kernel/arch/mips/kvm, branch linux-4.15.y

KVM: Let KVM_SET_SIGNAL_MASK work as advertised

2017-11-27T16:53:47Z

KVM API says for the signal mask you set via KVM_SET_SIGNAL_MASK, that "any unblocked signal received [...] will cause KVM_RUN to return with -EINTR" and that "the signal will only be delivered if not blocked by the original signal mask". This, however, is only true, when the calling task has a signal handler registered for a signal. If not, signal evaluation is short-circuited for SIG_IGN and SIG_DFL, and the signal is either ignored without KVM_RUN returning or the whole process is terminated. Make KVM_SET_SIGNAL_MASK behave as advertised by utilizing logic similar to that in do_sigtimedwait() to avoid short-circuiting of signals. Signed-off-by: Jan H. SchÃ¶nherr Signed-off-by: Paolo Bonzini

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

kvm,mips: Fix potential swait_active() races

2017-09-15T14:57:13Z

For example, the following could occur, making us miss a wakeup: CPU0 CPU1 kvm_vcpu_block kvm_mips_comparecount_func [L] swait_active(&vcpu->wq) [S] prepare_to_swait(&vcpu->wq) [L] if (!kvm_vcpu_has_pending_timer(vcpu)) schedule() [S] queue_timer_int(vcpu) Ensure that the swait_active() check is not hoisted over the interrupt. Signed-off-by: Davidlohr Bueso Signed-off-by: Paolo Bonzini

KVM: add spinlock optimization framework

2017-08-08T08:57:43Z

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) Signed-off-by: Paolo Bonzini

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2017-07-07T01:38:31Z

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 ...

KVM: MIPS: Fix maybe-uninitialized build failure

2017-06-20T15:02:48Z

This commit fixes a "maybe-uninitialized" build failure in arch/mips/kvm/tlb.c when KVM, DYNAMIC_DEBUG and JUMP_LABEL are all enabled. The failure is: In file included from ./include/linux/printk.h:329:0, from ./include/linux/kernel.h:13, from ./include/asm-generic/bug.h:15, from ./arch/mips/include/asm/bug.h:41, from ./include/linux/bug.h:4, from ./include/linux/thread_info.h:11, from ./include/asm-generic/current.h:4, from ./arch/mips/include/generated/asm/current.h:1, from ./include/linux/sched.h:11, from arch/mips/kvm/tlb.c:13: arch/mips/kvm/tlb.c: In function ‘kvm_mips_host_tlb_inv’: ./include/linux/dynamic_debug.h:126:3: error: ‘idx_kernel’ may be used uninitialized in this function [-Werror=maybe-uninitialized] __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ ^~~~~~~~~~~~~~~~~~ arch/mips/kvm/tlb.c:169:16: note: ‘idx_kernel’ was declared here int idx_user, idx_kernel; ^~~~~~~~~~ There is a similar error relating to "idx_user". Both errors were observed with GCC 6. As far as I can tell, it is impossible for either idx_user or idx_kernel to be uninitialized when they are later read in the calls to kvm_debug, but to satisfy the compiler, add zero initializers to both variables. Signed-off-by: James Cowgill Fixes: 57e3869cfaae ("KVM: MIPS/TLB: Generalise host TLB invalidate to kernel ASID") Cc: # 4.11+ Acked-by: James Hogan Signed-off-by: Radim Krčmář

KVM: add kvm_request_pending

2017-06-04T14:53:00Z

A first step in vcpu->requests encapsulation. Additionally, we now use READ_ONCE() when accessing vcpu->requests, which ensures we always load vcpu->requests when it's accessed. This is important as other threads can change it any time. Also, READ_ONCE() documents that vcpu->requests is used with other threads, likely requiring memory barriers, which it does. Signed-off-by: Radim Krčmář [ Documented the new use of READ_ONCE() and converted another check in arch/mips/kvm/vz.c ] Signed-off-by: Andrew Jones Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall

KVM: add kvm_{test,clear}_request to replace {test,clear}_bit

2017-04-27T12:12:22Z

Users were expected to use kvm_check_request() for testing and clearing, but request have expanded their use since then and some users want to only test or do a faster clear. Make sure that requests are not directly accessed with bit operations. Reviewed-by: Christian Borntraeger Signed-off-by: Radim Krčmář Reviewed-by: Andrew Jones Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini

kvm: make KVM_CAP_COALESCED_MMIO architecture agnostic

2017-04-07T14:49:00Z

Remove code from architecture files that can be moved to virt/kvm, since there is already common code for coalesced MMIO. Signed-off-by: Paolo Bonzini Reviewed-by: David Hildenbrand [Removed a pointless 'break' after 'return'.] Signed-off-by: Radim Krčmář

KVM: MIPS/Emulate: Properly implement TLBR for T&E

2017-03-28T15:31:37Z

Properly implement emulation of the TLBR instruction for Trap & Emulate. This instruction reads the TLB entry pointed at by the CP0_Index register into the other TLB registers, which may have the side effect of changing the current ASID. Therefore abstract the CP0_EntryHi and ASID changing code into a common function in the process. A comment indicated that Linux doesn't use TLBR, which is true during normal use, however dumping of the TLB does use it (for example with the relatively recent 'x' magic sysrq key), as does a wired TLB entries test case in my KVM tests. Signed-off-by: James Hogan Acked-by: Ralf Baechle Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org