_arch_vcpu_create(), we can postpone the action until Hyper-V specific MSRs are accessed or SynIC is enabled. Once allocated, let's keep the context alive for the lifetime of the vCPU as an attempt to free it would require additional synchronization with other vCPUs and normally it is not supposed to happen. Note, Hyper-V style hypercall enablement is done by writing to HV_X64_MSR_GUEST_OS_ID so we don't need to worry about allocating Hyper-V context from kvm_hv_hypercall(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-15-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Make Hyper-V emulation enablement conditionalVitaly Kuznetsov1-1/+2
Hyper-V emulation is enabled in KVM unconditionally. This is bad at least from security standpoint as it is an extra attack surface. Ideally, there should be a per-VM capability explicitly enabled by VMM but currently it is not the case and we can't mandate one without breaking backwards compatibility. We can, however, check guest visible CPUIDs and only enable Hyper-V emulation when "Hv#1" interface was exposed in HYPERV_CPUID_INTERFACE. Note, VMMs are free to act in any sequence they like, e.g. they can try to set MSRs first and CPUIDs later so we still need to allow the host to read/write Hyper-V specific MSRs unconditionally. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-14-vkuznets@redhat.com> [Add selftest vcpu_set_hv_cpuid API to avoid breaking xen_vmcall_test. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Allocate 'struct kvm_vcpu_hv' dynamicallyVitaly Kuznetsov1-7/+6
Hyper-V context is only needed for guests which use Hyper-V emulation in KVM (e.g. Windows/Hyper-V guests). 'struct kvm_vcpu_hv' is, however, quite big, it accounts for more than 1/4 of the total 'struct kvm_vcpu_arch' which is also quite big already. This all looks like a waste. Allocate 'struct kvm_vcpu_hv' dynamically. This patch does not bring any (intentional) functional change as we still allocate the context unconditionally but it paves the way to doing that only when needed. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-13-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Prepare to meet unallocated Hyper-V contextVitaly Kuznetsov1-0/+10
Currently, Hyper-V context is part of 'struct kvm_vcpu_arch' and is always available. As a preparation to allocating it dynamically, check that it is not NULL at call sites which can normally proceed without it i.e. the behavior is identical to the situation when Hyper-V emulation is not being used by the guest. When Hyper-V context for a particular vCPU is not allocated, we may still need to get 'vp_index' from there. E.g. in a hypothetical situation when Hyper-V emulation was enabled on one CPU and wasn't on another, Hyper-V style send-IPI hypercall may still be used. Luckily, vp_index is always initialized to kvm_vcpu_get_idx() and can only be changed when Hyper-V context is present. Introduce kvm_hv_get_vpindex() helper for simplification. No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-12-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Always use to_hv_vcpu() accessor to get to 'struct ↵Vitaly Kuznetsov1-1/+3
kvm_vcpu_hv' As a preparation to allocating Hyper-V context dynamically, make it clear who's the user of the said context. No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-11-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Introduce to_kvm_hv() helperVitaly Kuznetsov1-0/+5
Spelling '&kvm->arch.hyperv' correctly is hard. Also, this makes the code more consistent with vmx/svm where to_kvm_vmx()/to_kvm_svm() are already being used. Opportunistically change kvm_hv_msr_{get,set}_crash_{data,ctl}() and kvm_hv_msr_set_crash_data() to take 'kvm' instead of 'vcpu' as these MSRs are partition wide. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-9-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Rename vcpu_to_hv_syndbg() to to_hv_syndbg()Vitaly Kuznetsov1-1/+1
vcpu_to_hv_syndbg()'s argument is always 'vcpu' so there's no need to have an additional prefix. Also, this makes the code more consistent with vmx/svm where to_vmx()/to_svm() are being used. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-8-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Rename vcpu_to_stimer()/stimer_to_vcpu()Vitaly Kuznetsov1-3/+3
vcpu_to_stimers()'s argument is almost always 'vcpu' so there's no need to have an additional prefix. Also, this makes the naming more consistent with to_hv_vcpu()/to_hv_synic(). Rename stimer_to_vcpu() to hv_stimer_to_vcpu() for consitency. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-7-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Rename vcpu_to_synic()/synic_to_vcpu()Vitaly Kuznetsov1-2/+2
vcpu_to_synic()'s argument is almost always 'vcpu' so there's no need to have an additional prefix. Also, as this is used outside of hyper-v emulation code, add '_hv_' part to make it clear what this s. This makes the naming more consistent with to_hv_vcpu(). Rename synic_to_vcpu() to hv_synic_to_vcpu() for consistency. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-6-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-09KVM: x86: hyper-v: Rename vcpu_to_hv_vcpu() to to_hv_vcpu()Vitaly Kuznetsov1-2/+2
vcpu_to_hv_vcpu()'s argument is almost always 'vcpu' so there's no need to have an additional prefix. Also, this makes the code more consistent with vmx/svm where to_vmx()/to_svm() are being used. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210126134816.1880136-5-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15KVM: x86: hyper-v: allow KVM_GET_SUPPORTED_HV_CPUID as a system ioctlVitaly Kuznetsov1-2/+2
KVM_GET_SUPPORTED_HV_CPUID is a vCPU ioctl but its output is now independent from vCPU and in some cases VMMs may want to use it as a system ioctl instead. In particular, QEMU doesn CPU feature expansion before any vCPU gets created so KVM_GET_SUPPORTED_HV_CPUID can't be used. Convert KVM_GET_SUPPORTED_HV_CPUID to 'dual' system/vCPU ioctl with the same meaning. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200929150944.1235688-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01x86/kvm/hyper-v: Add support for synthetic debugger interfaceJon Doron1-0/+5
Add support for Hyper-V synthetic debugger (syndbg) interface. The syndbg interface is using MSRs to emulate a way to send/recv packets data. The debug transport dll (kdvm/kdnet) will identify if Hyper-V is enabled and if it supports the synthetic debugger interface it will attempt to use it, instead of trying to initialize a network adapter. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Jon Doron <arilou@gmail.com> Message-Id: <20200529134543.1127440-4-arilou@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01x86/hyper-v: Add synthetic debugger definitionsJon Doron1-0/+27
Hyper-V synthetic debugger has two modes, one that uses MSRs and the other that use Hypercalls. Add all the required definitions to both types of synthetic debugger interface. Some of the required new CPUIDs and MSRs are not documented in the TLFS so they are in hyperv.h instead. The reason they are not documented is because they are subjected to be removed in future versions of Windows. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Jon Doron <arilou@gmail.com> Message-Id: <20200529134543.1127440-3-arilou@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499Thomas Gleixner1-4/+1
Based on 1 normalized pattern(s): this work is licensed under the terms of the gnu gpl version 2 see the copying file in the top level directory extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 35 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-14x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUIDVitaly Kuznetsov1-0/+2
With every new Hyper-V Enlightenment we implement we're forced to add a KVM_CAP_HYPERV_* capability. While this approach works it is fairly inconvenient: the majority of the enlightenments we do have corresponding CPUID feature bit(s) and userspace has to know this anyways to be able to expose the feature to the guest. Add KVM_GET_SUPPORTED_HV_CPUID ioctl (backed by KVM_CAP_HYPERV_CPUID, "one cap to rule them all!") returning all Hyper-V CPUID feature leaves. Using the existing KVM_GET_SUPPORTED_CPUID doesn't seem to be possible: Hyper-V CPUID feature leaves intersect with KVM's (e.g. 0x40000000, 0x40000001) and we would probably confuse userspace in case we decide to return these twice. KVM_CAP_HYPERV_CPUID's number is interim: we're intended to drop KVM_CAP_HYPERV_STIMER_DIRECT and use its number instead. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14KVM: x86: Add requisite includes to hyperv.hSean Christopherson1-0/+2
Until this point vmx.c has been the only consumer and included the file after many others. Prepare for multiple consumers, i.e. the shattering of vmx.c Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-17KVM: hyperv: define VP assist page helpersLadi Prosek1-0/+4
The state related to the VP assist page is still managed by the LAPIC code in the pv_eoi field. Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-06KVM: x86: ensure all MSRs can always be KVM_GET/SET_MSR'dPaolo Bonzini1-1/+1
Some of the MSRs returned by GET_MSR_INDEX_LIST currently cannot be sent back to KVM_GET_MSR and/or KVM_SET_MSR; either they can never be sent back, or you they are only accepted under special conditions. This makes the API a pain to use. To avoid this pain, this patch makes it so that the result of the get-list ioctl can always be used for host-initiated get and set. Since we don't have a separate way to check for read-only MSRs, this means some Hyper-V MSRs are ignored when written. Arguably they should not even be in the result of GET_MSR_INDEX_LIST, but I am leaving there in case userspace is using the outcome of GET_MSR_INDEX_LIST to derive the support for the corresponding Hyper-V feature. Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-06kvm: x86: hyperv: guest->host event signaling via eventfdRoman Kagan1-0/+1
In Hyper-V, the fast guest->host notification mechanism is the SIGNAL_EVENT hypercall, with a single parameter of the connection ID to signal. Currently this hypercall incurs a user exit and requires the userspace to decode the parameters and trigger the notification of the potentially different I/O context. To avoid the costly user exit, process this hypercall and signal the corresponding eventfd in KVM, similar to ioeventfd. The association between the connection id and the eventfd is established via the newly introduced KVM_HYPERV_EVENTFD ioctl, and maintained in an (srcu-protected) IDR. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: David Hildenbrand <david@redhat.com> [asm/hyperv.h changes approved by KY Srinivasan. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06kvm: x86: factor out kvm.arch.hyperv (de)initRoman Kagan1-0/+3
Move kvm.arch.hyperv initialization and cleanup to separate functions. For now only a mutex is inited in the former, and the latter is empty; more stuff will go in there in a followup patch. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-07-14kvm: x86: hyperv: make VP_INDEX managed by userspaceRoman Kagan1-0/+1
Hyper-V identifies vCPUs by Virtual Processor Index, which can be queried via HV_X64_MSR_VP_INDEX msr. It is defined by the spec as a sequential number which can't exceed the maximum number of vCPUs per VM. APIC ids can be sparse and thus aren't a valid replacement for VP indices. Current KVM uses its internal vcpu index as VP_INDEX. However, to make it predictable and persistent across VM migrations, the userspace has to control the value of VP_INDEX. This patch achieves that, by storing vp_index explicitly on vcpu, and allowing HV_X64_MSR_VP_INDEX to be set from the host side. For compatibility it's initialized to KVM vcpu index. Also a few variables are renamed to make clear distinction betweed this Hyper-V vp_index and KVM vcpu_id (== APIC id). Besides, a new capability, KVM_CAP_HYPERV_VP_INDEX, is added to allow the userspace to skip attempting msr writes where unsupported, to avoid spamming error logs. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-07-13kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2Roman Kagan1-1/+1
There is a flaw in the Hyper-V SynIC implementation in KVM: when message page or event flags page is enabled by setting the corresponding msr, KVM zeroes it out. This is problematic because on migration the corresponding MSRs are loaded on the destination, so the content of those pages is lost. This went unnoticed so far because the only user of those pages was in-KVM hyperv synic timers, which could continue working despite that zeroing. Newer QEMU uses those pages for Hyper-V VMBus implementation, and zeroing them breaks the migration. Besides, in newer QEMU the content of those pages is fully managed by QEMU, so zeroing them is undesirable even when writing the MSRs from the guest side. To support this new scheme, introduce a new capability, KVM_CAP_HYPERV_SYNIC2, which, when enabled, makes sure that the synic pages aren't zeroed out in KVM. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-09-20KVM: x86: Hyper-V tsc page setupPaolo Bonzini1-0/+3
Lately tsc page was implemented but filled with empty values. This patch setup tsc page scale and offset based on vcpu tsc, tsc_khz and HV_X64_MSR_TIME_REF_COUNT value. The valid tsc page drops HV_X64_MSR_TIME_REF_COUNT msr reads count to zero which potentially improves performance. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Peter Hornyack <peterhornyack@google.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> [Computation of TSC page parameters rewritten to use the Linux timekeeper parameters. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16kvm/x86: Hyper-V SynIC timersAndrey Smetanin1-0/+24
Per Hyper-V specification (and as required by Hyper-V-aware guests), SynIC provides 4 per-vCPU timers. Each timer is programmed via a pair of MSRs, and signals expiration by delivering a special format message to the configured SynIC message slot and triggering the corresponding synthetic interrupt. Note: as implemented by this patch, all periodic timers are "lazy" (i.e. if the vCPU wasn't scheduled for more than the timer period the timer events are lost), regardless of the corresponding configuration MSR. If deemed necessary, the "catch up" mode (the timer period is shortened until the timer catches up) will be implemented later. Changes v2: * Use remainder to calculate periodic timer expiration time Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16kvm/x86: Added Hyper-V vcpu_to_hv_vcpu()/hv_vcpu_to_vcpu() helpersAndrey Smetanin1-6/+14
Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16kvm/x86: Rearrange func's declarations inside Hyper-V headerAndrey Smetanin1-10/+10
This rearrangement places functions declarations together according to their functionality, so future additions will be simplier. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: Vitaly Kuznetsov <vkuznets@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25kvm/x86: Hyper-V synthetic interrupt controllerAndrey Smetanin1-0/+23
SynIC (synthetic interrupt controller) is a lapic extension, which is controlled via MSRs and maintains for each vCPU - 16 synthetic interrupt "lines" (SINT's); each can be configured to trigger a specific interrupt vector optionally with auto-EOI semantics - a message page in the guest memory with 16 256-byte per-SINT message slots - an event flag page in the guest memory with 16 2048-bit per-SINT event flag areas The host triggers a SINT whenever it delivers a new message to the corresponding slot or flips an event flag bit in the corresponding area. The guest informs the host that it can try delivering a message by explicitly asserting EOI in lapic or writing to End-Of-Message (EOM) MSR. The userspace (qemu) triggers interrupts and receives EOM notifications via irqfd with resampler; for that, a GSI is allocated for each configured SINT, and irq_routing api is extended to support GSI-SINT mapping. Changes v4: * added activation of SynIC by vcpu KVM_ENABLE_CAP * added per SynIC active flag * added deactivation of APICv upon SynIC activation Changes v3: * added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into docs Changes v2: * do not use posted interrupts for Hyper-V SynIC AutoEOI vectors * add Hyper-V SynIC vectors into EOI exit bitmap * Hyper-V SyniIC SINT msr write logic simplified Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23kvm/x86: added hyper-v crash msrs into kvm hyperv contextAndrey Smetanin1-1/+1
Added kvm Hyper-V context hv crash variables as storage of Hyper-V crash msrs. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Peter Hornyack <peterhornyack@google.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Gleb Natapov <gleb@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23kvm/x86: move Hyper-V MSR's/hypercall code into hyperv.c fileAndrey Smetanin1-0/+32
This patch introduce Hyper-V related source code file - hyperv.c and per vm and per vcpu hyperv context structures. All Hyper-V MSR's and hypercall code moved into hyperv.c. All Hyper-V kvm/vcpu fields moved into appropriate hyperv context structures. Copyrights and authors information copied from x86.c to hyperv.c. Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Peter Hornyack <peterhornyack@google.com> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Gleb Natapov <gleb@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-27 05:21:20 +0300