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* kvm: x86: fix a compile warningPeng Hao2018-04-041-1/+1
| | | | | | | | fix a "warning: no previous prototype". Cc: stable@vger.kernel.org Signed-off-by: Peng Hao <peng.hao2@zte.com.cn> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: X86: Add Force Emulation Prefix for "emulate the next instruction"Wanpeng Li2018-04-041-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no easy way to force KVM to run an instruction through the emulator (by design as that will expose the x86 emulator as a significant attack-surface). However, we do wish to expose the x86 emulator in case we are testing it (e.g. via kvm-unit-tests). Therefore, this patch adds a "force emulation prefix" that is designed to raise #UD which KVM will trap and it's #UD exit-handler will match "force emulation prefix" to run instruction after prefix by the x86 emulator. To not expose the x86 emulator by default, we add a module parameter that should be off by default. A simple testcase here: #include <stdio.h> #include <string.h> #define HYPERVISOR_INFO 0x40000000 #define CPUID(idx, eax, ebx, ecx, edx) \ asm volatile (\ "ud2a; .ascii \"kvm\"; cpuid" \ :"=b" (*ebx), "=a" (*eax), "=c" (*ecx), "=d" (*edx) \ :"0"(idx) ); void main() { unsigned int eax, ebx, ecx, edx; char string[13]; CPUID(HYPERVISOR_INFO, &eax, &ebx, &ecx, &edx); *(unsigned int *)(string + 0) = ebx; *(unsigned int *)(string + 4) = ecx; *(unsigned int *)(string + 8) = edx; string[12] = 0; if (strncmp(string, "KVMKVMKVM\0\0\0", 12) == 0) printf("kvm guest\n"); else printf("bare hardware\n"); } Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Liran Alon <liran.alon@oracle.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> [Correctly handle usermode exits. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: X86: Introduce handle_ud()Wanpeng Li2018-04-041-0/+13
| | | | | | | | | | | | | | | Introduce handle_ud() to handle invalid opcode, this function will be used by later patches. Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <rkrcmar@redhat.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Liran Alon <liran.alon@oracle.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event ↵Liran Alon2018-03-281-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pending In case L2 VMExit to L0 during event-delivery, VMCS02 is filled with IDT-vectoring-info which vmx_complete_interrupts() makes sure to reinject before next resume of L2. While handling the VMExit in L0, an IPI could be sent by another L1 vCPU to the L1 vCPU which currently runs L2 and exited to L0. When L0 will reach vcpu_enter_guest() and call inject_pending_event(), it will note that a previous event was re-injected to L2 (by IDT-vectoring-info) and therefore won't check if there are pending L1 events which require exit from L2 to L1. Thus, L0 enters L2 without immediate VMExit even though there are pending L1 events! This commit fixes the issue by making sure to check for L1 pending events even if a previous event was reinjected to L2 and bailing out from inject_pending_event() before evaluating a new pending event in case an event was already reinjected. The bug was observed by the following setup: * L0 is a 64CPU machine which runs KVM. * L1 is a 16CPU machine which runs KVM. * L0 & L1 runs with APICv disabled. (Also reproduced with APICv enabled but easier to analyze below info with APICv disabled) * L1 runs a 16CPU L2 Windows Server 2012 R2 guest. During L2 boot, L1 hangs completely and analyzing the hang reveals that one L1 vCPU is holding KVM's mmu_lock and is waiting forever on an IPI that he has sent for another L1 vCPU. And all other L1 vCPUs are currently attempting to grab mmu_lock. Therefore, all L1 vCPUs are stuck forever (as L1 runs with kernel-preemption disabled). Observing /sys/kernel/debug/tracing/trace_pipe reveals the following series of events: (1) qemu-system-x86-19066 [030] kvm_nested_vmexit: rip: 0xfffff802c5dca82f reason: EPT_VIOLATION ext_inf1: 0x0000000000000182 ext_inf2: 0x00000000800000d2 ext_int: 0x00000000 ext_int_err: 0x00000000 (2) qemu-system-x86-19054 [028] kvm_apic_accept_irq: apicid f vec 252 (Fixed|edge) (3) qemu-system-x86-19066 [030] kvm_inj_virq: irq 210 (4) qemu-system-x86-19066 [030] kvm_entry: vcpu 15 (5) qemu-system-x86-19066 [030] kvm_exit: reason EPT_VIOLATION rip 0xffffe00069202690 info 83 0 (6) qemu-system-x86-19066 [030] kvm_nested_vmexit: rip: 0xffffe00069202690 reason: EPT_VIOLATION ext_inf1: 0x0000000000000083 ext_inf2: 0x0000000000000000 ext_int: 0x00000000 ext_int_err: 0x00000000 (7) qemu-system-x86-19066 [030] kvm_nested_vmexit_inject: reason: EPT_VIOLATION ext_inf1: 0x0000000000000083 ext_inf2: 0x0000000000000000 ext_int: 0x00000000 ext_int_err: 0x00000000 (8) qemu-system-x86-19066 [030] kvm_entry: vcpu 15 Which can be analyzed as follows: (1) L2 VMExit to L0 on EPT_VIOLATION during delivery of vector 0xd2. Therefore, vmx_complete_interrupts() will set KVM_REQ_EVENT and reinject a pending-interrupt of 0xd2. (2) L1 sends an IPI of vector 0xfc (CALL_FUNCTION_VECTOR) to destination vCPU 15. This will set relevant bit in LAPIC's IRR and set KVM_REQ_EVENT. (3) L0 reach vcpu_enter_guest() which calls inject_pending_event() which notes that interrupt 0xd2 was reinjected and therefore calls vmx_inject_irq() and returns. Without checking for pending L1 events! Note that at this point, KVM_REQ_EVENT was cleared by vcpu_enter_guest() before calling inject_pending_event(). (4) L0 resumes L2 without immediate-exit even though there is a pending L1 event (The IPI pending in LAPIC's IRR). We have already reached the buggy scenario but events could be furthered analyzed: (5+6) L2 VMExit to L0 on EPT_VIOLATION. This time not during event-delivery. (7) L0 decides to forward the VMExit to L1 for further handling. (8) L0 resumes into L1. Note that because KVM_REQ_EVENT is cleared, the LAPIC's IRR is not examined and therefore the IPI is still not delivered into L1! Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: Fix misleading comments on handling pending exceptionsLiran Alon2018-03-281-2/+12
| | | | | | | | | | | | | | | | | | | | The reason that exception.pending should block re-injection of NMI/interrupt is not described correctly in comment in code. Instead, it describes why a pending exception should be injected before a pending NMI/interrupt. Therefore, move currently present comment to code-block evaluating a new pending event which explains why exception.pending is evaluated first. In addition, create a new comment describing that exception.pending blocks re-injection of NMI/interrupt because the exception was queued by handling vmexit which was due to NMI/interrupt delivery. Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@orcle.com> [Used a comment from Sean J <sean.j.christopherson@intel.com>. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: Rename interrupt.pending to interrupt.injectedLiran Alon2018-03-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For exceptions & NMIs events, KVM code use the following coding convention: *) "pending" represents an event that should be injected to guest at some point but it's side-effects have not yet occurred. *) "injected" represents an event that it's side-effects have already occurred. However, interrupts don't conform to this coding convention. All current code flows mark interrupt.pending when it's side-effects have already taken place (For example, bit moved from LAPIC IRR to ISR). Therefore, it makes sense to just rename interrupt.pending to interrupt.injected. This change follows logic of previous commit 664f8e26b00c ("KVM: X86: Fix loss of exception which has not yet been injected") which changed exception to follow this coding convention as well. It is important to note that in case !lapic_in_kernel(vcpu), interrupt.pending usage was and still incorrect. In this case, interrrupt.pending can only be set using one of the following ioctls: KVM_INTERRUPT, KVM_SET_VCPU_EVENTS and KVM_SET_SREGS. Looking at how QEMU uses these ioctls, one can see that QEMU uses them either to re-set an "interrupt.pending" state it has received from KVM (via KVM_GET_VCPU_EVENTS interrupt.pending or via KVM_GET_SREGS interrupt_bitmap) or by dispatching a new interrupt from QEMU's emulated LAPIC which reset bit in IRR and set bit in ISR before sending ioctl to KVM. So it seems that indeed "interrupt.pending" in this case is also suppose to represent "interrupt.injected". However, kvm_cpu_has_interrupt() & kvm_cpu_has_injectable_intr() is misusing (now named) interrupt.injected in order to return if there is a pending interrupt. This leads to nVMX/nSVM not be able to distinguish if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on pending interrupt or should re-inject an injected interrupt. Therefore, add a FIXME at these functions for handling this issue. This patch introduce no semantics change. Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interruptLiran Alon2018-03-281-5/+0
| | | | | | | | | | | | | | | | | | | kvm_inject_realmode_interrupt() is called from one of the injection functions which writes event-injection to VMCS: vmx_queue_exception(), vmx_inject_irq() and vmx_inject_nmi(). All these functions are called just to cause an event-injection to guest. They are not responsible of manipulating the event-pending flag. The only purpose of kvm_inject_realmode_interrupt() should be to emulate real-mode interrupt-injection. This was also incorrect when called from vmx_queue_exception(). Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* x86/kvm: rename HV_X64_MSR_APIC_ASSIST_PAGE to HV_X64_MSR_VP_ASSIST_PAGELadi Prosek2018-03-281-1/+1
| | | | | | | | | | | The assist page has been used only for the paravirtual EOI so far, hence the "APIC" in the MSR name. Renaming to match the Hyper-V TLFS where it's called "Virtual VP Assist MSR". Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: Fix perf timer mode IP reportingAndi Kleen2018-03-281-13/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | KVM and perf have a special backdoor mechanism to report the IP for interrupts re-executed after vm exit. This works for the NMIs that perf normally uses. However when perf is in timer mode it doesn't work because the timer interrupt doesn't get this special treatment. This is common when KVM is running nested in another hypervisor which may not implement the PMU, so only timer mode is available. Call the functions to set up the backdoor IP also for non NMI interrupts. I renamed the functions to set up the backdoor IP reporting to be more appropiate for their new use. The SVM change is only compile tested. v2: Moved the functions inline. For the normal interrupt case the before/after functions are now called from x86.c, not arch specific code. For the NMI case we still need to call it in the architecture specific code, because it's already needed in the low level *_run functions. Signed-off-by: Andi Kleen <ak@linux.intel.com> [Removed unnecessary calls from arch handle_external_intr. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: move setting of ept_identity_map_addr to vmx.cSean Christopherson2018-03-231-2/+1
| | | | | | | | | Add kvm_x86_ops->set_identity_map_addr and set ept_identity_map_addr in VMX specific code so that ept_identity_map_addr can be moved out of 'struct kvm_arch' in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: nVMX: Do not load EOI-exitmap while running L2Liran Alon2018-03-211-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When L1 IOAPIC redirection-table is written, a request of KVM_REQ_SCAN_IOAPIC is set on all vCPUs. This is done such that all vCPUs will now recalc their IOAPIC handled vectors and load it to their EOI-exitmap. However, it could be that one of the vCPUs is currently running L2. In this case, load_eoi_exitmap() will be called which would write to vmcs02->eoi_exit_bitmap, which is wrong because vmcs02->eoi_exit_bitmap should always be equal to vmcs12->eoi_exit_bitmap. Furthermore, at this point KVM_REQ_SCAN_IOAPIC was already consumed and therefore we will never update vmcs01->eoi_exit_bitmap. This could lead to remote_irr of some IOAPIC level-triggered entry to remain set forever. Fix this issue by delaying the load of EOI-exitmap to when vCPU is running L1. One may wonder why not just delay entire KVM_REQ_SCAN_IOAPIC processing to when vCPU is running L1. This is done in order to handle correctly the case where LAPIC & IO-APIC of L1 is pass-throughed into L2. In this case, vmcs12->virtual_interrupt_delivery should be 0. In current nVMX implementation, that results in vmcs02->virtual_interrupt_delivery to also be 0. Thus, vmcs02->eoi_exit_bitmap is not used. Therefore, every L2 EOI cause a #VMExit into L0 (either on MSR_WRITE to x2APIC MSR or APIC_ACCESS/APIC_WRITE/EPT_MISCONFIG to APIC MMIO page). In order for such L2 EOI to be broadcasted, if needed, from LAPIC to IO-APIC, vcpu->arch.ioapic_handled_vectors must be updated while L2 is running. Therefore, patch makes sure to delay only the loading of EOI-exitmap but not the update of vcpu->arch.ioapic_handled_vectors. Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: X86: Provide a capability to disable PAUSE interceptsWanpeng Li2018-03-161-1/+3
| | | | | | | | | | | | | | | Allow to disable pause loop exit/pause filtering on a per VM basis. If some VMs have dedicated host CPUs, they won't be negatively affected due to needlessly intercepted PAUSE instructions. Thanks to Jan H. Schönherr's initial patch. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: X86: Provide a capability to disable HLT interceptsWanpeng Li2018-03-161-0/+3
| | | | | | | | | | | If host CPUs are dedicated to a VM, we can avoid VM exits on HLT. This patch adds the per-VM capability to disable them. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: X86: Provide a capability to disable MWAIT interceptsWanpeng Li2018-03-161-4/+20
| | | | | | | | | | | | | | | | Allowing a guest to execute MWAIT without interception enables a guest to put a (physical) CPU into a power saving state, where it takes longer to return from than what may be desired by the host. Don't give a guest that power over a host by default. (Especially, since nothing prevents a guest from using MWAIT even when it is not advertised via CPUID.) Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: Add support for VMware backdoor Pseudo-PMCsArbel Moshe2018-03-161-17/+24
| | | | | | | | | | | | | | | | | | | | VMware exposes the following Pseudo PMCs: 0x10000: Physical host TSC 0x10001: Elapsed real time in ns 0x10002: Elapsed apparent time in ns For more info refer to: https://www.vmware.com/files/pdf/techpaper/Timekeeping-In-VirtualMachines.pdf VMware allows access to these Pseduo-PMCs even when read via RDPMC in Ring3 and CR4.PCE=0. Therefore, commit modifies x86 emulator to allow access to these PMCs in this situation. In addition, emulation of these PMCs were added to kvm_pmu_rdpmc(). Signed-off-by: Arbel Moshe <arbel.moshe@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: Emulate only IN/OUT instructions when accessing VMware backdoorLiran Alon2018-03-161-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Access to VMware backdoor ports is done by one of the IN/OUT/INS/OUTS instructions. These ports must be allowed access even if TSS I/O permission bitmap don't allow it. To handle this, VMX/SVM will be changed in future commits to intercept #GP which was raised by such access and handle it by calling x86 emulator to emulate instruction. If it was one of these instructions, the x86 emulator already handles it correctly (Since commit "KVM: x86: Always allow access to VMware backdoor I/O ports") by not checking these ports against TSS I/O permission bitmap. One may wonder why checking for specific instructions is necessary as we can just forward all #GPs to the x86 emulator. There are multiple reasons for doing so: 1. We don't want the x86 emulator to be reached easily by guest by just executing an instruction that raises #GP as that exposes the x86 emulator as a bigger attack surface. 2. The x86 emulator is incomplete and therefore certain instructions that can cause #GP cannot be emulated. Such an example is "INT x" (opcode 0xcd) which reaches emulate_int() which can only emulate the instruction if vCPU is in real-mode. Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: Add emulation_type to not raise #UD on emulation failureLiran Alon2018-03-161-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Next commits are going introduce support for accessing VMware backdoor ports even though guest's TSS I/O permissions bitmap doesn't allow access. This mimic VMware hypervisor behavior. In order to support this, next commits will change VMX/SVM to intercept #GP which was raised by such access and handle it by calling the x86 emulator to emulate instruction. Since commit "KVM: x86: Always allow access to VMware backdoor I/O ports", the x86 emulator handles access to these I/O ports by not checking these ports against the TSS I/O permission bitmap. However, there could be cases that CPU rasies a #GP on instruction that fails to be disassembled by the x86 emulator (Because of incomplete implementation for example). In those cases, we would like the #GP intercept to just forward #GP as-is to guest as if there was no intercept to begin with. However, current emulator code always queues #UD exception in case emulator fails (including disassembly failures) which is not what is wanted in this flow. This commit addresses this issue by adding a new emulation_type flag that will allow the #GP intercept handler to specify that it wishes to be aware when instruction emulation fails and doesn't want #UD exception to be queued. Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: Add module parameter for supporting VMware backdoorLiran Alon2018-03-161-0/+4
| | | | | | | | | | | | | | | | | Support access to VMware backdoor requires KVM to intercept #GP exceptions from guest which introduce slight performance hit. Therefore, control this support by module parameter. Note that module parameter is exported as it should be consumed by kvm_intel & kvm_amd to determine if they should intercept #GP or not. This commit doesn't change semantics. It is done as a preparation for future commits. Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* KVM: x86: add kvm_fast_pio() to consolidate fast PIO codeSean Christopherson2018-03-161-4/+19
| | | | | | | | | Add kvm_fast_pio() to consolidate duplicate code in VMX and SVM. Unexport kvm_fast_pio_in() and kvm_fast_pio_out(). Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* x86/kvm/hyper-v: add reenlightenment MSRs supportVitaly Kuznetsov2018-03-161-1/+11
| | | | | | | | | | | | | | | | | | Nested Hyper-V/Windows guest running on top of KVM will use TSC page clocksource in two cases: - L0 exposes invariant TSC (CPUID.80000007H:EDX[8]). - L0 provides Hyper-V Reenlightenment support (CPUID.40000003H:EAX[13]). Exposing invariant TSC effectively blocks migration to hosts with different TSC frequencies, providing reenlightenment support will be needed when we start migrating nested workloads. Implement rudimentary support for reenlightenment MSRs. For now, these are just read/write MSRs with no effect. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: Add support for AMD Core Perf Extension in guestJanakarajan Natarajan2018-03-161-0/+1
| | | | | | | | | | | | | | | | | | Add support for AMD Core Performance counters in the guest. The base event select and counter MSRs are changed. In addition, with the core extension, there are 2 extra counters available for performance measurements for a total of 6. With the new MSRs, the logic to map them to the gp_counters[] is changed. New functions are added to check the validity of the get/set MSRs. If the guest has the X86_FEATURE_PERFCTR_CORE cpuid flag set, the number of counters available to the vcpu is set to 6. It the flag is not set then it is 4. Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> [Squashed "Expose AMD Core Perf Extension flag to guests" - Radim.] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: nVMX: expose VMX capabilities for nested hypervisors to userspacePaolo Bonzini2018-03-061-0/+19
| | | | | | | | | Use the new MSR feature framework to tell userspace which VMX capabilities are available for nested hypervisors. Before, these were only accessible with the KVM_GET_MSR VCPU ioctl, after VCPUs had been created. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: KVM_CAP_SYNC_REGSKen Hofsass2018-03-061-15/+87
| | | | | | | | | | | | | | | | | | | | | | | This commit implements an enhanced x86 version of S390 KVM_CAP_SYNC_REGS functionality. KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers without having to call SET/GET_*REGS”. This reduces ioctl overhead which is particularly important when userspace is making synchronous guest state modifications (e.g. when emulating and/or intercepting instructions). Originally implemented upstream for the S390, the x86 differences follow: - userspace can select the register sets to be synchronized with kvm_run using bit-flags in the kvm_valid_registers and kvm_dirty_registers fields. - vcpu_events is available in addition to the regs and sregs register sets. Signed-off-by: Ken Hofsass <hofsass@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> [Removed wrapper around check for reserved kvm_valid_regs. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* kvm: x86: hyperv: guest->host event signaling via eventfdRoman Kagan2018-03-061-0/+10
| | | | | | | | | | | | | | | | | | | | | 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>
* kvm: x86: factor out kvm.arch.hyperv (de)initRoman Kagan2018-03-061-1/+2
| | | | | | | | | | | 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>
* KVM: x86: fix vcpu initialization with userspace lapicRadim Krčmář2018-03-011-1/+2
| | | | | | | | | | | Moving the code around broke this rare configuration. Use this opportunity to finally call lapic reset from vcpu reset. Reported-by: syzbot+fb7a33a4b6c35007a72b@syzkaller.appspotmail.com Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Fixes: 0b2e9904c159 ("KVM: x86: move LAPIC initialization after VMCS creation") Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: X86: Allow userspace to define the microcode versionWanpeng Li2018-03-011-2/+9
| | | | | | | | | | | | | | | | | | | | | Linux (among the others) has checks to make sure that certain features aren't enabled on a certain family/model/stepping if the microcode version isn't greater than or equal to a known good version. By exposing the real microcode version, we're preventing buggy guests that don't check that they are running virtualized (i.e., they should trust the hypervisor) from disabling features that are effectively not buggy. Suggested-by: Filippo Sironi <sironi@amazon.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: X86: Introduce kvm_get_msr_feature()Wanpeng Li2018-03-011-3/+15
| | | | | | | | | | | | | | | Introduce kvm_get_msr_feature() to handle the msrs which are supported by different vendors and sharing the same emulation logic. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Liran Alon <liran.alon@oracle.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: SVM: Add MSR-based feature support for serializing LFENCETom Lendacky2018-03-011-0/+1
| | | | | | | | | | | | | | | | | | | | | In order to determine if LFENCE is a serializing instruction on AMD processors, MSR 0xc0011029 (MSR_F10H_DECFG) must be read and the state of bit 1 checked. This patch will add support to allow a guest to properly make this determination. Add the MSR feature callback operation to svm.c and add MSR 0xc0011029 to the list of MSR-based features. If LFENCE is serializing, then the feature is supported, allowing the hypervisor to set the value of the MSR that guest will see. Support is also added to write (hypervisor only) and read the MSR value for the guest. A write by the guest will result in a #GP. A read by the guest will return the value as set by the host. In this way, the support to expose the feature to the guest is controlled by the hypervisor. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: Add a framework for supporting MSR-based featuresTom Lendacky2018-03-011-5/+70
| | | | | | | | | | | | Provide a new KVM capability that allows bits within MSRs to be recognized as features. Two new ioctls are added to the /dev/kvm ioctl routine to retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops callback is used to determine support for the listed MSR-based features. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [Tweaked documentation. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM/x86: remove WARN_ON() for when vm_munmap() failsEric Biggers2018-02-241-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | On x86, special KVM memslots such as the TSS region have anonymous memory mappings created on behalf of userspace, and these mappings are removed when the VM is destroyed. It is however possible for removing these mappings via vm_munmap() to fail. This can most easily happen if the thread receives SIGKILL while it's waiting to acquire ->mmap_sem. This triggers the 'WARN_ON(r < 0)' in __x86_set_memory_region(). syzkaller was able to hit this, using 'exit()' to send the SIGKILL. Note that while the vm_munmap() failure results in the mapping not being removed immediately, it is not leaked forever but rather will be freed when the process exits. It's not really possible to handle this failure properly, so almost every other caller of vm_munmap() doesn't check the return value. It's a limitation of having the kernel manage these mappings rather than userspace. So just remove the WARN_ON() so that users can't spam the kernel log with this warning. Fixes: f0d648bdf0a5 ("KVM: x86: map/unmap private slots in __x86_set_memory_region") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
* KVM: x86: move LAPIC initialization after VMCS creationPaolo Bonzini2018-02-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | The initial reset of the local APIC is performed before the VMCS has been created, but it tries to do a vmwrite: vmwrite error: reg 810 value 4a00 (err 18944) CPU: 54 PID: 38652 Comm: qemu-kvm Tainted: G W I 4.16.0-0.rc2.git0.1.fc28.x86_64 #1 Hardware name: Intel Corporation S2600CW/S2600CW, BIOS SE5C610.86B.01.01.0003.090520141303 09/05/2014 Call Trace: vmx_set_rvi [kvm_intel] vmx_hwapic_irr_update [kvm_intel] kvm_lapic_reset [kvm] kvm_create_lapic [kvm] kvm_arch_vcpu_init [kvm] kvm_vcpu_init [kvm] vmx_create_vcpu [kvm_intel] kvm_vm_ioctl [kvm] Move it later, after the VMCS has been created. Fixes: 4191db26b714 ("KVM: x86: Update APICv on APIC reset") Cc: stable@vger.kernel.org Cc: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2018-02-101-76/+262
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull KVM updates from Radim Krčmář: "ARM: - icache invalidation optimizations, improving VM startup time - support for forwarded level-triggered interrupts, improving performance for timers and passthrough platform devices - a small fix for power-management notifiers, and some cosmetic changes PPC: - add MMIO emulation for vector loads and stores - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without requiring the complex thread synchronization of older CPU versions - improve the handling of escalation interrupts with the XIVE interrupt controller - support decrement register migration - various cleanups and bugfixes. s390: - Cornelia Huck passed maintainership to Janosch Frank - exitless interrupts for emulated devices - cleanup of cpuflag handling - kvm_stat counter improvements - VSIE improvements - mm cleanup x86: - hypervisor part of SEV - UMIP, RDPID, and MSR_SMI_COUNT emulation - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512 features - show vcpu id in its anonymous inode name - many fixes and cleanups - per-VCPU MSR bitmaps (already merged through x86/pti branch) - stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)" * tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits) KVM: PPC: Book3S: Add MMIO emulation for VMX instructions KVM: PPC: Book3S HV: Branch inside feature section KVM: PPC: Book3S HV: Make HPT resizing work on POWER9 KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code KVM: PPC: Book3S PR: Fix broken select due to misspelling KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs() KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled KVM: PPC: Book3S HV: Drop locks before reading guest memory kvm: x86: remove efer_reload entry in kvm_vcpu_stat KVM: x86: AMD Processor Topology Information x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested kvm: embed vcpu id to dentry of vcpu anon inode kvm: Map PFN-type memory regions as writable (if possible) x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n KVM: arm/arm64: Fixup userspace irqchip static key optimization KVM: arm/arm64: Fix userspace_irqchip_in_use counting KVM: arm/arm64: Fix incorrect timer_is_pending logic MAINTAINERS: update KVM/s390 maintainers MAINTAINERS: add Halil as additional vfio-ccw maintainer MAINTAINERS: add David as a reviewer for KVM/s390 ...
| * KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()Eric Biggers2018-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Due to a bad merge resolution between commit f29810335965 ("KVM/x86: Check input paging mode when cs.l is set") and commit b4ef9d4e8cb8 ("KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_sregs"), there is a case in kvm_arch_vcpu_ioctl_set_sregs() where vcpu_put() is not called after vcpu_get(). Fix it. Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * Merge branch 'x86/hyperv' of ↵Radim Krčmář2018-02-011-29/+143
| |\ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Topic branch for stable KVM clockource under Hyper-V. Thanks to Christoffer Dall for resolving the ARM conflict.
| | * x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=nThomas Gleixner2018-01-311-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reenlightment support for hyperv slapped a direct reference to x86_hyper_type into the kvm code which results in the following build failure when CONFIG_HYPERVISOR_GUEST=n: arch/x86/kvm/x86.c:6259:6: error: ‘x86_hyper_type’ undeclared (first use in this function) arch/x86/kvm/x86.c:6259:6: note: each undeclared identifier is reported only once for each function it appears in Use the proper helper function to cure that. The 32bit compile fails because of: arch/x86/kvm/x86.c:5936:13: warning: ‘kvm_hyperv_tsc_notifier’ defined but not used [-Wunused-function] which is a real trainwreck engineering artwork. The callsite is wrapped into #ifdef CONFIG_X86_64, but the function itself has the #ifdef inside the function body. Make the function itself wrapped into the ifdef to cure that. Qualiteee.... Fixes: 0092e4346f49 ("x86/kvm: Support Hyper-V reenlightenment") Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com>
| | * x86/kvm: Support Hyper-V reenlightenmentVitaly Kuznetsov2018-01-301-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running nested KVM on Hyper-V guests its required to update masterclocks for all guests when L1 migrates to a host with different TSC frequency. Implement the procedure in the following way: - Pause all guests. - Tell the host (Hyper-V) to stop emulating TSC accesses. - Update the gtod copy, recompute clocks. - Unpause all guests. This is somewhat similar to cpufreq but there are two important differences: - TSC emulation can only be disabled globally (on all CPUs) - The new TSC frequency is not known until emulation is turned off so there is no way to 'prepare' for the event upfront. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com> Link: https://lkml.kernel.org/r/20180124132337.30138-8-vkuznets@redhat.com
| | * x86/kvm: Pass stable clocksource to guests when running nested on Hyper-VVitaly Kuznetsov2018-01-301-25/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, KVM is able to work in 'masterclock' mode passing PVCLOCK_TSC_STABLE_BIT to guests when the clocksource which is used on the host is TSC. When running nested on Hyper-V the guest normally uses a different one: TSC page which is resistant to TSC frequency changes on events like L1 migration. Add support for it in KVM. The only non-trivial change is in vgettsc(): when updating the gtod copy both the clock readout and tsc value have to be updated now. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com> Link: https://lkml.kernel.org/r/20180124132337.30138-7-vkuznets@redhat.com
| * | kvm: x86: remove efer_reload entry in kvm_vcpu_statLongpeng(Mike)2018-01-311-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | The efer_reload is never used since commit 26bb0981b3ff ("KVM: VMX: Use shared msr infrastructure"), so remove it. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when ↵Vitaly Kuznetsov2018-01-311-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | running nested I was investigating an issue with seabios >= 1.10 which stopped working for nested KVM on Hyper-V. The problem appears to be in handle_ept_violation() function: when we do fast mmio we need to skip the instruction so we do kvm_skip_emulated_instruction(). This, however, depends on VM_EXIT_INSTRUCTION_LEN field being set correctly in VMCS. However, this is not the case. Intel's manual doesn't mandate VM_EXIT_INSTRUCTION_LEN to be set when EPT MISCONFIG occurs. While on real hardware it was observed to be set, some hypervisors follow the spec and don't set it; we end up advancing IP with some random value. I checked with Microsoft and they confirmed they don't fill VM_EXIT_INSTRUCTION_LEN on EPT MISCONFIG. Fix the issue by doing instruction skip through emulator when running nested. Fixes: 68c3b4d1676d870f0453c31d5a52e7e65c7448ae Suggested-by: Radim Krčmář <rkrcmar@redhat.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | KVM: x86: Optimization: Create SVM stubs for sync_pir_to_irr()Liran Alon2018-01-161-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sync_pir_to_irr() is only called if vcpu->arch.apicv_active()==true. In case it is false, VMX code make sure to set sync_pir_to_irr to NULL. Therefore, having SVM stubs allows to remove check for if sync_pir_to_irr != NULL from all calling sites. Signed-off-by: Liran Alon <liran.alon@oracle.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> [Return highest IRR in the SVM case. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | Merge branch 'sev-v9-p2' of https://github.com/codomania/kvmPaolo Bonzini2018-01-161-0/+30
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This part of Secure Encrypted Virtualization (SEV) patch series focuses on KVM changes required to create and manage SEV guests. SEV is an extension to the AMD-V architecture which supports running encrypted virtual machine (VMs) under the control of a hypervisor. Encrypted VMs have their pages (code and data) secured such that only the guest itself has access to unencrypted version. Each encrypted VM is associated with a unique encryption key; if its data is accessed to a different entity using a different key the encrypted guest's data will be incorrectly decrypted, leading to unintelligible data. This security model ensures that hypervisor will no longer able to inspect or alter any guest code or data. The key management of this feature is handled by a separate processor known as the AMD Secure Processor (AMD-SP) which is present on AMD SOCs. The SEV Key Management Specification (see below) provides a set of commands which can be used by hypervisor to load virtual machine keys through the AMD-SP driver. The patch series adds a new ioctl in KVM driver (KVM_MEMORY_ENCRYPT_OP). The ioctl will be used by qemu to issue SEV guest-specific commands defined in Key Management Specification. The following links provide additional details: AMD Memory Encryption white paper: http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf AMD64 Architecture Programmer's Manual: http://support.amd.com/TechDocs/24593.pdf SME is section 7.10 SEV is section 15.34 SEV Key Management: http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf KVM Forum Presentation: http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf SEV Guest BIOS support: SEV support has been add to EDKII/OVMF BIOS https://github.com/tianocore/edk2 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | KVM: Introduce KVM_MEMORY_ENCRYPT_{UN,}REG_REGION ioctlBrijesh Singh2017-12-041-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If hardware supports memory encryption then KVM_MEMORY_ENCRYPT_REG_REGION and KVM_MEMORY_ENCRYPT_UNREG_REGION ioctl's can be used by userspace to register/unregister the guest memory regions which may contain the encrypted data (e.g guest RAM, PCI BAR, SMRAM etc). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Improvements-by: Borislav Petkov <bp@suse.de> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Borislav Petkov <bp@suse.de>
| | * | KVM: Introduce KVM_MEMORY_ENCRYPT_OP ioctlBrijesh Singh2017-12-041-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the hardware supports memory encryption then the KVM_MEMORY_ENCRYPT_OP ioctl can be used by qemu to issue a platform specific memory encryption commands. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Borislav Petkov <bp@suse.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Borislav Petkov <bp@suse.de>
| * | | KVM: x86: avoid unnecessary XSETBV on guest entryPaolo Bonzini2018-01-161-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xsetbv can be expensive when running on nested virtualization, try to avoid it. Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Quan Xu <quan.xu0@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | KVM: x86: fix escape of guest dr6 to the hostWanpeng Li2018-01-161-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzkaller reported: WARNING: CPU: 0 PID: 12927 at arch/x86/kernel/traps.c:780 do_debug+0x222/0x250 CPU: 0 PID: 12927 Comm: syz-executor Tainted: G OE 4.15.0-rc2+ #16 RIP: 0010:do_debug+0x222/0x250 Call Trace: <#DB> debug+0x3e/0x70 RIP: 0010:copy_user_enhanced_fast_string+0x10/0x20 </#DB> _copy_from_user+0x5b/0x90 SyS_timer_create+0x33/0x80 entry_SYSCALL_64_fastpath+0x23/0x9a The testcase sets a watchpoint (with perf_event_open) on a buffer that is passed to timer_create() as the struct sigevent argument. In timer_create(), copy_from_user()'s rep movsb triggers the BP. The testcase also sets the debug registers for the guest. However, KVM only restores host debug registers when the host has active watchpoints, which triggers a race condition when running the testcase with multiple threads. The guest's DR6.BS bit can escape to the host before another thread invokes timer_create(), and do_debug() complains. The fix is to respect do_debug()'s dr6 invariant when leaving KVM. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | KVM: X86: support paravirtualized help for TLB shootdownsWanpeng Li2018-01-161-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running on a virtual machine, IPIs are expensive when the target CPU is sleeping. Thus, it is nice to be able to avoid them for TLB shootdowns. KVM can just do the flush via INVVPID on the guest's behalf the next time the CPU is scheduled. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> [Use "&" to test the bit instead of "==". - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | KVM: X86: introduce invalidate_gpa argument to tlb flushWanpeng Li2018-01-161-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new bool invalidate_gpa argument to kvm_x86_ops->tlb_flush, it will be used by later patches to just flush guest tlb. For VMX, this will use INVVPID instead of INVEPT, which will invalidate combined mappings while keeping guest-physical mappings. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | KVM: X86: Add KVM_VCPU_PREEMPTEDWanpeng Li2018-01-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The next patch will add another bit to the preempted field in kvm_steal_time. Define a constant for bit 0 (the only one that is currently used). Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctlChristoffer Dall2017-12-141-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the calls to vcpu_load() and vcpu_put() in to the architecture specific implementations of kvm_arch_vcpu_ioctl() which dispatches further architecture-specific ioctls on to other functions. Some architectures support asynchronous vcpu ioctls which cannot call vcpu_load() or take the vcpu->mutex, because that would prevent concurrent execution with a running VCPU, which is the intended purpose of these ioctls, for example because they inject interrupts. We repeat the separate checks for these specifics in the architecture code for MIPS, S390 and PPC, and avoid taking the vcpu->mutex and calling vcpu_load for these ioctls. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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