- 30 Apr, 2019 10 commits
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Paul Mackerras authored
When running on POWER9 with kvm_hv.indep_threads_mode = N and the host in SMT1 mode, KVM will run guest VCPUs on offline secondary threads. If those guests are in radix mode, we fail to load the LPID and flush the TLB if necessary, leading to the guest crashing with an unsupported MMU fault. This arises from commit 9a4506e1 ("KVM: PPC: Book3S HV: Make radix handle process scoped LPID flush in C, with relocation on", 2018-05-17), which didn't consider the case where indep_threads_mode = N. For simplicity, this makes the real-mode guest entry path flush the TLB in the same place for both radix and hash guests, as we did before 9a4506e1, though the code is now C code rather than assembly code. We also have the radix TLB flush open-coded rather than calling radix__local_flush_tlb_lpid_guest(), because the TLB flush can be called in real mode, and in real mode we don't want to invoke the tracepoint code. Fixes: 9a4506e1 ("KVM: PPC: Book3S HV: Make radix handle process scoped LPID flush in C, with relocation on") Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Paul Mackerras authored
This replaces assembler code in book3s_hv_rmhandlers.S that checks the kvm->arch.need_tlb_flush cpumask and optionally does a TLB flush with C code in book3s_hv_builtin.c. Note that unlike the radix version, the hash version doesn't do an explicit ERAT invalidation because we will invalidate and load up the SLB before entering the guest, and that will invalidate the ERAT. Signed-off-by: -
Suraj Jitindar Singh authored
The code in book3s_hv_rmhandlers.S that pushes the XIVE virtual CPU context to the hardware currently assumes it is being called in real mode, which is usually true. There is however a path by which it can be executed in virtual mode, in the case where indep_threads_mode = N. A virtual CPU executing on an offline secondary thread can take a hypervisor interrupt in virtual mode and return from the kvmppc_hv_entry() call after the kvm_secondary_got_guest label. It is possible for it to be given another vcpu to execute before it gets to execute the stop instruction. In that case it will call kvmppc_hv_entry() for the second VCPU in virtual mode, and the XIVE vCPU push code will be executed in virtual mode. The result in that case will be a host crash due to an unexpected data storage interrupt caused by executing the stdcix instruction in virtual mode. This fixes it by adding a code path for virtual mode, which uses the virtual TIMA pointer and normal load/store instructions. [paulus@ozlabs.org - wrote patch description] Signed-off-by:
Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by:
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Paul Mackerras authored
This fixes a bug in the XICS emulation on POWER9 machines which is triggered by the guest doing a H_IPI with priority = 0 (the highest priority). What happens is that the notification interrupt arrives at the destination at priority zero. The loop in scan_interrupts() sees that a priority 0 interrupt is pending, but because xc->mfrr is zero, we break out of the loop before taking the notification interrupt out of the queue and EOI-ing it. (This doesn't happen when xc->mfrr != 0; in that case we process the priority-0 notification interrupt on the first iteration of the loop, and then break out of a subsequent iteration of the loop with hirq == XICS_IPI.) To fix this, we move the prio >= xc->mfrr check down to near the end of the loop. However, there are then some other things that need to be adjusted. Since we are potentially handling the notification interrupt and also delivering an IPI to the guest in the same loop iteration, we need to update pending and handle any q->pending_count value before the xc->mfrr check, rather than at the end of the loop. Also, we need to update the queue pointers when we have processed and EOI-ed the notification interrupt, since we may not do it later. Signed-off-by: -
Palmer Dabbelt authored
I made the same typo when trying to grep for uses of smp_wmb and figured I might as well fix it. Signed-off-by:
Palmer Dabbelt <palmer@sifive.com> Signed-off-by:
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Alexey Kardashevskiy authored
We already allocate hardware TCE tables in multiple levels and skip intermediate levels when we can, now it is a turn of the KVM TCE tables. Thankfully these are allocated already in 2 levels. This moves the table's last level allocation from the creating helper to kvmppc_tce_put() and kvm_spapr_tce_fault(). Since such allocation cannot be done in real mode, this creates a virtual mode version of kvmppc_tce_put() which handles allocations. This adds kvmppc_rm_ioba_validate() to do an additional test if the consequent kvmppc_tce_put() needs a page which has not been allocated; if this is the case, we bail out to virtual mode handlers. The allocations are protected by a new mutex as kvm->lock is not suitable for the task because the fault handler is called with the mmap_sem held but kvmhv_setup_mmu() locks kvm->lock and mmap_sem in the reverse order. Signed-off-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
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Alexey Kardashevskiy authored
The kvmppc_tce_to_ua() helper is called from real and virtual modes and it works fine as long as CONFIG_DEBUG_LOCKDEP is not enabled. However if the lockdep debugging is on, the lockdep will most likely break in kvm_memslots() because of srcu_dereference_check() so we need to use PPC-own kvm_memslots_raw() which uses realmode safe rcu_dereference_raw_notrace(). This creates a realmode copy of kvmppc_tce_to_ua() which replaces kvm_memslots() with kvm_memslots_raw(). Since kvmppc_rm_tce_to_ua() becomes static and can only be used inside HV KVM, this moves it earlier under CONFIG_KVM_BOOK3S_HV_POSSIBLE. This moves truly virtual-mode kvmppc_tce_to_ua() to where it belongs and drops the prmap parameter which was never used in the virtual mode. Fixes: d3695aa4 ("KVM: PPC: Add support for multiple-TCE hcalls", 2016-02-15) Signed-off-by:
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Alexey Kardashevskiy authored
The trace_hardirqs_on() sets current->hardirqs_enabled and from here the lockdep assumes interrupts are enabled although they are remain disabled until the context switches to the guest. Consequent srcu_read_lock() checks the flags in rcu_lock_acquire(), observes disabled interrupts and prints a warning (see below). This moves trace_hardirqs_on/off closer to __kvmppc_vcore_entry to prevent lockdep from being confused. DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) WARNING: CPU: 16 PID: 8038 at kernel/locking/lockdep.c:4128 check_flags.part.25+0x224/0x280 [...] NIP [c000000000185b84] check_flags.part.25+0x224/0x280 LR [c000000000185b80] check_flags.part.25+0x220/0x280 Call Trace: [c000003fec253710] [c000000000185b80] check_flags.part.25+0x220/0x280 (unreliable) [c000003fec253780] [c000000000187ea4] lock_acquire+0x94/0x260 [c000003fec253840] [c00800001a1e9768] kvmppc_run_core+0xa60/0x1ab0 [kvm_hv] [c000003fec253a10] [c00800001a1ed944] kvmppc_vcpu_run_hv+0x73c/0xec0 [kvm_hv] [c000003fec253ae0] [c00800001a1095dc] kvmppc_vcpu_run+0x34/0x48 [kvm] [c000003fec253b00] [c00800001a1056bc] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm] [c000003fec253b90] [c00800001a0f3618] kvm_vcpu_ioctl+0x460/0x850 [kvm] [c000003fec253d00] [c00000000041c4f4] do_vfs_ioctl+0xe4/0x930 [c000003fec253db0] [c00000000041ce04] ksys_ioctl+0xc4/0x110 [c000003fec253e00] [c00000000041ce78] sys_ioctl+0x28/0x80 [c000003fec253e20] [c00000000000b5a4] system_call+0x5c/0x70 Instruction dump: 419e0034 3d220004 39291730 81290000 2f890000 409e0020 3c82ffc6 3c62ffc5 3884be70 386329c0 4bf6ea71 60000000 <0fe00000> 3c62ffc6 3863be90 4801273d irq event stamp: 1025 hardirqs last enabled at (1025): [<c00800001a1e9728>] kvmppc_run_core+0xa20/0x1ab0 [kvm_hv] hardirqs last disabled at (1024): [<c00800001a1e9358>] kvmppc_run_core+0x650/0x1ab0 [kvm_hv] softirqs last enabled at (0): [<c0000000000f1210>] copy_process.isra.4.part.5+0x5f0/0x1d00 softirqs last disabled at (0): [<0000000000000000>] (null) ---[ end trace 31180adcc848993e ]--- possible reason: unannotated irqs-off. irq event stamp: 1025 hardirqs last enabled at (1025): [<c00800001a1e9728>] kvmppc_run_core+0xa20/0x1ab0 [kvm_hv] hardirqs last disabled at (1024): [<c00800001a1e9358>] kvmppc_run_core+0x650/0x1ab0 [kvm_hv] softirqs last enabled at (0): [<c0000000000f1210>] copy_process.isra.4.part.5+0x5f0/0x1d00 softirqs last disabled at (0): [<0000000000000000>] (null) Fixes: 8b24e69f ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry", 2017-06-26) Signed-off-by:
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Suraj Jitindar Singh authored
Implement a real mode handler for the H_CALL H_PAGE_INIT which can be used to zero or copy a guest page. The page is defined to be 4k and must be 4k aligned. The in-kernel real mode handler halves the time to handle this H_CALL compared to handling it in userspace for a hash guest. Signed-off-by:
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Suraj Jitindar Singh authored
Implement a virtual mode handler for the H_CALL H_PAGE_INIT which can be used to zero or copy a guest page. The page is defined to be 4k and must be 4k aligned. The in-kernel handler halves the time to handle this H_CALL compared to handling it in userspace for a radix guest. Signed-off-by:
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- 05 Apr, 2019 2 commits
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Alexey Kardashevskiy authored
Guest physical to user address translation uses KVM memslots and reading these requires holding the kvm->srcu lock. However recently introduced kvmppc_tce_validate() broke the rule (see the lockdep warning below). This moves srcu_read_lock(&vcpu->kvm->srcu) earlier to protect kvmppc_tce_validate() as well. ============================= WARNING: suspicious RCU usage 5.1.0-rc2-le_nv2_aikATfstn1-p1 #380 Not tainted ----------------------------- include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by qemu-system-ppc/8020: #0: 0000000094972fe9 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0xdc/0x850 [kvm] stack backtrace: CPU: 44 PID: 8020 Comm: qemu-system-ppc Not tainted 5.1.0-rc2-le_nv2_aikATfstn1-p1 #380 Call Trace: [c000003fece8f740] [c000000000bcc134] dump_stack+0xe8/0x164 (unreliable) [c000003fece8f790] [c000000000181be0] lockdep_rcu_suspicious+0x130/0x170 [c000003fece8f810] [c0000000000d5f50] kvmppc_tce_to_ua+0x280/0x290 [c000003fece8f870] [c00800001a7e2c78] kvmppc_tce_validate+0x80/0x1b0 [kvm] [c000003fece8f8e0] [c00800001a7e3fac] kvmppc_h_put_tce+0x94/0x3e4 [kvm] [c000003fece8f9a0] [c00800001a8baac4] kvmppc_pseries_do_hcall+0x30c/0xce0 [kvm_hv] [c000003fece8fa10] [c00800001a8bd89c] kvmppc_vcpu_run_hv+0x694/0xec0 [kvm_hv] [c000003fece8fae0] [c00800001a7d95dc] kvmppc_vcpu_run+0x34/0x48 [kvm] [c000003fece8fb00] [c00800001a7d56bc] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm] [c000003fece8fb90] [c00800001a7c3618] kvm_vcpu_ioctl+0x460/0x850 [kvm] [c000003fece8fd00] [c00000000041c4f4] do_vfs_ioctl+0xe4/0x930 [c000003fece8fdb0] [c00000000041ce04] ksys_ioctl+0xc4/0x110 [c000003fece8fe00] [c00000000041ce78] sys_ioctl+0x28/0x80 [c000003fece8fe20] [c00000000000b5a4] system_call+0x5c/0x70 Fixes: 42de7b9e ("KVM: PPC: Validate TCEs against preregistered memory page sizes", 2018-09-10) Signed-off-by: -
Suraj Jitindar Singh authored
There is a hardware bug in some POWER9 processors where a treclaim in fake suspend mode can cause an inconsistency in the XER[SO] bit across the threads of a core, the workaround being to force the core into SMT4 when doing the treclaim. The FAKE_SUSPEND bit (bit 10) in the PSSCR is used to control whether a thread is in fake suspend or real suspend. The important difference here being that thread reconfiguration is blocked in real suspend but not fake suspend mode. When we exit a guest which was in fake suspend mode, we force the core into SMT4 while we do the treclaim in kvmppc_save_tm_hv(). However on the new exit path introduced with the function kvmhv_run_single_vcpu() we restore the host PSSCR before calling kvmppc_save_tm_hv() which means that if we were in fake suspend mode we put the thread into real suspend mode when we clear the PSSCR[FAKE_SUSPEND] bit. This means that we block thread reconfiguration and the thread which is trying to get the core into SMT4 before it can do the treclaim spins forever since it itself is blocking thread reconfiguration. The result is that that core is essentially lost. This results in a trace such as: [ 93.512904] CPU: 7 PID: 13352 Comm: qemu-system-ppc Not tainted 5.0.0 #4 [ 93.512905] NIP: c000000000098a04 LR: c0000000000cc59c CTR: 0000000000000000 [ 93.512908] REGS: c000003fffd2bd70 TRAP: 0100 Not tainted (5.0.0) [ 93.512908] MSR: 9000000302883033 <SF,HV,VEC,VSX,FP,ME,IR,DR,RI,LE,TM[SE]> CR: 22222444 XER: 00000000 [ 93.512914] CFAR: c000000000098a5c IRQMASK: 3 [ 93.512915] PACATMSCRATCH: 0000000000000001 [ 93.512916] GPR00: 0000000000000001 c000003f6cc1b830 c000000001033100 0000000000000004 [ 93.512928] GPR04: 0000000000000004 0000000000000002 0000000000000004 0000000000000007 [ 93.512930] GPR08: 0000000000000000 0000000000000004 0000000000000000 0000000000000004 [ 93.512932] GPR12: c000203fff7fc000 c000003fffff9500 0000000000000000 0000000000000000 [ 93.512935] GPR16: 2000000000300375 000000000000059f 0000000000000000 0000000000000000 [ 93.512951] GPR20: 0000000000000000 0000000000080053 004000000256f41f c000003f6aa88ef0 [ 93.512953] GPR24: c000003f6aa89100 0000000000000010 0000000000000000 0000000000000000 [ 93.512956] GPR28: c000003f9e9a0800 0000000000000000 0000000000000001 c000203fff7fc000 [ 93.512959] NIP [c000000000098a04] pnv_power9_force_smt4_catch+0x1b4/0x2c0 [ 93.512960] LR [c0000000000cc59c] kvmppc_save_tm_hv+0x40/0x88 [ 93.512960] Call Trace: [ 93.512961] [c000003f6cc1b830] [0000000000080053] 0x80053 (unreliable) [ 93.512965] [c000003f6cc1b8a0] [c00800001e9cb030] kvmhv_p9_guest_entry+0x508/0x6b0 [kvm_hv] [ 93.512967] [c000003f6cc1b940] [c00800001e9cba44] kvmhv_run_single_vcpu+0x2dc/0xb90 [kvm_hv] [ 93.512968] [c000003f6cc1ba10] [c00800001e9cc948] kvmppc_vcpu_run_hv+0x650/0xb90 [kvm_hv] [ 93.512969] [c000003f6cc1bae0] [c00800001e8f620c] kvmppc_vcpu_run+0x34/0x48 [kvm] [ 93.512971] [c000003f6cc1bb00] [c00800001e8f2d4c] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm] [ 93.512972] [c000003f6cc1bb90] [c00800001e8e3918] kvm_vcpu_ioctl+0x460/0x7d0 [kvm] [ 93.512974] [c000003f6cc1bd00] [c0000000003ae2c0] do_vfs_ioctl+0xe0/0x8e0 [ 93.512975] [c000003f6cc1bdb0] [c0000000003aeb24] ksys_ioctl+0x64/0xe0 [ 93.512978] [c000003f6cc1be00] [c0000000003aebc8] sys_ioctl+0x28/0x80 [ 93.512981] [c000003f6cc1be20] [c00000000000b3a4] system_call+0x5c/0x70 [ 93.512983] Instruction dump: [ 93.512986] 419dffbc e98c0000 2e8b0000 38000001 60000000 60000000 60000000 40950068 [ 93.512993] 392bffff 39400000 79290020 39290001 <7d2903a6> 60000000 60000000 7d235214 To fix this we preserve the PSSCR[FAKE_SUSPEND] bit until we call kvmppc_save_tm_hv() which will mean the core can get into SMT4 and perform the treclaim. Note kvmppc_save_tm_hv() clears the PSSCR[FAKE_SUSPEND] bit again so there is no need to explicitly do that. Fixes: 95a6432c ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Signed-off-by:
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- 28 Mar, 2019 22 commits
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Paolo Bonzini authored
Merge tag 'kvmarm-fixes-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/ARM fixes for 5.1 - Fix THP handling in the presence of pre-existing PTEs - Honor request for PTE mappings even when THPs are available - GICv4 performance improvement - Take the srcu lock when writing to guest-controlled ITS data structures - Reset the virtual PMU in preemptible context - Various cleanups
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Paolo Bonzini authored
The documentation does not mention how to delete a slot, add the information. Reported-by:
Nathaniel McCallum <npmccallum@redhat.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
The series to add memcg accounting to KVM allocations[1] states: There are many KVM kernel memory allocations which are tied to the life of the VM process and should be charged to the VM process's cgroup. While it is correct to account KVM kernel allocations to the cgroup of the process that created the VM, it's technically incorrect to state that the KVM kernel memory allocations are tied to the life of the VM process. This is because the VM itself, i.e. struct kvm, is not tied to the life of the process which created it, rather it is tied to the life of its associated file descriptor. In other words, kvm_destroy_vm() is not invoked until fput() decrements its associated file's refcount to zero. A simple example is to fork() in Qemu and have the child sleep indefinitely; kvm_destroy_vm() isn't called until Qemu closes its file descriptor *and* the rogue child is killed. The allocations are guaranteed to be *accounted* to the process which created the VM, but only because KVM's per-{VM,vCPU} ioctls reject the ioctl() with -EIO if kvm->mm != current->mm. I.e. the child can keep the VM "alive" but can't do anything useful with its reference. Note that because 'struct kvm' also holds a reference to the mm_struct of its owner, the above behavior also applies to userspace allocations. Given that mucking with a VM's file descriptor can lead to subtle and undesirable behavior, e.g. memcg charges persisting after a VM is shut down, explicitly document a VM's lifecycle and its impact on the VM's resources. Alternatively, KVM could aggressively free resources when the creating process exits, e.g. via mmu_notifier->release(). However, mmu_notifier isn't guaranteed to be available, and freeing resources when the creator exits is likely to be error prone and fragile as KVM would need to ensure that it only freed resources that are truly out of reach. In practice, the existing behavior shouldn't be problematic as a properly configured system will prevent a child process from being moved out of the appropriate cgroup hierarchy, i.e. prevent hiding the process from the OOM killer, and will prevent an unprivileged user from being able to to hold a reference to struct kvm via another method, e.g. debugfs. [1]https://patchwork.kernel.org/patch/10806707/Signed-off-by:Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by:
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Sean Christopherson authored
Documentation/virtual/kvm/api.txt states: NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR and KVM_EXIT_EPR the corresponding operations are complete (and guest state is consistent) only after userspace has re-entered the kernel with KVM_RUN. The kernel side will first finish incomplete operations and then check for pending signals. Userspace can re-enter the guest with an unmasked signal pending to complete pending operations. Because guest state may be inconsistent, starting state migration after an IO exit without first completing IO may result in test failures, e.g. a proposed change to KVM's handling of %rip in its fast PIO handling[1] will cause the new VM, i.e. the post-migration VM, to have its %rip set to the IN instruction that triggered KVM_EXIT_IO, leading to a test assertion due to a stage mismatch. For simplicitly, require KVM_CAP_IMMEDIATE_EXIT to complete IO and skip the test if it's not available. The addition of KVM_CAP_IMMEDIATE_EXIT predates the state selftest by more than a year. [1] https://patchwork.kernel.org/patch/10848545/ Fixes: fa3899ad ("kvm: selftests: add basic test for state save and restore") Reported-by:Jim Mattson <jmattson@google.com> Signed-off-by:
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Sean Christopherson authored
Since 4.8.3, gcc has enabled -fstack-protector by default. This is problematic for the KVM selftests as they do not configure fs or gs segments (the stack canary is pulled from fs:0x28). With the default behavior, gcc will insert a stack canary on any function that creates buffers of 8 bytes or more. As a result, ucall() will hit a triple fault shutdown due to reading a bad fs segment when inserting its stack canary, i.e. every test fails with an unexpected SHUTDOWN. Fixes: 14c47b75 ("kvm: selftests: introduce ucall") Signed-off-by:
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Sean Christopherson authored
KVM selftests embed the guest "image" as a function in the test itself and extract the guest code at runtime by manually parsing the elf headers. The parsing is very simple and doesn't supporting fancy things like position independent executables. Recent versions of gcc enable pie by default, which results in triple fault shutdowns in the guest due to the virtual address in the headers not matching up with the virtual address retrieved from the function pointer. Signed-off-by:
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Sean Christopherson authored
...so that the test doesn't end up in an infinite loop if it fails for whatever reason, e.g. SHUTDOWN due to gcc inserting stack canary code into ucall() and attempting to derefence a null segment. Fixes: ca359066 ("kvm: selftests: add cr4_cpuid_sync_test") Cc: Wei Huang <wei@redhat.com> Signed-off-by:
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Sean Christopherson authored
Most (all?) x86 platforms provide a port IO based reset mechanism, e.g. OUT 92h or CF9h. Userspace may emulate said mechanism, i.e. reset a vCPU in response to KVM_EXIT_IO, without explicitly announcing to KVM that it is doing a reset, e.g. Qemu jams vCPU state and resumes running. To avoid corruping %rip after such a reset, commit 0967b7bf ("KVM: Skip pio instruction when it is emulated, not executed") changed the behavior of PIO handlers, i.e. today's "fast" PIO handling to skip the instruction prior to exiting to userspace. Full emulation doesn't need such tricks becase re-emulating the instruction will naturally handle %rip being changed to point at the reset vector. Updating %rip prior to executing to userspace has several drawbacks: - Userspace sees the wrong %rip on the exit, e.g. if PIO emulation fails it will likely yell about the wrong address. - Single step exits to userspace for are effectively dropped as KVM_EXIT_DEBUG is overwritten with KVM_EXIT_IO. - Behavior of PIO emulation is different depending on whether it goes down the fast path or the slow path. Rather than skip the PIO instruction before exiting to userspace, snapshot the linear %rip and cancel PIO completion if the current value does not match the snapshot. For a 64-bit vCPU, i.e. the most common scenario, the snapshot and comparison has negligible overhead as VMCS.GUEST_RIP will be cached regardless, i.e. there is no extra VMREAD in this case. All other alternatives to snapshotting the linear %rip that don't rely on an explicit reset announcenment suffer from one corner case or another. For example, canceling PIO completion on any write to %rip fails if userspace does a save/restore of %rip, and attempting to avoid that issue by canceling PIO only if %rip changed then fails if PIO collides with the reset %rip. Attempting to zero in on the exact reset vector won't work for APs, which means adding more hooks such as the vCPU's MP_STATE, and so on and so forth. Checking for a linear %rip match technically suffers from corner cases, e.g. userspace could theoretically rewrite the underlying code page and expect a different instruction to execute, or the guest hardcodes a PIO reset at 0xfffffff0, but those are far, far outside of what can be considered normal operation. Fixes: 432baf60 ("KVM: VMX: use kvm_fast_pio_in for handling IN I/O") Cc: <stable@vger.kernel.org> Reported-by:
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Vitaly Kuznetsov authored
When userspace initializes guest vCPUs it may want to zero all supported MSRs including Hyper-V related ones including HV_X64_MSR_STIMERn_CONFIG/ HV_X64_MSR_STIMERn_COUNT. With commit f3b138c5 ("kvm/x86: Update SynIC timers on guest entry only") we began doing stimer_mark_pending() unconditionally on every config change. The issue I'm observing manifests itself as following: - Qemu writes 0 to STIMERn_{CONFIG,COUNT} MSRs and marks all stimers as pending in stimer_pending_bitmap, arms KVM_REQ_HV_STIMER; - kvm_hv_has_stimer_pending() starts returning true; - kvm_vcpu_has_events() starts returning true; - kvm_arch_vcpu_runnable() starts returning true; - when kvm_arch_vcpu_ioctl_run() gets into (vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED) case: - kvm_vcpu_block() gets in 'kvm_vcpu_check_block(vcpu) < 0' and returns immediately, avoiding normal wait path; - -EAGAIN is returned from kvm_arch_vcpu_ioctl_run() immediately forcing userspace to retry. So instead of normal wait path we get a busy loop on all secondary vCPUs before they get INIT signal. This seems to be undesirable, especially given that this happens even when Hyper-V extensions are not used. Generally, it seems to be pointless to mark an stimer as pending in stimer_pending_bitmap and arm KVM_REQ_HV_STIMER as the only thing kvm_hv_process_stimers() will do is clear the corresponding bit. We may just not mark disabled timers as pending instead. Fixes: f3b138c5 ("kvm/x86: Update SynIC timers on guest entry only") Signed-off-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
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Xiaoyao Li authored
Since MSR_IA32_ARCH_CAPABILITIES is emualted unconditionally even if host doesn't suppot it. We should move it to array emulated_msrs from arry msrs_to_save, to report to userspace that guest support this msr. Signed-off-by:
Xiaoyao Li <xiaoyao.li@linux.intel.com> Signed-off-by:
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Sean Christopherson authored
The CPUID flag ARCH_CAPABILITIES is unconditioinally exposed to host userspace for all x86 hosts, i.e. KVM advertises ARCH_CAPABILITIES regardless of hardware support under the pretense that KVM fully emulates MSR_IA32_ARCH_CAPABILITIES. Unfortunately, only VMX hosts handle accesses to MSR_IA32_ARCH_CAPABILITIES (despite KVM_GET_MSRS also reporting MSR_IA32_ARCH_CAPABILITIES for all hosts). Move the MSR_IA32_ARCH_CAPABILITIES handling to common x86 code so that it's emulated on AMD hosts. Fixes: 1eaafe91 ("kvm: x86: IA32_ARCH_CAPABILITIES is always supported") Cc: stable@vger.kernel.org Reported-by:
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Sebastian Andrzej Siewior authored
The function irqfd_wakeup() has flags defined as __poll_t and then it has additional flags which is used for irqflags. Redefine the inner flags variable as iflags so it does not shadow the outer flags. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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Ben Gardon authored
Replace kvm_flush_remote_tlbs with kvm_flush_remote_tlbs_with_address in slot_handle_level_range. When range based flushes are not enabled kvm_flush_remote_tlbs_with_address falls back to kvm_flush_remote_tlbs. This changes the behavior of many functions that indirectly use slot_handle_level_range, iff the range based flushes are enabled. The only potential problem I see with this is that kvm->tlbs_dirty will be cleared less often, however the only caller of slot_handle_level_range that checks tlbs_dirty is kvm_mmu_notifier_invalidate_range_start which checks it and does a kvm_flush_remote_tlbs after calling kvm_unmap_hva_range anyway. Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and without this patch. The patch introduced no new failures. Signed-off-by:
Ben Gardon <bgardon@google.com> Signed-off-by:
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Masahiro Yamada authored
I do not see any consistency about headers_install of <linux/kvm_para.h> and <asm/kvm_para.h>. According to my analysis of Linux 5.1-rc1, there are 3 groups: [1] Both <linux/kvm_para.h> and <asm/kvm_para.h> are exported alpha, arm, hexagon, mips, powerpc, s390, sparc, x86 [2] <asm/kvm_para.h> is exported, but <linux/kvm_para.h> is not arc, arm64, c6x, h8300, ia64, m68k, microblaze, nios2, openrisc, parisc, sh, unicore32, xtensa [3] Neither <linux/kvm_para.h> nor <asm/kvm_para.h> is exported csky, nds32, riscv This does not match to the actual KVM support. At least, [2] is half-baked. Nor do arch maintainers look like they care about this. For example, commit 0add5371 ("microblaze: Add missing kvm_para.h to Kbuild") exported <asm/kvm_para.h> to user-space in order to fix an in-kernel build error. We have two ways to make this consistent: [A] export both <linux/kvm_para.h> and <asm/kvm_para.h> for all architectures, irrespective of the KVM support [B] Match the header export of <linux/kvm_para.h> and <asm/kvm_para.h> to the KVM support My first attempt was [A] because the code looks cleaner, but Paolo suggested [B]. So, this commit goes with [B]. For most architectures, <asm/kvm_para.h> was moved to the kernel-space. I changed include/uapi/linux/Kbuild so that it checks generated asm/kvm_para.h as well as check-in ones. After this commit, there will be two groups: [1] Both <linux/kvm_para.h> and <asm/kvm_para.h> are exported arm, arm64, mips, powerpc, s390, x86 [2] Neither <linux/kvm_para.h> nor <asm/kvm_para.h> is exported alpha, arc, c6x, csky, h8300, hexagon, ia64, m68k, microblaze, nds32, nios2, openrisc, parisc, riscv, sh, sparc, unicore32, xtensa Signed-off-by:Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by:
Cornelia Huck <cohuck@redhat.com> Signed-off-by:
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Wei Yang authored
* nr_mmu_pages would be non-zero only if kvm->arch.n_requested_mmu_pages is non-zero. * nr_mmu_pages is always non-zero, since kvm_mmu_calculate_mmu_pages() never return zero. Based on these two reasons, we can merge the two *if* clause and use the return value from kvm_mmu_calculate_mmu_pages() directly. This simplify the code and also eliminate the possibility for reader to believe nr_mmu_pages would be zero. Signed-off-by:
Wei Yang <richard.weiyang@gmail.com> Reviewed-by:
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Krish Sadhukhan authored
According to section "Checks on VMX Controls" in Intel SDM vol 3C, the following check is performed on vmentry of L2 guests: On processors that support Intel 64 architecture, the IA32_SYSENTER_ESP field and the IA32_SYSENTER_EIP field must each contain a canonical address. Signed-off-by:Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by:
Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by:
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Singh, Brijesh authored
Errata#1096: On a nested data page fault when CR.SMAP=1 and the guest data read generates a SMAP violation, GuestInstrBytes field of the VMCB on a VMEXIT will incorrectly return 0h instead the correct guest instruction bytes . Recommend Workaround: To determine what instruction the guest was executing the hypervisor will have to decode the instruction at the instruction pointer. The recommended workaround can not be implemented for the SEV guest because guest memory is encrypted with the guest specific key, and instruction decoder will not be able to decode the instruction bytes. If we hit this errata in the SEV guest then log the message and request a guest shutdown. Reported-by:
Venkatesh Srinivas <venkateshs@google.com> Cc: Jim Mattson <jmattson@google.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
Brijesh Singh <brijesh.singh@amd.com> Signed-off-by:
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Sean Christopherson authored
KVM's API requires thats ioctls must be issued from the same process that created the VM. In other words, userspace can play games with a VM's file descriptors, e.g. fork(), SCM_RIGHTS, etc..., but only the creator can do anything useful. Explicitly reject device ioctls that are issued by a process other than the VM's creator, and update KVM's API documentation to extend its requirements to device ioctls. Fixes: 852b6d57 ("kvm: add device control API") Cc: <stable@vger.kernel.org> Signed-off-by:
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Sean Christopherson authored
Per Paolo[1], instantiating multiple VMs in a single process is legal; but this conflicts with KVM's API documentation, which states: The only supported use is one virtual machine per process, and one vcpu per thread. However, an earlier section in the documentation states: Only run VM ioctls from the same process (address space) that was used to create the VM. and: Only run vcpu ioctls from the same thread that was used to create the vcpu. This suggests that the conflicting documentation is simply an incorrect ordering of of words, i.e. what's really meant is that a virtual machine can't be shared across multiple processes and a vCPU can't be shared across multiple threads. Tweak the blurb on issuing ioctls to use a more assertive tone, and rewrite the "supported use" sentence to reference said blurb instead of poorly restating it in different terms. Opportunistically add missing punctuation. [1] https://lkml.kernel.org/r/f23265d4-528e-3bd4-011f-4d7b8f3281db@redhat.com Fixes: 9c1b96e3 ("KVM: Document basic API") Signed-off-by:
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Sean Christopherson authored
The cr4_pae flag is a bit of a misnomer, its purpose is really to track whether the guest PTE that is being shadowed is a 4-byte entry or an 8-byte entry. Prior to supporting nested EPT, the size of the gpte was reflected purely by CR4.PAE. KVM fudged things a bit for direct sptes, but it was mostly harmless since the size of the gpte never mattered. Now that a spte may be tracking an indirect EPT entry, relying on CR4.PAE is wrong and ill-named. For direct shadow pages, force the gpte_size to '1' as they are always 8-byte entries; EPT entries can only be 8-bytes and KVM always uses 8-byte entries for NPT and its identity map (when running with EPT but not unrestricted guest). Likewise, nested EPT entries are always 8-bytes. Nested EPT presents a unique scenario as the size of the entries are not dictated by CR4.PAE, but neither is the shadow page a direct map. To handle this scenario, set cr0_wp=1 and smap_andnot_wp=1, an otherwise impossible combination, to denote a nested EPT shadow page. Use the information to avoid incorrectly zapping an unsync'd indirect page in __kvm_sync_page(). Providing a consistent and accurate gpte_size fixes a bug reported by Vitaly where fast_cr3_switch() always fails when switching from L2 to L1 as kvm_mmu_get_page() would force role.cr4_pae=0 for direct pages, whereas kvm_calc_mmu_role_common() would set it according to CR4.PAE. Fixes: 7dcd5755 ("x86/kvm/mmu: check if tdp/shadow MMU reconfiguration is needed") Reported-by:
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Sean Christopherson authored
Explicitly zero out quadrant and invalid instead of inheriting them from the root_mmu. Functionally, this patch is a nop as we (should) never set quadrant for a direct mapped (EPT) root_mmu and nested EPT is only allowed if EPT is used for L1, and the root_mmu will never be invalid at this point. Explicitly setting flags sets the stage for repurposing the legacy paging bits in role, e.g. nxe, cr0_wp, and sm{a,e}p_andnot_wp, at which point 'smm' would be the only flag to be inherited from root_mmu. Signed-off-by: -
Zenghui Yu authored
Some comments in virt/kvm/arm/mmu.c are outdated. Update them to reflect the current state of the code. Signed-off-by:
Zenghui Yu <yuzenghui@huawei.com> Reviewed-by:
Suzuki K Poulose <suzuki.poulose@arm.com> [maz: commit message tidy-up] Signed-off-by:
Marc Zyngier <marc.zyngier@arm.com>
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- 24 Mar, 2019 6 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4Linus Torvalds authored
Pull ext4 fixes from Ted Ts'o: "Miscellaneous ext4 bug fixes for 5.1" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: prohibit fstrim in norecovery mode ext4: cleanup bh release code in ext4_ind_remove_space() ext4: brelse all indirect buffer in ext4_ind_remove_space() ext4: report real fs size after failed resize ext4: add missing brelse() in add_new_gdb_meta_bg() ext4: remove useless ext4_pin_inode() ext4: avoid panic during forced reboot ext4: fix data corruption caused by unaligned direct AIO ext4: fix NULL pointer dereference while journal is aborted
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler updates from Thomas Gleixner: "Third more careful attempt for this set of fixes: - Prevent a 32bit math overflow in the cpufreq code - Fix a buffer overflow when scanning the cgroup2 cpu.max property - A set of fixes for the NOHZ scheduler logic to prevent waking up CPUs even if the capacity of the busy CPUs is sufficient along with other tweaks optimizing the behaviour for asymmetric systems (big/little)" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Skip LLC NOHZ logic for asymmetric systems sched/fair: Tune down misfit NOHZ kicks sched/fair: Comment some nohz_balancer_kick() kick conditions sched/core: Fix buffer overflow in cgroup2 property cpu.max sched/cpufreq: Fix 32-bit math overflow -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf updates from Thomas Gleixner: "A larger set of perf updates. Not all of them are strictly fixes, but that's solely the tip maintainers fault as they let the timely -rc1 pull request fall through the cracks for various reasons including travel. So I'm sending this nevertheless because rebasing and distangling fixes and updates would be a mess and risky as well. As of tomorrow, a strict fixes separation is happening again. Sorry for the slip-up. Kernel: - Handle RECORD_MMAP vs. RECORD_MMAP2 correctly so different consumers of the mmap event get what they requested. Tools: - A larger set of updates to perf record/report/scripts vs. time stamp handling - More Python3 fixups - A pile of memory leak plumbing - perf BPF improvements and fixes - Finalize the perf.data directory storage" [ Note: the kernel part is strictly a fix, the updates are purely to tooling - Linus ] * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) perf bpf: Show more BPF program info in print_bpf_prog_info() perf bpf: Extract logic to create program names from perf_event__synthesize_one_bpf_prog() perf tools: Save bpf_prog_info and BTF of new BPF programs perf evlist: Introduce side band thread perf annotate: Enable annotation of BPF programs perf build: Check what binutils's 'disassembler()' signature to use perf bpf: Process PERF_BPF_EVENT_PROG_LOAD for annotation perf symbols: Introduce DSO_BINARY_TYPE__BPF_PROG_INFO perf feature detection: Add -lopcodes to feature-libbfd perf top: Add option --no-bpf-event perf bpf: Save BTF information as headers to perf.data perf bpf: Save BTF in a rbtree in perf_env perf bpf: Save bpf_prog_info information as headers to perf.data perf bpf: Save bpf_prog_info in a rbtree in perf_env perf bpf: Make synthesize_bpf_events() receive perf_session pointer instead of perf_tool perf bpf: Synthesize bpf events with bpf_program__get_prog_info_linear() bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump() tools lib bpf: Introduce bpf_program__get_prog_info_linear() perf record: Replace option --bpf-event with --no-bpf-event perf tests: Fix a memory leak in test__perf_evsel__tp_sched_test() ... -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: "A set of x86 fixes: - Prevent potential NULL pointer dereferences in the HPET and HyperV code - Exclude the GART aperture from /proc/kcore to prevent kernel crashes on access - Use the correct macros for Cyrix I/O on Geode processors - Remove yet another kernel address printk leak - Announce microcode reload completion as requested by quite some people. Microcode loading has become popular recently. - Some 'Make Clang' happy fixlets - A few cleanups for recently added code" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/gart: Exclude GART aperture from kcore x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error x86/mm/pti: Make local symbols static x86/cpu/cyrix: Remove {get,set}Cx86_old macros used for Cyrix processors x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors x86/microcode: Announce reload operation's completion x86/hyperv: Prevent potential NULL pointer dereference x86/hpet: Prevent potential NULL pointer dereference x86/lib: Fix indentation issue, remove extra tab x86/boot: Restrict header scope to make Clang happy x86/mm: Don't leak kernel addresses x86/cpufeature: Fix various quality problems in the <asm/cpu_device_hd.h> header -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer fixes from Thomas Gleixner: "A set of small fixes plus the removal of stale board support code: - Remove the board support code from the clpx711x clocksource driver. This change had fallen through the cracks and I'm sending it now rather than dealing with people who want to improve that stale code for 3 month. - Use the proper clocksource mask on RICSV - Make local scope functions and variables static" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/clps711x: Remove board support clocksource/drivers/riscv: Fix clocksource mask clocksource/drivers/mips-gic-timer: Make gic_compare_irqaction static clocksource/drivers/timer-ti-dm: Make omap_dm_timer_set_load_start() static clocksource/drivers/tcb_clksrc: Make tc_clksrc_suspend/resume() static clocksource/drivers/clps711x: Make clps711x_clksrc_init() static time/jiffies: Make refined_jiffies static
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