summaryrefslogtreecommitdiffstats
path: root/Documentation/virt
AgeCommit message (Collapse)Author
2020-07-05Documentation: virt: kvm/s390-pv: drop doubled wordsRandy Dunlap
Drop the doubled word "the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20200703212906.30655-2-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05Documentation: virt: kvm/api: drop doubled wordsRandy Dunlap
Drop multiple doubled words. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20200703212906.30655-3-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-03Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches x86: - Rework of TLB flushing - Rework of event injection, especially with respect to nested virtualization - Nested AMD event injection facelift, building on the rework of generic code and fixing a lot of corner cases - Nested AMD live migration support - Optimization for TSC deadline MSR writes and IPIs - Various cleanups - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree) - Interrupt-based delivery of asynchronous "page ready" events (host side) - Hyper-V MSRs and hypercalls for guest debugging - VMX preemption timer fixes s390: - Cleanups Generic: - switch vCPU thread wakeup from swait to rcuwait The other architectures, and the guest side of the asynchronous page fault work, will come next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits) KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test KVM: check userspace_addr for all memslots KVM: selftests: update hyperv_cpuid with SynDBG tests x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls x86/kvm/hyper-v: enable hypercalls regardless of hypercall page x86/kvm/hyper-v: Add support for synthetic debugger interface x86/hyper-v: Add synthetic debugger definitions KVM: selftests: VMX preemption timer migration test KVM: nVMX: Fix VMX preemption timer migration x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit KVM: x86/pmu: Support full width counting KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT KVM: x86: acknowledgment mechanism for async pf page ready notifications KVM: x86: interrupt based APF 'page ready' event delivery KVM: introduce kvm_read_guest_offset_cached() KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present() KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously" KVM: VMX: Replace zero-length array with flexible-array ...
2020-06-01Merge tag 'docs-5.8' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "A fair amount of stuff this time around, dominated by yet another massive set from Mauro toward the completion of the RST conversion. I *really* hope we are getting close to the end of this. Meanwhile, those patches reach pretty far afield to update document references around the tree; there should be no actual code changes there. There will be, alas, more of the usual trivial merge conflicts. Beyond that we have more translations, improvements to the sphinx scripting, a number of additions to the sysctl documentation, and lots of fixes" * tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits) Documentation: fixes to the maintainer-entry-profile template zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst tracing: Fix events.rst section numbering docs: acpi: fix old http link and improve document format docs: filesystems: add info about efivars content Documentation: LSM: Correct the basic LSM description mailmap: change email for Ricardo Ribalda docs: sysctl/kernel: document unaligned controls Documentation: admin-guide: update bug-hunting.rst docs: sysctl/kernel: document ngroups_max nvdimm: fixes to maintainter-entry-profile Documentation/features: Correct RISC-V kprobes support entry Documentation/features: Refresh the arch support status files Revert "docs: sysctl/kernel: document ngroups_max" docs: move locking-specific documents to locking/ docs: move digsig docs to the security book docs: move the kref doc into the core-api book docs: add IRQ documentation at the core-api book docs: debugging-via-ohci1394.txt: add it to the core-api book docs: fix references for ipmi.rst file ...
2020-06-01Merge tag 'kvmarm-5.8' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for Linux 5.8: - Move the arch-specific code into arch/arm64/kvm - Start the post-32bit cleanup - Cherry-pick a few non-invasive pre-NV patches
2020-06-01x86/kvm/hyper-v: Add support for synthetic debugger interfaceJon Doron
Add support for Hyper-V synthetic debugger (syndbg) interface. The syndbg interface is using MSRs to emulate a way to send/recv packets data. The debug transport dll (kdvm/kdnet) will identify if Hyper-V is enabled and if it supports the synthetic debugger interface it will attempt to use it, instead of trying to initialize a network adapter. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Jon Doron <arilou@gmail.com> Message-Id: <20200529134543.1127440-4-arilou@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: nVMX: Fix VMX preemption timer migrationPeter Shier
Add new field to hold preemption timer expiration deadline appended to struct kvm_vmx_nested_state_hdr. This is to prevent the first VM-Enter after migration from incorrectly restarting the timer with the full timer value instead of partially decayed timer value. KVM_SET_NESTED_STATE restarts timer using migrated state regardless of whether L1 sets VM_EXIT_SAVE_VMX_PREEMPTION_TIMER. Fixes: cf8b84f48a593 ("kvm: nVMX: Prepare for checkpointing L2 state") Signed-off-by: Peter Shier <pshier@google.com> Signed-off-by: Makarand Sonare <makarandsonare@google.com> Message-Id: <20200526215107.205814-2-makarandsonare@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exitJon Doron
The problem the patch is trying to address is the fact that 'struct kvm_hyperv_exit' has different layout on when compiling in 32 and 64 bit modes. In 64-bit mode the default alignment boundary is 64 bits thus forcing extra gaps after 'type' and 'msr' but in 32-bit mode the boundary is at 32 bits thus no extra gaps. This is an issue as even when the kernel is 64 bit, the userspace using the interface can be both 32 and 64 bit but the same 32 bit userspace has to work with 32 bit kernel. The issue is fixed by forcing the 64 bit layout, this leads to ABI change for 32 bit builds and while we are obviously breaking '32 bit userspace with 32 bit kernel' case, we're fixing the '32 bit userspace with 64 bit kernel' one. As the interface has no (known) users and 32 bit KVM is rather baroque nowadays, this seems like a reasonable decision. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Jon Doron <arilou@gmail.com> Message-Id: <20200424113746.3473563-2-arilou@gmail.com> Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: x86: announce KVM_FEATURE_ASYNC_PF_INTVitaly Kuznetsov
Introduce new capability to indicate that KVM supports interrupt based delivery of 'page ready' APF events. This includes support for both MSR_KVM_ASYNC_PF_INT and MSR_KVM_ASYNC_PF_ACK. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-8-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: x86: acknowledgment mechanism for async pf page ready notificationsVitaly Kuznetsov
If two page ready notifications happen back to back the second one is not delivered and the only mechanism we currently have is kvm_check_async_pf_completion() check in vcpu_run() loop. The check will only be performed with the next vmexit when it happens and in some cases it may take a while. With interrupt based page ready notification delivery the situation is even worse: unlike exceptions, interrupts are not handled immediately so we must check if the slot is empty. This is slow and unnecessary. Introduce dedicated MSR_KVM_ASYNC_PF_ACK MSR to communicate the fact that the slot is free and host should check its notification queue. Mandate using it for interrupt based 'page ready' APF event delivery. As kvm_check_async_pf_completion() is going away from vcpu_run() we need a way to communicate the fact that vcpu->async_pf.done queue has transitioned from empty to non-empty state. Introduce kvm_arch_async_page_present_queued() and KVM_REQ_APF_READY to do the job. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-7-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-01KVM: x86: interrupt based APF 'page ready' event deliveryVitaly Kuznetsov
Concerns were expressed around APF delivery via synthetic #PF exception as in some cases such delivery may collide with real page fault. For 'page ready' notifications we can easily switch to using an interrupt instead. Introduce new MSR_KVM_ASYNC_PF_INT mechanism and deprecate the legacy one. One notable difference between the two mechanisms is that interrupt may not get handled immediately so whenever we would like to deliver next event (regardless of its type) we must be sure the guest had read and cleared previous event in the slot. While on it, get rid on 'type 1/type 2' names for APF events in the documentation as they are causing confusion. Use 'page not present' and 'page ready' everywhere instead. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200525144125.143875-6-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-16KVM: arm64: Support enabling dirty log gradually in small chunksKeqian Zhu
There is already support of enabling dirty log gradually in small chunks for x86 in commit 3c9bd4006bfc ("KVM: x86: enable dirty log gradually in small chunks"). This adds support for arm64. x86 still writes protect all huge pages when DIRTY_LOG_INITIALLY_ALL_SET is enabled. However, for arm64, both huge pages and normal pages can be write protected gradually by userspace. Under the Huawei Kunpeng 920 2.6GHz platform, I did some tests on 128G Linux VMs with different page size. The memory pressure is 127G in each case. The time taken of memory_global_dirty_log_start in QEMU is listed below: Page Size Before After Optimization 4K 650ms 1.8ms 2M 4ms 1.8ms 1G 2ms 1.8ms Besides the time reduction, the biggest improvement is that we will minimize the performance side effect (because of dissolving huge pages and marking memslots dirty) on guest after enabling dirty log. Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200413122023.52583-1-zhukeqian1@huawei.com
2020-05-15KVM: Documentation: Fix up cpuid pagePeter Xu
0x4b564d00 and 0x4b564d01 belong to KVM_FEATURE_CLOCKSOURCE2. Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20200416155913.267562-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-13Merge branch 'kvm-amd-fixes' into HEADPaolo Bonzini
2020-05-06docs/virt/kvm: Document configuring and running nested guestsKashyap Chamarthy
This is a rewrite of this[1] Wiki page with further enhancements. The doc also includes a section on debugging problems in nested environments, among other improvements. [1] https://www.linux-kvm.org/page/Nested_Guests Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com> Message-Id: <20200505112839.30534-1-kchamart@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-05docs: kvm: Fix KVM_KVMCLOCK_CTRL API docJoshua Abraham
The KVM_KVMCLOCK_CTRL ioctl signals to supported KVM guests that the hypervisor has paused it. Update the documentation to reflect that the guest is notified by this API. Signed-off-by: Joshua Abraham <sinisterpatrician@gmail.com> Link: https://lore.kernel.org/r/20200501223624.GA25826@josh-ZenBook Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-28docs: virt/kvm: close inline string literalStephen Kitt
This fixes Documentation/virt/kvm/amd-memory-encryption.rst:76: WARNING: Inline literal start-string without end-string. Fixes: 2da1ed62d55c ("KVM: SVM: document KVM_MEM_ENCRYPT_OP, let userspace detect if SEV is available") Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20200424152637.120876-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-24kvm: add capability for halt pollingDavid Matlack
KVM_CAP_HALT_POLL is a per-VM capability that lets userspace control the halt-polling time, allowing halt-polling to be tuned or disabled on particular VMs. With dynamic halt-polling, a VM's VCPUs can poll from anywhere from [0, halt_poll_ns] on each halt. KVM_CAP_HALT_POLL sets the upper limit on the poll time. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Jon Cargille <jcargill@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20200417221446.108733-1-jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-21KVM: nVMX: Remove non-functional "support" for CR3 target valuesSean Christopherson
Remove all references to cr3_target_value[0-3] and replace the fields in vmcs12 with "dead_space" to preserve the vmcs12 layout. KVM doesn't support emulating CR3-target values, despite a variety of code that implies otherwise, as KVM unconditionally reports '0' for the number of supported CR3-target values. This technically fixes a bug where KVM would incorrectly allow VMREAD and VMWRITE to nonexistent fields, i.e. cr3_target_value[0-3]. Per Intel's SDM, the number of supported CR3-target values reported in VMX_MISC also enumerates the existence of the associated VMCS fields: If a future implementation supports more than 4 CR3-target values, they will be encoded consecutively following the 4 encodings given here. Alternatively, the "bug" could be fixed by actually advertisting support for 4 CR3-target values, but that'd likely just enable kvm-unit-tests given that no one has complained about lack of support for going on ten years, e.g. KVM, Xen and HyperV don't use CR3-target values. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200416000739.9012-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-20docs: fix broken references for ReST files that moved aroundMauro Carvalho Chehab
Some broken references happened due to shifting files around and ReST renames. Those can't be auto-fixed by the script, so let's fix them manually. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com> Link: https://lore.kernel.org/r/64773a12b4410aaf3e3be89e3ec7e34de2484eea.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-20docs: fix broken references to text filesMauro Carvalho Chehab
Several references got broken due to txt to ReST conversion. Several of them can be automatically fixed with: scripts/documentation-file-ref-check --fix Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> # hwtracing/coresight/Kconfig Reviewed-by: Paul E. McKenney <paulmck@kernel.org> # memory-barrier.txt Acked-by: Alex Shi <alex.shi@linux.alibaba.com> # translations/zh_CN Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> # translations/it_IT Acked-by: Marc Zyngier <maz@kernel.org> # kvm/arm64 Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/6f919ddb83a33b5f2a63b6b5f0575737bb2b36aa.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - GICv4.1 support - 32bit host removal PPC: - secure (encrypted) using under the Protected Execution Framework ultravisor s390: - allow disabling GISA (hardware interrupt injection) and protected VMs/ultravisor support. x86: - New dirty bitmap flag that sets all bits in the bitmap when dirty page logging is enabled; this is faster because it doesn't require bulk modification of the page tables. - Initial work on making nested SVM event injection more similar to VMX, and less buggy. - Various cleanups to MMU code (though the big ones and related optimizations were delayed to 5.8). Instead of using cr3 in function names which occasionally means eptp, KVM too has standardized on "pgd". - A large refactoring of CPUID features, which now use an array that parallels the core x86_features. - Some removal of pointer chasing from kvm_x86_ops, which will also be switched to static calls as soon as they are available. - New Tigerlake CPUID features. - More bugfixes, optimizations and cleanups. Generic: - selftests: cleanups, new MMU notifier stress test, steal-time test - CSV output for kvm_stat" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (277 commits) x86/kvm: fix a missing-prototypes "vmread_error" KVM: x86: Fix BUILD_BUG() in __cpuid_entry_get_reg() w/ CONFIG_UBSAN=y KVM: VMX: Add a trampoline to fix VMREAD error handling KVM: SVM: Annotate svm_x86_ops as __initdata KVM: VMX: Annotate vmx_x86_ops as __initdata KVM: x86: Drop __exit from kvm_x86_ops' hardware_unsetup() KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection KVM: x86: Set kvm_x86_ops only after ->hardware_setup() completes KVM: VMX: Configure runtime hooks using vmx_x86_ops KVM: VMX: Move hardware_setup() definition below vmx_x86_ops KVM: x86: Move init-only kvm_x86_ops to separate struct KVM: Pass kvm_init()'s opaque param to additional arch funcs s390/gmap: return proper error code on ksm unsharing KVM: selftests: Fix cosmetic copy-paste error in vm_mem_region_move() KVM: Fix out of range accesses to memslots KVM: X86: Micro-optimize IPI fastpath delay KVM: X86: Delay read msr data iff writes ICR MSR KVM: PPC: Book3S HV: Add a capability for enabling secure guests KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs ...
2020-03-31Merge tag 'kvm-ppc-next-5.7-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD KVM PPC update for 5.7 * Add a capability for enabling secure guests under the Protected Execution Framework ultravisor * Various bug fixes and cleanups.
2020-03-31Merge tag 'kvmarm-5.7' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for Linux 5.7 - GICv4.1 support - 32bit host removal
2020-03-30Merge tag 'kvm-s390-next-5.7-3' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fix for error codes - return the proper error to userspace when a signal interrupts the KSM unsharing operation
2020-03-27s390/gmap: return proper error code on ksm unsharingChristian Borntraeger
If a signal is pending we might return -ENOMEM instead of -EINTR. We should propagate the proper error during KSM unsharing. unmerge_ksm_pages returns -ERESTARTSYS on signal_pending. This gets translated by entry.S to -EINTR. It is important to get this error code so that userspace can retry. To make this clearer we also add -EINTR to the documentation of the PV_ENABLE call, which calls unmerge_ksm_pages. Fixes: 3ac8e38015d4 ("s390/mm: disable KSM for storage key enabled pages") Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-03-26KVM: PPC: Book3S HV: Add a capability for enabling secure guestsPaul Mackerras
At present, on Power systems with Protected Execution Facility hardware and an ultravisor, a KVM guest can transition to being a secure guest at will. Userspace (QEMU) has no way of knowing whether a host system is capable of running secure guests. This will present a problem in future when the ultravisor is capable of migrating secure guests from one host to another, because virtualization management software will have no way to ensure that secure guests only run in domains where all of the hosts can support secure guests. This adds a VM capability which has two functions: (a) userspace can query it to find out whether the host can support secure guests, and (b) userspace can enable it for a guest, which allows that guest to become a secure guest. If userspace does not enable it, KVM will return an error when the ultravisor does the hypercall that indicates that the guest is starting to transition to a secure guest. The ultravisor will then abort the transition and the guest will terminate. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Ram Pai <linuxram@us.ibm.com>
2020-03-24arm: Remove 32bit KVM host supportMarc Zyngier
That's it. Remove all references to KVM itself, and document that although it is no more, the ABI between SVC and HYP still exists. Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Will Deacon <will@kernel.org> Acked-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@arm.com>
2020-03-20KVM: SVM: document KVM_MEM_ENCRYPT_OP, let userspace detect if SEV is availablePaolo Bonzini
Userspace has no way to query if SEV has been disabled with the sev module parameter of kvm-amd.ko. Actually it has one, but it is a hack: do ioctl(KVM_MEM_ENCRYPT_OP, NULL) and check if it returns EFAULT. Make it a little nicer by returning zero for SEV enabled and NULL argument, and while at it document the ioctl arguments. Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16Merge tag 'kvm-s390-next-5.7-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Features and Enhancements for 5.7 part1 1. Allow to disable gisa 2. protected virtual machines Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state like guest memory and guest registers anymore. Instead the PVMs are mostly managed by a new entity called Ultravisor (UV), which provides an API, so KVM and the PV can request management actions. PVMs are encrypted at rest and protected from hypervisor access while running. They switch from a normal operation into protected mode, so we can still use the standard boot process to load a encrypted blob and then move it into protected mode. Rebooting is only possible by passing through the unprotected/normal mode and switching to protected again. One mm related patch will go via Andrews mm tree ( mm/gup/writeback: add callbacks for inaccessible pages)
2020-03-16KVM: Documentation: Update fast page fault for indirect spPeter Xu
Clarify locking.rst to mention early that we're not enabling fast page fault for indirect sps. The previous wording is confusing, in that it seems the proposed solution has been already implemented but it has not. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16KVM: x86: Remove stateful CPUID handlingSean Christopherson
Remove the code for handling stateful CPUID 0x2 and mark the associated flags as deprecated. WARN if host CPUID 0x2.0.AL > 1, i.e. if by some miracle a host with stateful CPUID 0x2 is encountered. No known CPU exists that supports hardware accelerated virtualization _and_ a stateful CPUID 0x2. Barring an extremely contrived nested virtualization scenario, stateful CPUID support is dead code. Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> 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>
2020-03-16KVM: x86: enable dirty log gradually in small chunksJay Zhou
It could take kvm->mmu_lock for an extended period of time when enabling dirty log for the first time. The main cost is to clear all the D-bits of last level SPTEs. This situation can benefit from manual dirty log protect as well, which can reduce the mmu_lock time taken. The sequence is like this: 1. Initialize all the bits of the dirty bitmap to 1 when enabling dirty log for the first time 2. Only write protect the huge pages 3. KVM_GET_DIRTY_LOG returns the dirty bitmap info 4. KVM_CLEAR_DIRTY_LOG will clear D-bit for each of the leaf level SPTEs gradually in small chunks Under the Intel(R) Xeon(R) Gold 6152 CPU @ 2.10GHz environment, I did some tests with a 128G windows VM and counted the time taken of memory_global_dirty_log_start, here is the numbers: VM Size Before After optimization 128G 460ms 10ms Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-27KVM: s390: protvirt: Add KVM api documentationJanosch Frank
Add documentation for KVM_CAP_S390_PROTECTED capability and the KVM_S390_PV_COMMAND ioctl. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27DOCUMENTATION: Protected virtual machine introduction and IPLJanosch Frank
Add documentation about protected KVM guests and description of changes that are necessary to move a KVM VM into Protected Virtualization mode. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: fixing and conversion to rst] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390: protvirt: disallow one_regJanosch Frank
A lot of the registers are controlled by the Ultravisor and never visible to KVM. Some fields in the sie control block are overlayed, like gbea. As no known userspace uses the ONE_REG interface on s390 if sync regs are available, no functionality is lost if it is disabled for protected guests. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27KVM: s390/interrupt: do not pin adapter interrupt pagesUlrich Weigand
The adapter interrupt page containing the indicator bits is currently pinned. That means that a guest with many devices can pin a lot of memory pages in the host. This also complicates the reference tracking which is needed for memory management handling of protected virtual machines. It might also have some strange side effects for madvise MADV_DONTNEED and other things. We can simply try to get the userspace page set the bits and free the page. By storing the userspace address in the irq routing entry instead of the guest address we can actually avoid many lookups and list walks so that this variant is very likely not slower. If userspace messes around with the memory slots the worst thing that can happen is that we write to some other memory within that process. As we get the the page with FOLL_WRITE this can also not be used to write to shared read-only pages. Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch simplification] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-24KVM: s390: rstify new ioctls in api.rstChristian Borntraeger
We also need to rstify the new ioctls that we added in parallel to the rstification of the kvm docs. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: virt: guest-halt-polling.txt convert to ReSTMauro Carvalho Chehab
Due to some merge conflict, this file ended being alone under Documentation/virtual. The file itself is almost at ReST format. Just minor adjustments are needed: - Adjust title markup; - Adjust a list identation; - add a literal block markup; - Add some blank lines. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: review-checklist.txt: rename to ReSTMauro Carvalho Chehab
This file is already in ReST compatible format. So, rename it and add to the kvm's index.rst. While here, use the standard conversion for document titles. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert timekeeping.txt to ReST formatMauro Carvalho Chehab
- Use document title and chapter markups; - Add markups for literal blocks; - Add markups for tables; - use :field: for field descriptions; - Add blank lines and adjust indentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert s390-diag.txt to ReST formatMauro Carvalho Chehab
This file is almost in ReST format. Just one change was needed: - Add markups for a literal block and change its indentation. While here, use the standard markup for the document title. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert ppc-pv.txt to ReST formatMauro Carvalho Chehab
- Use document title and chapter markups; - Add markups for tables; - Use list markups; - Add markups for literal blocks; - Add blank lines. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert nested-vmx.txt to ReST formatMauro Carvalho Chehab
This file is almost in ReST format. Just a small set of changes were needed: - Add markups for lists; - Add markups for a literal block; - Adjust whitespaces. While here, use the standard markup for the document title. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert mmu.txt to ReST formatMauro Carvalho Chehab
- Use document title and chapter markups; - Add markups for tables; - Add markups for literal blocks; - Add blank lines and adjust indentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert locking.txt to ReST formatMauro Carvalho Chehab
- Use document title and chapter markups; - Add markups for literal blocks; - use :field: for field descriptions; - Add blank lines and adjust indentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert hypercalls.txt to ReST formatMauro Carvalho Chehab
- Use document title and chapter markups; - Convert tables; - Add markups for literal blocks; - use :field: for field descriptions; - Add blank lines and adjust indentation Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: arm/psci.txt: convert to ReSTMauro Carvalho Chehab
- Add a title for the document; - Adjust whitespaces for it to be properly formatted after parsed. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert arm/hyp-abi.txt to ReSTMauro Carvalho Chehab
- Add proper markups for titles; - Adjust whitespaces and blank lines to match ReST needs; - Mark literal blocks as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: Convert api.txt to ReST formatMauro Carvalho Chehab
convert api.txt document to ReST format while trying to keep its format as close as possible with the authors intent, and avoid adding uneeded markups. - Use document title and chapter markups; - Convert tables; - Add markups for literal blocks; - use :field: for field descriptions; - Add blank lines and adjust indentation Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>