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2018-01-16KVM: x86: Optimization: Create SVM stubs for sync_pir_to_irr()Liran Alon
sync_pir_to_irr() is only called if vcpu->arch.apicv_active()==true. In case it is false, VMX code make sure to set sync_pir_to_irr to NULL. Therefore, having SVM stubs allows to remove check for if sync_pir_to_irr != NULL from all calling sites. Signed-off-by: Liran Alon <liran.alon@oracle.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> [Return highest IRR in the SVM case. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: nVMX: Fix bug of injecting L2 exception into L1Liran Alon
kvm_clear_exception_queue() should clear pending exception. This also includes exceptions which were only marked pending but not yet injected. This is because exception.pending is used for both L1 and L2 to determine if an exception should be raised to guest. Note that an exception which is pending but not yet injected will be raised again once the guest will be resumed. Consider the following scenario: 1) L0 KVM with ignore_msrs=false. 2) L1 prepare vmcs12 with the following: a) No intercepts on MSR (MSR_BITMAP exist and is filled with 0). b) No intercept for #GP. c) vmx-preemption-timer is configured. 3) L1 enters into L2. 4) L2 reads an unhandled MSR that exists in MSR_BITMAP (such as 0x1fff). L2 RDMSR could be handled as described below: 1) L2 exits to L0 on RDMSR and calls handle_rdmsr(). 2) handle_rdmsr() calls kvm_inject_gp() which sets KVM_REQ_EVENT, exception.pending=true and exception.injected=false. 3) vcpu_enter_guest() consumes KVM_REQ_EVENT and calls inject_pending_event() which calls vmx_check_nested_events() which sees that exception.pending=true but nested_vmx_check_exception() returns 0 and therefore does nothing at this point. However let's assume it later sees vmx-preemption-timer expired and therefore exits from L2 to L1 by calling nested_vmx_vmexit(). 4) nested_vmx_vmexit() calls prepare_vmcs12() which calls vmcs12_save_pending_event() but it does nothing as exception.injected is false. Also prepare_vmcs12() calls kvm_clear_exception_queue() which does nothing as exception.injected is already false. 5) We now return from vmx_check_nested_events() with 0 while still having exception.pending=true! 6) Therefore inject_pending_event() continues and we inject L2 exception to L1!... This commit will fix above issue by changing step (4) to clear exception.pending in kvm_clear_exception_queue(). Fixes: 664f8e26b00c ("KVM: X86: Fix loss of exception which has not yet been injected") Signed-off-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16kvm/vmx: Use local vmx variable in vmx_get_msr()Borislav Petkov
... just like in vmx_set_msr(). No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: MMU: consider host cache mode in MMIO page checkHaozhong Zhang
Some reserved pages, such as those from NVDIMM DAX devices, are not for MMIO, and can be mapped with cached memory type for better performance. However, the above check misconceives those pages as MMIO. Because KVM maps MMIO pages with UC memory type, the performance of guest accesses to those pages would be harmed. Therefore, we check the host memory type in addition and only treat UC/UC-/WC pages as MMIO. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Reported-by: Cuevas Escareno, Ivan D <ivan.d.cuevas.escareno@intel.com> Reported-by: Kumar, Karthik <karthik.kumar@intel.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16x86/mm: add a function to check if a pfn is UC/UC-/WCHaozhong Zhang
Check whether the PAT memory type of a pfn cannot be overridden by MTRR UC memory type, i.e. the PAT memory type is UC, UC- or WC. This function will be used by KVM to distinguish MMIO pfns and give them UC memory type in the EPT page tables (on Intel processors, EPT memory types work like MTRRs). Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16Merge branch 'kvm-insert-lfence'Paolo Bonzini
Topic branch for CVE-2017-5753, avoiding conflicts in the next merge window.
2018-01-16KVM: x86: prefer "depends on" to "select" for SEVPaolo Bonzini
Avoid reverse dependencies. Instead, SEV will only be enabled if the PSP driver is available. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16Merge branch 'sev-v9-p2' of https://github.com/codomania/kvmPaolo Bonzini
This part of Secure Encrypted Virtualization (SEV) patch series focuses on KVM changes required to create and manage SEV guests. SEV is an extension to the AMD-V architecture which supports running encrypted virtual machine (VMs) under the control of a hypervisor. Encrypted VMs have their pages (code and data) secured such that only the guest itself has access to unencrypted version. Each encrypted VM is associated with a unique encryption key; if its data is accessed to a different entity using a different key the encrypted guest's data will be incorrectly decrypted, leading to unintelligible data. This security model ensures that hypervisor will no longer able to inspect or alter any guest code or data. The key management of this feature is handled by a separate processor known as the AMD Secure Processor (AMD-SP) which is present on AMD SOCs. The SEV Key Management Specification (see below) provides a set of commands which can be used by hypervisor to load virtual machine keys through the AMD-SP driver. The patch series adds a new ioctl in KVM driver (KVM_MEMORY_ENCRYPT_OP). The ioctl will be used by qemu to issue SEV guest-specific commands defined in Key Management Specification. The following links provide additional details: AMD Memory Encryption white paper: http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf AMD64 Architecture Programmer's Manual: http://support.amd.com/TechDocs/24593.pdf SME is section 7.10 SEV is section 15.34 SEV Key Management: http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf KVM Forum Presentation: http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf SEV Guest BIOS support: SEV support has been add to EDKII/OVMF BIOS https://github.com/tianocore/edk2 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-01-16KVM: x86: avoid unnecessary XSETBV on guest entryPaolo Bonzini
xsetbv can be expensive when running on nested virtualization, try to avoid it. Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Quan Xu <quan.xu0@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: x86: fix escape of guest dr6 to the hostWanpeng Li
syzkaller reported: WARNING: CPU: 0 PID: 12927 at arch/x86/kernel/traps.c:780 do_debug+0x222/0x250 CPU: 0 PID: 12927 Comm: syz-executor Tainted: G OE 4.15.0-rc2+ #16 RIP: 0010:do_debug+0x222/0x250 Call Trace: <#DB> debug+0x3e/0x70 RIP: 0010:copy_user_enhanced_fast_string+0x10/0x20 </#DB> _copy_from_user+0x5b/0x90 SyS_timer_create+0x33/0x80 entry_SYSCALL_64_fastpath+0x23/0x9a The testcase sets a watchpoint (with perf_event_open) on a buffer that is passed to timer_create() as the struct sigevent argument. In timer_create(), copy_from_user()'s rep movsb triggers the BP. The testcase also sets the debug registers for the guest. However, KVM only restores host debug registers when the host has active watchpoints, which triggers a race condition when running the testcase with multiple threads. The guest's DR6.BS bit can escape to the host before another thread invokes timer_create(), and do_debug() complains. The fix is to respect do_debug()'s dr6 invariant when leaving KVM. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: X86: support paravirtualized help for TLB shootdownsWanpeng Li
When running on a virtual machine, IPIs are expensive when the target CPU is sleeping. Thus, it is nice to be able to avoid them for TLB shootdowns. KVM can just do the flush via INVVPID on the guest's behalf the next time the CPU is scheduled. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> [Use "&" to test the bit instead of "==". - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: X86: introduce invalidate_gpa argument to tlb flushWanpeng Li
Introduce a new bool invalidate_gpa argument to kvm_x86_ops->tlb_flush, it will be used by later patches to just flush guest tlb. For VMX, this will use INVVPID instead of INVEPT, which will invalidate combined mappings while keeping guest-physical mappings. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: X86: use paravirtualized TLB ShootdownWanpeng Li
Remote TLB flush does a busy wait which is fine in bare-metal scenario. But with-in the guest, the vcpus might have been pre-empted or blocked. In this scenario, the initator vcpu would end up busy-waiting for a long amount of time; it also consumes CPU unnecessarily to wake up the target of the shootdown. This patch set adds support for KVM's new paravirtualized TLB flush; remote TLB flush does not wait for vcpus that are sleeping, instead KVM will flush the TLB as soon as the vCPU starts running again. The improvement is clearly visible when the host is overcommitted; in this case, the PV TLB flush (in addition to avoiding the wait on the main CPU) prevents preempted vCPUs from stealing precious execution time from the running ones. Testing on a Xeon Gold 6142 2.6GHz 2 sockets, 32 cores, 64 threads, so 64 pCPUs, and each VM is 64 vCPUs. ebizzy -M vanilla optimized boost 1VM 46799 48670 4% 2VM 23962 42691 78% 3VM 16152 37539 132% Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: X86: Add KVM_VCPU_PREEMPTEDWanpeng Li
The next patch will add another bit to the preempted field in kvm_steal_time. Define a constant for bit 0 (the only one that is currently used). Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-16KVM: s390: cleanup struct kvm_s390_float_interruptDavid Hildenbrand
"wq" is not used at all. "cpuflags" can be access directly via the vcpu, just as "float_int" via vcpu->kvm. While at it, reuse _set_cpuflag() to make the code look nicer. Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20180108193747.10818-1-david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-01-16KVM: s390: drop use of spin lock in __floating_irq_kickMichael Mueller
It is not required to take to a lock to protect access to the cpuflags of the local interrupt structure of a vcpu as the performed operation is an atomic_or. Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-01-16KVM: s390: add debug tracing for cpu features of CPU modelChristian Borntraeger
The cpu model already traces the cpu facilities, the ibc and guest CPU ids. We should do the same for the cpu features (on success only). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2018-01-16KVM: s390: use created_vcpus in more placesChristian Borntraeger
commit a03825bbd0c3 ("KVM: s390: use kvm->created_vcpus") introduced kvm->created_vcpus to avoid races with the existing kvm->online_vcpus scheme. One place was "forgotten" and one new place was "added". Let's fix those. Reported-by: Halil Pasic <pasic@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Fixes: 4e0b1ab72b8a ("KVM: s390: gs support for kvm guests") Fixes: a03825bbd0c3 ("KVM: s390: use kvm->created_vcpus")
2018-01-16s390x/mm: cleanup gmap_pte_op_walk()David Hildenbrand
gmap_mprotect_notify() refuses shadow gmaps. Turns out that a) gmap_protect_range() b) gmap_read_table() c) gmap_pte_op_walk() Are never called for gmap shadows. And never should be. This dates back to gmap shadow prototypes where we allowed to call mprotect_notify() on the gmap shadow (to get notified about the prefix pages getting removed). This is avoided by always getting notified about any change on the gmap shadow. The only real function for walking page tables on shadow gmaps is gmap_table_walk(). So, essentially, these functions should never get called and gmap_pte_op_walk() can be cleaned up. Add some checks to callers of gmap_pte_op_walk(). Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20171110151805.7541-1-david@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-01-16KVM: arm64: Emulate RAS error registers and set HCR_EL2's TERR & TEADongjiu Geng
ARMv8.2 adds a new bit HCR_EL2.TEA which routes synchronous external aborts to EL2, and adds a trap control bit HCR_EL2.TERR which traps all Non-secure EL1&0 error record accesses to EL2. This patch enables the two bits for the guest OS, guaranteeing that KVM takes external aborts and traps attempts to access the physical error registers. ERRIDR_EL1 advertises the number of error records, we return zero meaning we can treat all the other registers as RAZ/WI too. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> [removed specific emulation, use trap_raz_wi() directly for everything, rephrased parts of the commit message] Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm64: Handle RAS SErrors from EL2 on guest exitJames Morse
We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. The current SError from EL2 code unmasks SError and tries to fence any pending SError into a single instruction window. It then leaves SError unmasked. With the v8.2 RAS Extensions we may take an SError for a 'corrected' error, but KVM is only able to handle SError from EL2 if they occur during this single instruction window... The RAS Extensions give us a new instruction to synchronise and consume SErrors. The RAS Extensions document (ARM DDI0587), '2.4.1 ESB and Unrecoverable errors' describes ESB as synchronising SError interrupts generated by 'instructions, translation table walks, hardware updates to the translation tables, and instruction fetches on the same PE'. This makes ESB equivalent to KVMs existing 'dsb, mrs-daifclr, isb' sequence. Use the alternatives to synchronise and consume any SError using ESB instead of unmasking and taking the SError. Set ARM_EXIT_WITH_SERROR_BIT in the exit_code so that we can restart the vcpu if it turns out this SError has no impact on the vcpu. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm64: Handle RAS SErrors from EL1 on guest exitJames Morse
We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. For SError that interrupt a guest and are routed to EL2 the existing behaviour is to inject an impdef SError into the guest. Add code to handle RAS SError based on the ESR. For uncontained and uncategorized errors arm64_is_fatal_ras_serror() will panic(), these errors compromise the host too. All other error types are contained: For the fatal errors the vCPU can't make progress, so we inject a virtual SError. We ignore contained errors where we can make progress as if we're lucky, we may not hit them again. If only some of the CPUs support RAS the guest will see the cpufeature sanitised version of the id registers, but we may still take RAS SError on this CPU. Move the SError handling out of handle_exit() into a new handler that runs before we can be preempted. This allows us to use this_cpu_has_cap(), via arm64_is_ras_serror(). Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm64: Save ESR_EL2 on guest SErrorJames Morse
When we exit a guest due to an SError the vcpu fault info isn't updated with the ESR. Today this is only done for traps. The v8.2 RAS Extensions define ISS values for SError. Update the vcpu's fault_info with the ESR on SError so that handle_exit() can determine if this was a RAS SError and decode its severity. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm64: Save/Restore guest DISR_EL1James Morse
If we deliver a virtual SError to the guest, the guest may defer it with an ESB instruction. The guest reads the deferred value via DISR_EL1, but the guests view of DISR_EL1 is re-mapped to VDISR_EL2 when HCR_EL2.AMO is set. Add the KVM code to save/restore VDISR_EL2, and make it accessible to userspace as DISR_EL1. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm64: Set an impdef ESR for Virtual-SError using VSESR_EL2.James Morse
Prior to v8.2's RAS Extensions, the HCR_EL2.VSE 'virtual SError' feature generated an SError with an implementation defined ESR_EL1.ISS, because we had no mechanism to specify the ESR value. On Juno this generates an all-zero ESR, the most significant bit 'ISV' is clear indicating the remainder of the ISS field is invalid. With the RAS Extensions we have a mechanism to specify this value, and the most significant bit has a new meaning: 'IDS - Implementation Defined Syndrome'. An all-zero SError ESR now means: 'RAS error: Uncategorized' instead of 'no valid ISS'. Add KVM support for the VSESR_EL2 register to specify an ESR value when HCR_EL2.VSE generates a virtual SError. Change kvm_inject_vabt() to specify an implementation-defined value. We only need to restore the VSESR_EL2 value when HCR_EL2.VSE is set, KVM save/restores this bit during __{,de}activate_traps() and hardware clears the bit once the guest has consumed the virtual-SError. Future patches may add an API (or KVM CAP) to pend a virtual SError with a specified ESR. Cc: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16KVM: arm/arm64: mask/unmask daif around VHE guestsJames Morse
Non-VHE systems take an exception to EL2 in order to world-switch into the guest. When returning from the guest KVM implicitly restores the DAIF flags when it returns to the kernel at EL1. With VHE none of this exception-level jumping happens, so KVMs world-switch code is exposed to the host kernel's DAIF values, and KVM spills the guest-exit DAIF values back into the host kernel. On entry to a guest we have Debug and SError exceptions unmasked, KVM has switched VBAR but isn't prepared to handle these. On guest exit Debug exceptions are left disabled once we return to the host and will stay this way until we enter user space. Add a helper to mask/unmask DAIF around VHE guests. The unmask can only happen after the hosts VBAR value has been synchronised by the isb in __vhe_hyp_call (via kvm_call_hyp()). Masking could be as late as setting KVMs VBAR value, but is kept here for symmetry. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: kernel: Prepare for a DISR userJames Morse
KVM would like to consume any pending SError (or RAS error) after guest exit. Today it has to unmask SError and use dsb+isb to synchronise the CPU. With the RAS extensions we can use ESB to synchronise any pending SError. Add the necessary macros to allow DISR to be read and converted to an ESR. We clear the DISR register when we enable the RAS cpufeature, and the kernel has not executed any ESB instructions. Any value we find in DISR must have belonged to firmware. Executing an ESB instruction is the only way to update DISR, so we can expect firmware to have handled any deferred SError. By the same logic we clear DISR in the idle path. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: Unconditionally enable IESB on exception entry/return for firmware-firstJames Morse
ARM v8.2 has a feature to add implicit error synchronization barriers whenever the CPU enters or returns from an exception level. Add this to the features we always enable. CPUs that don't support this feature will treat the bit as RES0. This feature causes RAS errors that are not yet visible to software to become pending SErrors. We expect to have firmware-first RAS support so synchronised RAS errors will be take immediately to EL3. Any system without firmware-first handling of errors will take the SError either immediatly after exception return, or when we unmask SError after entry.S's work. Adding IESB to the ELx flags causes it to be enabled by KVM and kexec too. Platform level RAS support may require additional firmware support. Cc: Christoffer Dall <christoffer.dall@linaro.org> Suggested-by: Will Deacon <will.deacon@arm.com> Link: https://www.spinics.net/lists/kvm-arm/msg28192.html Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: kernel: Survive corrected RAS errors notified by SErrorJames Morse
Prior to v8.2, SError is an uncontainable fatal exception. The v8.2 RAS extensions use SError to notify software about RAS errors, these can be contained by the Error Syncronization Barrier. An ACPI system with firmware-first may use SError as its 'SEI' notification. Future patches may add code to 'claim' this SError as a notification. Other systems can distinguish these RAS errors from the SError ESR and use the AET bits and additional data from RAS-Error registers to handle the error. Future patches may add this kernel-first handling. Without support for either of these we will panic(), even if we received a corrected error. Add code to decode the severity of RAS errors. We can safely ignore contained errors where the CPU can continue to make progress. For all other errors we continue to panic(). Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: cpufeature: Detect CPU RAS ExtentionsXie XiuQi
ARM's v8.2 Extentions add support for Reliability, Availability and Serviceability (RAS). On CPUs with these extensions system software can use additional barriers to isolate errors and determine if faults are pending. Add cpufeature detection. Platform level RAS support may require additional firmware support. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com> [Rebased added config option, reworded commit message] Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: sysreg: Move to use definitions for all the SCTLR bitsJames Morse
__cpu_setup() configures SCTLR_EL1 using some hard coded hex masks, and el2_setup() duplicates some this when setting RES1 bits. Lets make this the same as KVM's hyp_init, which uses named bits. First, we add definitions for all the SCTLR_EL{1,2} bits, the RES{1,0} bits, and those we want to set or clear. Add a build_bug checks to ensures all bits are either set or clear. This means we don't need to preserve endian-ness configuration generated elsewhere. Finally, move the head.S and proc.S users of these hard-coded masks over to the macro versions. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: cpufeature: __this_cpu_has_cap() shouldn't stop earlyJames Morse
this_cpu_has_cap() tests caps->desc not caps->matches, so it stops walking the list when it finds a 'silent' feature, instead of walking to the end of the list. Prior to v4.6's 644c2ae198412 ("arm64: cpufeature: Test 'matches' pointer to find the end of the list") we always tested desc to find the end of a capability list. This was changed for dubious things like PAN_NOT_UAO. v4.7's e3661b128e53e ("arm64: Allow a capability to be checked on single CPU") added this_cpu_has_cap() using the old desc style test. CC: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16arm64: fpsimd: Fix state leakage when migrating after sigreturnDave Martin
When refactoring the sigreturn code to handle SVE, I changed the sigreturn implementation to store the new FPSIMD state from the user sigframe into task_struct before reloading the state into the CPU regs. This makes it easier to convert the data for SVE when needed. However, it turns out that the fpsimd_state structure passed into fpsimd_update_current_state is not fully initialised, so assigning the structure as a whole corrupts current->thread.fpsimd_state.cpu with uninitialised data. This means that if the garbage data written to .cpu happens to be a valid cpu number, and the task is subsequently migrated to the cpu identified by the that number, and then tries to enter userspace, the CPU FPSIMD regs will be assumed to be correct for the task and not reloaded as they should be. This can result in returning to userspace with the FPSIMD registers containing data that is stale or that belongs to another task or to the kernel. Knowingly handing around a kernel structure that is incompletely initialised with user data is a potential source of mistakes, especially across source file boundaries. To help avoid a repeat of this issue, this patch adapts the relevant internal API to hand around the user-accessible subset only: struct user_fpsimd_state. To avoid future surprises, this patch also converts all uses of struct fpsimd_state that really only access the user subset, to use struct user_fpsimd_state. A few missing consts are added to function prototypes for good measure. Thanks to Will for spotting the cause of the bug here. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16powerpc: Use the TRAP macro whenever comparing a trap numberBenjamin Herrenschmidt
Trap numbers can have extra bits at the bottom that need to be filtered out. There are a few cases where we don't do that. It's possible that we got lucky but better safe than sorry. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc: Remove useless EXC_COMMON_HVBenjamin Herrenschmidt
The only difference between EXC_COMMON_HV and EXC_COMMON is that the former adds "2" to the trap number which is supposed to represent the fact that this is an "HV" interrupt which uses HSRR0/1. However KVM is the only one who cares and it has its own separate macros. In fact, we only have one user of EXC_COMMON_HV and it's for an unknown interrupt case. All the other ones already using EXC_COMMON. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/xive: Remove incorrect debug codeBenjamin Herrenschmidt
WORD2 if the TIMA isn't byte accessible and isn't that useful to know about, take out the pr_devel statement. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc: Cosmetic cleanup of cpuinfo_opBenjamin Herrenschmidt
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc: Make newline in cpuinfo unconditionalBenjamin Herrenschmidt
We used to not put the newline between the CPU part and the summary part on UP kernels. This is a rather pointless ifdef so take it out. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc: Add aacraid and nvme to powernv_defconfigBenjamin Herrenschmidt
These adapters can be found in a number of our systems, so let's enable the corresponding drivers by default. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: Use L1 entry APG to handle _PAGE_ACCESSED for CONFIG_SWAPChristophe Leroy
When CONFIG_SWAP is set, the TLB miss handlers have to also take into account _PAGE_ACCESSED flag. At the moment it is done by anding _PAGE_ACCESSED into _PAGE_PRESENT using 3 instructions. This patch uses APG for handling _PAGE_ACCESSED, allowing to just copy _PAGE_ACCESSED bit into APG field, hence reducing the action to a single instruction. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: Remove _PAGE_USER and handle user access at PMD levelChristophe Leroy
As Linux kernel separates KERNEL and USER address spaces, there is therefore no need to flag USER access at page level. Today, the 8xx TLB handlers already handle user access in the L1 entry through Access Protection Groups, it is then natural to move the user access handling at PMD level once _PAGE_NA allows to handle PAGE_NONE protection without _PAGE_USER In the mean time, as we free up one bit in the PTE, we can use it to include SPS (page size flag) in the PTE and avoid handling it at every TLB miss hence removing special handling based on compiled page size. For _PAGE_EXEC, we rework it to use PP PTE bits, avoiding the copy of _PAGE_EXEC bit into the L1 entry. Unfortunatly we are not able to put it at the correct location as it conflicts with NA/RO/RW bits for data entries. Upper bits of APG in L1 entry overlap with PMD base address. In order to avoid having to filter that out, we set up all groups so that upper bits can have any value. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/mm: Introduce _PAGE_NAChristophe Leroy
Today, PAGE_NONE is defined as a page not having _PAGE_USER. In some circunstances, when the CPU supports it, it might be better to be able to flag a page with NO ACCESS. In a following patch, the 8xx will switch user access being flagged in the PMD, therefore it will not be possible anymore to use _PAGE_USER as a way to flag a page with no access. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/mm: extend _PAGE_PRIVILEGED to all CPUsChristophe Leroy
commit ac29c64089b74 ("powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64 This patch generalises _PAGE_PRIVILEGED for all CPUs, allowing to have either _PAGE_PRIVILEGED or _PAGE_USER or both. PPC_8xx has a _PAGE_SHARED flag which is set for and only for all non user pages. Lets rename it _PAGE_PRIVILEGED to remove confusion as it has nothing to do with Linux shared pages. On BookE, there's a _PAGE_BAP_SR which has to be set for kernel pages: defining _PAGE_PRIVILEGED as _PAGE_BAP_SR will make this generic Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: remove unused _PAGE_WRITETHRUChristophe Leroy
_PAGE_WRITETHRU is only used in: * AMIGA_Z2RAM block driver which is never activated on powerPC * Video/FB driver which is for PPC_PMAC Therefore, no need to spend time in 8xx TLB miss handlers for handling it. And by removing it, we free up bit 20 which then avoids having to clear it on each TLB miss. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: Only perform perf counting when perf is in use.Christophe Leroy
In TLB miss handlers, updating the perf counter is only useful when performing a perf analysis. As it has a noticeable overhead, let's only do it when needed. In order to do so, the exit of the miss handlers will be patched when starting/stopping 'perf': the first register restore instruction of each exit point will be replaced by a jump to the counting code. Once this is done, CONFIG_PPC_8xx_PERF_EVENT becomes useless as this feature doesn't add any overhead. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: remove EXCEPTION_PROLOG/EPILOG_0 and change r3 to r12Christophe Leroy
EXCEPTION_PROLOG_0 and EXCEPTION_EPILOG_0 were added some time ago in order to regroup the two mtspr/mfspr to SCRATCH0 and SCRATCH1 and the mfcr/mtcr in order to ease entry and exit of function not using the full EXCEPTION_PROLOG. Since then, the mfcr/mtcr has been taken out, hence just leaving the two mtspr/mfspr in the macro. In order to improve readability of the exception functions, we remove those two macros and copy back the two mtspr/mfspr instead. As r10 and r11 are used for SCRATCH0 and SCRATCH1, lets also use r12 for SCRATCH2. It will also improve the readability/maintenance. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: Remove CPU6 ERRATA WorkaroundChristophe Leroy
CPU6 ERRATA affects only MPC860 revisions prior to C.0. Manufacturing of those revisiosn was stopped in 1999-2000. Therefore, it has been almost 20 years since this ERRATA has been fixed in the silicon. This patch removes the workaround for that ERRATA. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/8xx: do not select CONFIG_PPC_LIB_RHEAPChristophe Leroy
Since commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram"), rheap is not used anymore. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powernv/kdump: Fix cases where the kdump kernel can get HMI'sBalbir Singh
Certain HMI's such as malfunction error propagate through all threads/core on the system. If a thread was offline prior to us crashing the system and jumping to the kdump kernel, bad things happen when it wakes up due to an HMI in the kdump kernel. There are several possible ways to solve this problem 1. Put the offline cores in a state such that they are not woken up for machine check and HMI errors. This does not work, since we might need to wake up offline threads to handle TB errors 2. Ignore HMI errors, setup HMEER to mask HMI errors, but this still leads the window open for any MCEs and masking them for the duration of the dump might be a concern 3. Wake up offline CPUs, as in send them to crash_ipi_callback (not wake them up as in mark them online as seen by the hotplug). kexec does a wake_online_cpus() call, this patch does something similar, but instead sends an IPI and forces them to crash_ipi_callback() This patch takes approach #3. Care is taken to enable this only for powenv platforms via crash_wake_offline (a global value set at setup time). The crash code sends out IPI's to all CPU's which then move to crash_ipi_callback and kexec_smp_wait(). Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-16powerpc/crash: Remove the test for cpu_online in the IPI callbackBalbir Singh
Our check was extra cautious, we've audited crash_send_ipi and it sends an IPI only to online CPU's. Removal of this check should have not functional impact on crash kdump. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>