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2017-09-15kvm,powerpc: Serialize wq active checks in ops->vcpu_kickDavidlohr Bueso
Particularly because kvmppc_fast_vcpu_kick_hv() is a callback, ensure that we properly serialize wq active checks in order to avoid potentially missing a wakeup due to racing with the waiter side. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-14Merge branch 'kvm-ppc-fixes' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc Bug fixes for stable.
2017-09-12KVM: PPC: Book3S HV: Fix bug causing host SLB to be restored incorrectlyPaul Mackerras
Aneesh Kumar reported seeing host crashes when running recent kernels on POWER8. The symptom was an oops like this: Unable to handle kernel paging request for data at address 0xf00000000786c620 Faulting instruction address: 0xc00000000030e1e4 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: powernv_op_panel CPU: 24 PID: 6663 Comm: qemu-system-ppc Tainted: G W 4.13.0-rc7-43932-gfc36c59 #2 task: c000000fdeadfe80 task.stack: c000000fdeb68000 NIP: c00000000030e1e4 LR: c00000000030de6c CTR: c000000000103620 REGS: c000000fdeb6b450 TRAP: 0300 Tainted: G W (4.13.0-rc7-43932-gfc36c59) MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 24044428 XER: 20000000 CFAR: c00000000030e134 DAR: f00000000786c620 DSISR: 40000000 SOFTE: 0 GPR00: 0000000000000000 c000000fdeb6b6d0 c0000000010bd000 000000000000e1b0 GPR04: c00000000115e168 c000001fffa6e4b0 c00000000115d000 c000001e1b180386 GPR08: f000000000000000 c000000f9a8913e0 f00000000786c600 00007fff587d0000 GPR12: c000000fdeb68000 c00000000fb0f000 0000000000000001 00007fff587cffff GPR16: 0000000000000000 c000000000000000 00000000003fffff c000000fdebfe1f8 GPR20: 0000000000000004 c000000fdeb6b8a8 0000000000000001 0008000000000040 GPR24: 07000000000000c0 00007fff587cffff c000000fdec20bf8 00007fff587d0000 GPR28: c000000fdeca9ac0 00007fff587d0000 00007fff587c0000 00007fff587d0000 NIP [c00000000030e1e4] __get_user_pages_fast+0x434/0x1070 LR [c00000000030de6c] __get_user_pages_fast+0xbc/0x1070 Call Trace: [c000000fdeb6b6d0] [c00000000139dab8] lock_classes+0x0/0x35fe50 (unreliable) [c000000fdeb6b7e0] [c00000000030ef38] get_user_pages_fast+0xf8/0x120 [c000000fdeb6b830] [c000000000112318] kvmppc_book3s_hv_page_fault+0x308/0xf30 [c000000fdeb6b960] [c00000000010e10c] kvmppc_vcpu_run_hv+0xfdc/0x1f00 [c000000fdeb6bb20] [c0000000000e915c] kvmppc_vcpu_run+0x2c/0x40 [c000000fdeb6bb40] [c0000000000e5650] kvm_arch_vcpu_ioctl_run+0x110/0x300 [c000000fdeb6bbe0] [c0000000000d6468] kvm_vcpu_ioctl+0x528/0x900 [c000000fdeb6bd40] [c0000000003bc04c] do_vfs_ioctl+0xcc/0x950 [c000000fdeb6bde0] [c0000000003bc930] SyS_ioctl+0x60/0x100 [c000000fdeb6be30] [c00000000000b96c] system_call+0x58/0x6c Instruction dump: 7ca81a14 2fa50000 41de0010 7cc8182a 68c60002 78c6ffe2 0b060000 3cc2000a 794a3664 390610d8 e9080000 7d485214 <e90a0020> 7d435378 790507e1 408202f0 ---[ end trace fad4a342d0414aa2 ]--- It turns out that what has happened is that the SLB entry for the vmmemap region hasn't been reloaded on exit from a guest, and it has the wrong page size. Then, when the host next accesses the vmemmap region, it gets a page fault. Commit a25bd72badfa ("powerpc/mm/radix: Workaround prefetch issue with KVM", 2017-07-24) modified the guest exit code so that it now only clears out the SLB for hash guest. The code tests the radix flag and puts the result in a non-volatile CR field, CR2, and later branches based on CR2. Unfortunately, the kvmppc_save_tm function, which gets called between those two points, modifies all the user-visible registers in the case where the guest was in transactional or suspended state, except for a few which it restores (namely r1, r2, r9 and r13). Thus the hash/radix indication in CR2 gets corrupted. This fixes the problem by re-doing the comparison just before the result is needed. For good measure, this also adds comments next to the call sites of kvmppc_save_tm and kvmppc_restore_tm pointing out that non-volatile register state will be lost. Cc: stable@vger.kernel.org # v4.13 Fixes: a25bd72badfa ("powerpc/mm/radix: Workaround prefetch issue with KVM") Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-12KVM: PPC: Book3S HV: Hold kvm->lock around call to kvmppc_update_lpcrPaul Mackerras
Commit 468808bd35c4 ("KVM: PPC: Book3S HV: Set process table for HPT guests on POWER9", 2017-01-30) added a call to kvmppc_update_lpcr() which doesn't hold the kvm->lock mutex around the call, as required. This adds the lock/unlock pair, and for good measure, includes the kvmppc_setup_partition_table() call in the locked region, since it is altering global state of the VM. This error appears not to have any fatal consequences for the host; the consequences would be that the VCPUs could end up running with different LPCR values, or an update to the LPCR value by userspace using the one_reg interface could get overwritten, or the update done by kvmhv_configure_mmu() could get overwritten. Cc: stable@vger.kernel.org # v4.10+ Fixes: 468808bd35c4 ("KVM: PPC: Book3S HV: Set process table for HPT guests on POWER9") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-12KVM: PPC: Book3S HV: Don't access XIVE PIPR register using byte accessesBenjamin Herrenschmidt
The XIVE interrupt controller on POWER9 machines doesn't support byte accesses to any register in the thread management area other than the CPPR (current processor priority register). In particular, when reading the PIPR (pending interrupt priority register), we need to do a 32-bit or 64-bit load. Cc: stable@vger.kernel.org # v4.13 Fixes: 2c4fb78f78b6 ("KVM: PPC: Book3S HV: Workaround POWER9 DD1.0 bug causing IPB bit loss") Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-08Merge tag 'kvm-4.14-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Radim Krčmář: "First batch of KVM changes for 4.14 Common: - improve heuristic for boosting preempted spinlocks by ignoring VCPUs in user mode ARM: - fix for decoding external abort types from guests - added support for migrating the active priority of interrupts when running a GICv2 guest on a GICv3 host - minor cleanup PPC: - expose storage keys to userspace - merge kvm-ppc-fixes with a fix that missed 4.13 because of vacations - fixes s390: - merge of kvm/master to avoid conflicts with additional sthyi fixes - wire up the no-dat enhancements in KVM - multiple epoch facility (z14 feature) - Configuration z/Architecture Mode - more sthyi fixes - gdb server range checking fix - small code cleanups x86: - emulate Hyper-V TSC frequency MSRs - add nested INVPCID - emulate EPTP switching VMFUNC - support Virtual GIF - support 5 level page tables - speedup nested VM exits by packing byte operations - speedup MMIO by using hardware provided physical address - a lot of fixes and cleanups, especially nested" * tag 'kvm-4.14-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits) KVM: arm/arm64: Support uaccess of GICC_APRn KVM: arm/arm64: Extract GICv3 max APRn index calculation KVM: arm/arm64: vITS: Drop its_ite->lpi field KVM: arm/arm64: vgic: constify seq_operations and file_operations KVM: arm/arm64: Fix guest external abort matching KVM: PPC: Book3S HV: Fix memory leak in kvm_vm_ioctl_get_htab_fd KVM: s390: vsie: cleanup mcck reinjection KVM: s390: use WARN_ON_ONCE only for checking KVM: s390: guestdbg: fix range check KVM: PPC: Book3S HV: Report storage key support to userspace KVM: PPC: Book3S HV: Fix case where HDEC is treated as 32-bit on POWER9 KVM: PPC: Book3S HV: Fix invalid use of register expression KVM: PPC: Book3S HV: Fix H_REGISTER_VPA VPA size validation KVM: PPC: Book3S HV: Fix setting of storage key in H_ENTER KVM: PPC: e500mc: Fix a NULL dereference KVM: PPC: e500: Fix some NULL dereferences on error KVM: PPC: Book3S HV: Protect updates to spapr_tce_tables list KVM: s390: we are always in czam mode KVM: s390: expose no-DAT to guest and migration support KVM: s390: sthyi: remove invalid guest write access ...
2017-09-08Merge branch 'kvm-ppc-fixes' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc This fix was intended for 4.13, but didn't get in because both maintainers were on vacation. Paul Mackerras: "It adds mutual exclusion between list_add_rcu and list_del_rcu calls on the kvm->arch.spapr_tce_tables list. Without this, userspace could potentially trigger corruption of the list and cause a host crash or worse."
2017-09-07Merge tag 'powerpc-4.14-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Nothing really major this release, despite quite a lot of activity. Just lots of things all over the place. Some things of note include: - Access via perf to a new type of PMU (IMC) on Power9, which can count both core events as well as nest unit events (Memory controller etc). - Optimisations to the radix MMU TLB flushing, mostly to avoid unnecessary Page Walk Cache (PWC) flushes when the structure of the tree is not changing. - Reworks/cleanups of do_page_fault() to modernise it and bring it closer to other architectures where possible. - Rework of our page table walking so that THP updates only need to send IPIs to CPUs where the affected mm has run, rather than all CPUs. - The size of our vmalloc area is increased to 56T on 64-bit hash MMU systems. This avoids problems with the percpu allocator on systems with very sparse NUMA layouts. - STRICT_KERNEL_RWX support on PPC32. - A new sched domain topology for Power9, to capture the fact that pairs of cores may share an L2 cache. - Power9 support for VAS, which is a new mechanism for accessing coprocessors, and initial support for using it with the NX compression accelerator. - Major work on the instruction emulation support, adding support for many new instructions, and reworking it so it can be used to implement the emulation needed to fixup alignment faults. - Support for guests under PowerVM to use the Power9 XIVE interrupt controller. And probably that many things again that are almost as interesting, but I had to keep the list short. Plus the usual fixes and cleanups as always. Thanks to: Alexey Kardashevskiy, Alistair Popple, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Arvind Yadav, Balbir Singh, Benjamin Herrenschmidt, Bhumika Goyal, Breno Leitao, Bryant G. Ly, Christophe Leroy, Cédric Le Goater, Dan Carpenter, Dou Liyang, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Hannes Reinecke, Haren Myneni, Ivan Mikhaylov, John Allen, Julia Lawall, LABBE Corentin, Laurentiu Tudor, Madhavan Srinivasan, Markus Elfring, Masahiro Yamada, Matt Brown, Michael Neuling, Murilo Opsfelder Araujo, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Rashmica Gupta, Rob Herring, Rui Teng, Sam Bobroff, Santosh Sivaraj, Scott Wood, Shilpasri G Bhat, Sukadev Bhattiprolu, Suraj Jitindar Singh, Tobin C. Harding, Victor Aoqui" * tag 'powerpc-4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (321 commits) powerpc/xive: Fix section __init warning powerpc: Fix kernel crash in emulation of vector loads and stores powerpc/xive: improve debugging macros powerpc/xive: add XIVE Exploitation Mode to CAS powerpc/xive: introduce H_INT_ESB hcall powerpc/xive: add the HW IRQ number under xive_irq_data powerpc/xive: introduce xive_esb_write() powerpc/xive: rename xive_poke_esb() in xive_esb_read() powerpc/xive: guest exploitation of the XIVE interrupt controller powerpc/xive: introduce a common routine xive_queue_page_alloc() powerpc/sstep: Avoid used uninitialized error axonram: Return directly after a failed kzalloc() in axon_ram_probe() axonram: Improve a size determination in axon_ram_probe() axonram: Delete an error message for a failed memory allocation in axon_ram_probe() powerpc/powernv/npu: Move tlb flush before launching ATSD powerpc/macintosh: constify wf_sensor_ops structures powerpc/iommu: Use permission-specific DEVICE_ATTR variants powerpc/eeh: Delete an error out of memory message at init time powerpc/mm: Use seq_putc() in two functions macintosh: Convert to using %pOF instead of full_name ...
2017-09-01KVM: PPC: Book3S HV: Fix memory leak in kvm_vm_ioctl_get_htab_fdnixiaoming
We do ctx = kzalloc(sizeof(*ctx), GFP_KERNEL) and then later on call anon_inode_getfd(), but if that fails we don't free ctx, so that memory gets leaked. To fix it, this adds kfree(ctx) in the failure path. Signed-off-by: nixiaoming <nixiaoming@huawei.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-nextPaul Mackerras
This merges in the 'ppc-kvm' topic branch from the powerpc tree in order to bring in some fixes which touch both powerpc and KVM code. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: Book3S HV: Report storage key support to userspacePaul Mackerras
This adds information about storage keys to the struct returned by the KVM_PPC_GET_SMMU_INFO ioctl. The new fields replace a pad field, which was zeroed by previous kernel versions. Thus userspace that knows about the new fields will see zeroes when running on an older kernel, indicating that storage keys are not supported. The size of the structure has not changed. The number of keys is hard-coded for the CPUs supported by HV KVM, which is just POWER7, POWER8 and POWER9. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: Book3S HV: Fix case where HDEC is treated as 32-bit on POWER9Paul Mackerras
Commit 2f2724630f7a ("KVM: PPC: Book3S HV: Cope with host using large decrementer mode", 2017-05-22) added code to treat the hypervisor decrementer (HDEC) as a 64-bit value on POWER9 rather than 32-bit. Unfortunately, that commit missed one place where HDEC is treated as a 32-bit value. This fixes it. This bug should not have any user-visible consequences that I can think of, beyond an occasional unnecessary exit to the host kernel. If the hypervisor decrementer has gone negative, then the bottom 32 bits will be negative for about 4 seconds after that, so as long as we get out of the guest within those 4 seconds we won't conclude that the HDEC interrupt is spurious. Reported-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Fixes: 2f2724630f7a ("KVM: PPC: Book3S HV: Cope with host using large decrementer mode") Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: Book3S HV: Fix invalid use of register expressionAndreas Schwab
binutils >= 2.26 now warns about misuse of register expressions in assembler operands that are actually literals. In this instance r0 is being used where a literal 0 should be used. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> [mpe: Split into separate KVM patch, tweak change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: Book3S HV: Fix H_REGISTER_VPA VPA size validationNicholas Piggin
KVM currently validates the size of the VPA registered by the client against sizeof(struct lppaca), however we align (and therefore size) that struct to 1kB to avoid crossing a 4kB boundary in the client. PAPR calls for sizes >= 640 bytes to be accepted. Hard code this with a comment. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: Book3S HV: Fix setting of storage key in H_ENTERRam Pai
In handling a H_ENTER hypercall, the code in kvmppc_do_h_enter clobbers the high-order two bits of the storage key, which is stored in a split field in the second doubleword of the HPTE. Any storage key number above 7 hence fails to operate correctly. This makes sure we preserve all the bits of the storage key. Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: e500mc: Fix a NULL dereferenceDan Carpenter
We should set "err = -ENOMEM;", otherwise it means we're returning ERR_PTR(0) which is NULL. It results in a NULL pointer dereference in the caller. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-31KVM: PPC: e500: Fix some NULL dereferences on errorDan Carpenter
There are some error paths in kvmppc_core_vcpu_create_e500() where we forget to set the error code. It means that we return ERR_PTR(0) which is NULL and it results in a NULL pointer dereference in the caller. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-30KVM: PPC: Book3S HV: Protect updates to spapr_tce_tables listPaul Mackerras
Al Viro pointed out that while one thread of a process is executing in kvm_vm_ioctl_create_spapr_tce(), another thread could guess the file descriptor returned by anon_inode_getfd() and close() it before the first thread has added it to the kvm->arch.spapr_tce_tables list. That highlights a more general problem: there is no mutual exclusion between writers to the spapr_tce_tables list, leading to the possibility of the list becoming corrupted, which could cause a host kernel crash. To fix the mutual exclusion problem, we add a mutex_lock/unlock pair around the list_del_rce in kvm_spapr_tce_release(). Also, this moves the call to anon_inode_getfd() inside the region protected by the kvm->lock mutex, after we have done the check for a duplicate LIOBN. This means that if another thread does guess the file descriptor and closes it, its call to kvm_spapr_tce_release() will not do any harm because it will have to wait until the first thread has released kvm->lock. With this, there are no failure points in kvm_vm_ioctl_create_spapr_tce() after the call to anon_inode_getfd(). The other things that the second thread could do with the guessed file descriptor are to mmap it or to pass it as a parameter to a KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE ioctl on a KVM device fd. An mmap call won't cause any harm because kvm_spapr_tce_mmap() and kvm_spapr_tce_fault() don't access the spapr_tce_tables list or the kvmppc_spapr_tce_table.list field, and the fields that they do use have been properly initialized by the time of the anon_inode_getfd() call. The KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE ioctl calls kvm_spapr_tce_attach_iommu_group(), which scans the spapr_tce_tables list looking for the kvmppc_spapr_tce_table struct corresponding to the fd given as the parameter. Either it will find the new entry or it won't; if it doesn't, it just returns an error, and if it does, it will function normally. So, in each case there is no harmful effect. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-29Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
Merge Nicks commit to rework the KVM thread management, shared with the KVM tree via the ppc-kvm topic branch.
2017-08-29KVM: PPC: Book3S HV: POWER9 does not require secondary thread managementNicholas Piggin
POWER9 CPUs have independent MMU contexts per thread, so KVM does not need to quiesce secondary threads, so the hwthread_req/hwthread_state protocol does not have to be used. So patch it away on POWER9, and patch away the branch from the Linux idle wakeup to kvm_start_guest that is never used. Add a warning and error out of kvmppc_grab_hwthread in case it is ever called on POWER9. This avoids a hwsync in the idle wakeup path on POWER9. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> [mpe: Use WARN(...) instead of WARN_ON()/pr_err(...)] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-25KVM: PPC: Book3S: Fix race and leak in kvm_vm_ioctl_create_spapr_tce()Paul Mackerras
Nixiaoming pointed out that there is a memory leak in kvm_vm_ioctl_create_spapr_tce() if the call to anon_inode_getfd() fails; the memory allocated for the kvmppc_spapr_tce_table struct is not freed, and nor are the pages allocated for the iommu tables. In addition, we have already incremented the process's count of locked memory pages, and this doesn't get restored on error. David Hildenbrand pointed out that there is a race in that the function checks early on that there is not already an entry in the stt->iommu_tables list with the same LIOBN, but an entry with the same LIOBN could get added between then and when the new entry is added to the list. This fixes all three problems. To simplify things, we now call anon_inode_getfd() before placing the new entry in the list. The check for an existing entry is done while holding the kvm->lock mutex, immediately before adding the new entry to the list. Finally, on failure we now call kvmppc_account_memlimit to decrement the process's count of locked memory pages. Reported-by: Nixiaoming <nixiaoming@huawei.com> Reported-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-24KVM: PPC: Book3S HV: Add missing barriers to XIVE code and document themBenjamin Herrenschmidt
This adds missing memory barriers to order updates/tests of the virtual CPPR and MFRR, thus fixing a lost IPI problem. While at it also document all barriers in this file. This fixes a bug causing guest IPIs to occasionally get lost. The symptom then is hangs or stalls in the guest. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-24KVM: PPC: Book3S HV: Workaround POWER9 DD1.0 bug causing IPB bit lossBenjamin Herrenschmidt
This adds a workaround for a bug in POWER9 DD1 chips where changing the CPPR (Current Processor Priority Register) can cause bits in the IPB (Interrupt Pending Buffer) to get lost. Thankfully it only happens when manually manipulating CPPR which is quite rare. When it does happen it can cause interrupts to be delayed or lost. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-24KVM: PPC: Book3S HV: Use msgsync with hypervisor doorbells on POWER9Nicholas Piggin
When msgsnd is used for IPIs to other cores, msgsync must be executed by the target to order stores performed on the source before its msgsnd (provided the source executes the appropriate sync). Fixes: 1704a81ccebc ("KVM: PPC: Book3S HV: Use msgsnd for IPIs to other cores on POWER9") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-08-23Merge branch 'fixes' into nextMichael Ellerman
There's a non-trivial dependency between some commits we want to put in next and the KVM prefetch work around that went into fixes. So merge fixes into next.
2017-08-17Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
Bring in the commit to rename find_linux_pte_or_hugepte() which touches arch and KVM code, and might need to be merged with the kvmppc tree to avoid conflicts.
2017-08-17powerpc/mm: Rename find_linux_pte_or_hugepte()Aneesh Kumar K.V
Add newer helpers to make the function usage simpler. It is always recommended to use find_current_mm_pte() for walking the page table. If we cannot use find_current_mm_pte(), it should be documented why the said usage of __find_linux_pte() is safe against a parallel THP split. For now we have KVM code using __find_linux_pte(). This is because kvm code ends up calling __find_linux_pte() in real mode with MSR_EE=0 but with PACA soft_enabled = 1. We may want to fix that later and make sure we keep the MSR_EE and PACA soft_enabled in sync. When we do that we can switch kvm to use find_linux_pte(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-08KVM: add spinlock optimization frameworkLongpeng(Mike)
If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-03powerpc/mm: Update definitions of DSISR bitsBenjamin Herrenschmidt
This updates the definitions for the various DSISR bits to match both some historical stuff and to match new bits on POWER9. In addition, we define some masks corresponding to the "bad" faults on Book3S, and some masks corresponding to the bits that match between DSISR and SRR1 for a DSI and an ISI. This comes with a small code update to change the definition of DSISR_PGDIRFAULT which becomes DSISR_PRTABLE_FAULT to match architecture 3.0B Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-31Merge tag 'v4.13-rc1' into fixesMichael Ellerman
The fixes branch is based off a random pre-rc1 commit, because we had some fixes that needed to go in before rc1 was released. However we now need to fix some code that went in after that point, but before rc1, so merge rc1 to get that code into fixes so we can fix it!
2017-07-28Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "s390: - SRCU fix PPC: - host crash fixes x86: - bugfixes, including making nested posted interrupts really work Generic: - tweaks to kvm_stat and to uevents" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: LAPIC: Fix reentrancy issues with preempt notifiers tools/kvm_stat: add '-f help' to get the available event list tools/kvm_stat: use variables instead of hard paths in help output KVM: nVMX: Fix loss of L2's NMI blocking state KVM: nVMX: Fix posted intr delivery when vcpu is in guest mode x86: irq: Define a global vector for nested posted interrupts KVM: x86: do mask out upper bits of PAE CR3 KVM: make pid available for uevents without debugfs KVM: s390: take srcu lock when getting/setting storage keys KVM: VMX: remove unused field KVM: PPC: Book3S HV: Fix host crash on changing HPT size KVM: PPC: Book3S HV: Enable TM before accessing TM registers
2017-07-28Merge tag 'powerpc-4.13-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "The highlight is Ben's patch to work around a host killing bug when running KVM guests with the Radix MMU on Power9. See the long change log of that commit for more detail. And then three fairly minor fixes: - fix of_node_put() underflow during reconfig remove, using old DLPAR tools. - fix recently introduced ld version check with 64-bit LE-only toolchain. - free the subpage_prot_table correctly, avoiding a memory leak. Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier" * tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm/hash: Free the subpage_prot_table correctly powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchain powerpc/pseries: Fix of_node_put() underflow during reconfig remove powerpc/mm/radix: Workaround prefetch issue with KVM
2017-07-26powerpc/mm/radix: Workaround prefetch issue with KVMBenjamin Herrenschmidt
There's a somewhat architectural issue with Radix MMU and KVM. When coming out of a guest with AIL (Alternate Interrupt Location, ie, MMU enabled), we start executing hypervisor code with the PID register still containing whatever the guest has been using. The problem is that the CPU can (and will) then start prefetching or speculatively load from whatever host context has that same PID (if any), thus bringing translations for that context into the TLB, which Linux doesn't know about. This can cause stale translations and subsequent crashes. Fixing this in a way that is neither racy nor a huge performance impact is difficult. We could just make the host invalidations always use broadcast forms but that would hurt single threaded programs for example. We chose to fix it instead by partitioning the PID space between guest and host. This is possible because today Linux only use 19 out of the 20 bits of PID space, so existing guests will work if we make the host use the top half of the 20 bits space. We additionally add support for a property to indicate to Linux the size of the PID register which will be useful if we eventually have processors with a larger PID space available. There is still an issue with malicious guests purposefully setting the PID register to a value in the hosts PID range. Hopefully future HW can prevent that, but in the meantime, we handle it with a pair of kludges: - On the way out of a guest, before we clear the current VCPU in the PACA, we check the PID and if it's outside of the permitted range we flush the TLB for that PID. - When context switching, if the mm is "new" on that CPU (the corresponding bit was set for the first time in the mm cpumask), we check if any sibling thread is in KVM (has a non-NULL VCPU pointer in the PACA). If that is the case, we also flush the PID for that CPU (core). This second part is needed to handle the case where a process is migrated (or starts a new pthread) on a sibling thread of the CPU coming out of KVM, as there's a window where stale translations can exist before we detect it and flush them out. A future optimization could be added by keeping track of whether the PID has ever been used and avoid doing that for completely fresh PIDs. We could similarily mark PIDs that have been the subject of a global invalidation as "fresh". But for now this will do. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Rework the asm to build with CONFIG_PPC_RADIX_MMU=n, drop unneeded include of kvm_book3s_asm.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-24KVM: PPC: Book3S HV: Fix host crash on changing HPT sizePaul Mackerras
Commit f98a8bf9ee20 ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size", 2016-12-20) changed the behaviour of the KVM_PPC_ALLOCATE_HTAB ioctl so that it now allocates a new HPT and new revmap array if there was a previously-allocated HPT of a different size from the size being requested. In this case, we need to reset the rmap arrays of the memslots, because the rmap arrays will contain references to HPTEs which are no longer valid. Worse, these references are also references to slots in the new revmap array (which parallels the HPT), and the new revmap array contains random contents, since it doesn't get zeroed on allocation. The effect of having these stale references to slots in the revmap array that contain random contents is that subsequent calls to functions such as kvmppc_add_revmap_chain will crash because they will interpret the non-zero contents of the revmap array as HPTE indexes and thus index outside of the revmap array. This leads to host crashes such as the following. [ 7072.862122] Unable to handle kernel paging request for data at address 0xd000000c250c00f8 [ 7072.862218] Faulting instruction address: 0xc0000000000e1c78 [ 7072.862233] Oops: Kernel access of bad area, sig: 11 [#1] [ 7072.862286] SMP NR_CPUS=1024 [ 7072.862286] NUMA [ 7072.862325] PowerNV [ 7072.862378] Modules linked in: kvm_hv vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm iw_cxgb3 mlx5_ib ib_core ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel i2c_opal nfsd auth_rpcgss oid_registry [ 7072.863085] nfs_acl lockd grace sunrpc kvm_pr kvm xfs libcrc32c scsi_dh_alua dm_service_time radeon lpfc nvme_fc nvme_fabrics nvme_core scsi_transport_fc i2c_algo_bit tg3 drm_kms_helper ptp pps_core syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm dm_multipath i2c_core cxgb3 mlx5_core mdio [last unloaded: kvm_hv] [ 7072.863381] CPU: 72 PID: 56929 Comm: qemu-system-ppc Not tainted 4.12.0-kvm+ #59 [ 7072.863457] task: c000000fe29e7600 task.stack: c000001e3ffec000 [ 7072.863520] NIP: c0000000000e1c78 LR: c0000000000e2e3c CTR: c0000000000e25f0 [ 7072.863596] REGS: c000001e3ffef560 TRAP: 0300 Not tainted (4.12.0-kvm+) [ 7072.863658] MSR: 9000000100009033 <SF,HV,EE,ME,IR,DR,RI,LE,TM[E]> [ 7072.863667] CR: 44082882 XER: 20000000 [ 7072.863767] CFAR: c0000000000e2e38 DAR: d000000c250c00f8 DSISR: 42000000 SOFTE: 1 GPR00: c0000000000e2e3c c000001e3ffef7e0 c000000001407d00 d000000c250c00f0 GPR04: d00000006509fb70 d00000000b3d2048 0000000003ffdfb7 0000000000000000 GPR08: 00000001007fdfb7 00000000c000000f d0000000250c0000 000000000070f7bf GPR12: 0000000000000008 c00000000fdad000 0000000010879478 00000000105a0d78 GPR16: 00007ffaf4080000 0000000000001190 0000000000000000 0000000000010000 GPR20: 4001ffffff000415 d00000006509fb70 0000000004091190 0000000ee1881190 GPR24: 0000000003ffdfb7 0000000003ffdfb7 00000000007fdfb7 c000000f5c958000 GPR28: d00000002d09fb70 0000000003ffdfb7 d00000006509fb70 d00000000b3d2048 [ 7072.864439] NIP [c0000000000e1c78] kvmppc_add_revmap_chain+0x88/0x130 [ 7072.864503] LR [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0 [ 7072.864566] Call Trace: [ 7072.864594] [c000001e3ffef7e0] [c000001e3ffef830] 0xc000001e3ffef830 (unreliable) [ 7072.864671] [c000001e3ffef830] [c0000000000e2e3c] kvmppc_do_h_enter+0x84c/0x9e0 [ 7072.864751] [c000001e3ffef920] [d00000000b38d878] kvmppc_map_vrma+0x168/0x200 [kvm_hv] [ 7072.864831] [c000001e3ffef9e0] [d00000000b38a684] kvmppc_vcpu_run_hv+0x1284/0x1300 [kvm_hv] [ 7072.864914] [c000001e3ffefb30] [d00000000f465664] kvmppc_vcpu_run+0x44/0x60 [kvm] [ 7072.865008] [c000001e3ffefb60] [d00000000f461864] kvm_arch_vcpu_ioctl_run+0x114/0x290 [kvm] [ 7072.865152] [c000001e3ffefbe0] [d00000000f453c98] kvm_vcpu_ioctl+0x598/0x7a0 [kvm] [ 7072.865292] [c000001e3ffefd40] [c000000000389328] do_vfs_ioctl+0xd8/0x8c0 [ 7072.865410] [c000001e3ffefde0] [c000000000389be4] SyS_ioctl+0xd4/0x130 [ 7072.865526] [c000001e3ffefe30] [c00000000000b760] system_call+0x58/0x6c [ 7072.865644] Instruction dump: [ 7072.865715] e95b2110 793a0020 7b4926e4 7f8a4a14 409e0098 807c000c 786326e4 7c6a1a14 [ 7072.865857] 935e0008 7bbd0020 813c000c 913e000c <93a30008> 93bc000c 48000038 60000000 [ 7072.866001] ---[ end trace 627b6e4bf8080edc ]--- Note that to trigger this, it is necessary to use a recent upstream QEMU (or other userspace that resizes the HPT at CAS time), specify a maximum memory size substantially larger than the current memory size, and boot a guest kernel that does not support HPT resizing. This fixes the problem by resetting the rmap arrays when the old HPT is freed. Fixes: f98a8bf9ee20 ("KVM: PPC: Book3S HV: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size") Cc: stable@vger.kernel.org # v4.11+ Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-24KVM: PPC: Book3S HV: Enable TM before accessing TM registersPaul Mackerras
Commit 46a704f8409f ("KVM: PPC: Book3S HV: Preserve userspace HTM state properly", 2017-06-15) added code to read transactional memory (TM) registers but forgot to enable TM before doing so. The result is that if userspace does have live values in the TM registers, a KVM_RUN ioctl will cause a host kernel crash like this: [ 181.328511] Unrecoverable TM Unavailable Exception f60 at d00000001e7d9980 [ 181.328605] Oops: Unrecoverable TM Unavailable Exception, sig: 6 [#1] [ 181.328613] SMP NR_CPUS=2048 [ 181.328613] NUMA [ 181.328618] PowerNV [ 181.328646] Modules linked in: vhost_net vhost tap nfs_layout_nfsv41_files rpcsec_gss_krb5 nfsv4 dns_resolver nfs +fscache xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat +nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun ebtable_filter ebtables +ip6table_filter ip6_tables iptable_filter bridge stp llc kvm_hv kvm nfsd ses enclosure scsi_transport_sas ghash_generic +auth_rpcgss gf128mul xts sg ctr nfs_acl lockd vmx_crypto shpchp ipmi_powernv i2c_opal grace ipmi_devintf i2c_core +powernv_rng sunrpc ipmi_msghandler ibmpowernv uio_pdrv_genirq uio leds_powernv powernv_op_panel ip_tables xfs sd_mod +lpfc ipr bnx2x libata mdio ptp pps_core scsi_transport_fc libcrc32c dm_mirror dm_region_hash dm_log dm_mod [ 181.329278] CPU: 40 PID: 9926 Comm: CPU 0/KVM Not tainted 4.12.0+ #1 [ 181.329337] task: c000003fc6980000 task.stack: c000003fe4d80000 [ 181.329396] NIP: d00000001e7d9980 LR: d00000001e77381c CTR: d00000001e7d98f0 [ 181.329465] REGS: c000003fe4d837e0 TRAP: 0f60 Not tainted (4.12.0+) [ 181.329523] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> [ 181.329527] CR: 24022448 XER: 00000000 [ 181.329608] CFAR: d00000001e773818 SOFTE: 1 [ 181.329608] GPR00: d00000001e77381c c000003fe4d83a60 d00000001e7ef410 c000003fdcfe0000 [ 181.329608] GPR04: c000003fe4f00000 0000000000000000 0000000000000000 c000003fd7954800 [ 181.329608] GPR08: 0000000000000001 c000003fc6980000 0000000000000000 d00000001e7e2880 [ 181.329608] GPR12: d00000001e7d98f0 c000000007b19000 00000001295220e0 00007fffc0ce2090 [ 181.329608] GPR16: 0000010011886608 00007fff8c89f260 0000000000000001 00007fff8c080028 [ 181.329608] GPR20: 0000000000000000 00000100118500a6 0000010011850000 0000010011850000 [ 181.329608] GPR24: 00007fffc0ce1b48 0000010011850000 00000000d673b901 0000000000000000 [ 181.329608] GPR28: 0000000000000000 c000003fdcfe0000 c000003fdcfe0000 c000003fe4f00000 [ 181.330199] NIP [d00000001e7d9980] kvmppc_vcpu_run_hv+0x90/0x6b0 [kvm_hv] [ 181.330264] LR [d00000001e77381c] kvmppc_vcpu_run+0x2c/0x40 [kvm] [ 181.330322] Call Trace: [ 181.330351] [c000003fe4d83a60] [d00000001e773478] kvmppc_set_one_reg+0x48/0x340 [kvm] (unreliable) [ 181.330437] [c000003fe4d83b30] [d00000001e77381c] kvmppc_vcpu_run+0x2c/0x40 [kvm] [ 181.330513] [c000003fe4d83b50] [d00000001e7700b4] kvm_arch_vcpu_ioctl_run+0x114/0x2a0 [kvm] [ 181.330586] [c000003fe4d83bd0] [d00000001e7642f8] kvm_vcpu_ioctl+0x598/0x7a0 [kvm] [ 181.330658] [c000003fe4d83d40] [c0000000003451b8] do_vfs_ioctl+0xc8/0x8b0 [ 181.330717] [c000003fe4d83de0] [c000000000345a64] SyS_ioctl+0xc4/0x120 [ 181.330776] [c000003fe4d83e30] [c00000000000b004] system_call+0x58/0x6c [ 181.330833] Instruction dump: [ 181.330869] e92d0260 e9290b50 e9290108 792807e3 41820058 e92d0260 e9290b50 e9290108 [ 181.330941] 792ae8a4 794a1f87 408204f4 e92d0260 <7d4022a6> f9490ff0 e92d0260 7d4122a6 [ 181.331013] ---[ end trace 6f6ddeb4bfe92a92 ]--- The fix is just to turn on the TM bit in the MSR before accessing the registers. Cc: stable@vger.kernel.org # v3.14+ Fixes: 46a704f8409f ("KVM: PPC: Book3S HV: Preserve userspace HTM state properly") Reported-by: Jan Stancek <jstancek@redhat.com> Tested-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-12mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful ↵Michal Hocko
semantic __GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07Merge tag 'powerpc-4.13-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Highlights include: - Support for STRICT_KERNEL_RWX on 64-bit server CPUs. - Platform support for FSP2 (476fpe) board - Enable ZONE_DEVICE on 64-bit server CPUs. - Generic & powerpc spin loop primitives to optimise busy waiting - Convert VDSO update function to use new update_vsyscall() interface - Optimisations to hypercall/syscall/context-switch paths - Improvements to the CPU idle code on Power8 and Power9. As well as many other fixes and improvements. Thanks to: Akshay Adiga, Andrew Donnellan, Andrew Jeffery, Anshuman Khandual, Anton Blanchard, Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe Lombard, Colin Ian King, Dan Carpenter, Gautham R. Shenoy, Hari Bathini, Ian Munsie, Ivan Mikhaylov, Javier Martinez Canillas, Madhavan Srinivasan, Masahiro Yamada, Matt Brown, Michael Neuling, Michal Suchanek, Murilo Opsfelder Araujo, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pavel Machek, Russell Currey, Santosh Sivaraj, Stephen Rothwell, Thiago Jung Bauermann, Yang Li" * tag 'powerpc-4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits) powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs powerpc/mm/radix: Implement STRICT_RWX/mark_rodata_ro() for Radix powerpc/mm/hash: Implement mark_rodata_ro() for hash powerpc/vmlinux.lds: Align __init_begin to 16M powerpc/lib/code-patching: Use alternate map for patch_instruction() powerpc/xmon: Add patch_instruction() support for xmon powerpc/kprobes/optprobes: Use patch_instruction() powerpc/kprobes: Move kprobes over to patch_instruction() powerpc/mm/radix: Fix execute permissions for interrupt_vectors powerpc/pseries: Fix passing of pp0 in updatepp() and updateboltedpp() powerpc/64s: Blacklist rtas entry/exit from kprobes powerpc/64s: Blacklist functions invoked on a trap powerpc/64s: Un-blacklist system_call() from kprobes powerpc/64s: Move system_call() symbol to just after setting MSR_EE powerpc/64s: Blacklist system_call() and system_call_common() from kprobes powerpc/64s: Convert .L__replay_interrupt_return to a local label powerpc64/elfv1: Only dereference function descriptor for non-text symbols cxl: Export library to support IBM XSL powerpc/dts: Use #include "..." to include local DT powerpc/perf/hv-24x7: Aggregate result elements on POWER9 SMT8 ...
2017-07-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "PPC: - Better machine check handling for HV KVM - Ability to support guests with threads=2, 4 or 8 on POWER9 - Fix for a race that could cause delayed recognition of signals - Fix for a bug where POWER9 guests could sleep with interrupts pending. ARM: - VCPU request overhaul - allow timer and PMU to have their interrupt number selected from userspace - workaround for Cavium erratum 30115 - handling of memory poisonning - the usual crop of fixes and cleanups s390: - initial machine check forwarding - migration support for the CMMA page hinting information - cleanups and fixes x86: - nested VMX bugfixes and improvements - more reliable NMI window detection on AMD - APIC timer optimizations Generic: - VCPU request overhaul + documentation of common code patterns - kvm_stat improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (124 commits) Update my email address kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS x86: kvm: mmu: use ept a/d in vmcs02 iff used in vmcs12 kvm: x86: mmu: allow A/D bits to be disabled in an mmu x86: kvm: mmu: make spte mmio mask more explicit x86: kvm: mmu: dead code thanks to access tracking KVM: PPC: Book3S: Fix typo in XICS-on-XIVE state saving code KVM: PPC: Book3S HV: Close race with testing for signals on guest entry KVM: PPC: Book3S HV: Simplify dynamic micro-threading code KVM: x86: remove ignored type attribute KVM: LAPIC: Fix lapic timer injection delay KVM: lapic: reorganize restart_apic_timer KVM: lapic: reorganize start_hv_timer kvm: nVMX: Check memory operand to INVVPID KVM: s390: Inject machine check into the nested guest KVM: s390: Inject machine check into the guest tools/kvm_stat: add new interactive command 'b' tools/kvm_stat: add new command line switch '-i' tools/kvm_stat: fix error on interactive command 'g' KVM: SVM: suppress unnecessary NMI singlestep on GIF=0 and nested exit ...
2017-07-03Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP hotplug updates from Thomas Gleixner: "This update is primarily a cleanup of the CPU hotplug locking code. The hotplug locking mechanism is an open coded RWSEM, which allows recursive locking. The main problem with that is the recursive nature as it evades the full lockdep coverage and hides potential deadlocks. The rework replaces the open coded RWSEM with a percpu RWSEM and establishes full lockdep coverage that way. The bulk of the changes fix up recursive locking issues and address the now fully reported potential deadlocks all over the place. Some of these deadlocks have been observed in the RT tree, but on mainline the probability was low enough to hide them away." * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) cpu/hotplug: Constify attribute_group structures powerpc: Only obtain cpu_hotplug_lock if called by rtasd ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init cpu/hotplug: Remove unused check_for_tasks() function perf/core: Don't release cred_guard_mutex if not taken cpuhotplug: Link lock stacks for hotplug callbacks acpi/processor: Prevent cpu hotplug deadlock sched: Provide is_percpu_thread() helper cpu/hotplug: Convert hotplug locking to percpu rwsem s390: Prevent hotplug rwsem recursion arm: Prevent hotplug rwsem recursion arm64: Prevent cpu hotplug rwsem recursion kprobes: Cure hotplug lock ordering issues jump_label: Reorder hotplug lock and jump_label_lock perf/tracing/cpuhotplug: Fix locking order ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus() PCI: Replace the racy recursion prevention PCI: Use cpu_hotplug_disable() instead of get_online_cpus() perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode() x86/perf: Drop EXPORT of perf_check_microcode ...
2017-07-03Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch, a few of them are tripping people up while working on top of next, and we also have a dependency between the CXL fixes and new CXL code we want to merge into next.
2017-07-03Merge branch 'kvm-ppc-next' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD - Better machine check handling for HV KVM - Ability to support guests with threads=2, 4 or 8 on POWER9 - Fix for a race that could cause delayed recognition of signals - Fix for a bug where POWER9 guests could sleep with interrupts pending.
2017-07-03KVM: PPC: Book3S: Fix typo in XICS-on-XIVE state saving codePaul Mackerras
This fixes a typo where the wrong loop index was used to index the kvmppc_xive_vcpu.queues[] array in xive_pre_save_scan(). The variable i contains the vcpu number; we need to index queues[] using j, which iterates from 0 to KVMPPC_XIVE_Q_COUNT-1. The effect of this bug is that things that save the interrupt controller state, such as "virsh dump", on a VM with more than 8 vCPUs, result in xive_pre_save_queue() getting called on a bogus queue structure, usually resulting in a crash like this: [ 501.821107] Unable to handle kernel paging request for data at address 0x00000084 [ 501.821212] Faulting instruction address: 0xc008000004c7c6f8 [ 501.821234] Oops: Kernel access of bad area, sig: 11 [#1] [ 501.821305] SMP NR_CPUS=1024 [ 501.821307] NUMA [ 501.821376] PowerNV [ 501.821470] Modules linked in: vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables ses enclosure scsi_transport_sas ipmi_powernv ipmi_devintf ipmi_msghandler powernv_op_panel kvm_hv nfsd auth_rpcgss oid_registry nfs_acl lockd grace sunrpc kvm tg3 ptp pps_core [ 501.822477] CPU: 3 PID: 3934 Comm: live_migration Not tainted 4.11.0-4.git8caa70f.el7.centos.ppc64le #1 [ 501.822633] task: c0000003f9e3ae80 task.stack: c0000003f9ed4000 [ 501.822745] NIP: c008000004c7c6f8 LR: c008000004c7c628 CTR: 0000000030058018 [ 501.822877] REGS: c0000003f9ed7980 TRAP: 0300 Not tainted (4.11.0-4.git8caa70f.el7.centos.ppc64le) [ 501.823030] MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> [ 501.823047] CR: 28022244 XER: 00000000 [ 501.823203] CFAR: c008000004c7c77c DAR: 0000000000000084 DSISR: 40000000 SOFTE: 1 [ 501.823203] GPR00: c008000004c7c628 c0000003f9ed7c00 c008000004c91450 00000000000000ff [ 501.823203] GPR04: c0000003f5580000 c0000003f559bf98 9000000000009033 0000000000000000 [ 501.823203] GPR08: 0000000000000084 0000000000000000 00000000000001e0 9000000000001003 [ 501.823203] GPR12: c00000000008a7d0 c00000000fdc1b00 000000000a9a0000 0000000000000000 [ 501.823203] GPR16: 00000000402954e8 000000000a9a0000 0000000000000004 0000000000000000 [ 501.823203] GPR20: 0000000000000008 c000000002e8f180 c000000002e8f1e0 0000000000000001 [ 501.823203] GPR24: 0000000000000008 c0000003f5580008 c0000003f4564018 c000000002e8f1e8 [ 501.823203] GPR28: 00003ff6e58bdc28 c0000003f4564000 0000000000000000 0000000000000000 [ 501.825441] NIP [c008000004c7c6f8] xive_get_attr+0x3b8/0x5b0 [kvm] [ 501.825671] LR [c008000004c7c628] xive_get_attr+0x2e8/0x5b0 [kvm] [ 501.825887] Call Trace: [ 501.825991] [c0000003f9ed7c00] [c008000004c7c628] xive_get_attr+0x2e8/0x5b0 [kvm] (unreliable) [ 501.826312] [c0000003f9ed7cd0] [c008000004c62ec4] kvm_device_ioctl_attr+0x64/0xa0 [kvm] [ 501.826581] [c0000003f9ed7d20] [c008000004c62fcc] kvm_device_ioctl+0xcc/0xf0 [kvm] [ 501.826843] [c0000003f9ed7d40] [c000000000350c70] do_vfs_ioctl+0xd0/0x8c0 [ 501.827060] [c0000003f9ed7de0] [c000000000351534] SyS_ioctl+0xd4/0xf0 [ 501.827282] [c0000003f9ed7e30] [c00000000000b8e0] system_call+0x38/0xfc [ 501.827496] Instruction dump: [ 501.827632] 419e0078 3b760008 e9160008 83fb000c 83db0010 80fb0008 2f280000 60000000 [ 501.827901] 60000000 60420000 419a0050 7be91764 <7d284c2c> 552a0ffe 7f8af040 419e003c [ 501.828176] ---[ end trace 2d0529a5bbbbafed ]--- Cc: stable@vger.kernel.org Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-01KVM: PPC: Book3S HV: Close race with testing for signals on guest entryPaul Mackerras
At present, interrupts are hard-disabled fairly late in the guest entry path, in the assembly code. Since we check for pending signals for the vCPU(s) task(s) earlier in the guest entry path, it is possible for a signal to be delivered before we enter the guest but not be noticed until after we exit the guest for some other reason. Similarly, it is possible for the scheduler to request a reschedule while we are in the guest entry path, and we won't notice until after we have run the guest, potentially for a whole timeslice. Furthermore, with a radix guest on POWER9, we can take the interrupt with the MMU on. In this case we end up leaving interrupts hard-disabled after the guest exit, and they are likely to stay hard-disabled until we exit to userspace or context-switch to another process. This was masking the fact that we were also not setting the RI (recoverable interrupt) bit in the MSR, meaning that if we had taken an interrupt, it would have crashed the host kernel with an unrecoverable interrupt message. To close these races, we need to check for signals and reschedule requests after hard-disabling interrupts, and then keep interrupts hard-disabled until we enter the guest. If there is a signal or a reschedule request from another CPU, it will send an IPI, which will cause a guest exit. This puts the interrupt disabling before we call kvmppc_start_thread() for all the secondary threads of this core that are going to run vCPUs. The reason for that is that once we have started the secondary threads there is no easy way to back out without going through at least part of the guest entry path. However, kvmppc_start_thread() includes some code for radix guests which needs to call smp_call_function(), which must be called with interrupts enabled. To solve this problem, this patch moves that code into a separate function that is called earlier. When the guest exit is caused by an external interrupt, a hypervisor doorbell or a hypervisor maintenance interrupt, we now handle these using the replay facility. __kvmppc_vcore_entry() now returns the trap number that caused the exit on this thread, and instead of the assembly code jumping to the handler entry, we return to C code with interrupts still hard-disabled and set the irq_happened flag in the PACA, so that when we do local_irq_enable() the appropriate handler gets called. With all this, we now have the interrupt soft-enable flag clear while we are in the guest. This is useful because code in the real-mode hypercall handlers that checks whether interrupts are enabled will now see that they are disabled, which is correct, since interrupts are hard-disabled in the real-mode code. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-07-01KVM: PPC: Book3S HV: Simplify dynamic micro-threading codePaul Mackerras
Since commit b009031f74da ("KVM: PPC: Book3S HV: Take out virtual core piggybacking code", 2016-09-15), we only have at most one vcore per subcore. Previously, the fact that there might be more than one vcore per subcore meant that we had the notion of a "master vcore", which was the vcore that controlled thread 0 of the subcore. We also needed a list per subcore in the core_info struct to record which vcores belonged to each subcore. Now that there can only be one vcore in the subcore, we can replace the list with a simple pointer and get rid of the notion of the master vcore (and in fact treat every vcore as a master vcore). We can also get rid of the subcore_vm[] field in the core_info struct since it is never read. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-30Merge tag 'kvmarm-for-4.13' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM updates for 4.13 - vcpu request overhaul - allow timer and PMU to have their interrupt number selected from userspace - workaround for Cavium erratum 30115 - handling of memory poisonning - the usual crop of fixes and cleanups Conflicts: arch/s390/include/asm/kvm_host.h
2017-06-23powerpc/mm: Trace tlbie(l) instructionsBalbir Singh
Add a trace point for tlbie(l) (Translation Lookaside Buffer Invalidate Entry (Local)) instructions. The tlbie instruction has changed over the years, so not all versions accept the same operands. Use the ISA v3 field operands because they are the most verbose, we may change them in future. Example output: qemu-system-ppc-5371 [016] 1412.369519: tlbie: tlbie with lpid 0, local 1, rb=67bd8900174c11c1, rs=0, ric=0 prs=0 r=0 Signed-off-by: Balbir Singh <bsingharora@gmail.com> [mpe: Add some missing trace_tlbie()s, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-22KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modesPaul Mackerras
Now that userspace can set the virtual SMT mode by enabling the KVM_CAP_PPC_SMT capability, it is useful for userspace to be able to query the set of possible virtual SMT modes. This provides a new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this information. The return value is a bitmap of possible modes, with bit N set if virtual SMT mode 2^N is available. That is, 1 indicates SMT1 is available, 2 indicates that SMT2 is available, 3 indicates that both SMT1 and SMT2 are available, and so on. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-22KVM: PPC: Book3S HV: Exit guest upon MCE when FWNMI capability is enabledAravinda Prasad
Enhance KVM to cause a guest exit with KVM_EXIT_NMI exit reason upon a machine check exception (MCE) in the guest address space if the KVM_CAP_PPC_FWNMI capability is enabled (instead of delivering a 0x200 interrupt to guest). This enables QEMU to build error log and deliver machine check exception to guest via guest registered machine check handler. This approach simplifies the delivery of machine check exception to guest OS compared to the earlier approach of KVM directly invoking 0x200 guest interrupt vector. This design/approach is based on the feedback for the QEMU patches to handle machine check exception. Details of earlier approach of handling machine check exception in QEMU and related discussions can be found at: https://lists.nongnu.org/archive/html/qemu-devel/2014-11/msg00813.html Note: This patch now directly invokes machine_check_print_event_info() from kvmppc_handle_exit_hv() to print the event to host console at the time of guest exit before the exception is passed on to the guest. Hence, the host-side handling which was performed earlier via machine_check_fwnmi is removed. The reasons for this approach is (i) it is not possible to distinguish whether the exception occurred in the guest or the host from the pt_regs passed on the machine_check_exception(). Hence machine_check_exception() calls panic, instead of passing on the exception to the guest, if the machine check exception is not recoverable. (ii) the approach introduced in this patch gives opportunity to the host kernel to perform actions in virtual mode before passing on the exception to the guest. This approach does not require complex tweaks to machine_check_fwnmi and friends. Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-21KVM: PPC: Book3S HV: Add new capability to control MCE behaviourAravinda Prasad
This introduces a new KVM capability to control how KVM behaves on machine check exception (MCE) in HV KVM guests. If this capability has not been enabled, KVM redirects machine check exceptions to guest's 0x200 vector, if the address in error belongs to the guest. With this capability enabled, KVM will cause a guest exit with the exit reason indicating an NMI. The new capability is required to avoid problems if a new kernel/KVM is used with an old QEMU, running a guest that doesn't issue "ibm,nmi-register". As old QEMU does not understand the NMI exit type, it treats it as a fatal error. However, the guest could have handled the machine check error if the exception was delivered to guest's 0x200 interrupt vector instead of NMI exit in case of old QEMU. [paulus@ozlabs.org - Reworded the commit message to be clearer, enable only on HV KVM.] Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-20Merge branch 'kvm-ppc-fixes' of ↵Radim Krčmář
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc * fix problems that could cause hangs or crashes in the host on POWER9 * fix problems that could allow guests to potentially affect or disrupt the execution of the controlling userspace