kernel/arch/arm/kvm/hyp, branch linux-4.15.y

ARM: kvm: fix building with gcc-8

2018-03-09T06:47:47Z

commit 67870eb1204223598ea6d8a4467b482e9f5875b5 upstream. In banked-sr.c, we use a top-level '__asm__(".arch_extension virt")' statement to allow compilation of a multi-CPU kernel for ARMv6 and older ARMv7-A that don't normally support access to the banked registers. This is considered to be a programming error by the gcc developers and will no longer work in gcc-8, where we now get a build error: /tmp/cc4Qy7GR.s:34: Error: Banked registers are not available with this architecture. -- `mrs r3,SP_usr' /tmp/cc4Qy7GR.s:41: Error: Banked registers are not available with this architecture. -- `mrs r3,ELR_hyp' /tmp/cc4Qy7GR.s:55: Error: Banked registers are not available with this architecture. -- `mrs r3,SP_svc' /tmp/cc4Qy7GR.s:62: Error: Banked registers are not available with this architecture. -- `mrs r3,LR_svc' /tmp/cc4Qy7GR.s:69: Error: Banked registers are not available with this architecture. -- `mrs r3,SPSR_svc' /tmp/cc4Qy7GR.s:76: Error: Banked registers are not available with this architecture. -- `mrs r3,SP_abt' Passign the '-march-armv7ve' flag to gcc works, and is ok here, because we know the functions won't ever be called on pre-ARMv7VE machines. Unfortunately, older compiler versions (4.8 and earlier) do not understand that flag, so we still need to keep the asm around. Backporting to stable kernels (4.6+) is needed to allow those to be built with future compilers as well. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84129 Fixes: 33280b4cd1dc ("ARM: KVM: Add banked registers save/restore") Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman

Merge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2017-11-16T21:00:24Z

Pull KVM updates from Radim Krčmář: "First batch of KVM changes for 4.15 Common: - Python 3 support in kvm_stat - Accounting of slabs to kmemcg ARM: - Optimized arch timer handling for KVM/ARM - Improvements to the VGIC ITS code and introduction of an ITS reset ioctl - Unification of the 32-bit fault injection logic - More exact external abort matching logic PPC: - Support for running hashed page table (HPT) MMU mode on a host that is using the radix MMU mode; single threaded mode on POWER 9 is added as a pre-requisite - Resolution of merge conflicts with the last second 4.14 HPT fixes - Fixes and cleanups s390: - Some initial preparation patches for exitless interrupts and crypto - New capability for AIS migration - Fixes x86: - Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs, and after-reset state - Refined dependencies for VMX features - Fixes for nested SMI injection - A lot of cleanups" * tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (89 commits) KVM: s390: provide a capability for AIS state migration KVM: s390: clear_io_irq() requests are not expected for adapter interrupts KVM: s390: abstract conversion between isc and enum irq_types KVM: s390: vsie: use common code functions for pinning KVM: s390: SIE considerations for AP Queue virtualization KVM: s390: document memory ordering for kvm_s390_vcpu_wakeup KVM: PPC: Book3S HV: Cosmetic post-merge cleanups KVM: arm/arm64: fix the incompatible matching for external abort KVM: arm/arm64: Unify 32bit fault injection KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared KVM: arm/arm64: vgic-its: New helper functions to free the caches KVM: arm/arm64: vgic-its: Remove kvm_its_unmap_device arm/arm64: KVM: Load the timer state when enabling the timer KVM: arm/arm64: Rework kvm_timer_should_fire KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit KVM: arm/arm64: Move phys_timer_emulate function KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps ...

KVM: arm/arm64: Move timer save/restore out of the hyp code

2017-11-06T15:23:13Z

As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier

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

2017-11-04T18:44:55Z

Pull KVM fixes from Paolo Bonzini: "Fixes for interrupt controller emulation in ARM/ARM64 and x86, plus a one-liner x86 KVM guest fix" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Update APICv on APIC reset KVM: VMX: Do not fully reset PI descriptor on vCPU reset kvm: Return -ENODEV from update_persistent_clock KVM: arm/arm64: vgic-its: Check GITS_BASER Valid bit before saving tables KVM: arm/arm64: vgic-its: Check CBASER/BASER validity before enabling the ITS KVM: arm/arm64: vgic-its: Fix vgic_its_restore_collection_table returned value KVM: arm/arm64: vgic-its: Fix return value for device table restore arm/arm64: kvm: Disable branch profiling in HYP code arm/arm64: kvm: Move initialization completion message arm/arm64: KVM: set right LR register value for 32 bit guest when inject abort KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table

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

arm/arm64: kvm: Disable branch profiling in HYP code

2017-10-21T15:03:20Z

When HYP code runs into branch profiling code, it attempts to jump to unmapped memory, causing a HYP Panic. Disable the branch profiling for code designed to run at HYP mode. Signed-off-by: Julien Thierry Acked-by: Marc Zyngier Cc: Christoffer Dall Cc: Catalin Marinas Cc: Will Deacon Cc: Russell King Cc: Signed-off-by: Christoffer Dall

Merge branch 'kvmarm-master/master' into HEAD

2017-06-15T08:35:15Z

KVM: arm: Restore banked registers and physical timer access on hyp_panic()

2017-05-16T07:54:24Z

When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. This looks like it was copied from arm64, the 32bit KVM panic code needs to restore the host's banked registers too. At some point panic() touches the physical timer/counter, this will trap back to HYP. If we're lucky, we panic again. Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the guest registers and disables the traps for the host. Fixes: c36b6db5f3e4 ("ARM: KVM: Add panic handling code") Signed-off-by: James Morse Reviewed-by: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall

KVM: arm: plug potential guest hardware debug leakage

2017-05-15T12:29:19Z

Hardware debugging in guests is not intercepted currently, it means that a malicious guest can bring down the entire machine by writing to the debug registers. This patch enable trapping of all debug registers, preventing the guests to access the debug registers. This includes access to the debug mode(DBGDSCR) in the guest world all the time which could otherwise mess with the host state. Reads return 0 and writes are ignored (RAZ_WI). The result is the guest cannot detect any working hardware based debug support. As debug exceptions are still routed to the guest normal debug using software based breakpoints still works. To support debugging using hardware registers we need to implement a debug register aware world switch as well as special trapping for registers that may affect the host state. Cc: stable@vger.kernel.org Signed-off-by: Zhichao Huang Signed-off-by: Alex Bennée Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall

arm: KVM: Do not use stack-protector to compile HYP code

2017-05-15T09:31:38Z

We like living dangerously. Nothing explicitely forbids stack-protector to be used in the HYP code, while distributions routinely compile their kernel with it. We're just lucky that no code actually triggers the instrumentation. Let's not try our luck for much longer, and disable stack-protector for code living at HYP. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall