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| * | | | | | | | | module: allow symbol exports to be disabledArd Biesheuvel2018-08-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To allow existing C code to be incorporated into the decompressor or the UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx declarations into nops, and #define it in places where such exports are undesirable. Note that this gets rid of a rather dodgy redefine of linux/export.h's header guard. Link: http://lkml.kernel.org/r/20180704083651.24360-3-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | | | arch: enable relative relocations for arm64, power and x86Ard Biesheuvel2018-08-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "add support for relative references in special sections", v10. This adds support for emitting special sections such as initcall arrays, PCI fixups and tracepoints as relative references rather than absolute references. This reduces the size by 50% on 64-bit architectures, but more importantly, it removes the need for carrying relocation metadata for these sections in relocatable kernels (e.g., for KASLR) that needs to be fixed up at boot time. On arm64, this reduces the vmlinux footprint of such a reference by 8x (8 byte absolute reference + 24 byte RELA entry vs 4 byte relative reference) Patch #3 was sent out before as a single patch. This series supersedes the previous submission. This version makes relative ksymtab entries dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather than trying to infer from kbuild test robot replies for which architectures it should be blacklisted. Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS, and sets it for the main architectures that are expected to benefit the most from this feature, i.e., 64-bit architectures or ones that use runtime relocations. Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of ksymtab/kcrctab sections in decompressor and EFI stub objects when rebuilding existing C files to run in a different context. Patches #4 - #6 implement relative references for initcalls, PCI fixups and tracepoints, respectively, all of which produce sections with order ~1000 entries on an arm64 defconfig kernel with tracing enabled. This means we save about 28 KB of vmlinux space for each of these patches. [From the v7 series blurb, which included the jump_label patches as well]: For the arm64 kernel, all patches combined reduce the memory footprint of vmlinux by about 1.3 MB (using a config copied from Ubuntu that has KASLR enabled), of which ~1 MB is the size reduction of the RELA section in .init, and the remaining 300 KB is reduction of .text/.data. This patch (of 6): Before updating certain subsystems to use place relative 32-bit relocations in special sections, to save space and reduce the number of absolute relocations that need to be processed at runtime by relocatable kernels, introduce the Kconfig symbol and define it for some architectures that should be able to support and benefit from it. Link: http://lkml.kernel.org/r/20180704083651.24360-2-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: James Morris <jmorris@namei.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, Cc: James Morris <james.morris@microsoft.com> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | | | mm, oom: distinguish blockable mode for mmu notifiersMichal Hocko2018-08-22
| |/ / / / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several blockable mmu notifiers which might sleep in mmu_notifier_invalidate_range_start and that is a problem for the oom_reaper because it needs to guarantee a forward progress so it cannot depend on any sleepable locks. Currently we simply back off and mark an oom victim with blockable mmu notifiers as done after a short sleep. That can result in selecting a new oom victim prematurely because the previous one still hasn't torn its memory down yet. We can do much better though. Even if mmu notifiers use sleepable locks there is no reason to automatically assume those locks are held. Moreover majority of notifiers only care about a portion of the address space and there is absolutely zero reason to fail when we are unmapping an unrelated range. Many notifiers do really block and wait for HW which is harder to handle and we have to bail out though. This patch handles the low hanging fruit. __mmu_notifier_invalidate_range_start gets a blockable flag and callbacks are not allowed to sleep if the flag is set to false. This is achieved by using trylock instead of the sleepable lock for most callbacks and continue as long as we do not block down the call chain. I think we can improve that even further because there is a common pattern to do a range lookup first and then do something about that. The first part can be done without a sleeping lock in most cases AFAICS. The oom_reaper end then simply retries if there is at least one notifier which couldn't make any progress in !blockable mode. A retry loop is already implemented to wait for the mmap_sem and this is basically the same thing. The simplest way for driver developers to test this code path is to wrap userspace code which uses these notifiers into a memcg and set the hard limit to hit the oom. This can be done e.g. after the test faults in all the mmu notifier managed memory and set the hard limit to something really small. Then we are looking for a proper process tear down. [akpm@linux-foundation.org: coding style fixes] [akpm@linux-foundation.org: minor code simplification] Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp Reported-by: David Rientjes <rientjes@google.com> Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Mike Marciniszyn <mike.marciniszyn@intel.com> Cc: Dennis Dalessandro <dennis.dalessandro@intel.com> Cc: Sudeep Dutt <sudeep.dutt@intel.com> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | | | Merge tag 'pm-4.19-rc1-2' of ↵Linus Torvalds2018-08-22
|\ \ \ \ \ \ \ \ \ | |/ / / / / / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These fix the main idle loop and the menu cpuidle governor, clean up the latter, fix a mistake in the PCI bus type's support for system suspend and resume, fix the ondemand and conservative cpufreq governors, address a build issue in the system wakeup framework and make the ACPI C-states desciptions less confusing. Specifics: - Make the idle loop handle stopped scheduler tick correctly (Rafael Wysocki). - Prevent the menu cpuidle governor from letting CPUs spend too much time in shallow idle states when it is invoked with scheduler tick stopped and clean it up somewhat (Rafael Wysocki). - Avoid invoking the platform firmware to make the platform enter the ACPI S3 sleep state with suspended PCIe root ports which may confuse the firmware and cause it to crash (Rafael Wysocki). - Fix sysfs-related race in the ondemand and conservative cpufreq governors which may cause the system to crash if the governor module is removed during an update of CPU frequency limits (Henry Willard). - Select SRCU when building the system wakeup framework to avoid a build issue in it (zhangyi). - Make the descriptions of ACPI C-states vendor-neutral to avoid confusion (Prarit Bhargava)" * tag 'pm-4.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: menu: Handle stopped tick more aggressively sched: idle: Avoid retaining the tick when it has been stopped PCI / ACPI / PM: Resume all bridges on suspend-to-RAM cpuidle: menu: Update stale polling override comment cpufreq: governor: Avoid accessing invalid governor_data x86/ACPI/cstate: Make APCI C1 FFH MWAIT C-state description vendor-neutral cpuidle: menu: Fix white space PM / sleep: wakeup: Fix build error caused by missing SRCU support
| * | | | | | | | x86/ACPI/cstate: Make APCI C1 FFH MWAIT C-state description vendor-neutralPrarit Bhargava2018-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5209654a46ee (x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems) forgot to update the ACPI C1 idle state description and tools like turbostat display "ACPI FFH INTEL MWAIT 0x0" which is quite confusing on an AMD system. Drop the "INTEL" part from the ACPI C1 FFH MWAIT C-state description to avoid confusion. Fixes: 5209654a46ee (x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems) Signed-off-by: Prarit Bhargava <prarit@redhat.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | | | | | | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2018-08-19
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull first set of KVM updates from Paolo Bonzini: "PPC: - minor code cleanups x86: - PCID emulation and CR3 caching for shadow page tables - nested VMX live migration - nested VMCS shadowing - optimized IPI hypercall - some optimizations ARM will come next week" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (85 commits) kvm: x86: Set highest physical address bits in non-present/reserved SPTEs KVM/x86: Use CC_SET()/CC_OUT in arch/x86/kvm/vmx.c KVM: X86: Implement PV IPIs in linux guest KVM: X86: Add kvm hypervisor init time platform setup callback KVM: X86: Implement "send IPI" hypercall KVM/x86: Move X86_CR4_OSXSAVE check into kvm_valid_sregs() KVM: x86: Skip pae_root shadow allocation if tdp enabled KVM/MMU: Combine flushing remote tlb in mmu_set_spte() KVM: vmx: skip VMWRITE of HOST_{FS,GS}_BASE when possible KVM: vmx: skip VMWRITE of HOST_{FS,GS}_SEL when possible KVM: vmx: always initialize HOST_{FS,GS}_BASE to zero during setup KVM: vmx: move struct host_state usage to struct loaded_vmcs KVM: vmx: compute need to reload FS/GS/LDT on demand KVM: nVMX: remove a misleading comment regarding vmcs02 fields KVM: vmx: rename __vmx_load_host_state() and vmx_save_host_state() KVM: vmx: add dedicated utility to access guest's kernel_gs_base KVM: vmx: track host_state.loaded using a loaded_vmcs pointer KVM: vmx: refactor segmentation code in vmx_save_host_state() kvm: nVMX: Fix fault priority for VMX operations kvm: nVMX: Fix fault vector for VMX operation at CPL > 0 ...
| * | | | | | | | | kvm: x86: Set highest physical address bits in non-present/reserved SPTEsJunaid Shahid2018-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always set the 5 upper-most supported physical address bits to 1 for SPTEs that are marked as non-present or reserved, to make them unusable for L1TF attacks from the guest. Currently, this just applies to MMIO SPTEs. (We do not need to mark PTEs that are completely 0 as physical page 0 is already reserved.) This allows mitigation of L1TF without disabling hyper-threading by using shadow paging mode instead of EPT. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM/x86: Use CC_SET()/CC_OUT in arch/x86/kvm/vmx.cUros Bizjak2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove open-coded uses of set instructions to use CC_SET()/CC_OUT() in arch/x86/kvm/vmx.c. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> [Mark error paths as unlikely while touching this. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: X86: Implement PV IPIs in linux guestWanpeng Li2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement paravirtual apic hooks to enable PV IPIs for KVM if the "send IPI" hypercall is available. The hypercall lets a guest send IPIs, with at most 128 destinations per hypercall in 64-bit mode and 64 vCPUs per hypercall in 32-bit mode. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: X86: Add kvm hypervisor init time platform setup callbackWanpeng Li2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add kvm hypervisor init time platform setup callback which will be used to replace native apic hooks by pararvirtual hooks. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: X86: Implement "send IPI" hypercallWanpeng Li2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using hypercall to send IPIs by one vmexit instead of one by one for xAPIC/x2APIC physical mode and one vmexit per-cluster for x2APIC cluster mode. Intel guest can enter x2apic cluster mode when interrupt remmaping is enabled in qemu, however, latest AMD EPYC still just supports xapic mode which can get great improvement by Exit-less IPIs. This patchset lets a guest send multicast IPIs, with at most 128 destinations per hypercall in 64-bit mode and 64 vCPUs per hypercall in 32-bit mode. Hardware: Xeon Skylake 2.5GHz, 2 sockets, 40 cores, 80 threads, the VM is 80 vCPUs, IPI microbenchmark(https://lkml.org/lkml/2017/12/19/141): x2apic cluster mode, vanilla Dry-run: 0, 2392199 ns Self-IPI: 6907514, 15027589 ns Normal IPI: 223910476, 251301666 ns Broadcast IPI: 0, 9282161150 ns Broadcast lock: 0, 8812934104 ns x2apic cluster mode, pv-ipi Dry-run: 0, 2449341 ns Self-IPI: 6720360, 15028732 ns Normal IPI: 228643307, 255708477 ns Broadcast IPI: 0, 7572293590 ns => 22% performance boost Broadcast lock: 0, 8316124651 ns x2apic physical mode, vanilla Dry-run: 0, 3135933 ns Self-IPI: 8572670, 17901757 ns Normal IPI: 226444334, 255421709 ns Broadcast IPI: 0, 19845070887 ns Broadcast lock: 0, 19827383656 ns x2apic physical mode, pv-ipi Dry-run: 0, 2446381 ns Self-IPI: 6788217, 15021056 ns Normal IPI: 219454441, 249583458 ns Broadcast IPI: 0, 7806540019 ns => 154% performance boost Broadcast lock: 0, 9143618799 ns Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM/x86: Move X86_CR4_OSXSAVE check into kvm_valid_sregs()Tianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | X86_CR4_OSXSAVE check belongs to sregs check and so move into kvm_valid_sregs(). Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: x86: Skip pae_root shadow allocation if tdp enabledLiang Chen2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Considering the fact that the pae_root shadow is not needed when tdp is in use, skip the pae_root shadow page allocation to allow mmu creation even not being able to obtain memory from DMA32 zone when particular cgroup cpuset.mems or mempolicy control is applied. Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM/MMU: Combine flushing remote tlb in mmu_set_spte()Tianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mmu_set_spte() flushes remote tlbs for drop_parent_pte/drop_spte() and set_spte() separately. This may introduce redundant flush. This patch is to combine these flushes and check flush request after calling set_spte(). Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Reviewed-by: Junaid Shahid <junaids@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: skip VMWRITE of HOST_{FS,GS}_BASE when possibleSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The host's FS.base and GS.base rarely change, e.g. ~0.1% of host/guest swaps on my system. Cache the last value written to the VMCS and skip the VMWRITE to the associated VMCS fields when loading host state if the value hasn't changed since the last VMWRITE. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: skip VMWRITE of HOST_{FS,GS}_SEL when possibleSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a 64-bit host, FS.sel and GS.sel are all but guaranteed to be 0, which in turn means they'll rarely change. Skip the VMWRITE for the associated VMCS fields when loading host state if the selector hasn't changed since the last VMWRITE. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: always initialize HOST_{FS,GS}_BASE to zero during setupSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The HOST_{FS,GS}_BASE fields are guaranteed to be written prior to VMENTER, by way of vmx_prepare_switch_to_guest(). Initialize the fields to zero for 64-bit kernels instead of pulling the base values from their respective MSRs. In addition to eliminating two RDMSRs, vmx_prepare_switch_to_guest() can safely assume the initial value of the fields is zero in all cases. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: move struct host_state usage to struct loaded_vmcsSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make host_state a property of a loaded_vmcs so that it can be used as a cache of the VMCS fields, e.g. to lazily VMWRITE the corresponding VMCS field. Treating host_state as a cache does not work if it's not VMCS specific as the cache would become incoherent when switching between vmcs01 and vmcs02. Move vmcs_host_cr3 and vmcs_host_cr4 into host_state. Explicitly zero out host_state when allocating a new VMCS for a loaded_vmcs. Unlike the pre-existing vmcs_host_cr{3,4} usage, the segment information is not guaranteed to be (re)initialized when running a new nested VMCS, e.g. HOST_FS_BASE is not written in vmx_set_constant_host_state(). Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: compute need to reload FS/GS/LDT on demandSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove fs_reload_needed and gs_ldt_reload_needed from host_state and instead compute whether we need to reload various state at the time we actually do the reload. The state that is tracked by the *_reload_needed variables is not any more volatile than the trackers themselves. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: nVMX: remove a misleading comment regarding vmcs02 fieldsSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | prepare_vmcs02() has an odd comment that says certain fields are "not in vmcs02". AFAICT the intent of the comment is to document that various VMCS fields are not handled by prepare_vmcs02(), e.g. HOST_{FS,GS}_{BASE,SELECTOR}. While technically true, the comment is misleading, e.g. it can lead the reader to think that KVM never writes those fields to vmcs02. Remove the comment altogether as the handling of FS and GS is not specific to nested VMX, and GUEST_PML_INDEX has been written by prepare_vmcs02() since commit "4e59516a12a6 (kvm: vmx: ensure VMCS is current while enabling PML)" Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: rename __vmx_load_host_state() and vmx_save_host_state()Sean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the vmx_load_host_state() wrapper is gone, i.e. the only time we call the core functions is when we're actually about to switch between guest/host, rename the functions that handle lazy state switching to vmx_prepare_switch_to_{guest,host}_state() to better document the full extent of their functionality. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: add dedicated utility to access guest's kernel_gs_baseSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When lazy save/restore of MSR_KERNEL_GS_BASE was introduced[1], the MSR was intercepted in all modes and was only restored for the host when the guest is in 64-bit mode. So at the time, going through the full host restore prior to accessing MSR_KERNEL_GS_BASE was necessary to load host state and was not a significant waste of cycles. Later, MSR_KERNEL_GS_BASE interception was disabled for a 64-bit guest[2], and then unconditionally saved/restored for the host[3]. As a result, loading full host state is overkill for accesses to MSR_KERNEL_GS_BASE, and completely unnecessary when the guest is not in 64-bit mode. Add a dedicated utility to read/write the guest's MSR_KERNEL_GS_BASE (outside of the save/restore flow) to minimize the overhead incurred when accessing the MSR. When setting EFER, only decache the MSR if the new EFER will disable long mode. Removing out-of-band usage of vmx_load_host_state() also eliminates, or at least reduces, potential corner cases in its usage, which in turn will (hopefuly) make it easier to reason about future changes to the save/restore flow, e.g. optimization of saving host state. [1] commit 44ea2b1758d8 ("KVM: VMX: Move MSR_KERNEL_GS_BASE out of the vmx autoload msr area") [2] commit 5897297bc228 ("KVM: VMX: Don't intercept MSR_KERNEL_GS_BASE") [3] commit c8770e7ba63b ("KVM: VMX: Fix host userspace gsbase corruption") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: track host_state.loaded using a loaded_vmcs pointerSean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using 'struct loaded_vmcs*' to track whether the CPU registers contain host or guest state kills two birds with one stone. 1. The (effective) boolean host_state.loaded is poorly named. It does not track whether or not host state is loaded into the CPU registers (which most readers would expect), but rather tracks if host state has been saved AND guest state is loaded. 2. Using a loaded_vmcs pointer provides a more robust framework for the optimized guest/host state switching, especially when consideration per-VMCS enhancements. To that end, WARN_ONCE if we try to switch to host state with a different VMCS than was last used to save host state. Resolve an occurrence of the new WARN by setting loaded_vmcs after the call to vmx_vcpu_put() in vmx_switch_vmcs(). Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: refactor segmentation code in vmx_save_host_state()Sean Christopherson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use local variables in vmx_save_host_state() to temporarily track the selector and base values for FS and GS, and reorganize the code so that the 64-bit vs 32-bit portions are contained within a single #ifdef. This refactoring paves the way for future patches to modify the updating of VMCS state with minimal changes to the code, and (hopefully) simplifies resolving a likely conflict with another in-flight patch[1] by being the whipping boy for future patches. [1] https://www.spinics.net/lists/kvm/msg171647.html Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: nVMX: Fix fault priority for VMX operationsJim Mattson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When checking emulated VMX instructions for faults, the #UD for "IF (not in VMX operation)" should take precedence over the #GP for "ELSIF CPL > 0." Suggested-by: Eric Northup <digitaleric@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: nVMX: Fix fault vector for VMX operation at CPL > 0Jim Mattson2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fault that should be raised for a privilege level violation is #GP rather than #UD. Fixes: 727ba748e110b4 ("kvm: nVMX: Enforce cpl=0 for VMX instructions") Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: vmx: Add tlb_remote_flush callback supportTianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Register tlb_remote_flush callback for vmx when hyperv capability of nested guest mapping flush is detected. The interface can help to reduce overhead when flush ept table among vcpus for nested VM. The tradition way is to send IPIs to all affected vcpus and executes INVEPT on each vcpus. It will trigger several vmexits for IPI and INVEPT emulation. Hyper-V provides such hypercall to do flush for all vcpus and call the hypercall when all ept table pointers of single VM are same. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM: x86: Add tlb remote flush callback in kvm_x86_ops.Tianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is to provide a way for platforms to register hv tlb remote flush callback and this helps to optimize operation of tlb flush among vcpus for nested virtualization case. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | X86/Hyper-V: Add hyperv_nested_flush_guest_mapping ftrace supportTianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is to add hyperv_nested_flush_guest_mapping support to trace hvFlushGuestPhysicalAddressSpace hypercall. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | X86/Hyper-V: Add flush HvFlushGuestPhysicalAddressSpace hypercall supportTianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hyper-V supports a pv hypercall HvFlushGuestPhysicalAddressSpace to flush nested VM address space mapping in l1 hypervisor and it's to reduce overhead of flushing ept tlb among vcpus. This patch is to implement it. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | x86/kvm: Don't use pvqspinlock code if only 1 vCPUWaiman Long2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On a VM with only 1 vCPU, the locking fast path will always be successful. In this case, there is no need to use the the PV qspinlock code which has higher overhead on the unlock side than the native qspinlock code. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | KVM/MMU: Simplify __kvm_sync_page() functionTianyu Lan2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge check of "sp->role.cr4_pae != !!is_pae(vcpu))" and "vcpu-> arch.mmu.sync_page(vcpu, sp) == 0". kvm_mmu_prepare_zap_page() is called under both these conditions. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Remove CR3_PCID_INVD flagJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is a duplicate of X86_CR3_PCID_NOFLUSH. So just use that instead. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Add multi-entry LRU cache for previous CR3sJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds support for storing multiple previous CR3/root_hpa pairs maintained as an LRU cache, so that the lockless CR3 switch path can be used when switching back to any of them. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Flush only affected TLB entries in kvm_mmu_invlpg*Junaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This needs a minor bug fix. The updated patch is as follows. Thanks, Junaid ------------------------------------------------------------------------------ kvm_mmu_invlpg() and kvm_mmu_invpcid_gva() only need to flush the TLB entries for the specific guest virtual address, instead of flushing all TLB entries associated with the VM. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Skip shadow page resync on CR3 switch when indicated by guestJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the guest indicates that the TLB doesn't need to be flushed in a CR3 switch, we can also skip resyncing the shadow page tables since an out-of-sync shadow page table is equivalent to an out-of-sync TLB. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Support selectively freeing either current or previous MMU rootJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_mmu_free_roots() now takes a mask specifying which roots to free, so that either one of the roots (active/previous) can be individually freed when needed. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Add a root_hpa parameter to kvm_mmu->invlpg()Junaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows invlpg() to be called using either the active root_hpa or the prev_root_hpa. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Skip TLB flush on fast CR3 switch when indicated by guestJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When PCIDs are enabled, the MSb of the source operand for a MOV-to-CR3 instruction indicates that the TLB doesn't need to be flushed. This change enables this optimization for MOV-to-CR3s in the guest that have been intercepted by KVM for shadow paging and are handled within the fast CR3 switch path. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: vmx: Support INVPCID in shadow paging modeJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement support for INVPCID in shadow paging mode as well. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Propagate guest PCIDs to host PCIDsJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using shadow paging mode, propagate the guest's PCID value to the shadow CR3 in the host instead of always using PCID 0. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Add ability to skip TLB flush when switching CR3Junaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the implicit flush from the set_cr3 handlers, so that the callers are able to decide whether to flush the TLB or not. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Use fast CR3 switch for nested VMXJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the fast CR3 switch mechanism to locklessly change the MMU root page when switching between L1 and L2. The switch from L2 to L1 should always go through the fast path, while the switch from L1 to L2 should go through the fast path if L1's CR3/EPTP for L2 hasn't changed since the last time. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Support resetting the MMU context without resetting rootsJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for re-initializing the MMU context in a different mode while preserving the active root_hpa and the prev_root. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Add support for fast CR3 switch across different MMU modesJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This generalizes the lockless CR3 switch path to be able to work across different MMU modes (e.g. nested vs non-nested) by checking that the expected page role of the new root page matches the page role of the previously stored root page in addition to checking that the new CR3 matches the previous CR3. Furthermore, instead of loading the hardware CR3 in fast_cr3_switch(), it is now done in vcpu_enter_guest(), as by that time the MMU context would be up-to-date with the VCPU mode. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Introduce KVM_REQ_LOAD_CR3Junaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The KVM_REQ_LOAD_CR3 request loads the hardware CR3 using the current root_hpa. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Introduce kvm_mmu_calc_root_page_role()Junaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions factor out the base role calculation from the corresponding kvm_init_*_mmu() functions. The new functions return what would be the role assigned to a root page in the current VCPU state. This can be masked with mmu_base_role_mask to derive the base role. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Add fast CR3 switch code pathJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using shadow paging, a CR3 switch in the guest results in a VM Exit. In the common case, that VM exit doesn't require much processing by KVM. However, it does acquire the MMU lock, which can start showing signs of contention under some workloads even on a 2 VCPU VM when the guest is using KPTI. Therefore, we add a fast path that avoids acquiring the MMU lock in the most common cases e.g. when switching back and forth between the kernel and user mode CR3s used by KPTI with no guest page table changes in between. For now, this fast path is implemented only for 64-bit guests and hosts to avoid the handling of PDPTEs, but it can be extended later to 32-bit guests and/or hosts as well. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Avoid taking MMU lock in kvm_mmu_sync_roots if no sync is neededJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_mmu_sync_roots() can locklessly check whether a sync is needed and just bail out if it isn't. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | | | | | | kvm: x86: Make sync_page() flush remote TLBs once onlyJunaid Shahid2018-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sync_page() calls set_spte() from a loop across a page table. It would work better if set_spte() left the TLB flushing to its callers, so that sync_page() can aggregate into a single call. Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>