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| | * | | | | KVM: SVM: Reserve ASID range for SEV guestBrijesh Singh2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A SEV-enabled guest must use ASIDs from the defined subset, while non-SEV guests can use the remaining ASID range. The range of allowed SEV guest ASIDs is [1 - CPUID_8000_001F[ECX][31:0]]. 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: X86: Add CONFIG_KVM_AMD_SEVBrijesh Singh2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The config option can be used to enable SEV support on AMD Processors. 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: Borislav Petkov <bp@suse.de>
| | * | | | | KVM: Introduce KVM_MEMORY_ENCRYPT_{UN,}REG_REGION ioctlBrijesh Singh2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Singh2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Extend CPUID range to include new leafBrijesh Singh2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This CPUID leaf provides the memory encryption support information on AMD Platform. Its complete description is available in APM volume 2, Section 15.34 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 Reviewed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
| | * | | | | KVM: SVM: Prepare to reserve asid for SEV guestBrijesh Singh2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, ASID allocation start at 1. Add a svm_vcpu_data.min_asid which allows supplying a dynamic start ASID. 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: svm: prepare for new bit definition in nested_ctlTom Lendacky2017-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the nested_ctl variable in the vmcb_control_area structure is used to indicate nested paging support. The nested paging support field is actually defined as bit 0 of the field. In order to support a new feature flag the usage of the nested_ctl and nested paging support must be converted to operate on a single bit. 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: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> Reviewed-by: Borislav Petkov <bp@suse.de>
| * | | | | | KVM: x86: avoid unnecessary XSETBV on guest entryPaolo Bonzini2018-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Li2018-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Li2018-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Li2018-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Li2018-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_fpuChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_set_fpu(). Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_fpuChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_get_fpu(). Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_guest_debugChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_set_guest_debug(). Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_translateChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_translate(). Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_mpstateChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_set_mpstate(). Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_mpstateChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_get_mpstate(). Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_sregsChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_set_sregs(). Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_sregsChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_get_sregs(). Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_regsChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_set_regs(). Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_regsChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_get_regs(). Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_runChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move vcpu_load() and vcpu_put() into the architecture specific implementations of kvm_arch_vcpu_ioctl_run(). Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390 parts Reviewed-by: Cornelia Huck <cohuck@redhat.com> [Rebased. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: Take vcpu->mutex outside vcpu_loadChristoffer Dall2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we're about to call vcpu_load() from architecture-specific implementations of the KVM vcpu ioctls, but yet we access data structures protected by the vcpu->mutex in the generic code, factor this logic out from vcpu_load(). x86 is the only architecture which calls vcpu_load() outside of the main vcpu ioctl function, and these calls will no longer take the vcpu mutex following this patch. However, with the exception of kvm_arch_vcpu_postcreate (see below), the callers are either in the creation or destruction path of the VCPU, which means there cannot be any concurrent access to the data structure, because the file descriptor is not yet accessible, or is already gone. kvm_arch_vcpu_postcreate makes the newly created vcpu potentially accessible by other in-kernel threads through the kvm->vcpus array, and we therefore take the vcpu mutex in this case directly. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: VMX: drop I/O permission bitmapsQuan Xu2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since KVM removes the only I/O port 0x80 bypass on Intel hosts, clear CPU_BASED_USE_IO_BITMAPS and set CPU_BASED_UNCOND_IO_EXITING bit. Then these I/O permission bitmaps are not used at all, so drop I/O permission bitmaps. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim KrÄmář <rkrcmar@redhat.com> Signed-off-by: Quan Xu <quan.xu0@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: X86: Reduce the overhead when lapic_timer_advance is disabledWanpeng Li2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I run ebizzy in a 32 vCPUs guest on a 32 pCPUs Xeon box, I can observe ~8000 kvm_wait_lapic_expire CurAvg/s through kvm_stat tool even if the advance tscdeadline hrtimer expiration is disabled. Each call to wait_lapic_expire() will consume ~70 cycles when a timer fires since apic_timer_expire() will set expired_tscdeadline and then wait_lapic_expire() will do some caculation before bailing out. So total ~175us per second is lost on this 3.2Ghz machine. This patch reduces the overhead by skipping the function wait_lapic_expire() when lapic_timer_advance is disabled. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: VMX: Cache IA32_DEBUGCTL in memoryWanpeng Li2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MSR_IA32_DEBUGCTLMSR is zeroed on VMEXIT, so it is saved/restored each time during world switch. This patch caches the host IA32_DEBUGCTL MSR and saves/restores the host IA32_DEBUGCTL msr when guest/host switches to avoid to save/restore each time during world switch. This saves about 100 clock cycles per vmexit. Suggested-by: Jim Mattson <jmattson@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | | | KVM: nVMX: Add a WARN for freeing a loaded VMCS02Mark Kanda2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When attempting to free a loaded VMCS02, add a WARN and avoid freeing it (to avoid use-after-free situations). Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Ameya More <ameya.more@oracle.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | | | KVM: nVMX: Eliminate vmcs02 poolJim Mattson2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The potential performance advantages of a vmcs02 pool have never been realized. To simplify the code, eliminate the pool. Instead, a single vmcs02 is allocated per VCPU when the VCPU enters VMX operation. Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Ameya More <ameya.more@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | | | KVM: Expose new cpu features to guestYang Zhong2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel IceLake cpu has added new cpu features,AVX512_VBMI2/GFNI/ VAES/VPCLMULQDQ/AVX512_VNNI/AVX512_BITALG. Those new cpu features need expose to guest VM. The bit definition: CPUID.(EAX=7,ECX=0):ECX[bit 06] AVX512_VBMI2 CPUID.(EAX=7,ECX=0):ECX[bit 08] GFNI CPUID.(EAX=7,ECX=0):ECX[bit 09] VAES CPUID.(EAX=7,ECX=0):ECX[bit 10] VPCLMULQDQ CPUID.(EAX=7,ECX=0):ECX[bit 11] AVX512_VNNI CPUID.(EAX=7,ECX=0):ECX[bit 12] AVX512_BITALG The release document ref below link: https://software.intel.com/sites/default/files/managed/c5/15/\ architecture-instruction-set-extensions-programming-reference.pdf The kernel dependency commit in kvm.git: (c128dbfa0f879f8ce7b79054037889b0b2240728) Signed-off-by: Yang Zhong <yang.zhong@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | | | KVM: x86: Add emulation of MSR_SMI_COUNTLiran Alon2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This MSR returns the number of #SMIs that occurred on CPU since boot. It was seen to be used frequently by ESXi guest. Patch adds a new vcpu-arch specific var called smi_count to save the number of #SMIs which occurred on CPU since boot. It is exposed as a read-only MSR to guest (causing #GP on wrmsr) in RDMSR/WRMSR emulation code. MSR_SMI_COUNT is also added to emulated_msrs[] to make sure user-space can save/restore it for migration purposes. 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: Bhavesh Davda <bhavesh.davda@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| * | | | | | KVM: x86: simplify kvm_mwait_in_guest()Radim Krčmář2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If Intel/AMD implements MWAIT, we expect that it works well and only reject known bugs; no reason to do it the other way around for minor vendors. (Not that they are relevant ATM.) This allows further simplification of kvm_mwait_in_guest(). And use boot_cpu_has() instead of "cpu_has(&boot_cpu_data," while at it. Reviewed-by: Alexander Graf <agraf@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: drop bogus MWAIT checkRadim Krčmář2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The check was added in some iteration while trying to fix a reported OS X on Core 2 bug, but that bug is elsewhere. The comment is misleading because the guest can call MWAIT with ECX = 0 even if we enforce CPUID5_ECX_INTERRUPT_BREAK; the call would have the exactly the same effect as if the host didn't have the feature. A problem is that a QEMU feature exposes CPUID5_ECX_INTERRUPT_BREAK on CPUs that do not support it. Removing the check changes behavior on last Pentium 4 lines (Presler, Dempsey, and Tulsa, which had VMX and MONITOR while missing INTERRUPT_BREAK) when running a guest OS that uses MWAIT without checking for its presence (QEMU doesn't expose MONITOR). The only known OS that ignores the MONITOR flag is old Mac OS X and we allowed it to bug on Core 2 (MWAIT used to throw #UD and only that OS noticed), so we can save another 20 lines letting it bug on even older CPUs. Alternatively, we can return MWAIT exiting by default and let userspace toggle it. Reviewed-by: Alexander Graf <agraf@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: prevent MWAIT in guest with buggy MONITORRadim Krčmář2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bug prevents MWAIT from waking up after a write to the monitored cache line. KVM might emulate a CPU model that shouldn't have the bug, so the guest would not employ a workaround and possibly miss wakeups. Better to avoid the situation. Reviewed-by: Alexander Graf <agraf@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: MMU: make array audit_point_name staticColin Ian King2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The array audit_point_name is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: arch/x86/kvm/mmu_audit.c:22:12: warning: symbol 'audit_point_name' was not declared. Should it be static? Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | x86: kvm: mmu: make kvm_mmu_clear_all_pte_masks staticGimcuan Hui2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kvm_mmu_clear_all_pte_masks interface is only used by kvm_mmu_module_init locally, and does not need to be called by other module, make it static. This patch cleans up sparse warning: symbol 'kvm_mmu_clear_all_pte_masks' was not declared. Should it be static? Signed-off-by: Gimcuan Hui <gimcuan@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: emulate RDPIDPaolo Bonzini2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is encoded as F3 0F C7 /7 with a register argument. The register argument is the second array in the group9 GroupDual, while F3 is the fourth element of a Prefix. Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: vmx: add support for emulating UMIPPaolo Bonzini2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UMIP can be emulated almost perfectly on Intel processor by enabling descriptor-table exits. SMSW does not cause a vmexit and hence it cannot be changed into a #GP fault, but all in all it's the most "innocuous" of the unprivileged instructions that UMIP blocks. In fact, Linux is _also_ emulating SMSW instructions on behalf of the program that executes them, because some 16-bit programs expect to use SMSW to detect vm86 mode, so this is an even smaller issue. Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: add support for emulating UMIPPaolo Bonzini2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The User-Mode Instruction Prevention feature present in recent Intel processor prevents a group of instructions (sgdt, sidt, sldt, smsw, and str) from being executed with CPL > 0. Otherwise, a general protection fault is issued. UMIP instructions in general are also able to trigger vmexits, so we can actually emulate UMIP on older processors. This commit sets up the infrastructure so that kvm-intel.ko and kvm-amd.ko can set the UMIP feature bit for CPUID even if the feature is not actually available in hardware. Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: emulate sldt and strPaolo Bonzini2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are needed to handle the descriptor table vmexits when emulating UMIP. Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | KVM: x86: add support for UMIPPaolo Bonzini2017-12-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the CPUID bits, make the CR4.UMIP bit not reserved anymore, and add UMIP support for instructions that are already emulated by KVM. Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | | | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-02-04
|\ \ \ \ \ \ \ | | |_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull spectre/meltdown updates from Thomas Gleixner: "The next round of updates related to melted spectrum: - The initial set of spectre V1 mitigations: - Array index speculation blocker and its usage for syscall, fdtable and the n180211 driver. - Speculation barrier and its usage in user access functions - Make indirect calls in KVM speculation safe - Blacklisting of known to be broken microcodes so IPBP/IBSR are not touched. - The initial IBPB support and its usage in context switch - The exposure of the new speculation MSRs to KVM guests. - A fix for a regression in x86/32 related to the cpu entry area - Proper whitelisting for known to be safe CPUs from the mitigations. - objtool fixes to deal proper with retpolines and alternatives - Exclude __init functions from retpolines which speeds up the boot process. - Removal of the syscall64 fast path and related cleanups and simplifications - Removal of the unpatched paravirt mode which is yet another source of indirect unproteced calls. - A new and undisputed version of the module mismatch warning - A couple of cleanup and correctness fixes all over the place Yet another step towards full mitigation. There are a few things still missing like the RBS underflow mitigation for Skylake and other small details, but that's being worked on. That said, I'm taking a belated christmas vacation for a week and hope that everything is magically solved when I'm back on Feb 12th" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/x86: Add IBPB support KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL x86/pti: Mark constant arrays as __initconst x86/spectre: Simplify spectre_v2 command line parsing x86/retpoline: Avoid retpolines for built-in __init functions x86/kvm: Update spectre-v1 mitigation KVM: VMX: make MSR bitmaps per-VCPU x86/paravirt: Remove 'noreplace-paravirt' cmdline option x86/speculation: Use Indirect Branch Prediction Barrier in context switch x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable" x86/spectre: Report get_user mitigation for spectre_v1 nl80211: Sanitize array index in parse_txq_params vfs, fdtable: Prevent bounds-check bypass via speculative execution x86/syscall: Sanitize syscall table de-references under speculation x86/get_user: Use pointer masking to limit speculation ...
| * | | | | | KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRLKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ] ... basically doing exactly what we do for VMX: - Passthrough SPEC_CTRL to guests (if enabled in guest CPUID) - Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest actually used it. Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de
| * | | | | | KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRLKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Based on a patch from Ashok Raj <ashok.raj@intel.com> ] Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for guests that will only mitigate Spectre V2 through IBRS+IBPB and will not be using a retpoline+IBPB based approach. To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for guests that do not actually use the MSR, only start saving and restoring when a non-zero is written to it. No attempt is made to handle STIBP here, intentionally. Filtering STIBP may be added in a future patch, which may require trapping all writes if we don't want to pass it through directly to the guest. [dwmw2: Clean up CPUID bits, save/restore manually, handle reset] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-5-git-send-email-karahmed@amazon.de
| * | | | | | KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIESKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the contents will come directly from the hardware, but user-space can still override it. [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: kvm@vger.kernel.org Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lkml.kernel.org/r/1517522386-18410-4-git-send-email-karahmed@amazon.de
| * | | | | | KVM/x86: Add IBPB supportAshok Raj2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Indirect Branch Predictor Barrier (IBPB) is an indirect branch control mechanism. It keeps earlier branches from influencing later ones. Unlike IBRS and STIBP, IBPB does not define a new mode of operation. It's a command that ensures predicted branch targets aren't used after the barrier. Although IBRS and IBPB are enumerated by the same CPUID enumeration, IBPB is very different. IBPB helps mitigate against three potential attacks: * Mitigate guests from being attacked by other guests. - This is addressed by issing IBPB when we do a guest switch. * Mitigate attacks from guest/ring3->host/ring3. These would require a IBPB during context switch in host, or after VMEXIT. The host process has two ways to mitigate - Either it can be compiled with retpoline - If its going through context switch, and has set !dumpable then there is a IBPB in that path. (Tim's patch: https://patchwork.kernel.org/patch/10192871) - The case where after a VMEXIT you return back to Qemu might make Qemu attackable from guest when Qemu isn't compiled with retpoline. There are issues reported when doing IBPB on every VMEXIT that resulted in some tsc calibration woes in guest. * Mitigate guest/ring0->host/ring0 attacks. When host kernel is using retpoline it is safe against these attacks. If host kernel isn't using retpoline we might need to do a IBPB flush on every VMEXIT. Even when using retpoline for indirect calls, in certain conditions 'ret' can use the BTB on Skylake-era CPUs. There are other mitigations available like RSB stuffing/clearing. * IBPB is issued only for SVM during svm_free_vcpu(). VMX has a vmclear and SVM doesn't. Follow discussion here: https://lkml.org/lkml/2018/1/15/146 Please refer to the following spec for more details on the enumeration and control. Refer here to get documentation about mitigations. https://software.intel.com/en-us/side-channel-security-support [peterz: rebase and changelog rewrite] [karahmed: - rebase - vmx: expose PRED_CMD if guest has it in CPUID - svm: only pass through IBPB if guest has it in CPUID - vmx: support !cpu_has_vmx_msr_bitmap()] - vmx: support nested] [dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS) PRED_CMD is a write-only MSR] Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: kvm@vger.kernel.org Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Jun Nakajima <jun.nakajima@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de
| * | | | | | KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDXKarimAllah Ahmed2018-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [dwmw2: Stop using KF() for bits in it, too] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Link: https://lkml.kernel.org/r/1517522386-18410-2-git-send-email-karahmed@amazon.de
| * | | | | | Merge branch 'msr-bitmaps' of git://git.kernel.org/pub/scm/virt/kvm/kvm into ↵Thomas Gleixner2018-02-03
| |\ \ \ \ \ \ | | | |_|_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | x86/pti Pull the KVM prerequisites so the IBPB patches apply.
| | * | | | | KVM: VMX: make MSR bitmaps per-VCPUPaolo Bonzini2018-01-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Place the MSR bitmap in struct loaded_vmcs, and update it in place every time the x2apic or APICv state can change. This is rare and the loop can handle 64 MSRs per iteration, in a similar fashion as nested_vmx_prepare_msr_bitmap. This prepares for choosing, on a per-VM basis, whether to intercept the SPEC_CTRL and PRED_CMD MSRs. Cc: stable@vger.kernel.org # prereq for Spectre mitigation Suggested-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>