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2021-08-10KVM: PPC: Use arch_get_random_seed_long instead of powernv variantAlexey Kardashevskiy
The powernv_get_random_long() does not work in nested KVM (which is pseries) and produces a crash when accessing in_be64(rng->regs) in powernv_get_random_long(). This replaces powernv_get_random_long with the ppc_md machine hook wrapper. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210805075649.2086567-1-aik@ozlabs.ru
2021-07-17KVM: PPC: Book3S: Fix CONFIG_TRANSACTIONAL_MEM=n crashNicholas Piggin
When running CPU_FTR_P9_TM_HV_ASSIST, HFSCR[TM] is set for the guest even if the host has CONFIG_TRANSACTIONAL_MEM=n, which causes it to be unprepared to handle guest exits while transactional. Normal guests don't have a problem because the HTM capability will not be advertised, but a rogue or buggy one could crash the host. Fixes: 4bb3c7a0208f ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210716024310.164448-1-npiggin@gmail.com
2021-07-02Merge tag 'powerpc-5.14-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A big series refactoring parts of our KVM code, and converting some to C. - Support for ARCH_HAS_SET_MEMORY, and ARCH_HAS_STRICT_MODULE_RWX on some CPUs. - Support for the Microwatt soft-core. - Optimisations to our interrupt return path on 64-bit. - Support for userspace access to the NX GZIP accelerator on PowerVM on Power10. - Enable KUAP and KUEP by default on 32-bit Book3S CPUs. - Other smaller features, fixes & cleanups. Thanks to: Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Baokun Li, Benjamin Herrenschmidt, Bharata B Rao, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Finn Thain, Geoff Levand, Haren Myneni, Jason Wang, Jiapeng Chong, Joel Stanley, Jordan Niethe, Kajol Jain, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Paul Mackerras, Russell Currey, Sathvika Vasireddy, Shaokun Zhang, Stephen Rothwell, Sudeep Holla, Suraj Jitindar Singh, Tom Rix, Vaibhav Jain, YueHaibing, Zhang Jianhua, and Zhen Lei. * tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (218 commits) powerpc: Only build restart_table.c for 64s powerpc/64s: move ret_from_fork etc above __end_soft_masked powerpc/64s/interrupt: clean up interrupt return labels powerpc/64/interrupt: add missing kprobe annotations on interrupt exit symbols powerpc/64: enable MSR[EE] in irq replay pt_regs powerpc/64s/interrupt: preserve regs->softe for NMI interrupts powerpc/64s: add a table of implicit soft-masked addresses powerpc/64e: remove implicit soft-masking and interrupt exit restart logic powerpc/64e: fix CONFIG_RELOCATABLE build warnings powerpc/64s: fix hash page fault interrupt handler powerpc/4xx: Fix setup_kuep() on SMP powerpc/32s: Fix setup_{kuap/kuep}() on SMP powerpc/interrupt: Use names in check_return_regs_valid() powerpc/interrupt: Also use exit_must_hard_disable() on PPC32 powerpc/sysfs: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE powerpc/ptrace: Refactor regs_set_return_{msr/ip} powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip} powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi() powerpc/pseries/vas: Include irqdomain.h powerpc: mark local variables around longjmp as volatile ...
2021-06-29Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29arch/powerpc/kvm/book3s: use vma_lookup() in kvmppc_hv_setup_htab_rma()Liam Howlett
Using vma_lookup() removes the requirement to check if the address is within the returned vma. The code is easier to understand and more compact. Link: https://lkml.kernel.org/r/20210521174745.2219620-7-Liam.Howlett@Oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-24KVM: stats: Separate generic stats from architecture specific onesJing Zhang
Generic KVM stats are those collected in architecture independent code or those supported by all architectures; put all generic statistics in a separate structure. This ensures that they are defined the same way in the statistics API which is being added, removing duplication among different architectures in the declaration of the descriptors. No functional change intended. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-2-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-25powerpc/64s: avoid reloading (H)SRR registers if they are still validNicholas Piggin
When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-06-23Merge branch 'topic/ppc-kvm' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux into HEAD - Support for the H_RPT_INVALIDATE hypercall - Conversion of Book3S entry/exit to C - Bug fixes
2021-06-22KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATEBharata B Rao
Enable support for process-scoped invalidations from nested guests and partition-scoped invalidations for nested guests. Process-scoped invalidations for any level of nested guests are handled by implementing H_RPT_INVALIDATE handler in the nested guest exit path in L0. Partition-scoped invalidation requests are forwarded to the right nested guest, handled there and passed down to L0 for eventual handling. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> [aneesh: Nested guest partition-scoped invalidation changes] Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Squash in fixup patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210621085003.904767-5-bharata@linux.ibm.com
2021-06-21KVM: PPC: Book3S HV: Add support for H_RPT_INVALIDATEBharata B Rao
H_RPT_INVALIDATE does two types of TLB invalidations: 1. Process-scoped invalidations for guests when LPCR[GTSE]=0. This is currently not used in KVM as GTSE is not usually disabled in KVM. 2. Partition-scoped invalidations that an L1 hypervisor does on behalf of an L2 guest. This is currently handled by H_TLB_INVALIDATE hcall and this new replaces the old that. This commit enables process-scoped invalidations for L1 guests. Support for process-scoped and partition-scoped invalidations from/for nested guests will be added separately. Process scoped tlbie invalidations from L1 and nested guests need RS register for TLBIE instruction to contain both PID and LPID. This patch introduces primitives that execute tlbie instruction with both PID and LPID set in prepartion for H_RPT_INVALIDATE hcall. A description of H_RPT_INVALIDATE follows: int64   /* H_Success: Return code on successful completion */         /* H_Busy - repeat the call with the same */         /* H_Parameter, H_P2, H_P3, H_P4, H_P5 : Invalid parameters */ hcall(const uint64 H_RPT_INVALIDATE, /* Invalidate RPT translation lookaside information */       uint64 id,        /* PID/LPID to invalidate */       uint64 target,    /* Invalidation target */       uint64 type,      /* Type of lookaside information */       uint64 pg_sizes, /* Page sizes */       uint64 start,     /* Start of Effective Address (EA) range (inclusive) */       uint64 end)       /* End of EA range (exclusive) */ Invalidation targets (target) ----------------------------- Core MMU        0x01 /* All virtual processors in the partition */ Core local MMU  0x02 /* Current virtual processor */ Nest MMU        0x04 /* All nest/accelerator agents in use by the partition */ A combination of the above can be specified, except core and core local. Type of translation to invalidate (type) --------------------------------------- NESTED       0x0001  /* invalidate nested guest partition-scope */ TLB          0x0002  /* Invalidate TLB */ PWC          0x0004  /* Invalidate Page Walk Cache */ PRT          0x0008  /* Invalidate caching of Process Table Entries if NESTED is clear */ PAT          0x0008  /* Invalidate caching of Partition Table Entries if NESTED is set */ A combination of the above can be specified. Page size mask (pages) ---------------------- 4K              0x01 64K             0x02 2M              0x04 1G              0x08 All sizes       (-1UL) A combination of the above can be specified. All page sizes can be selected with -1. Semantics: Invalidate radix tree lookaside information            matching the parameters given. * Return H_P2, H_P3 or H_P4 if target, type, or pageSizes parameters are different from the defined values. * Return H_PARAMETER if NESTED is set and pid is not a valid nested LPID allocated to this partition * Return H_P5 if (start, end) doesn't form a valid range. Start and end should be a valid Quadrant address and  end > start. * Return H_NotSupported if the partition is not in running in radix translation mode. * May invalidate more translation information than requested. * If start = 0 and end = -1, set the range to cover all valid addresses. Else start and end should be aligned to 4kB (lower 11 bits clear). * If NESTED is clear, then invalidate process scoped lookaside information. Else pid specifies a nested LPID, and the invalidation is performed   on nested guest partition table and nested guest partition scope real addresses. * If pid = 0 and NESTED is clear, then valid addresses are quadrant 3 and quadrant 0 spaces, Else valid addresses are quadrant 0. * Pages which are fully covered by the range are to be invalidated.   Those which are partially covered are considered outside invalidation range, which allows a caller to optimally invalidate ranges that may   contain mixed page sizes. * Return H_SUCCESS on success. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210621085003.904767-4-bharata@linux.ibm.com
2021-06-21KVM: PPC: Book3S HV: Fix TLB management on SMT8 POWER9 and POWER10 processorsSuraj Jitindar Singh
The POWER9 vCPU TLB management code assumes all threads in a core share a TLB, and that TLBIEL execued by one thread will invalidate TLBs for all threads. This is not the case for SMT8 capable POWER9 and POWER10 (big core) processors, where the TLB is split between groups of threads. This results in TLB multi-hits, random data corruption, etc. Fix this by introducing cpu_first_tlb_thread_sibling etc., to determine which siblings share TLBs, and use that in the guest TLB flushing code. [npiggin@gmail.com: add changelog and comment] Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210602040441.3984352-1-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV: remove ISA v3.0 and v3.1 support from P7/8 pathNicholas Piggin
POWER9 and later processors always go via the P9 guest entry path now. Remove the remaining support from the P7/8 path. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-33-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: implement hash host / hash guest supportNicholas Piggin
Implement support for hash guests under hash host. This has to save and restore the host SLB, and ensure that the MMU is off while switching into the guest SLB. POWER9 and later CPUs now always go via the P9 path. The "fast" guest mode is now renamed to the P9 mode, which is consistent with its functionality and the rest of the naming. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-32-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: implement hash guest supportNicholas Piggin
Implement hash guest support. Guest entry/exit has to restore and save/clear the SLB, plus several other bits to accommodate hash guests in the P9 path. Radix host, hash guest support is removed from the P7/8 path. The HPT hcalls and faults are not handled in real mode, which is a performance regression. A worst-case fork/exit microbenchmark takes 3x longer after this patch. kbuild benchmark performance is in the noise, but the slowdown is likely to be noticed somewhere. For now, accept this penalty for the benefit of simplifying the P7/8 paths and unifying P9 hash with the new code, because hash is a less important configuration than radix on processors that support it. Hash will benefit from future optimisations to this path, including possibly a faster path to handle such hcalls and interrupts without doing a full exit. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-31-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Reflect userspace hcalls to hash guests to support ↵Nicholas Piggin
PR KVM The reflection of sc 1 interrupts from guest PR=1 to the guest kernel is required to support a hash guest running PR KVM where its guest is making hcalls with sc 1. In preparation for hash guest support, add this hcall reflection to the P9 path. The P7/8 path does this in its realmode hcall handler (sc_1_fast_return). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-30-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faultsNicholas Piggin
In order to support hash guests in the P9 path (which does not do real mode hcalls or page fault handling), these real-mode hash specific interrupts need to be implemented in virt mode. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-29-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV: small pseries_do_hcall cleanupNicholas Piggin
Functionality should not be changed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-28-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Allow all P9 processors to enable nested HVNicholas Piggin
All radix guests go via the P9 path now, so there is no need to limit nested HV to processors that support "mixed mode" MMU. Remove the restriction. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-27-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9Nicholas Piggin
Dependent-threads mode is the normal KVM mode for pre-POWER9 SMT processors, where all threads in a core (or subcore) would run the same partition at the same time, or they would run the host. This design was mandated by MMU state that is shared between threads in a processor, so the synchronisation point is in hypervisor real-mode that has essentially no shared state, so it's safe for multiple threads to gather and switch to the correct mode. It is implemented by having the host unplug all secondary threads and always run in SMT1 mode, and host QEMU threads essentially represent virtual cores that wake these secondary threads out of unplug when the ioctl is called to run the guest. This happens via a side-path that is mostly invisible to the rest of the Linux host and the secondary threads still appear to be unplugged. POWER9 / ISA v3.0 has a more flexible MMU design that is independent per-thread and allows a much simpler KVM implementation. Before the new "P9 fast path" was added that began to take advantage of this, POWER9 support was implemented in the existing path which has support to run in the dependent threads mode. So it was not much work to add support to run POWER9 in this dependent threads mode. The mode is not required by the POWER9 MMU (although "mixed-mode" hash / radix MMU limitations of early processors were worked around using this mode). But it is one way to run SMT guests without running different guests or guest and host on different threads of the same core, so it could avoid or reduce some SMT attack surfaces without turning off SMT entirely. This security feature has some real, if indeterminate, value. However the old path is lagging in features (nested HV), and with this series the new P9 path adds remaining missing features (radix prefetch bug and hash support, in later patches), so POWER9 dependent threads mode support would be the only remaining reason to keep that code in and keep supporting POWER9/POWER10 in the old path. So here we make the call to drop this feature. Remove dependent threads mode support for POWER9 and above processors. Systems can still achieve this security by disabling SMT entirely, but that would generally come at a larger performance cost for guests. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-23-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMUNicholas Piggin
Rather than partition the guest PID space + flush a rogue guest PID to work around this problem, instead fix it by always disabling the MMU when switching in or out of guest MMU context in HV mode. This may be a bit less efficient, but it is a lot less complicated and allows the P9 path to trivally implement the workaround too. Newer CPUs are not subject to this issue. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-22-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Add helpers for OS SPR handlingNicholas Piggin
This is a first step to wrapping supervisor and user SPR saving and loading up into helpers, which will then be called independently in bare metal and nested HV cases in order to optimise SPR access. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-20-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0Nicholas Piggin
SRR0/1, DAR, DSISR must all be protected from machine check which can clobber them. Ensure MSR[RI] is clear while they are live. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-17-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into ↵Nicholas Piggin
__kvmhv_vcpu_entry_p9 Now the initial C implementation is done, inline more HV code to make rearranging things easier. And rename __kvmhv_vcpu_entry_p9 to drop the leading underscores as it's now C, and is now a more complete vcpu entry. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-16-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in CNicholas Piggin
Almost all logic is moved to C, by introducing a new in_guest mode for the P9 path that branches very early in the KVM interrupt handler to P9 exit code. The main P9 entry and exit assembly is now only about 160 lines of low level stack setup and register save/restore, plus a bad-interrupt handler. There are two motivations for this, the first is just make the code more maintainable being in C. The second is to reduce the amount of code running in a special KVM mode, "realmode". In quotes because with radix it is no longer necessarily real-mode in the MMU, but it still has to be treated specially because it may be in real-mode, and has various important registers like PID, DEC, TB, etc set to guest. This is hostile to the rest of Linux and can't use arbitrary kernel functionality or be instrumented well. This initial patch is a reasonably faithful conversion of the asm code, but it does lack any loop to return quickly back into the guest without switching out of realmode in the case of unimportant or easily handled interrupts. As explained in previous changes, handling HV interrupts very quickly in this low level realmode is not so important for P9 performance, and are important to avoid for security, observability, debugability reasons. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-15-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 pathNicholas Piggin
In the interest of minimising the amount of code that is run in "real-mode", don't handle hcalls in real mode in the P9 path. This requires some new handlers for H_CEDE and xics-on-xive to be added before xive is pulled or cede logic is checked. This introduces a change in radix guest behaviour where radix guests that execute 'sc 1' in userspace now get a privilege fault whereas previously the 'sc 1' would be reflected as a syscall interrupt to the guest kernel. That reflection is only required for hash guests that run PR KVM. Background: In POWER8 and earlier processors, it is very expensive to exit from the HV real mode context of a guest hypervisor interrupt, and switch to host virtual mode. On those processors, guest->HV interrupts reach the hypervisor with the MMU off because the MMU is loaded with guest context (LPCR, SDR1, SLB), and the other threads in the sub-core need to be pulled out of the guest too. Then the primary must save off guest state, invalidate SLB and ERAT, and load up host state before the MMU can be enabled to run in host virtual mode (~= regular Linux mode). Hash guests also require a lot of hcalls to run due to the nature of the MMU architecture and paravirtualisation design. The XICS interrupt controller requires hcalls to run. So KVM traditionally tries hard to avoid the full exit, by handling hcalls and other interrupts in real mode as much as possible. By contrast, POWER9 has independent MMU context per-thread, and in radix mode the hypervisor is in host virtual memory mode when the HV interrupt is taken. Radix guests do not require significant hcalls to manage their translations, and xive guests don't need hcalls to handle interrupts. So it's much less important for performance to handle hcalls in real mode on POWER9. One caveat is that the TCE hcalls are performance critical, real-mode variants introduced for POWER8 in order to achieve 10GbE performance. Real mode TCE hcalls were found to be less important on POWER9, which was able to drive 40GBe networking without them (using the virt mode hcalls) but performance is still important. These hcalls will benefit from subsequent guest entry/exit optimisation including possibly a faster "partial exit" that does not entirely switch to host context to handle the hcall. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-14-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Move radix MMU switching instructions togetherNicholas Piggin
Switching the MMU from radix<->radix mode is tricky particularly as the MMU can remain enabled and requires a certain sequence of SPR updates. Move these together into their own functions. This also includes the radix TLB check / flush because it's tied in to MMU switching due to tlbiel getting LPID from LPIDR. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-13-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Move xive vcpu context management into ↵Nicholas Piggin
kvmhv_p9_guest_entry Move the xive management up so the low level register switching can be pushed further down in a later patch. XIVE MMIO CI operations can run in higher level code with machine checks, tracing, etc., available. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-12-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer racesNicholas Piggin
irq_work's use of the DEC SPR is racy with guest<->host switch and guest entry which flips the DEC interrupt to guest, which could lose a host work interrupt. This patch closes one race, and attempts to comment another class of races. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-11-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCRNicholas Piggin
LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some processors, so it must be enabled before HDEC is set. Rather than set it in the host LPCR then setting HDEC, move the HDEC update to after the guest MMU context (including LPCR) is loaded. There shouldn't be much concern with delaying HDEC by some 10s or 100s of nanoseconds by setting it a bit later. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-10-npiggin@gmail.com
2021-06-10KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in CNicholas Piggin
This is more symmetric with kvmppc_xive_push_vcpu, and has the advantage that it runs with the MMU on. The extra test added to the asm will go away with a future change. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210528090752.3542186-9-npiggin@gmail.com
2021-06-06Merge tag 'powerpc-5.13-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fix our KVM reverse map real-mode handling since we enabled huge vmalloc (in some configurations). Revert a recent change to our IOMMU code which broke some devices. Fix KVM handling of FSCR on P7/P8, which could have possibly let a guest crash it's Qemu. Fix kprobes validation of prefixed instructions across page boundary. Thanks to Alexey Kardashevskiy, Christophe Leroy, Fabiano Rosas, Frederic Barrat, Naveen N. Rao, and Nicholas Piggin" * tag 'powerpc-5.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs" KVM: PPC: Book3S HV: Save host FSCR in the P7/8 path powerpc: Fix reverse map real-mode address lookup with huge vmalloc powerpc/kprobes: Fix validation of prefixed instructions across page boundary
2021-06-04KVM: PPC: Book3S HV: Save host FSCR in the P7/8 pathNicholas Piggin
Similar to commit 25edcc50d76c ("KVM: PPC: Book3S HV: Save and restore FSCR in the P9 path"), ensure the P7/8 path saves and restores the host FSCR. The logic explained in that patch actually applies there to the old path well: a context switch can be made before kvmppc_vcpu_run_hv restores the host FSCR and returns. Now both the p9 and the p7/8 paths now save and restore their FSCR, it no longer needs to be restored at the end of kvmppc_vcpu_run_hv Fixes: b005255e12a3 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs") Cc: stable@vger.kernel.org # v3.14+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210526125851.3436735-1-npiggin@gmail.com
2021-05-28KVM: PPC: Book3S HV: Save host FSCR in the P7/8 pathNicholas Piggin
Similar to commit 25edcc50d76c ("KVM: PPC: Book3S HV: Save and restore FSCR in the P9 path"), ensure the P7/8 path saves and restores the host FSCR. The logic explained in that patch actually applies there to the old path well: a context switch can be made before kvmppc_vcpu_run_hv restores the host FSCR and returns. Now both the p9 and the p7/8 paths now save and restore their FSCR, it no longer needs to be restored at the end of kvmppc_vcpu_run_hv Fixes: b005255e12a3 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs") Cc: stable@vger.kernel.org # v3.14+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210526125851.3436735-1-npiggin@gmail.com
2021-05-27KVM: PPC: exit halt polling on need_resched()Wanpeng Li
This is inspired by commit 262de4102c7bb8 (kvm: exit halt polling on need_resched() as well). Due to PPC implements an arch specific halt polling logic, we have to the need_resched() check there as well. This patch adds a helper function that can be shared between book3s and generic halt-polling loops. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Venkatesh Srinivas <venkateshs@chromium.org> Cc: Ben Segall <bsegall@google.com> Cc: Venkatesh Srinivas <venkateshs@chromium.org> Cc: Jim Mattson <jmattson@google.com> Cc: David Matlack <dmatlack@google.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1621339235-11131-1-git-send-email-wanpengli@tencent.com> [Make the function inline. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...
2021-04-17KVM: PPC: Convert to the gfn-based MMU notifier callbacksSean Christopherson
Move PPC to the gfn-base MMU notifier APIs, and update all 15 bajillion PPC-internal hooks to work with gfns instead of hvas. No meaningful functional change intended, though the exact order of operations is slightly different since the memslot lookups occur before calling into arch code. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-12KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcallsNicholas Piggin
This config option causes the warning in init_default_hcalls to fire because the TCE handlers are in the default hcall list but not implemented. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210412014845.1517916-9-npiggin@gmail.com
2021-04-12KVM: PPC: Book3S HV: Remove redundant mtspr PSPBNicholas Piggin
This SPR is set to 0 twice when exiting the guest. Suggested-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210412014845.1517916-7-npiggin@gmail.com
2021-04-12KVM: PPC: Book3S HV: Prevent radix guests setting LPCR[TC]Nicholas Piggin
Prevent radix guests setting LPCR[TC]. This bit only applies to hash partitions. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210412014845.1517916-6-npiggin@gmail.com
2021-04-12KVM: PPC: Book3S HV: Disallow LPCR[AIL] to be set to 1 or 2Nicholas Piggin
These are already disallowed by H_SET_MODE from the guest, also disallow these by updating LPCR directly. AIL modes can affect the host interrupt behaviour while the guest LPCR value is set, so filter it here too. Suggested-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210412014845.1517916-5-npiggin@gmail.com
2021-04-12KVM: PPC: Book3S HV: Add a function to filter guest LPCR bitsNicholas Piggin
Guest LPCR depends on hardware type, and future changes will add restrictions based on errata and guest MMU mode. Move this logic to a common function and use it for the cases where the guest wants to update its LPCR (or the LPCR of a nested guest). This also adds a warning in other places that set or update LPCR if we try to set something that would have been disallowed by the filter, as a sanity check. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210412014845.1517916-4-npiggin@gmail.com
2021-04-12KVM: PPC: Book3S HV P9: Restore host CTRL SPR after guest exitNicholas Piggin
The host CTRL (runlatch) value is not restored after guest exit. The host CTRL should always be 1 except in CPU idle code, so this can result in the host running with runlatch clear, and potentially switching to a different vCPU which then runs with runlatch clear as well. This has little effect on P9 machines, CTRL is only responsible for some PMU counter logic in the host and so other than corner cases of software relying on that, or explicitly reading the runlatch value (Linux does not appear to be affected but it's possible non-Linux guests could be), there should be no execution correctness problem, though it could be used as a covert channel between guests. There may be microcontrollers, firmware or monitoring tools that sample the runlatch value out-of-band, however since the register is writable by guests, these values would (should) not be relied upon for correct operation of the host, so suboptimal performance or incorrect reporting should be the worst problem. Fixes: 95a6432ce9038 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210412014845.1517916-2-npiggin@gmail.com
2021-02-22Merge tag 'powerpc-5.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A large series adding wrappers for our interrupt handlers, so that irq/nmi/user tracking can be isolated in the wrappers rather than spread in each handler. - Conversion of the 32-bit syscall handling into C. - A series from Nick to streamline our TLB flushing when using the Radix MMU. - Switch to using queued spinlocks by default for 64-bit server CPUs. - A rework of our PCI probing so that it happens later in boot, when more generic infrastructure is available. - Two small fixes to allow 32-bit little-endian processes to run on 64-bit kernels. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun. * tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits) powerpc/perf: Adds support for programming of Thresholding in P10 powerpc/pci: Remove unimplemented prototypes powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user() powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size() powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user() powerpc/64: Fix stack trace not displaying final frame powerpc/time: Remove get_tbl() powerpc/time: Avoid using get_tbl() spi: mpc52xx: Avoid using get_tbl() powerpc/syscall: Avoid storing 'current' in another pointer powerpc/32: Handle bookE debugging in C in syscall entry/exit powerpc/syscall: Do not check unsupported scv vector on PPC32 powerpc/32: Remove the counter in global_dbcr0 powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry powerpc/syscall: implement system call entry/exit logic in C for PPC32 powerpc/32: Always save non volatile GPRs at syscall entry powerpc/syscall: Change condition to check MSR_RI powerpc/syscall: Save r3 in regs->orig_r3 powerpc/syscall: Use is_compat_task() powerpc/syscall: Make interrupt.c buildable on PPC32 ...
2021-02-10KVM: PPC: Don't always report hash MMU capability for P9 < DD2.2Fabiano Rosas
These machines don't support running both MMU types at the same time, so remove the KVM_CAP_PPC_MMU_HASH_V3 capability when the host is using Radix MMU. [paulus@ozlabs.org - added defensive check on kvmppc_hv_ops->hash_v3_possible] Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2021-02-10KVM: PPC: Book3S HV: Save and restore FSCR in the P9 pathFabiano Rosas
The Facility Status and Control Register is a privileged SPR that defines the availability of some features in problem state. Since it can be written by the guest, we must restore it to the previous host value after guest exit. This restoration is currently done by taking the value from current->thread.fscr, which in the P9 path is not enough anymore because the guest could context switch the QEMU thread, causing the guest-current value to be saved into the thread struct. The above situation manifested when running a QEMU linked against a libc with System Call Vectored support, which causes scv instructions to be run by QEMU early during the guest boot (during SLOF), at which point the FSCR is 0 due to guest entry. After a few scv calls (1 to a couple hundred), the context switching happens and the QEMU thread runs with the guest value, resulting in a Facility Unavailable interrupt. This patch saves and restores the host value of FSCR in the inner guest entry loop in a way independent of current->thread.fscr. The old way of doing it is still kept in place because it works for the old entry path. Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2021-02-10KVM: PPC: Book3S HV: Remove support for running HPT guest on RPT host ↵Nicholas Piggin
without mixed mode support This reverts much of commit c01015091a770 ("KVM: PPC: Book3S HV: Run HPT guests on POWER9 radix hosts"), which was required to run HPT guests on RPT hosts on early POWER9 CPUs without support for "mixed mode", which meant the host could not run with MMU on while guests were running. This code has some corner case bugs, e.g., when the guest hits a machine check or HMI the primary locks up waiting for secondaries to switch LPCR to host, which they never do. This could all be fixed in software, but most CPUs in production have mixed mode support, and those that don't are believed to be all in installations that don't use this capability. So simplify things and remove support. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2021-02-10KVM: PPC: Book3S HV: Introduce new capability for 2nd DAWRRavi Bangoria
Introduce KVM_CAP_PPC_DAWR1 which can be used by QEMU to query whether KVM supports 2nd DAWR or not. The capability is by default disabled even when the underlying CPU supports 2nd DAWR. QEMU needs to check and enable it manually to use the feature. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2021-02-10KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWRRavi Bangoria
KVM code assumes single DAWR everywhere. Add code to support 2nd DAWR. DAWR is a hypervisor resource and thus H_SET_MODE hcall is used to set/ unset it. Introduce new case H_SET_MODE_RESOURCE_SET_DAWR1 for 2nd DAWR. Also, KVM will support 2nd DAWR only if CPU_FTR_DAWR1 is set. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2021-02-10KVM: PPC: Book3S HV: Rename current DAWR macros and variablesRavi Bangoria
Power10 is introducing a second DAWR (Data Address Watchpoint Register). Use real register names (with suffix 0) from ISA for current macros and variables used by kvm. One exception is KVM_REG_PPC_DAWR. Keep it as it is because it's uapi so changing it will break userspace. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2021-02-09powerpc: convert interrupt handlers to use wrappersNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-29-npiggin@gmail.com