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2018-10-03kvm: arm64: Allow tuning the physical address size for VMSuzuki K Poulose
Allow specifying the physical address size limit for a new VM via the kvm_type argument for the KVM_CREATE_VM ioctl. This allows us to finalise the stage2 page table as early as possible and hence perform the right checks on the memory slots without complication. The size is encoded as Log2(PA_Size) in bits[7:0] of the type field. For backward compatibility the value 0 is reserved and implies 40bits. Also, lift the limit of the IPA to host limit and allow lower IPA sizes (e.g, 32). The userspace could check the extension KVM_CAP_ARM_VM_IPA_SIZE for the availability of this feature. The cap check returns the maximum limit for the physical address shift supported by the host. Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-20KVM: x86: Control guest reads of MSR_PLATFORM_INFODrew Schmitt
Add KVM_CAP_MSR_PLATFORM_INFO so that userspace can disable guest access to reads of MSR_PLATFORM_INFO. Disabling access to reads of this MSR gives userspace the control to "expose" this platform-dependent information to guests in a clear way. As it exists today, guests that read this MSR would get unpopulated information if userspace hadn't already set it (and prior to this patch series, only the CPUID faulting information could have been populated). This existing interface could be confusing if guests don't handle the potential for incorrect/incomplete information gracefully (e.g. zero reported for base frequency). Signed-off-by: Drew Schmitt <dasch@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-09-12KVM: s390: Make huge pages unavailable in ucontrol VMsJanosch Frank
We currently do not notify all gmaps when using gmap_pmdp_xchg(), due to locking constraints. This makes ucontrol VMs, which is the only VM type that creates multiple gmaps, incompatible with huge pages. Also we would need to hold the guest_table_lock of all gmaps that have this vmaddr maped to synchronize access to the pmd. ucontrol VMs are rather exotic and creating a new locking concept is no easy task. Hence we return EINVAL when trying to active KVM_CAP_S390_HPAGE_1M and report it as being not available when checking for it. Fixes: a4499382 ("KVM: s390: Add huge page enablement control") Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <20180801112508.138159-1-frankja@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2018-08-22KVM: Documentation: rename the capability of KVM_CAP_ARM_SET_SERROR_ESRDongjiu Geng
In the documentation description, this capability's name is KVM_CAP_ARM_SET_SERROR_ESR, but in the header file this capability's name is KVM_CAP_ARM_INJECT_SERROR_ESR, so change the documentation description to make it same. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reported-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-22Merge tag 'kvmarm-for-v4.19' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for 4.19 - Support for Group0 interrupts in guests - Cache management optimizations for ARMv8.4 systems - Userspace interface for RAS, allowing error retrival and injection - Fault path optimization - Emulated physical timer fixes - Random cleanups
2018-08-06kvm: nVMX: Introduce KVM_CAP_NESTED_STATEJim Mattson
For nested virtualization L0 KVM is managing a bit of state for L2 guests, this state can not be captured through the currently available IOCTLs. In fact the state captured through all of these IOCTLs is usually a mix of L1 and L2 state. It is also dependent on whether the L2 guest was running at the moment when the process was interrupted to save its state. With this capability, there are two new vcpu ioctls: KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE. These can be used for saving and restoring a VM that is in VMX operation. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jim Mattson <jmattson@google.com> [karahmed@ - rename structs and functions and make them ready for AMD and address previous comments. - handle nested.smm state. - rebase & a bit of refactoring. - Merge 7/8 and 8/8 into one patch. ] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-30KVM: s390: Add huge page enablement controlJanosch Frank
General KVM huge page support on s390 has to be enabled via the kvm.hpage module parameter. Either nested or hpage can be enabled, as we currently do not support vSIE for huge backed guests. Once the vSIE support is added we will either drop the parameter or enable it as default. For a guest the feature has to be enabled through the new KVM_CAP_S390_HPAGE_1M capability and the hpage module parameter. Enabling it means that cmm can't be enabled for the vm and disables pfmf and storage key interpretation. This is due to the fact that in some cases, in upcoming patches, we have to split huge pages in the guest mapping to be able to set more granular memory protection on 4k pages. These split pages have fake page tables that are not visible to the Linux memory management which subsequently will not manage its PGSTEs, while the SIE will. Disabling these features lets us manage PGSTE data in a consistent matter and solve that problem. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2018-07-21KVM: arm: Add 32bit get/set events supportJames Morse
arm64's new use of KVMs get_events/set_events API calls isn't just or RAS, it allows an SError that has been made pending by KVM as part of its device emulation to be migrated. Wire this up for 32bit too. We only need to read/write the HCR_VA bit, and check that no esr has been provided, as we don't yet support VDFSR. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Dongjiu Geng <gengdongjiu@huawei.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21arm64: KVM: export the capability to set guest SError syndromeDongjiu Geng
For the arm64 RAS Extension, user space can inject a virtual-SError with specified ESR. So user space needs to know whether KVM support to inject such SError, this interface adds this query for this capability. KVM will check whether system support RAS Extension, if supported, KVM returns true to user space, otherwise returns false. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: James Morse <james.morse@arm.com> [expanded documentation wording] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21arm/arm64: KVM: Add KVM_GET/SET_VCPU_EVENTSDongjiu Geng
For the migrating VMs, user space may need to know the exception state. For example, in the machine A, KVM make an SError pending, when migrate to B, KVM also needs to pend an SError. This new IOCTL exports user-invisible states related to SError. Together with appropriate user space changes, user space can get/set the SError exception state to do migrate/snapshot/suspend. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: James Morse <james.morse@arm.com> [expanded documentation wording] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-06-22KVM: fix KVM_CAP_HYPERV_TLBFLUSH paragraph numberVitaly Kuznetsov
KVM_CAP_HYPERV_TLBFLUSH collided with KVM_CAP_S390_PSW-BPB, its paragraph number should now be 8.18. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-05-26kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentationJim Mattson
Document the subtle nuances that KVM_CAP_X86_DISABLE_EXITS induces in the KVM_GET_SUPPORTED_CPUID API. Fixes: 4d5422cea3b6 ("KVM: X86: Provide a capability to disable MWAIT intercepts") Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-05-26KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capabilityVitaly Kuznetsov
We need a new capability to indicate support for the newly added HvFlushVirtualAddress{List,Space}{,Ex} hypercalls. Upon seeing this capability, userspace is supposed to announce PV TLB flush features by setting the appropriate CPUID bits (if needed). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-04-20arm/arm64: KVM: Add PSCI version selection APIMarc Zyngier
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1 or 1.0 to a guest, defaulting to the latest version of the PSCI implementation that is compatible with the requested version. This is no different from doing a firmware upgrade on KVM. But in order to give a chance to hypothetical badly implemented guests that would have a fit by discovering something other than PSCI 0.2, let's provide a new API that allows userspace to pick one particular version of the API. This is implemented as a new class of "firmware" registers, where we expose the PSCI version. This allows the PSCI version to be save/restored as part of a guest migration, and also set to any supported version if the guest requires it. Cc: stable@vger.kernel.org #4.16 Reviewed-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-28KVM: trivial documentation cleanupsAndrew Jones
Add missing entries to the index and ensure the entries are in alphabetical order. Also amd-memory-encryption.rst is an .rst not a .txt. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: X86: Provide a capability to disable HLT interceptsWanpeng Li
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>
2018-03-16KVM: X86: Provide a capability to disable MWAIT interceptsWanpeng Li
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>
2018-03-16Merge tag 'kvm-s390-next-4.17-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: fixes and features - more kvm stat counters - virtio gpu plumbing. The 3 non-KVM/s390 patches have Acks from Bartlomiej Zolnierkiewicz, Heiko Carstens and Greg Kroah-Hartman but all belong together to make virtio-gpu work as a tty. So I carried them in the KVM/s390 tree. - document some KVM_CAPs - cpu-model only facilities - cleanups
2018-03-14KVM: document KVM_CAP_S390_[BPB|PSW|GMAP|COW]Christian Borntraeger
commit 35b3fde6203b ("KVM: s390: wire up bpb feature") has no documentation for KVM_CAP_S390_BPB. While adding this let's also add other missing capabilities like KVM_CAP_S390_PSW, KVM_CAP_S390_GMAP and KVM_CAP_S390_COW. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-06KVM: x86: KVM_CAP_SYNC_REGSKen Hofsass
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>
2018-03-06KVM: x86: add SYNC_REGS_SIZE_BYTES #define.Ken Hofsass
Replace hardcoded padding size value for struct kvm_sync_regs with #define SYNC_REGS_SIZE_BYTES. Also update the value specified in api.txt from outdated hardcoded value to SYNC_REGS_SIZE_BYTES. Signed-off-by: Ken Hofsass <hofsass@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06kvm: x86: hyperv: guest->host event signaling via eventfdRoman Kagan
In Hyper-V, the fast guest->host notification mechanism is the SIGNAL_EVENT hypercall, with a single parameter of the connection ID to signal. Currently this hypercall incurs a user exit and requires the userspace to decode the parameters and trigger the notification of the potentially different I/O context. To avoid the costly user exit, process this hypercall and signal the corresponding eventfd in KVM, similar to ioeventfd. The association between the connection id and the eventfd is established via the newly introduced KVM_HYPERV_EVENTFD ioctl, and maintained in an (srcu-protected) IDR. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: David Hildenbrand <david@redhat.com> [asm/hyperv.h changes approved by KY Srinivasan. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-01KVM: x86: Add a framework for supporting MSR-based featuresTom Lendacky
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>
2018-02-01Merge tag 'kvm-ppc-next-4.16-1' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc PPC KVM update for 4.16 - Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without requiring the complex thread synchronization that earlier CPU versions required. - A series from Ben Herrenschmidt to improve the handling of escalation interrupts with the XIVE interrupt controller. - Provide for the decrementer register to be copied across on migration. - Various minor cleanups and bugfixes.
2018-02-01Merge branch 'x86/hyperv' of ↵Radim Krčmář
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.
2018-01-19KVM: PPC: Book3S: Provide information about hardware/firmware CVE workaroundsPaul Mackerras
This adds a new ioctl, KVM_PPC_GET_CPU_CHAR, that gives userspace information about the underlying machine's level of vulnerability to the recently announced vulnerabilities CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754, and whether the machine provides instructions to assist software to work around the vulnerabilities. The ioctl returns two u64 words describing characteristics of the CPU and required software behaviour respectively, plus two mask words which indicate which bits have been filled in by the kernel, for extensibility. The bit definitions are the same as for the new H_GET_CPU_CHARACTERISTICS hypercall. There is also a new capability, KVM_CAP_PPC_GET_CPU_CHAR, which indicates whether the new ioctl is available. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-01-16Merge branch 'sev-v9-p2' of https://github.com/codomania/kvmPaolo Bonzini
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>
2018-01-16KVM: PPC: Book3S HV: Enable migration of decrementer registerPaul Mackerras
This adds a register identifier for use with the one_reg interface to allow the decrementer expiry time to be read and written by userspace. The decrementer expiry time is in guest timebase units and is equal to the sum of the decrementer and the guest timebase. (The expiry time is used rather than the decrementer value itself because the expiry time is not constantly changing, though the decrementer value is, while the guest vcpu is not running.) Without this, a guest vcpu migrated to a new host will see its decrementer set to some random value. On POWER8 and earlier, the decrementer is 32 bits wide and counts down at 512MHz, so the guest vcpu will potentially see no decrementer interrupts for up to about 4 seconds, which will lead to a stall. With POWER9, the decrementer is now 56 bits side, so the stall can be much longer (up to 2.23 years) and more noticeable. To help work around the problem in cases where userspace has not been updated to migrate the decrementer expiry time, we now set the default decrementer expiry at vcpu creation time to the current time rather than the maximum possible value. This should mean an immediate decrementer interrupt when a migrated vcpu starts running. In cases where the decrementer is 32 bits wide and more than 4 seconds elapse between the creation of the vcpu and when it first runs, the decrementer would have wrapped around to positive values and there may still be a stall - but this is no worse than the current situation. In the large-decrementer case, we are sure to get an immediate decrementer interrupt (assuming the time from vcpu creation to first run is less than 2.23 years) and we thus avoid a very long stall. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-12-06KVM: s390: mark irq_state.flags as non-usableChristian Borntraeger
Old kernels did not check for zero in the irq_state.flags field and old QEMUs did not zero the flag/reserved fields when calling KVM_S390_*_IRQ_STATE. Let's add comments to prevent future uses of these fields. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-12-04KVM: Introduce KVM_MEMORY_ENCRYPT_{UN,}REG_REGION ioctlBrijesh Singh
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>
2017-12-04KVM: Introduce KVM_MEMORY_ENCRYPT_OP ioctlBrijesh Singh
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>
2017-11-16Merge tag 'kvm-s390-next-4.15-1' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux KVM: s390: fixes and improvements for 4.15 - Some initial preparation patches for exitless interrupts and crypto - New capability for AIS migration - Fixes - merge of the sthyi tree from the base s390 team, which moves the sthyi out of KVM into a shared function also for non-KVM
2017-11-09KVM: s390: provide a capability for AIS state migrationChristian Borntraeger
The AIS capability was introduced in 4.12, while the interface to migrate the state was added in 4.13. Unfortunately it is not possible for userspace to detect the migration capability without creating a flic kvm device. As in QEMU the cpu model detection runs on the "none" machine this will result in cpu model issues regarding the "ais" capability. To get the "ais" capability properly let's add a new KVM capability that tells userspace that AIS states can be migrated. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com>
2017-10-12KVM: x86: allow setting identity map addr with no vcpus onlyDavid Hildenbrand
Changing it afterwards doesn't make too much sense and will only result in inconsistencies. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-10-12KVM: x86: document special identity map address valueDavid Hildenbrand
Setting it to 0 leads to setting it to the default value, let's document this. Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-07-14kvm: x86: hyperv: make VP_INDEX managed by userspaceRoman Kagan
Hyper-V identifies vCPUs by Virtual Processor Index, which can be queried via HV_X64_MSR_VP_INDEX msr. It is defined by the spec as a sequential number which can't exceed the maximum number of vCPUs per VM. APIC ids can be sparse and thus aren't a valid replacement for VP indices. Current KVM uses its internal vcpu index as VP_INDEX. However, to make it predictable and persistent across VM migrations, the userspace has to control the value of VP_INDEX. This patch achieves that, by storing vp_index explicitly on vcpu, and allowing HV_X64_MSR_VP_INDEX to be set from the host side. For compatibility it's initialized to KVM vcpu index. Also a few variables are renamed to make clear distinction betweed this Hyper-V vp_index and KVM vcpu_id (== APIC id). Besides, a new capability, KVM_CAP_HYPERV_VP_INDEX, is added to allow the userspace to skip attempting msr writes where unsupported, to avoid spamming error logs. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-07-13kvm: x86: hyperv: add KVM_CAP_HYPERV_SYNIC2Roman Kagan
There is a flaw in the Hyper-V SynIC implementation in KVM: when message page or event flags page is enabled by setting the corresponding msr, KVM zeroes it out. This is problematic because on migration the corresponding MSRs are loaded on the destination, so the content of those pages is lost. This went unnoticed so far because the only user of those pages was in-KVM hyperv synic timers, which could continue working despite that zeroing. Newer QEMU uses those pages for Hyper-V VMBus implementation, and zeroing them breaks the migration. Besides, in newer QEMU the content of those pages is fully managed by QEMU, so zeroing them is undesirable even when writing the MSRs from the guest side. To support this new scheme, introduce a new capability, KVM_CAP_HYPERV_SYNIC2, which, when enabled, makes sure that the synic pages aren't zeroed out in KVM. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-07-03Merge branch 'kvm-ppc-next' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD - Better machine check handling for HV KVM - Ability to support guests with threads=2, 4 or 8 on POWER9 - Fix for a race that could cause delayed recognition of signals - Fix for a bug where POWER9 guests could sleep with interrupts pending.
2017-06-22KVM: s390: ioctls to get and set guest storage attributesClaudio Imbrenda
* Add the struct used in the ioctls to get and set CMMA attributes. * Add the two functions needed to get and set the CMMA attributes for guest pages. * Add the two ioctls that use the aforementioned functions. Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-06-22KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modesPaul Mackerras
Now that userspace can set the virtual SMT mode by enabling the KVM_CAP_PPC_SMT capability, it is useful for userspace to be able to query the set of possible virtual SMT modes. This provides a new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this information. The return value is a bitmap of possible modes, with bit N set if virtual SMT mode 2^N is available. That is, 1 indicates SMT1 is available, 2 indicates that SMT2 is available, 3 indicates that both SMT1 and SMT2 are available, and so on. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-21KVM: PPC: Book3S HV: Add new capability to control MCE behaviourAravinda Prasad
This introduces a new KVM capability to control how KVM behaves on machine check exception (MCE) in HV KVM guests. If this capability has not been enabled, KVM redirects machine check exceptions to guest's 0x200 vector, if the address in error belongs to the guest. With this capability enabled, KVM will cause a guest exit with the exit reason indicating an NMI. The new capability is required to avoid problems if a new kernel/KVM is used with an old QEMU, running a guest that doesn't issue "ibm,nmi-register". As old QEMU does not understand the NMI exit type, it treats it as a fatal error. However, the guest could have handled the machine check error if the exception was delivered to guest's 0x200 interrupt vector instead of NMI exit in case of old QEMU. [paulus@ozlabs.org - Reworded the commit message to be clearer, enable only on HV KVM.] Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-19KVM: PPC: Book3S HV: Allow userspace to set the desired SMT modePaul Mackerras
This allows userspace to set the desired virtual SMT (simultaneous multithreading) mode for a VM, that is, the number of VCPUs that get assigned to each virtual core. Previously, the virtual SMT mode was fixed to the number of threads per subcore, and if userspace wanted to have fewer vcpus per vcore, then it would achieve that by using a sparse CPU numbering. This had the disadvantage that the vcpu numbers can get quite large, particularly for SMT1 guests on a POWER8 with 8 threads per core. With this patch, userspace can set its desired virtual SMT mode and then use contiguous vcpu numbering. On POWER8, where the threading mode is "strict", the virtual SMT mode must be less than or equal to the number of threads per subcore. On POWER9, which implements a "loose" threading mode, the virtual SMT mode can be any power of 2 between 1 and 8, even though there is effectively one thread per subcore, since the threads are independent and can all be in different partitions. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-04-28KVM: Documentation: remove VM mmap documentationJann Horn
Since commit 80f5b5e700fa9c ("KVM: remove vm mmap method"), the VM mmap handler is gone. Remove the corresponding documentation. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-27Merge tag 'kvm-arm-for-v4.12' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM Changes for v4.12. Changes include: - Using the common sysreg definitions between KVM and arm64 - Improved hyp-stub implementation with support for kexec and kdump on the 32-bit side - Proper PMU exception handling - Performance improvements of our GIC handling - Support for irqchip in userspace with in-kernel arch-timers and PMU support - A fix for a race condition in our PSCI code Conflicts: Documentation/virtual/kvm/api.txt include/uapi/linux/kvm.h
2017-04-21kvm: better MWAIT emulation for guestsMichael S. Tsirkin
Guests that are heavy on futexes end up IPI'ing each other a lot. That can lead to significant slowdowns and latency increase for those guests when running within KVM. If only a single guest is needed on a host, we have a lot of spare host CPU time we can throw at the problem. Modern CPUs implement a feature called "MWAIT" which allows guests to wake up sleeping remote CPUs without an IPI - thus without an exit - at the expense of never going out of guest context. The decision whether this is something sensible to use should be up to the VM admin, so to user space. We can however allow MWAIT execution on systems that support it properly hardware wise. This patch adds a CAP to user space and a KVM cpuid leaf to indicate availability of native MWAIT execution. With that enabled, the worst a guest can do is waste as many cycles as a "jmp ." would do, so it's not a privilege problem. We consciously do *not* expose the feature in our CPUID bitmap, as most people will want to benefit from sleeping vCPUs to allow for over commit. Reported-by: "Gabriel L. Somlo" <gsomlo@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> [agraf: fix amd, change commit message] Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-11Merge tag 'kvm-s390-next-4.12-1' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux From: Christian Borntraeger <borntraeger@de.ibm.com> KVM: s390: features for 4.12 1. guarded storage support for guests This contains an s390 base Linux feature branch that is necessary to implement the KVM part 2. Provide an interface to implement adapter interruption suppression which is necessary for proper zPCI support 3. Use more defines instead of numbers 4. Provide logging for lazy enablement of runtime instrumentation
2017-04-09KVM: arm/arm64: Add ARM user space interrupt signaling ABIAlexander Graf
We have 2 modes for dealing with interrupts in the ARM world. We can either handle them all using hardware acceleration through the vgic or we can emulate a gic in user space and only drive CPU IRQ pins from there. Unfortunately, when driving IRQs from user space, we never tell user space about events from devices emulated inside the kernel, which may result in interrupt line state changes, so we lose out on for example timer and PMU events if we run with user space gic emulation. Define an ABI to publish such device output levels to userspace. Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07KVM: x86: drop legacy device assignmentPaolo Bonzini
Legacy device assignment has been deprecated since 4.2 (released 1.5 years ago). VFIO is better and everyone should have switched to it. If they haven't, this should convince them. :) Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-07KVM: s390: introduce AIS capabilityYi Min Zhao
Introduce a cap to enable AIS facility bit, and add documentation for this capability. Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com> Signed-off-by: Fei Li <sherrylf@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-04-06Merge tag 'kvm_mips_4.12_1' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/kvm-mips From: James Hogan <james.hogan@imgtec.com> KVM: MIPS: VZ support, Octeon III, and TLBR Add basic support for the MIPS Virtualization Module (generally known as MIPS VZ) in KVM. We primarily support the ImgTec P5600, P6600, I6400, and Cavium Octeon III cores so far. Support is included for the following VZ / guest hardware features: - MIPS32 and MIPS64, r5 (VZ requires r5 or later) and r6 - TLBs with GuestID (IMG cores) or Root ASID Dealias (Octeon III) - Shared physical root/guest TLB (IMG cores) - FPU / MSA - Cop0 timer (up to 1GHz for now due to soft timer limit) - Segmentation control (EVA) - Hardware page table walker (HTW) both for root and guest TLB Also included is a proper implementation of the TLBR instruction for the trap & emulate MIPS KVM implementation. Preliminary MIPS architecture changes are applied directly with Ralf's ack.