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2021-11-14Merge tag 'for-5.16/parisc-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull more parisc fixes from Helge Deller: "Fix a build error in stracktrace.c, fix resolving of addresses to function names in backtraces, fix single-stepping in assembly code and flush userspace pte's when using set_pte_at()" * tag 'for-5.16/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc/entry: fix trace test in syscall exit path parisc: Flush kernel data mapping in set_pte_at() when installing pte for user page parisc: Fix implicit declaration of function '__kernel_text_address' parisc: Fix backtrace to always include init funtion names
2021-11-14Merge tag 'sh-for-5.16' of git://git.libc.org/linux-shLinus Torvalds
Pull arch/sh updates from Rich Felker. * tag 'sh-for-5.16' of git://git.libc.org/linux-sh: sh: pgtable-3level: Fix cast to pointer from integer of different size sh: fix READ/WRITE redefinition warnings sh: define __BIG_ENDIAN for math-emu sh: math-emu: drop unused functions sh: fix kconfig unmet dependency warning for FRAME_POINTER sh: Cleanup about SPARSE_IRQ sh: kdump: add some attribute to function maple: fix wrong return value of maple_bus_init(). sh: boot: avoid unneeded rebuilds under arch/sh/boot/compressed/ sh: boot: add intermediate vmlinux.bin* to targets instead of extra-y sh: boards: Fix the cacography in irq.c sh: check return code of request_irq sh: fix trivial misannotations
2021-11-14Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM fixes from Russell King: - Fix early_iounmap - Drop cc-option fallbacks for architecture selection * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 9156/1: drop cc-option fallbacks for architecture selection ARM: 9155/1: fix early early_iounmap()
2021-11-14Merge tag 'devicetree-fixes-for-5.16-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull devicetree fixes from Rob Herring: - Two fixes due to DT node name changes on Arm, Ltd. boards - Treewide rename of Ingenic CGU headers - Update ST email addresses - Remove Netlogic DT bindings - Dropping few more cases of redundant 'maxItems' in schemas - Convert toshiba,tc358767 bridge binding to schema * tag 'devicetree-fixes-for-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: dt-bindings: watchdog: sunxi: fix error in schema bindings: media: venus: Drop redundant maxItems for power-domain-names dt-bindings: Remove Netlogic bindings clk: versatile: clk-icst: Ensure clock names are unique of: Support using 'mask' in making device bus id dt-bindings: treewide: Update @st.com email address to @foss.st.com dt-bindings: media: Update maintainers for st,stm32-hwspinlock.yaml dt-bindings: media: Update maintainers for st,stm32-cec.yaml dt-bindings: mfd: timers: Update maintainers for st,stm32-timers dt-bindings: timer: Update maintainers for st,stm32-timer dt-bindings: i2c: imx: hardware do not restrict clock-frequency to only 100 and 400 kHz dt-bindings: display: bridge: Convert toshiba,tc358767.txt to yaml dt-bindings: Rename Ingenic CGU headers to ingenic,*.h
2021-11-14Merge tag 'locking-urgent-2021-11-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 static call update from Thomas Gleixner: "A single fix for static calls to make the trampoline patching more robust by placing explicit signature bytes after the call trampoline to prevent patching random other jumps like the CFI jump table entries" * tag 'locking-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: static_call,x86: Robustify trampoline patching
2021-11-14Merge tag 'sched_urgent_for_v5.16_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Borislav Petkov: - Avoid touching ~100 config files in order to be able to select the preemption model - clear cluster CPU masks too, on the CPU unplug path - prevent use-after-free in cfs - Prevent a race condition when updating CPU cache domains - Factor out common shared part of smp_prepare_cpus() into a common helper which can be called by both baremetal and Xen, in order to fix a booting of Xen PV guests * tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: preempt: Restore preemption model selection configs arch_topology: Fix missing clear cluster_cpumask in remove_cpu_topology() sched/fair: Prevent dead task groups from regaining cfs_rq's sched/core: Mitigate race cpus_share_cache()/update_top_cache_domain() x86/smp: Factor out parts of native_smp_prepare_cpus()
2021-11-14Merge tag 'perf_urgent_for_v5.16_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Prevent unintentional page sharing by checking whether a page reference to a PMU samples page has been acquired properly before that - Make sure the LBR_SELECT MSR is saved/restored too - Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any residual data left * tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Avoid put_page() when GUP fails perf/x86/vlbr: Add c->flags to vlbr event constraints perf/x86/lbr: Reset LBR_SELECT during vlbr reset
2021-11-14Merge tag 'x86_urgent_for_v5.16_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Add the model number of a new, Raptor Lake CPU, to intel-family.h - Do not log spurious corrected MCEs on SKL too, due to an erratum - Clarify the path of paravirt ops patches upstream - Add an optimization to avoid writing out AMX components to sigframes when former are in init state * tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add Raptor Lake to Intel family x86/mce: Add errata workaround for Skylake SKX37 MAINTAINERS: Add some information to PARAVIRT_OPS entry x86/fpu: Optimize out sigframe xfeatures when in init state
2021-11-13parisc/entry: fix trace test in syscall exit pathSven Schnelle
commit 8779e05ba8aa ("parisc: Fix ptrace check on syscall return") fixed testing of TI_FLAGS. This uncovered a bug in the test mask. syscall_restore_rfi is only used when the kernel needs to exit to usespace with single or block stepping and the recovery counter enabled. The test however used _TIF_SYSCALL_TRACE_MASK, which includes a lot of bits that shouldn't be tested here. Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly. I encountered this bug by enabling syscall tracepoints. Both in qemu and on real hardware. As soon as i enabled the tracepoint (sys_exit_read, but i guess it doesn't really matter which one), i got random page faults in userspace almost immediately. Signed-off-by: Sven Schnelle <svens@stackframe.org> Signed-off-by: Helge Deller <deller@gmx.de>
2021-11-13parisc: Flush kernel data mapping in set_pte_at() when installing pte for ↵John David Anglin
user page For years, there have been random segmentation faults in userspace on SMP PA-RISC machines. It occurred to me that this might be a problem in set_pte_at(). MIPS and some other architectures do cache flushes when installing PTEs with the present bit set. Here I have adapted the code in update_mmu_cache() to flush the kernel mapping when the kernel flush is deferred, or when the kernel mapping may alias with the user mapping. This simplifies calls to update_mmu_cache(). I also changed the barrier in set_pte() from a compiler barrier to a full memory barrier. I know this change is not sufficient to fix the problem. It might not be needed. I have had a few days of operation with 5.14.16 to 5.15.1 and haven't seen any random segmentation faults on rp3440 or c8000 so far. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@kernel.org # 5.12+
2021-11-13parisc: Fix implicit declaration of function '__kernel_text_address'Helge Deller
Signed-off-by: Helge Deller <deller@gmx.de>
2021-11-13parisc: Fix backtrace to always include init funtion namesHelge Deller
I noticed that sometimes at kernel startup the backtraces did not included the function names of init functions. Their address were not resolved to function names and instead only the address was printed. Debugging shows that the culprit is is_ksym_addr() which is called by the backtrace functions to check if an address belongs to a function in the kernel. The problem occurs only for CONFIG_KALLSYMS_ALL=y. When looking at is_ksym_addr() one can see that for CONFIG_KALLSYMS_ALL=y the function only tries to resolve the address via is_kernel() function, which checks like this: if (addr >= _stext && addr <= _end) return 1; On parisc the init functions are located before _stext, so this check fails. Other platforms seem to have all functions (including init functions) behind _stext. The following patch moves the _stext symbol at the beginning of the kernel and thus includes the init section. This fixes the check and does not seem to have any negative side effects on where the kernel mapping happens in the map_pages() function in arch/parisc/mm/init.c. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@kernel.org # 5.4+
2021-11-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull more kvm updates from Paolo Bonzini: "New x86 features: - Guest API and guest kernel support for SEV live migration - SEV and SEV-ES intra-host migration Bugfixes and cleanups for x86: - Fix misuse of gfn-to-pfn cache when recording guest steal time / preempted status - Fix selftests on APICv machines - Fix sparse warnings - Fix detection of KVM features in CPUID - Cleanups for bogus writes to MSR_KVM_PV_EOI_EN - Fixes and cleanups for MSR bitmap handling - Cleanups for INVPCID - Make x86 KVM_SOFT_MAX_VCPUS consistent with other architectures Bugfixes for ARM: - Fix finalization of host stage2 mappings - Tighten the return value of kvm_vcpu_preferred_target() - Make sure the extraction of ESR_ELx.EC is limited to architected bits" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (34 commits) KVM: SEV: unify cgroup cleanup code for svm_vm_migrate_from KVM: x86: move guest_pv_has out of user_access section KVM: x86: Drop arbitrary KVM_SOFT_MAX_VCPUS KVM: Move INVPCID type check from vmx and svm to the common kvm_handle_invpcid() KVM: VMX: Add a helper function to retrieve the GPR index for INVPCID, INVVPID, and INVEPT KVM: nVMX: Clean up x2APIC MSR handling for L2 KVM: VMX: Macrofy the MSR bitmap getters and setters KVM: nVMX: Handle dynamic MSR intercept toggling KVM: nVMX: Query current VMCS when determining if MSR bitmaps are in use KVM: x86: Don't update vcpu->arch.pv_eoi.msr_val when a bogus value was written to MSR_KVM_PV_EOI_EN KVM: x86: Rename kvm_lapic_enable_pv_eoi() KVM: x86: Make sure KVM_CPUID_FEATURES really are KVM_CPUID_FEATURES KVM: x86: Add helper to consolidate core logic of SET_CPUID{2} flows kvm: mmu: Use fast PF path for access tracking of huge pages when possible KVM: x86/mmu: Properly dereference rcu-protected TDP MMU sptep iterator KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active kvm: x86: Convert return type of *is_valid_rdpmc_ecx() to bool KVM: x86: Fix recording of guest steal time / preempted status selftest: KVM: Add intra host migration tests selftest: KVM: Add open sev dev helper ...
2021-11-13Merge branch 'exit-cleanups-for-v5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull vm86 fix from Eric Biederman: "Just the removal of an unnecessary (and incorrect) test from a BUG_ON" * 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: signal/vm86_32: Remove pointless test in BUG_ON
2021-11-13Merge tag 's390-5.16-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Add PCI automatic error recovery. - Fix tape driver timer initialization broken during timers api cleanup. - Fix bogus CPU measurement counters values on CPUs offlining. - Check the validity of subchanel before reading other fields in the schib in cio code. * tag 's390-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/cio: check the subchannel validity for dev_busid s390/cpumf: cpum_cf PMU displays invalid value after hotplug remove s390/tape: fix timer initialization in tape_std_assign() s390/pci: implement minimal PCI error recovery PCI: Export pci_dev_lock() s390/pci: implement reset_slot for hotplug slot s390/pci: refresh function handle in iomap
2021-11-13Merge tag 'riscv-for-linus-5.16-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for time namespaces in the VDSO, along with some associated cleanups. - Support for building rv32 randconfigs. - Improvements to the XIP port that allow larger kernels to function - Various device tree cleanups for both the SiFive and Microchip boards - A handful of defconfig updates, including enabling Nouveau. There are also various small cleanups. * tag 'riscv-for-linus-5.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: defconfig: enable DRM_NOUVEAU riscv/vdso: Drop unneeded part due to merge issue riscv: remove .text section size limitation for XIP riscv: dts: sifive: add missing compatible for plic riscv: dts: microchip: add missing compatibles for clint and plic riscv: dts: sifive: drop duplicated nodes and properties in sifive riscv: dts: sifive: fix Unleashed board compatible riscv: dts: sifive: use only generic JEDEC SPI NOR flash compatible riscv: dts: microchip: use vendor compatible for Cadence SD4HC riscv: dts: microchip: drop unused pinctrl-names riscv: dts: microchip: drop duplicated MMC/SDHC node riscv: dts: microchip: fix board compatible riscv: dts: microchip: drop duplicated nodes dt-bindings: mmc: cdns: document Microchip MPFS MMC/SDHCI controller riscv: add rv32 and rv64 randconfig build targets riscv: mm: don't advertise 1 num_asid for 0 asid bits riscv: set default pm_power_off to NULL riscv/vdso: Add support for time namespaces
2021-11-13Merge tag 'mips_5.16_1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull more MIPS updates from Thomas Bogendoerfer: - Config updates for BMIPS platform - Build fixes - Makefile cleanups * tag 'mips_5.16_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: mips: decompressor: do not copy source files while building MIPS: boot/compressed/: add __bswapdi2() to target for ZSTD decompression MIPS: fix duplicated slashes for Platform file path MIPS: fix *-pkg builds for loongson2ef platform PCI: brcmstb: Allow building for BMIPS_GENERIC MIPS: BMIPS: Enable PCI Kconfig MIPS: VDSO: remove -nostdlib compiler flag mips: BCM63XX: ensure that CPU_SUPPORTS_32BIT_KERNEL is set MIPS: Update bmips_stb_defconfig MIPS: Allow modules to set board_be_handler
2021-11-12signal/vm86_32: Remove pointless test in BUG_ONEric W. Biederman
kernel test robot <oliver.sang@intel.com> writes[1]: > > Greeting, > > FYI, we noticed the following commit (built with gcc-9): > > commit: 1a4d21a23c4ca7467726be7db9ae8077a62b2c62 ("signal/vm86_32: Replace open coded BUG_ON with an actual BUG_ON") > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master > > in testcase: trinity > version: trinity-static-i386-x86_64-1c734c75-1_2020-01-06 > with following parameters: > > > [ 70.645554][ T3747] kernel BUG at arch/x86/kernel/vm86_32.c:109! > [ 70.646185][ T3747] invalid opcode: 0000 [#1] SMP > [ 70.646682][ T3747] CPU: 0 PID: 3747 Comm: trinity-c6 Not tainted 5.15.0-rc1-00009-g1a4d21a23c4c #1 > [ 70.647598][ T3747] EIP: save_v86_state (arch/x86/kernel/vm86_32.c:109 (discriminator 3)) > [ 70.648113][ T3747] Code: 89 c3 64 8b 35 60 b8 25 c2 83 ec 08 89 55 f0 8b 96 10 19 00 00 89 55 ec e8 c6 2d 0c 00 fb 8b 55 ec 85 d2 74 05 83 3a 00 75 02 <0f> 0b 8b 86 10 19 00 00 8b 4b 38 8b 78 48 31 cf 89 f8 8b 7a 4c 81 > [ 70.650136][ T3747] EAX: 00000001 EBX: f5f49fac ECX: 0000000b EDX: f610b600 > [ 70.650852][ T3747] ESI: f5f79cc0 EDI: f5f79cc0 EBP: f5f49f04 ESP: f5f49ef0 > [ 70.651593][ T3747] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010246 > [ 70.652413][ T3747] CR0: 80050033 CR2: 00004000 CR3: 35fc7000 CR4: 000406d0 > [ 70.653169][ T3747] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 > [ 70.653897][ T3747] DR6: fffe0ff0 DR7: 00000400 > [ 70.654382][ T3747] Call Trace: > [ 70.654719][ T3747] arch_do_signal_or_restart (arch/x86/kernel/signal.c:792 arch/x86/kernel/signal.c:867) > [ 70.655288][ T3747] exit_to_user_mode_prepare (kernel/entry/common.c:174 kernel/entry/common.c:209) > [ 70.655854][ T3747] irqentry_exit_to_user_mode (kernel/entry/common.c:126 kernel/entry/common.c:317) > [ 70.656450][ T3747] irqentry_exit (kernel/entry/common.c:406) > [ 70.656897][ T3747] exc_page_fault (arch/x86/mm/fault.c:1535) > [ 70.657369][ T3747] ? sysvec_kvm_asyncpf_interrupt (arch/x86/mm/fault.c:1488) > [ 70.657989][ T3747] handle_exception (arch/x86/entry/entry_32.S:1085) vm86_32.c:109 is: "BUG_ON(!vm86 || !vm86->user_vm86)" When trying to understand the failure Brian Gerst pointed out[2] that the code does not need protection against vm86->user_vm86 being NULL. The copy_from_user code will already handles that case if the address is going to fault. Looking futher I realized that if we care about not allowing struct vm86plus_struct at address 0 it should be do_sys_vm86 (the system call) that does the filtering. Not way down deep when the emulation has completed in save_v86_state. So let's just remove the silly case of attempting to filter a userspace address with a BUG_ON. Existing userspace can't break and it won't make the kernel any more attackable as the userspace access helpers will handle it, if it isn't a good userspace pointer. I have run the reproducer the fuzzer gave me before I made this change and it reproduced, and after I made this change and I have not seen the reported failure. So it does looks like this fixes the reported issue. [1] https://lkml.kernel.org/r/20211112074030.GB19820@xsang-OptiPlex-9020 [2] https://lkml.kernel.org/r/CAMzpN2jkK5sAv-Kg_kVnCEyVySiqeTdUORcC=AdG1gV6r8nUew@mail.gmail.com Suggested-by: Brian Gerst <brgerst@gmail.com> Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-11-12Merge tag 'kvmarm-fixes-5.16-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm64 fixes for 5.16, take #1 - Fix the host S2 finalization by solely iterating over the memblocks instead of the whole IPA space - Tighten the return value of kvm_vcpu_preferred_target() now that 32bit support is long gone - Make sure the extraction of ESR_ELx.EC is limited to the architected bits - Comment fixups
2021-11-12x86/cpu: Add Raptor Lake to Intel familyTony Luck
Add model ID for Raptor Lake. [ dhansen: These get added as soon as possible so that folks doing development can leverage them. ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20211112182835.924977-1-tony.luck@intel.com
2021-11-12x86/mce: Add errata workaround for Skylake SKX37Dave Jones
Errata SKX37 is word-for-word identical to the other errata listed in this workaround. I happened to notice this after investigating a CMCI storm on a Skylake host. While I can't confirm this was the root cause, spurious corrected errors does sound like a likely suspect. Fixes: 2976908e4198 ("x86/mce: Do not log spurious corrected mce errors") Signed-off-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20211029205759.GA7385@codemonkey.org.uk
2021-11-12ARM: 9156/1: drop cc-option fallbacks for architecture selectionArnd Bergmann
Naresh and Antonio ran into a build failure with latest Debian armhf compilers, with lots of output like tmp/ccY3nOAs.s:2215: Error: selected processor does not support `cpsid i' in ARM mode As it turns out, $(cc-option) fails early here when the FPU is not selected before CPU architecture is selected, as the compiler option check runs before enabling -msoft-float, which causes a problem when testing a target architecture level without an FPU: cc1: error: '-mfloat-abi=hard': selected architecture lacks an FPU Passing e.g. -march=armv6k+fp in place of -march=armv6k would avoid this issue, but the fallback logic is already broken because all supported compilers (gcc-5 and higher) are much more recent than these options, and building with -march=armv5t as a fallback no longer works. The best way forward that I see is to just remove all the checks, which also has the nice side-effect of slightly improving the startup time for 'make'. The -mtune=marvell-f option was apparently never supported by any mainline compiler, and the custom Codesourcery gcc build that did support is now too old to build kernels, so just use -mtune=xscale unconditionally for those. This should be safe to apply on all stable kernels, and will be required in order to keep building them with gcc-11 and higher. Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=996419 Reported-by: Antonio Terceiro <antonio.terceiro@linaro.org> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com> Tested-by: Klaus Kudielka <klaus.kudielka@gmail.com> Cc: Matthias Klose <doko@debian.org> Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-11-12ARM: 9155/1: fix early early_iounmap()Michał Mirosław
Currently __set_fixmap() bails out with a warning when called in early boot from early_iounmap(). Fix it, and while at it, make the comment a bit easier to understand. Cc: <stable@vger.kernel.org> Fixes: b089c31c519c ("ARM: 8667/3: Fix memory attribute inconsistencies when using fixmap") Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-11-12KVM: SEV: unify cgroup cleanup code for svm_vm_migrate_fromPaolo Bonzini
Use the same cleanup code independent of whether the cgroup to be uncharged and unref'd is the source or the destination cgroup. Use a bool to track whether the destination cgroup has been charged, which also fixes a bug in the error case: the destination cgroup must be uncharged only if it does not match the source. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-12KVM: x86: move guest_pv_has out of user_access sectionPaolo Bonzini
When UBSAN is enabled, the code emitted for the call to guest_pv_has includes a call to __ubsan_handle_load_invalid_value. objtool complains that this call happens with UACCESS enabled; to avoid the warning, pull the calls to user_access_begin into both arms of the "if" statement, after the check for guest_pv_has. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11dt-bindings: Rename Ingenic CGU headers to ingenic,*.hPaul Cercueil
Tidy up a bit the tree, by prefixing all include/dt-bindings/clock/ files related to Ingenic SoCs with 'ingenic,'. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211016133322.40771-1-paul@crapouillou.net
2021-11-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "The post-linux-next material. 7 patches. Subsystems affected by this patch series (all mm): debug, slab-generic, migration, memcg, and kasan" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: kasan: add kasan mode messages when kasan init mm: unexport {,un}lock_page_memcg mm: unexport folio_memcg_{,un}lock mm/migrate.c: remove MIGRATE_PFN_LOCKED mm: migrate: simplify the file-backed pages validation when migrating its mapping mm: allow only SLUB on PREEMPT_RT mm/page_owner.c: modify the type of argument "order" in some functions
2021-11-11Merge tag 'm68knommu-for-v5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu Pull m68knommu updates from Greg Ungerer: "Only two changes. One removes the now unused CONFIG_MCPU32 symbol. The other sets a default for the CONFIG_MEMORY_RESERVE config symbol (this aids scripting and other automation) so you don't interactively get asked for a value at configure time. Summary: - remove unused CONFIG_MCPU32 symbol - default CONFIG_MEMORY_RESERVE value (for scripting)" * tag 'm68knommu-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: m68knommu: Remove MCPU32 config symbol m68k: set a default value for MEMORY_RESERVE
2021-11-11Merge tag 'net-5.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bpf, can and netfilter. Current release - regressions: - bpf: do not reject when the stack read size is different from the tracked scalar size - net: fix premature exit from NAPI state polling in napi_disable() - riscv, bpf: fix RV32 broken build, and silence RV64 warning Current release - new code bugs: - net: fix possible NULL deref in sock_reserve_memory - amt: fix error return code in amt_init(); fix stopping the workqueue - ax88796c: use the correct ioctl callback Previous releases - always broken: - bpf: stop caching subprog index in the bpf_pseudo_func insn - security: fixups for the security hooks in sctp - nfc: add necessary privilege flags in netlink layer, limit operations to admin only - vsock: prevent unnecessary refcnt inc for non-blocking connect - net/smc: fix sk_refcnt underflow on link down and fallback - nfnetlink_queue: fix OOB when mac header was cleared - can: j1939: ignore invalid messages per standard - bpf, sockmap: - fix race in ingress receive verdict with redirect to self - fix incorrect sk_skb data_end access when src_reg = dst_reg - strparser, and tls are reusing qdisc_skb_cb and colliding - ethtool: fix ethtool msg len calculation for pause stats - vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries to access an unregistering real_dev - udp6: make encap_rcv() bump the v6 not v4 stats - drv: prestera: add explicit padding to fix m68k build - drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge - drv: mvpp2: fix wrong SerDes reconfiguration order Misc & small latecomers: - ipvs: auto-load ipvs on genl access - mctp: sanity check the struct sockaddr_mctp padding fields - libfs: support RENAME_EXCHANGE in simple_rename() - avoid double accounting for pure zerocopy skbs" * tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (123 commits) selftests/net: udpgso_bench_rx: fix port argument net: wwan: iosm: fix compilation warning cxgb4: fix eeprom len when diagnostics not implemented net: fix premature exit from NAPI state polling in napi_disable() net/smc: fix sk_refcnt underflow on linkdown and fallback net/mlx5: Lag, fix a potential Oops with mlx5_lag_create_definer() gve: fix unmatched u64_stats_update_end() net: ethernet: lantiq_etop: Fix compilation error selftests: forwarding: Fix packet matching in mirroring selftests vsock: prevent unnecessary refcnt inc for nonblocking connect net: marvell: mvpp2: Fix wrong SerDes reconfiguration order net: ethernet: ti: cpsw_ale: Fix access to un-initialized memory net: stmmac: allow a tc-taprio base-time of zero selftests: net: test_vxlan_under_vrf: fix HV connectivity test net: hns3: allow configure ETS bandwidth of all TCs net: hns3: remove check VF uc mac exist when set by PF net: hns3: fix some mac statistics is always 0 in device version V2 net: hns3: fix kernel crash when unload VF while it is being reset net: hns3: sync rx ring head in echo common pull net: hns3: fix pfc packet number incorrect after querying pfc parameters ...
2021-11-11Merge tag 'char-misc-5.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc fix from Greg KH: "Here is a single fix for 5.16-rc1 to resolve a build problem that came in through the coresight tree (and as such came in through the char/misc tree merge in the 5.16-rc1 merge window). It resolves a build problem with 'allmodconfig' on arm64 and is acked by the proper subsystem maintainers. It has been in linux-next all week with no reported problems" * tag 'char-misc-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: arm64: cpufeature: Export this_cpu_has_cap helper
2021-11-11kasan: add kasan mode messages when kasan initKuan-Ying Lee
There are multiple kasan modes. It makes sense that we add some messages to know which kasan mode is active when booting up [1]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=212195 [1] Link: https://lkml.kernel.org/r/20211020094850.4113-1-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Yee Lee <yee.lee@mediatek.com> Cc: Nicholas Tang <nicholas.tang@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11mm/migrate.c: remove MIGRATE_PFN_LOCKEDAlistair Popple
MIGRATE_PFN_LOCKED is used to indicate to migrate_vma_prepare() that a source page was already locked during migrate_vma_collect(). If it wasn't then the a second attempt is made to lock the page. However if the first attempt failed it's unlikely a second attempt will succeed, and the retry adds complexity. So clean this up by removing the retry and MIGRATE_PFN_LOCKED flag. Destination pages are also meant to have the MIGRATE_PFN_LOCKED flag set, but nothing actually checks that. Link: https://lkml.kernel.org/r/20211025041608.289017-1-apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ben Skeggs <bskeggs@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-11Merge branch 'kvm-5.16-fixes' into kvm-masterPaolo Bonzini
* Fix misuse of gfn-to-pfn cache when recording guest steal time / preempted status * Fix selftests on APICv machines * Fix sparse warnings * Fix detection of KVM features in CPUID * Cleanups for bogus writes to MSR_KVM_PV_EOI_EN * Fixes and cleanups for MSR bitmap handling * Cleanups for INVPCID * Make x86 KVM_SOFT_MAX_VCPUS consistent with other architectures
2021-11-11Merge branch 'kvm-sev-move-context' into kvm-masterPaolo Bonzini
Add support for AMD SEV and SEV-ES intra-host migration support. Intra host migration provides a low-cost mechanism for userspace VMM upgrades. In the common case for intra host migration, we can rely on the normal ioctls for passing data from one VMM to the next. SEV, SEV-ES, and other confidential compute environments make most of this information opaque, and render KVM ioctls such as "KVM_GET_REGS" irrelevant. As a result, we need the ability to pass this opaque metadata from one VMM to the next. The easiest way to do this is to leave this data in the kernel, and transfer ownership of the metadata from one KVM VM (or vCPU) to the next. In-kernel hand off makes it possible to move any data that would be unsafe/impossible for the kernel to hand directly to userspace, and cannot be reproduced using data that can be handed to userspace. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: Drop arbitrary KVM_SOFT_MAX_VCPUSVitaly Kuznetsov
KVM_CAP_NR_VCPUS is used to get the "recommended" maximum number of VCPUs and arm64/mips/riscv report num_online_cpus(). Powerpc reports either num_online_cpus() or num_present_cpus(), s390 has multiple constants depending on hardware features. On x86, KVM reports an arbitrary value of '710' which is supposed to be the maximum tested value but it's possible to test all KVM_MAX_VCPUS even when there are less physical CPUs available. Drop the arbitrary '710' value and return num_online_cpus() on x86 as well. The recommendation will match other architectures and will mean 'no CPU overcommit'. For reference, QEMU only queries KVM_CAP_NR_VCPUS to print a warning when the requested vCPU number exceeds it. The static limit of '710' is quite weird as smaller systems with just a few physical CPUs should certainly "recommend" less. Suggested-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20211111134733.86601-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: Move INVPCID type check from vmx and svm to the common kvm_handle_invpcid()Vipin Sharma
Handle #GP on INVPCID due to an invalid type in the common switch statement instead of relying on the callers (VMX and SVM) to manually validate the type. Unlike INVVPID and INVEPT, INVPCID is not explicitly documented to check the type before reading the operand from memory, so deferring the type validity check until after that point is architecturally allowed. Signed-off-by: Vipin Sharma <vipinsh@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109174426.2350547-3-vipinsh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: VMX: Add a helper function to retrieve the GPR index for INVPCID, ↵Vipin Sharma
INVVPID, and INVEPT handle_invept(), handle_invvpid(), handle_invpcid() read the same reg2 field in vmcs.VMX_INSTRUCTION_INFO to get the index of the GPR that holds the invalidation type. Add a helper to retrieve reg2 from VMX instruction info to consolidate and document the shift+mask magic. Signed-off-by: Vipin Sharma <vipinsh@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109174426.2350547-2-vipinsh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: nVMX: Clean up x2APIC MSR handling for L2Sean Christopherson
Clean up the x2APIC MSR bitmap intereption code for L2, which is the last holdout of open coded bitmap manipulations. Freshen up the SDM/PRM comment, rename the function to make it abundantly clear the funky behavior is x2APIC specific, and explain _why_ vmcs01's bitmap is ignored (the previous comment was flat out wrong for x2APIC behavior). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109013047.2041518-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: VMX: Macrofy the MSR bitmap getters and settersSean Christopherson
Add builder macros to generate the MSR bitmap helpers to reduce the amount of copy-paste code, especially with respect to all the magic numbers needed to calc the correct bit location. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109013047.2041518-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: nVMX: Handle dynamic MSR intercept togglingSean Christopherson
Always check vmcs01's MSR bitmap when merging L0 and L1 bitmaps for L2, and always update the relevant bits in vmcs02. This fixes two distinct, but intertwined bugs related to dynamic MSR bitmap modifications. The first issue is that KVM fails to enable MSR interception in vmcs02 for the FS/GS base MSRs if L1 first runs L2 with interception disabled, and later enables interception. The second issue is that KVM fails to honor userspace MSR filtering when preparing vmcs02. Fix both issues simultaneous as fixing only one of the issues (doesn't matter which) would create a mess that no one should have to bisect. Fixing only the first bug would exacerbate the MSR filtering issue as userspace would see inconsistent behavior depending on the whims of L1. Fixing only the second bug (MSR filtering) effectively requires fixing the first, as the nVMX code only knows how to transition vmcs02's bitmap from 1->0. Move the various accessor/mutators that are currently buried in vmx.c into vmx.h so that they can be shared by the nested code. Fixes: 1a155254ff93 ("KVM: x86: Introduce MSR filtering") Fixes: d69129b4e46a ("KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible") Cc: stable@vger.kernel.org Cc: Alexander Graf <graf@amazon.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109013047.2041518-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: nVMX: Query current VMCS when determining if MSR bitmaps are in useSean Christopherson
Check the current VMCS controls to determine if an MSR write will be intercepted due to MSR bitmaps being disabled. In the nested VMX case, KVM will disable MSR bitmaps in vmcs02 if they're disabled in vmcs12 or if KVM can't map L1's bitmaps for whatever reason. Note, the bad behavior is relatively benign in the current code base as KVM sets all bits in vmcs02's MSR bitmap by default, clears bits if and only if L0 KVM also disables interception of an MSR, and only uses the buggy helper for MSR_IA32_SPEC_CTRL. Because KVM explicitly tests WRMSR before disabling interception of MSR_IA32_SPEC_CTRL, the flawed check will only result in KVM reading MSR_IA32_SPEC_CTRL from hardware when it isn't strictly necessary. Tag the fix for stable in case a future fix wants to use msr_write_intercepted(), in which case a buggy implementation in older kernels could prove subtly problematic. Fixes: d28b387fb74d ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109013047.2041518-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: Don't update vcpu->arch.pv_eoi.msr_val when a bogus value was ↵Vitaly Kuznetsov
written to MSR_KVM_PV_EOI_EN When kvm_gfn_to_hva_cache_init() call from kvm_lapic_set_pv_eoi() fails, MSR write to MSR_KVM_PV_EOI_EN results in #GP so it is reasonable to expect that the value we keep internally in KVM wasn't updated. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20211108152819.12485-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: Rename kvm_lapic_enable_pv_eoi()Vitaly Kuznetsov
kvm_lapic_enable_pv_eoi() is a misnomer as the function is also used to disable PV EOI. Rename it to kvm_lapic_set_pv_eoi(). No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20211108152819.12485-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: Make sure KVM_CPUID_FEATURES really are KVM_CPUID_FEATURESPaul Durrant
Currently when kvm_update_cpuid_runtime() runs, it assumes that the KVM_CPUID_FEATURES leaf is located at 0x40000001. This is not true, however, if Hyper-V support is enabled. In this case the KVM leaves will be offset. This patch introdues as new 'kvm_cpuid_base' field into struct kvm_vcpu_arch to track the location of the KVM leaves and function kvm_update_kvm_cpuid_base() (called from kvm_set_cpuid()) to locate the leaves using the 'KVMKVMKVM\0\0\0' signature (which is now given a definition in kvm_para.h). Adjustment of KVM_CPUID_FEATURES will hence now target the correct leaf. NOTE: A new for_each_possible_hypervisor_cpuid_base() macro is intoduced into processor.h to avoid having duplicate code for the iteration over possible hypervisor base leaves. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Message-Id: <20211105095101.5384-3-pdurrant@amazon.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: Add helper to consolidate core logic of SET_CPUID{2} flowsSean Christopherson
Move the core logic of SET_CPUID and SET_CPUID2 to a common helper, the only difference between the two ioctls() is the format of the userspace struct. A future fix will add yet more code to the core logic. No functional change intended. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211105095101.5384-2-pdurrant@amazon.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11kvm: mmu: Use fast PF path for access tracking of huge pages when possibleJunaid Shahid
The fast page fault path bails out on write faults to huge pages in order to accommodate dirty logging. This change adds a check to do that only when dirty logging is actually enabled, so that access tracking for huge pages can still use the fast path for write faults in the common case. Signed-off-by: Junaid Shahid <junaids@google.com> Reviewed-by: Ben Gardon <bgardon@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211104003359.2201967-1-junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86/mmu: Properly dereference rcu-protected TDP MMU sptep iteratorSean Christopherson
Wrap the read of iter->sptep in tdp_mmu_map_handle_target_level() with rcu_dereference(). Shadow pages in the TDP MMU, and thus their SPTEs, are protected by rcu. This fixes a Sparse warning at tdp_mmu.c:900:51: warning: incorrect type in argument 1 (different address spaces) expected unsigned long long [usertype] *sptep got unsigned long long [noderef] [usertype] __rcu *[usertype] sptep Fixes: 7158bee4b475 ("KVM: MMU: pass kvm_mmu_page struct to make_spte") Cc: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211103161833.3769487-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ activeMaxim Levitsky
KVM_GUESTDBG_BLOCKIRQ relies on interrupts being injected using standard kvm's inject_pending_event, and not via APICv/AVIC. Since this is a debug feature, just inhibit APICv/AVIC while KVM_GUESTDBG_BLOCKIRQ is in use on at least one vCPU. Fixes: 61e5f69ef0837 ("KVM: x86: implement KVM_GUESTDBG_BLOCKIRQ") Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Tested-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211108090245.166408-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11kvm: x86: Convert return type of *is_valid_rdpmc_ecx() to boolJim Mattson
These function names sound like predicates, and they have siblings, *is_valid_msr(), which _are_ predicates. Moreover, there are comments that essentially warn that these functions behave unexpectedly. Flip the polarity of the return values, so that they become predicates, and convert the boolean result to a success/failure code at the outer call site. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211105202058.1048757-1-jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-11KVM: x86: Fix recording of guest steal time / preempted statusDavid Woodhouse
In commit b043138246a4 ("x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is not missed") we switched to using a gfn_to_pfn_cache for accessing the guest steal time structure in order to allow for an atomic xchg of the preempted field. This has a couple of problems. Firstly, kvm_map_gfn() doesn't work at all for IOMEM pages when the atomic flag is set, which it is in kvm_steal_time_set_preempted(). So a guest vCPU using an IOMEM page for its steal time would never have its preempted field set. Secondly, the gfn_to_pfn_cache is not invalidated in all cases where it should have been. There are two stages to the GFN->PFN conversion; first the GFN is converted to a userspace HVA, and then that HVA is looked up in the process page tables to find the underlying host PFN. Correct invalidation of the latter would require being hooked up to the MMU notifiers, but that doesn't happen---so it just keeps mapping and unmapping the *wrong* PFN after the userspace page tables change. In the !IOMEM case at least the stale page *is* pinned all the time it's cached, so it won't be freed and reused by anyone else while still receiving the steal time updates. The map/unmap dance only takes care of the KVM administrivia such as marking the page dirty. Until the gfn_to_pfn cache handles the remapping automatically by integrating with the MMU notifiers, we might as well not get a kernel mapping of it, and use the perfectly serviceable userspace HVA that we already have. We just need to implement the atomic xchg on the userspace address with appropriate exception handling, which is fairly trivial. Cc: stable@vger.kernel.org Fixes: b043138246a4 ("x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is not missed") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <3645b9b889dac6438394194bb5586a46b68d581f.camel@infradead.org> [I didn't entirely agree with David's assessment of the usefulness of the gfn_to_pfn cache, and integrated the outcome of the discussion in the above commit message. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>