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2018-03-16KVM: x86: add kvm_fast_pio() to consolidate fast PIO codeSean Christopherson
Add kvm_fast_pio() to consolidate duplicate code in VMX and SVM. Unexport kvm_fast_pio_in() and kvm_fast_pio_out(). Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-16KVM: VMX: use kvm_fast_pio_in for handling IN I/OSean Christopherson
Fast emulation of processor I/O for IN was disabled on x86 (both VMX and SVM) some years ago due to a buggy implementation. The addition of kvm_fast_pio_in(), used by SVM, re-introduced (functional!) fast emulation of IN. Piggyback SVM's work and use kvm_fast_pio_in() on VMX instead of performing full emulation of IN. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-16KVM: vVMX: signal failure for nested VMEntry if emulation_requiredSean Christopherson
Fail a nested VMEntry with EXIT_REASON_INVALID_STATE if L2 guest state is invalid, i.e. vmcs12 contained invalid guest state, and unrestricted guest is disabled in L0 (and by extension disabled in L1). WARN_ON_ONCE in handle_invalid_guest_state() if we're attempting to emulate L2, i.e. nested_run_pending is true, to aid debug in the (hopefully unlikely) scenario that we somehow skip the nested VMEntry consistency check, e.g. due to a L0 bug. Note: KVM relies on hardware to detect the scenario where unrestricted guest is enabled in L0 but disabled in L1 and vmcs12 contains invalid guest state, i.e. checking emulation_required in prepare_vmcs02 is required only to handle the case were unrestricted guest is disabled in L0 since L0 never actually attempts VMLAUNCH/VMRESUME with vmcs02. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-16KVM: VMX: WARN on a MOV CR3 exit w/ unrestricted guestSean Christopherson
CR3 load/store exiting are always off when unrestricted guest is enabled. WARN on the associated CR3 VMEXIT to detect code that would re-introduce CR3 load/store exiting for unrestricted guest. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: VMX: give unrestricted guest full control of CR3Sean Christopherson
Now CR3 is not forced to a host-controlled value when paging is disabled in an unrestricted guest, CR3 load/store exiting can be left disabled (for an unrestricted guest). And because CR0.WP and CR4.PAE/PSE are also not force to host-controlled values, all of ept_update_paging_mode_cr0() is no longer needed, i.e. skip ept_update_paging_mode_cr0() for an unrestricted guest. Because MOV CR3 no longer exits when paging is disabled for an unrestricted guest, vmx_decache_cr3() must always read GUEST_CR3 from the VMCS for an unrestricted guest. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: VMX: don't force CR4.PAE/PSE for unrestricted guestSean Christopherson
CR4.PAE - Unrestricted guest can only be enabled when EPT is enabled, and vmx_set_cr4() clears hardware CR0.PAE based on the guest's CR4.PAE, i.e. CR4.PAE always follows the guest's value when unrestricted guest is enabled. CR4.PSE - Unrestricted guest no longer uses the identity mapped IA32 page tables since CR0.PG can be cleared in hardware, thus there is no need to set CR4.PSE when paging is disabled in the guest (and EPT is enabled). Define KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST (to X86_CR4_VMXE) and use it in lieu of KVM_*MODE_VM_CR4_ALWAYS_ON when unrestricted guest is enabled, which removes the forcing of CR4.PAE. Skip the manipulation of CR4.PAE/PSE for EPT when unrestricted guest is enabled, as CR4.PAE isn't forced and so doesn't need to be manually cleared, and CR4.PSE does not need to be set when paging is disabled since the identity mapped IA32 page tables are not used. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: VMX: remove CR0.WP from ..._ALWAYS_ON_UNRESTRICTED_GUESTSean Christopherson
Unrestricted guest can only be enabled when EPT is enabled, and when EPT is enabled, ept_update_paging_mode_cr0() will clear hardware CR0.WP based on the guest's CR0.WP, i.e. CR0.WP always follows the guest's value when unrestricted guest is enabled. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: VMX: don't configure EPT identity map for unrestricted guestSean Christopherson
An unrestricted guest can run with hardware CR0.PG==0, i.e. IA32 paging disabled, in which case there is no need to load the guest's CR3 with identity mapped IA32 page tables since hardware will effectively ignore CR3. If unrestricted guest is enabled, don't configure the identity mapped IA32 page table and always load the guest's desired CR3. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: VMX: don't configure RM TSS for unrestricted guestSean Christopherson
An unrestricted guest can run with CR0.PG==0 and/or CR0.PE==0, e.g. it can run in Real Mode without requiring host emulation. The RM TSS is only used for emulating RM, i.e. it will never be used when unrestricted guest is enabled and so doesn't need to be configured. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16x86/kvm/hyper-v: inject #GP only when invalid SINTx vector is unmaskedVitaly Kuznetsov
Hyper-V 2016 on KVM with SynIC enabled doesn't boot with the following trace: kvm_entry: vcpu 0 kvm_exit: reason MSR_WRITE rip 0xfffff8000131c1e5 info 0 0 kvm_hv_synic_set_msr: vcpu_id 0 msr 0x40000090 data 0x10000 host 0 kvm_msr: msr_write 40000090 = 0x10000 (#GP) kvm_inj_exception: #GP (0x0) KVM acts according to the following statement from TLFS: " 11.8.4 SINTx Registers ... Valid values for vector are 16-255 inclusive. Specifying an invalid vector number results in #GP. " However, I checked and genuine Hyper-V doesn't #GP when we write 0x10000 to SINTx. I checked with Microsoft and they confirmed that if either the Masked bit (bit 16) or the Polling bit (bit 18) is set to 1, then they ignore the value of Vector. Make KVM act accordingly. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16x86/kvm/hyper-v: remove stale entries from vec_bitmap/auto_eoi_bitmap on ↵Vitaly Kuznetsov
vector change When a new vector is written to SINx we update vec_bitmap/auto_eoi_bitmap but we forget to remove old vector from these masks (in case it is not present in some other SINTx). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16x86/kvm/hyper-v: add reenlightenment MSRs supportVitaly Kuznetsov
Nested Hyper-V/Windows guest running on top of KVM will use TSC page clocksource in two cases: - L0 exposes invariant TSC (CPUID.80000007H:EDX[8]). - L0 provides Hyper-V Reenlightenment support (CPUID.40000003H:EAX[13]). Exposing invariant TSC effectively blocks migration to hosts with different TSC frequencies, providing reenlightenment support will be needed when we start migrating nested workloads. Implement rudimentary support for reenlightenment MSRs. For now, these are just read/write MSRs with no effect. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: x86: Update the exit_qualification access bits while walking an addressKarimAllah Ahmed
... to avoid having a stale value when handling an EPT misconfig for MMIO regions. MMIO regions that are not passed-through to the guest are handled through EPT misconfigs. The first time a certain MMIO page is touched it causes an EPT violation, then KVM marks the EPT entry to cause an EPT misconfig instead. Any subsequent accesses to the entry will generate an EPT misconfig. Things gets slightly complicated with nested guest handling for MMIO regions that are not passed through from L0 (i.e. emulated by L0 user-space). An EPT violation for one of these MMIO regions from L2, exits to L0 hypervisor. L0 would then look at the EPT12 mapping for L1 hypervisor and realize it is not present (or not sufficient to serve the request). Then L0 injects an EPT violation to L1. L1 would then update its EPT mappings. The EXIT_QUALIFICATION value for L1 would come from exit_qualification variable in "struct vcpu". The problem is that this variable is only updated on EPT violation and not on EPT misconfig. So if an EPT violation because of a read happened first, then an EPT misconfig because of a write happened afterwards. The L0 hypervisor will still contain exit_qualification value from the previous read instead of the write and end up injecting an EPT violation to the L1 hypervisor with an out of date EXIT_QUALIFICATION. The EPT violation that is injected from L0 to L1 needs to have the correct EXIT_QUALIFICATION specially for the access bits because the individual access bits for MMIO EPTs are updated only on actual access of this specific type. So for the example above, the L1 hypervisor will keep updating only the read bit in the EPT then resume the L2 guest. The L2 guest would end up causing another exit where the L0 *again* will inject another EPT violation to L1 hypervisor with *again* an out of date exit_qualification which indicates a read and not a write. Then this ping-pong just keeps happening without making any forward progress. The behavior of mapping MMIO regions changed in: commit a340b3e229b24 ("kvm: Map PFN-type memory regions as writable (if possible)") ... where an EPT violation for a read would also fixup the write bits to avoid another EPT violation which by acciddent would fix the bug mentioned above. This commit fixes this situation and ensures that the access bits for the exit_qualifcation is up to date. That ensures that even L1 hypervisor running with a KVM version before the commit mentioned above would still work. ( The description above assumes EPT to be available and used by L1 hypervisor + the L1 hypervisor is passing through the MMIO region to the L2 guest while this MMIO region is emulated by the L0 user-space ). 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: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: x86: Make enum conversion explicit in kvm_pdptr_read()Matthias Kaehlcke
The type 'enum kvm_reg_ex' is an extension of 'enum kvm_reg', however the extension is only semantical and the compiler doesn't know about the relationship between the two types. In kvm_pdptr_read() a value of the extended type is passed to kvm_x86_ops->cache_reg(), which expects a value of the base type. Clang raises the following warning about the type mismatch: arch/x86/kvm/kvm_cache_regs.h:44:32: warning: implicit conversion from enumeration type 'enum kvm_reg_ex' to different enumeration type 'enum kvm_reg' [-Wenum-conversion] kvm_x86_ops->cache_reg(vcpu, VCPU_EXREG_PDPTR); Cast VCPU_EXREG_PDPTR to 'enum kvm_reg' to make the compiler happy. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in useVitaly Kuznetsov
Devices which use level-triggered interrupts under Windows 2016 with Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV unconditionally. Our in-kernel IOAPIC implementation emulates an old IOAPIC version which has no EOI register so EOI never happens. The issue was discovered and discussed a while ago: https://www.spinics.net/lists/kvm/msg148098.html While this is a guest OS bug (it should check that IOAPIC has the required capabilities before disabling EOI broadcast) we can workaround it in KVM: advertising DIRECTED_EOI with in-kernel IOAPIC makes little sense anyway. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16KVM: x86: Add support for AMD Core Perf Extension in guestJanakarajan Natarajan
Add support for AMD Core Performance counters in the guest. The base event select and counter MSRs are changed. In addition, with the core extension, there are 2 extra counters available for performance measurements for a total of 6. With the new MSRs, the logic to map them to the gp_counters[] is changed. New functions are added to check the validity of the get/set MSRs. If the guest has the X86_FEATURE_PERFCTR_CORE cpuid flag set, the number of counters available to the vcpu is set to 6. It the flag is not set then it is 4. Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> [Squashed "Expose AMD Core Perf Extension flag to guests" - Radim.] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-16x86/msr: Add AMD Core Perf Extension MSRsJanakarajan Natarajan
Add the EventSelect and Counter MSRs for AMD Core Perf Extension. Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-14KVM: s390: provide counters for all interrupt injects/deliveryChristian Borntraeger
For testing the exitless interrupt support it turned out useful to have separate counters for inject and delivery of I/O interrupt. While at it do the same for all interrupt types. For timer related interrupts (clock comparator and cpu timer) we even had no delivery counters. Fix this as well. On this way some counters are being renamed to have a similar name. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2018-03-14KVM: add machine check counter to kvm_statQingFeng Hao
This counter can be used for administration, debug or test purposes. Suggested-by: Vladislav Mironov <mironov@de.ibm.com> Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-14s390/setup: enable display support for KVM guestFarhan Ali
The S390 architecture does not support any graphics hardware, but with the latest support for Virtio GPU in Linux and Virtio GPU emulation in QEMU, it's possible to enable graphics for S390 using the Virtio GPU device. To enable display we need to enable the Linux Virtual Terminal (VT) layer for S390. But the VT subsystem initializes quite early at boot so we need a dummy console driver till the Virtio GPU driver is initialized and we can run the framebuffer console. The framebuffer console over a Virtio GPU device can be run in combination with the serial SCLP console (default on S390). The SCLP console can still be accessed by management applications (eg: via Libvirt's virsh console). Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <e23b61f4f599ba23881727a1e8880e9d60cc6a48.1519315352.git.alifm@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14s390/char: Rename EBCDIC keymap variablesFarhan Ali
The Linux Virtual Terminal (VT) layer provides a default keymap which is compiled when VT layer is enabled. But at the same time we are also compiling the EBCDIC keymap and this causes the linker to complain. So let's rename the EBCDIC keymap variables to prevent linker conflict. Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <f670a2698d2372e1e990c48a29334ffe894804b1.1519315352.git.alifm@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-14Kconfig: Remove HAS_IOMEM dependency for Graphics supportFarhan Ali
The 'commit e25df1205f37 ("[S390] Kconfig: menus with depends on HAS_IOMEM.")' added the HAS_IOMEM dependecy for "Graphics support". This disabled the "Graphics support" menu for S390. But if we enable VT layer for S390, we would also need to enable the dummy console. So let's remove the HAS_IOMEM dependency. Move this dependency to sub menu items and console drivers that use io memory. Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Message-Id: <6e8ef238162df5be4462126be155975c722e9863.1519315352.git.alifm@linux.vnet.ibm.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-14KVM: s390: fix fallthrough annotationSebastian Ott
A case statement in kvm_s390_shadow_tables uses fallthrough annotations which are not recognized by gcc because they are hidden within a block. Move these annotations out of the block to fix (W=1) warnings like below: arch/s390/kvm/gaccess.c: In function 'kvm_s390_shadow_tables': arch/s390/kvm/gaccess.c:1029:26: warning: this statement may fall through [-Wimplicit-fallthrough=] case ASCE_TYPE_REGION1: { ^ Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-14KVM: s390: add exit io request stats and simplify codeChristian Borntraeger
We want to count IO exit requests in kvm_stat. At the same time we can get rid of the handle_noop function. Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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>
2018-03-14kvm: arm/arm64: vgic-v3: Tighten synchronization for guests using v2 on v3Marc Zyngier
On guest exit, and when using GICv2 on GICv3, we use a dsb(st) to force synchronization between the memory-mapped guest view and the system-register view that the hypervisor uses. This is incorrect, as the spec calls out the need for "a DSB whose required access type is both loads and stores with any Shareability attribute", while we're only synchronizing stores. We also lack an isb after the dsb to ensure that the latter has actually been executed before we start reading stuff from the sysregs. The fix is pretty easy: turn dsb(st) into dsb(sy), and slap an isb() just after. Cc: stable@vger.kernel.org Fixes: f68d2b1b73cc ("arm64: KVM: Implement vgic-v3 save/restore") Acked-by: Christoffer Dall <cdall@kernel.org> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintidMarc Zyngier
The vgic code is trying to be clever when injecting GICv2 SGIs, and will happily populate LRs with the same interrupt number if they come from multiple vcpus (after all, they are distinct interrupt sources). Unfortunately, this is against the letter of the architecture, and the GICv2 architecture spec says "Each valid interrupt stored in the List registers must have a unique VirtualID for that virtual CPU interface.". GICv3 has similar (although slightly ambiguous) restrictions. This results in guests locking up when using GICv2-on-GICv3, for example. The obvious fix is to stop trying so hard, and inject a single vcpu per SGI per guest entry. After all, pending SGIs with multiple source vcpus are pretty rare, and are mostly seen in scenario where the physical CPUs are severely overcomitted. But as we now only inject a single instance of a multi-source SGI per vcpu entry, we may delay those interrupts for longer than strictly necessary, and run the risk of injecting lower priority interrupts in the meantime. In order to address this, we adopt a three stage strategy: - If we encounter a multi-source SGI in the AP list while computing its depth, we force the list to be sorted - When populating the LRs, we prevent the injection of any interrupt of lower priority than that of the first multi-source SGI we've injected. - Finally, the injection of a multi-source SGI triggers the request of a maintenance interrupt when there will be no pending interrupt in the LRs (HCR_NPIE). At the point where the last pending interrupt in the LRs switches from Pending to Active, the maintenance interrupt will be delivered, allowing us to add the remaining SGIs using the same process. Cc: stable@vger.kernel.org Fixes: 0919e84c0fc1 ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework") Acked-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14KVM: arm/arm64: Reduce verbosity of KVM init logArd Biesheuvel
On my GICv3 system, the following is printed to the kernel log at boot: kvm [1]: 8-bit VMID kvm [1]: IDMAP page: d20e35000 kvm [1]: HYP VA range: 800000000000:ffffffffffff kvm [1]: vgic-v2@2c020000 kvm [1]: GIC system register CPU interface enabled kvm [1]: vgic interrupt IRQ1 kvm [1]: virtual timer IRQ4 kvm [1]: Hyp mode initialized successfully The KVM IDMAP is a mapping of a statically allocated kernel structure, and so printing its physical address leaks the physical placement of the kernel when physical KASLR in effect. So change the kvm_info() to kvm_debug() to remove it from the log output. While at it, trim the output a bit more: IRQ numbers can be found in /proc/interrupts, and the HYP VA and vgic-v2 lines are not highly informational either. Cc: <stable@vger.kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14KVM: arm/arm64: Reset mapped IRQs on VM resetChristoffer Dall
We currently don't allow resetting mapped IRQs from userspace, because their state is controlled by the hardware. But we do need to reset the state when the VM is reset, so we provide a function for the 'owner' of the mapped interrupt to reset the interrupt state. Currently only the timer uses mapped interrupts, so we call this function from the timer reset logic. Cc: stable@vger.kernel.org Fixes: 4c60e360d6df ("KVM: arm/arm64: Provide a get_input_level for the arch timer") Signed-off-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14KVM: arm/arm64: Avoid vcpu_load for other vcpu ioctls than KVM_RUNChristoffer Dall
Calling vcpu_load() registers preempt notifiers for this vcpu and calls kvm_arch_vcpu_load(). The latter will soon be doing a lot of heavy lifting on arm/arm64 and will try to do things such as enabling the virtual timer and setting us up to handle interrupts from the timer hardware. Loading state onto hardware registers and enabling hardware to signal interrupts can be problematic when we're not actually about to run the VCPU, because it makes it difficult to establish the right context when handling interrupts from the timer, and it makes the register access code difficult to reason about. Luckily, now when we call vcpu_load in each ioctl implementation, we can simply remove the call from the non-KVM_RUN vcpu ioctls, and our kvm_arch_vcpu_load() is only used for loading vcpu content to the physical CPU when we're actually going to run the vcpu. Cc: stable@vger.kernel.org Fixes: 9b062471e52a ("KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl") Reviewed-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14KVM: arm/arm64: vgic: Add missing irq_lock to vgic_mmio_read_pendingAndre Przywara
Our irq_is_pending() helper function accesses multiple members of the vgic_irq struct, so we need to hold the lock when calling it. Add that requirement as a comment to the definition and take the lock around the call in vgic_mmio_read_pending(), where we were missing it before. Fixes: 96b298000db4 ("KVM: arm/arm64: vgic-new: Add PENDING registers handlers") Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-09KVM: s390: Refactor host cmma and pfmfi interpretation controlsJanosch Frank
use_cmma in kvm_arch means that the KVM hypervisor is allowed to use cmma, whereas use_cmma in the mm context means cmm has been used before. Let's rename the context one to uses_cmm, as the vm does use collaborative memory management but the host uses the cmm assist (interpretation facility). Also let's introduce use_pfmfi, so we can remove the pfmfi disablement when we activate cmma and rather not activate it in the first place. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Message-Id: <1518779775-256056-2-git-send-email-frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-09KVM: s390: implement CPU model only facilitiesChristian Borntraeger
Some facilities should only be provided to the guest, if they are enabled by a CPU model. This allows us to avoid capabilities and to simply fall back to the cpumodel for deciding about a facility without enabling it for older QEMUs or QEMUs without a CPU model. Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-08KVM: nVMX: Enforce NMI controls on vmentry of L2 guestsKrish Sadhukhan
According to Intel SDM 26.2.1.1, the following rules should be enforced on vmentry: * If the "NMI exiting" VM-execution control is 0, "Virtual NMIs" VM-execution control must be 0. * If the “virtual NMIs” VM-execution control is 0, the “NMI-window exiting” VM-execution control must be 0. This patch enforces these rules when entering an L2 guest. Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06KVM: nVMX: expose VMX capabilities for nested hypervisors to userspacePaolo Bonzini
Use the new MSR feature framework to tell userspace which VMX capabilities are available for nested hypervisors. Before, these were only accessible with the KVM_GET_MSR VCPU ioctl, after VCPUs had been created. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06KVM: nVMX: introduce struct nested_vmx_msrsPaolo Bonzini
Move the MSRs to a separate struct, so that we can introduce a global instance and return it from the /dev/kvm KVM_GET_MSRS ioctl. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06KVM: X86: Don't use PV TLB flush with dedicated physical CPUsWanpeng Li
vCPUs are very unlikely to get preempted when they are the only task running on a CPU. PV TLB flush is slower that the native flush in that case, so disable it. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06KVM: X86: Choose qspinlock when dedicated physical CPUs are availableWanpeng Li
Waiman Long mentioned that: > Generally speaking, unfair lock performs well for VMs with a small > number of vCPUs. Native qspinlock may perform better than pvqspinlock > if there is vCPU pinning and there is no vCPU over-commitment. This patch uses the KVM_HINTS_DEDICATED performance hint, which is provided by the hypervisor admin, to choose the qspinlock algorithm when a dedicated physical CPU is available. PV_DEDICATED = 1, PV_UNHALT = anything: default is qspinlock PV_DEDICATED = 0, PV_UNHALT = 1: default is Hybrid PV queued/unfair lock PV_DEDICATED = 0, PV_UNHALT = 0: default is tas Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06KVM: Introduce paravirtualization hints and KVM_HINTS_DEDICATEDWanpeng Li
This patch introduces kvm_para_has_hint() to query for hints about the configuration of the guests. The first hint KVM_HINTS_DEDICATED, is set if the guest has dedicated physical CPUs for each vCPU (i.e. pinning and no over-commitment). This allows optimizing spinlocks and tells the guest to avoid PV TLB flush. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06kvm: use insert sort in kvm_io_bus_register_dev functionGal Hammer
The loading time of a VM is quite significant with a CPU usage reaching 100% when loading a VM that its virtio devices use a large amount of virt-queues (e.g. a virtio-serial device with max_ports=511). Most of the time is spend in re-sorting the kvm_io_bus kvm_io_range array when a new eventfd is registered. The patch replaces the existing method with an insert sort. Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> Reviewed-by: Uri Lublin <ulublin@redhat.com> Signed-off-by: Gal Hammer <ghammer@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.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>
2018-03-06kvm: x86: factor out kvm.arch.hyperv (de)initRoman Kagan
Move kvm.arch.hyperv initialization and cleanup to separate functions. For now only a mutex is inited in the former, and the latter is empty; more stuff will go in there in a followup patch. Signed-off-by: Roman Kagan <rkagan@virtuozzo.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06KVM: s390: fix memory overwrites when not using SCA entriesDavid Hildenbrand
Even if we don't have extended SCA support, we can have more than 64 CPUs if we don't enable any HW features that might use the SCA entries. Now, this works just fine, but we missed a return, which is why we would actually store the SCA entries. If we have more than 64 CPUs, this means writing outside of the basic SCA - bad. Let's fix this. This allows > 64 CPUs when running nested (under vSIE) without random crashes. Fixes: a6940674c384 ("KVM: s390: allow 255 VCPUs when sca entries aren't used") Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20180306132758.21034-1-david@redhat.com> Cc: stable@vger.kernel.org Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-03-04Linux 4.16-rc4v4.16-rc4Linus Torvalds
2018-03-04Merge branch 'x86/urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A small set of fixes for x86: - Add missing instruction suffixes to assembly code so it can be compiled by newer GAS versions without warnings. - Switch refcount WARN exceptions to UD2 as we did in general - Make the reboot on Intel Edison platforms work - A small documentation update so text and sample command match" * 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation, x86, resctrl: Make text and sample command match x86/platform/intel-mid: Handle Intel Edison reboot correctly x86/asm: Add instruction suffixes to bitops x86/entry/64: Add instruction suffix x86/refcounts: Switch to UD2 for exceptions
2018-03-04Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/pti fixes from Thomas Gleixner: "Three fixes related to melted spectrum: - Sync the cpu_entry_area page table to initial_page_table on 32 bit. Otherwise suspend/resume fails because resume uses initial_page_table and triggers a triple fault when accessing the cpu entry area. - Zero the SPEC_CTL MRS on XEN before suspend to address a shortcoming in the hypervisor. - Fix another switch table detection issue in objtool" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table objtool: Fix another switch table detection issue x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
2018-03-04Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "A small set of fixes from the timer departement: - Add a missing timer wheel clock forward when migrating timers off a unplugged CPU to prevent operating on a stale clock base and missing timer deadlines. - Use the proper shift count to extract data from a register value to prevent evaluating unrelated bits - Make the error return check in the FSL timer driver work correctly. Checking an unsigned variable for less than zero does not really work well. - Clarify the confusing comments in the ARC timer code" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Forward timer base before migrating timers clocksource/drivers/arc_timer: Update some comments clocksource/drivers/mips-gic-timer: Use correct shift count to extract data clocksource/drivers/fsl_ftm_timer: Fix error return checking
2018-03-04Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixlet from Thomas Gleixner: "Just a documentation update for the missing device tree property of the R-Car M3N interrupt controller" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: dt-bindings/irqchip/renesas-irqc: Document R-Car M3-N support