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2023-05-11RISC-V: Align SBI probe implementation with specAndrew Jones
commit 41cad8284d5e6bf1d49d3c10a6b52ee1ae866a20 upstream. sbi_probe_extension() is specified with "Returns 0 if the given SBI extension ID (EID) is not available, or 1 if it is available unless defined as any other non-zero value by the implementation." Additionally, sbiret.value is a long. Fix the implementation to ensure any nonzero long value is considered a success, rather than only positive int values. Fixes: b9dcd9e41587 ("RISC-V: Add basic support for SBI v0.2") Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230427163626.101042-1-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-11KVM: RISC-V: Retry fault if vma_lookup() results become invalidDavid Matlack
commit 2ed90cb0938a45b12eb947af062d12c7af0067b3 upstream. Read mmu_invalidate_seq before dropping the mmap_lock so that KVM can detect if the results of vma_lookup() (e.g. vma_shift) become stale before it acquires kvm->mmu_lock. This fixes a theoretical bug where a VMA could be changed by userspace after vma_lookup() and before KVM reads the mmu_invalidate_seq, causing KVM to install page table entries based on a (possibly) no-longer-valid vma_shift. Re-order the MMU cache top-up to earlier in user_mem_abort() so that it is not done after KVM has read mmu_invalidate_seq (i.e. so as to avoid inducing spurious fault retries). It's unlikely that any sane userspace currently modifies VMAs in such a way as to trigger this race. And even with directed testing I was unable to reproduce it. But a sufficiently motivated host userspace might be able to exploit this race. Note KVM/ARM had the same bug and was fixed in a separate, near identical patch (see Link). Link: https://lore.kernel.org/kvm/20230313235454.2964067-1-dmatlack@google.com/ Fixes: 9955371cc014 ("RISC-V: KVM: Implement MMU notifiers") Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Tested-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-06riscv/kvm: Fix VM hang in case of timer delta being zero.Rajnesh Kanwal
[ Upstream commit 6eff38048944cadc3cddcf117acfa5199ec32490 ] In case when VCPU is blocked due to WFI, we schedule the timer from `kvm_riscv_vcpu_timer_blocking()` to keep timer interrupt ticking. But in case when delta_ns comes to be zero, we never schedule the timer and VCPU keeps sleeping indefinitely until any activity is done with VM console. This is easily reproduce-able using kvmtool. ./lkvm-static run -c1 --console virtio -p "earlycon root=/dev/vda" \ -k ./Image -d rootfs.ext4 Also, just add a print in kvm_riscv_vcpu_vstimer_expired() to check the interrupt delivery and run `top` or similar auto-upating cmd from guest. Within sometime one can notice that print from timer expiry routine stops and the `top` cmd output will stop updating. This change fixes this by making sure we schedule the timer even with delta_ns being zero to bring the VCPU out of sleep immediately. Fixes: 8f5cb44b1bae ("RISC-V: KVM: Support sstc extension") Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-31RISC-V: KVM: Fix reg_val check in kvm_riscv_vcpu_set_reg_config()Anup Patel
[ Upstream commit e482d9e33d5b0f222cbef7341dcd52cead6b9edc ] The reg_val check in kvm_riscv_vcpu_set_reg_config() should only be done for isa config register. Fixes: 9bfd900beeec ("RISC-V: KVM: Improve ISA extension by using a bitmap") Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-21RISC-V: KVM: Fix kvm_riscv_vcpu_timer_pending() for SstcAnup Patel
The kvm_riscv_vcpu_timer_pending() checks per-VCPU next_cycles and per-VCPU software injected VS timer interrupt. This function returns incorrect value when Sstc is available because the per-VCPU next_cycles are only updated by kvm_riscv_vcpu_timer_save() called from kvm_arch_vcpu_put(). As a result, when Sstc is available the VCPU does not block properly upon WFI traps. To fix the above issue, we introduce kvm_riscv_vcpu_timer_sync() which will update per-VCPU next_cycles upon every VM exit instead of kvm_riscv_vcpu_timer_save(). Fixes: 8f5cb44b1bae ("RISC-V: KVM: Support sstc extension") Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-03Merge tag 'kvm-riscv-6.1-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.1 - Improved instruction encoding infrastructure for instructions not yet supported by binutils - Svinval support for both KVM Host and KVM Guest - Zihintpause support for KVM Guest - Zicbom support for KVM Guest - Record number of signal exits as a VCPU stat - Use generic guest entry infrastructure
2022-10-02RISC-V: KVM: Use generic guest entry infrastructureJisheng Zhang
Use generic guest entry infrastructure to properly handle TIF_NOTIFY_RESUME. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Record number of signal exits as a vCPU statJisheng Zhang
Record a statistic indicating the number of times a vCPU has exited due to a pending signal. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org
2022-10-02RISC-V: KVM: add __init annotation to riscv_kvm_init()Xiu Jianfeng
The riscv_kvm_init() is a module_init entry so let us add __init annotation to it. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Expose Zicbom to the guestAndrew Jones
Guests may use the cbo.inval,clean,flush instructions when the CPU has the Zicbom extension and the hypervisor sets henvcfg.CBIE (for cbo.inval) and henvcfg.CBCFE (for cbo.clean,flush). Add Zicbom support for KVM guests which may be enabled and disabled from KVM userspace using the ISA extension ONE_REG API. Also opportunistically switch the other isa extension checks in kvm_riscv_vcpu_update_config() to riscv_isa_extension_available(). Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Provide UAPI for Zicbom block sizeAndrew Jones
We're about to allow guests to use the Zicbom extension. KVM userspace needs to know the cache block size in order to properly advertise it to the guest. Provide a virtual config register for userspace to get it with the GET_ONE_REG API, but setting it cannot be supported, so disallow SET_ONE_REG. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Make ISA ext mappings explicitAndrew Jones
While adding new extensions at the bottom of the array isn't hard to do, it's a pain to review in order to ensure we're not missing any. Also, resolving merge conflicts for multiple new ISA extensions can be error-prone. To make adding new mappings foolproof, explicitly assign the array elements. And, now that the order doesn't matter, we can alphabetize the extensions, so we do that too. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Allow Guest use Zihintpause extensionMayuresh Chitale
We should advertise Zihintpause ISA extension to KVM user-space whenever host supports it. This will allow KVM user-space (i.e. QEMU or KVMTOOL) to pass on this information to Guest via ISA string. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Allow Guest use Svinval extensionAnup Patel
We should advertise Svinval ISA extension to KVM user-space whenever host supports it. This will allow KVM user-space (i.e. QEMU or KVMTOOL) to pass on this information to Guest via ISA string. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02RISC-V: KVM: Use Svinval for local TLB maintenance when availableAnup Patel
We should prefer HINVAL.GVMA and HINVAL.VVMA instruction for local TLB maintenance when underlying host supports Svinval extension. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02riscv: KVM: Apply insn-def to hlv encodingsAndrew Jones
Introduce hlv instruction encodings and apply them to KVM's use. We're careful not to introduce hlv.d to 32-bit builds. Indeed, we ensure the build fails if someone tries to use it. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-10-02riscv: KVM: Apply insn-def to hfence encodingsAndrew Jones
Introduce hfence instruction encodings and apply them to KVM's use. With the self-documenting nature of the instruction encoding macros, and a spec always within arm's reach, it's safe to remove the comments, so we do that too. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-09-30Merge tag 'kvm-x86-6.1-2' of https://github.com/sean-jc/linux into HEADPaolo Bonzini
KVM x86 updates for 6.1, batch #2: - Misc PMU fixes and cleanups. - Fixes for Hyper-V hypercall selftest
2022-09-26KVM: remove KVM_REQ_UNHALTPaolo Bonzini
KVM_REQ_UNHALT is now unnecessary because it is replaced by the return value of kvm_vcpu_block/kvm_vcpu_halt. Remove it. No functional change intended. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Marc Zyngier <maz@kernel.org> Message-Id: <20220921003201.1441511-13-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-01Merge tag 'kvm-riscv-fixes-6.0-1' of https://github.com/kvm-riscv/linux into ↵Paolo Bonzini
HEAD KVM/riscv fixes for 6.0, take #1 - Fix unused variable warnings in vcpu_timer.c - Move extern sbi_ext declarations to a header
2022-08-19riscv: kvm: move extern sbi_ext declarations to a headerConor Dooley
Sparse complains about missing statics in the declarations of several variables: arch/riscv/kvm/vcpu_sbi_replace.c:38:37: warning: symbol 'vcpu_sbi_ext_time' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_replace.c:73:37: warning: symbol 'vcpu_sbi_ext_ipi' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_replace.c:126:37: warning: symbol 'vcpu_sbi_ext_rfence' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_replace.c:170:37: warning: symbol 'vcpu_sbi_ext_srst' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_base.c:69:37: warning: symbol 'vcpu_sbi_ext_base' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_base.c:90:37: warning: symbol 'vcpu_sbi_ext_experimental' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_base.c:96:37: warning: symbol 'vcpu_sbi_ext_vendor' was not declared. Should it be static? arch/riscv/kvm/vcpu_sbi_hsm.c:115:37: warning: symbol 'vcpu_sbi_ext_hsm' was not declared. Should it be static? These variables are however used in vcpu_sbi.c where they are declared as extern. Move them to kvm_vcpu_sbi.h which is handily already included by the three other files. Fixes: a046c2d8578c ("RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file") Fixes: 5f862df5585c ("RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2") Fixes: 3e1d86569c21 ("RISC-V: KVM: Add SBI HSM extension in KVM") Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-08-19riscv: kvm: vcpu_timer: fix unused variable warningsConor Dooley
In two places, csr is set but never used: arch/riscv/kvm/vcpu_timer.c:302:23: warning: variable 'csr' set but not used [-Wunused-but-set-variable] struct kvm_vcpu_csr *csr; ^ arch/riscv/kvm/vcpu_timer.c:327:23: warning: variable 'csr' set but not used [-Wunused-but-set-variable] struct kvm_vcpu_csr *csr; ^ Remove the variable. Fixes: 8f5cb44b1bae ("RISC-V: KVM: Support sstc extension") Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-08-19KVM: Rename mmu_notifier_* to mmu_invalidate_*Chao Peng
The motivation of this renaming is to make these variables and related helper functions less mmu_notifier bound and can also be used for non mmu_notifier based page invalidation. mmu_invalidate_* was chosen to better describe the purpose of 'invalidating' a page that those variables are used for. - mmu_notifier_seq/range_start/range_end are renamed to mmu_invalidate_seq/range_start/range_end. - mmu_notifier_retry{_hva} helper functions are renamed to mmu_invalidate_retry{_hva}. - mmu_notifier_count is renamed to mmu_invalidate_in_progress to avoid confusion with mn_active_invalidate_count. - While here, also update kvm_inc/dec_notifier_count() to kvm_mmu_invalidate_begin/end() to match the change for mmu_notifier_count. No functional change intended. Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Message-Id: <20220816125322.1110439-3-chao.p.peng@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-12RISC-V: KVM: Support sstc extensionAtish Patra
Sstc extension allows the guest to program the vstimecmp CSR directly instead of making an SBI call to the hypervisor to program the next event. The timer interrupt is also directly injected to the guest by the hardware in this case. To maintain backward compatibility, the hypervisors also update the vstimecmp in an SBI set_time call if the hardware supports it. Thus, the older kernels in guest also take advantage of the sstc extension. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Acked-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/all/CAAhSdy2mb6wyqy0NAn9BcTWKMYEc0Z4zU3s3j7oNqBz6eDQ9sg@mail.gmail.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-01Merge remote-tracking branch 'kvm/next' into kvm-next-5.20Paolo Bonzini
KVM/s390, KVM/x86 and common infrastructure changes for 5.20 x86: * Permit guests to ignore single-bit ECC errors * Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache * Intel IPI virtualization * Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS * PEBS virtualization * Simplify PMU emulation by just using PERF_TYPE_RAW events * More accurate event reinjection on SVM (avoid retrying instructions) * Allow getting/setting the state of the speaker port data bit * Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent * "Notify" VM exit (detect microarchitectural hangs) for Intel * Cleanups for MCE MSR emulation s390: * add an interface to provide a hypervisor dump for secure guests * improve selftests to use TAP interface * enable interpretive execution of zPCI instructions (for PCI passthrough) * First part of deferred teardown * CPU Topology * PV attestation * Minor fixes Generic: * new selftests API using struct kvm_vcpu instead of a (vm, id) tuple x86: * Use try_cmpxchg64 instead of cmpxchg64 * Bugfixes * Ignore benign host accesses to PMU MSRs when PMU is disabled * Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior * x86/MMU: Allow NX huge pages to be disabled on a per-vm basis * Port eager page splitting to shadow MMU as well * Enable CMCI capability by default and handle injected UCNA errors * Expose pid of vcpu threads in debugfs * x2AVIC support for AMD * cleanup PIO emulation * Fixes for LLDT/LTR emulation * Don't require refcounted "struct page" to create huge SPTEs x86 cleanups: * Use separate namespaces for guest PTEs and shadow PTEs bitmasks * PIO emulation * Reorganize rmap API, mostly around rmap destruction * Do not workaround very old KVM bugs for L0 that runs with nesting enabled * new selftests API for CPUID
2022-07-29RISC-V: KVM: Add support for Svpbmt inside Guest/VMAnup Patel
The Guest/VM can use Svpbmt in VS-stage page tables when allowed by the Hypervisor using the henvcfg.PBMTE bit. We add Svpbmt support for the KVM Guest/VM which can be enabled/disabled by the KVM user-space (QEMU/KVMTOOL) using the ISA extension ONE_REG interface. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Use PAGE_KERNEL_IO in kvm_riscv_gstage_ioremap()Anup Patel
When the host has Svpbmt extension, we should use page based memory type 2 (i.e. IO) for IO mappings in the G-stage page table. To achieve this, we replace use of PAGE_KERNEL with PAGE_KERNEL_IO in the kvm_riscv_gstage_ioremap(). Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Add G-stage ioremap() and iounmap() functionsAnup Patel
The in-kernel AIA IMSIC support requires on-demand mapping / unmapping of Guest IMSIC address to Host IMSIC guest files. To help achieve this, we add kvm_riscv_stage2_ioremap() and kvm_riscv_stage2_iounmap() functions. These new functions for updating G-stage page table mappings will be called in atomic context so we have special "in_atomic" parameter for this purpose. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Add extensible CSR emulation frameworkAnup Patel
We add an extensible CSR emulation framework which is based upon the existing system instruction emulation. This will be useful to upcoming AIA, PMU, Nested and other virtualization features. The CSR emulation framework also has provision to emulate CSR in user space but this will be used only in very specific cases such as AIA IMSIC CSR emulation in user space or vendor specific CSR emulation in user space. By default, all CSRs not handled by KVM RISC-V will be redirected back to Guest VCPU as illegal instruction trap. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Add extensible system instruction emulation frameworkAnup Patel
We will be emulating more system instructions in near future with upcoming AIA, PMU, Nested and other virtualization features. To accommodate above, we add an extensible system instruction emulation framework in vcpu_insn.c. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Factor-out instruction emulation into separate sourcesAnup Patel
The instruction and CSR emulation for VCPU is going to grow over time due to upcoming AIA, PMU, Nested and other virtualization features. Let us factor-out VCPU instruction emulation from vcpu_exit.c to a separate source dedicated for this purpose. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: move preempt_disable() call in kvm_arch_vcpu_ioctl_runNikolay Borisov
local_irq_disable provides stronger guarantees than preempt_disable so calling the latter is redundant when interrupts are disabled. Instead, explicitly disable preemption right before interrupts are enabled/disabled to ensure that the time accounted in guest_timing_exit_irqoff includes time taken by the guest or interrupts. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Make kvm_riscv_guest_timer_init a void functionNikolay Borisov
It can never fail so convey that fact explicitly by making the function void. Also in kvm_arch_init_vm it makes it clear that there no need to do any cleanup after kvm_riscv_gstage_vmid_init has been called. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Fix variable spelling mistakeZhang Jiaming
There is a spelling mistake in mmu.c and vcpu_exit.c. Fix it. Signed-off-by: Zhang Jiaming <jiaming@nfschina.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-29RISC-V: KVM: Improve ISA extension by using a bitmapAtish Patra
Currently, the every vcpu only stores the ISA extensions in a unsigned long which is not scalable as number of extensions will continue to grow. Using a bitmap allows the ISA extension to support any number of extensions. The CONFIG one reg interface implementation is modified to support the bitmap as well. But it is meant only for base extensions. Thus, the first element of the bitmap array is sufficient for that interface. In the future, all the new multi-letter extensions must use the ISA_EXT one reg interface that allows enabling/disabling any extension now. Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-11RISC-V: KVM: Fix SRCU deadlock caused by kvm_riscv_check_vcpu_requests()Anup Patel
The kvm_riscv_check_vcpu_requests() is called with SRCU read lock held and for KVM_REQ_SLEEP request it will block the VCPU without releasing SRCU read lock. This causes KVM ioctls (such as KVM_IOEVENTFD) from other VCPUs of the same Guest/VM to hang/deadlock if there is any synchronize_srcu() or synchronize_srcu_expedited() in the path. To fix the above in kvm_riscv_check_vcpu_requests(), we should do SRCU read unlock before blocking the VCPU and do SRCU read lock after VCPU wakeup. Fixes: cce69aff689e ("RISC-V: KVM: Implement VCPU interrupts and requests handling") Reported-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Tested-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-07-11riscv: Fix missing PAGE_PFN_MASKAlexandre Ghiti
There are a bunch of functions that use the PFN from a page table entry that end up with the svpbmt upper-bits because they are missing the newly introduced PAGE_PFN_MASK which leads to wrong addresses conversions and then crash: fix this by adding this mask. Fixes: 100631b48ded ("riscv: Fix accessing pfn bits in PTEs for non-32bit variants") Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-06-24KVM: Allow for different capacities in kvm_mmu_memory_cache structsDavid Matlack
Allow the capacity of the kvm_mmu_memory_cache struct to be chosen at declaration time rather than being fixed for all declarations. This will be used in a follow-up commit to declare an cache in x86 with a capacity of 512+ objects without having to increase the capacity of all caches in KVM. This change requires each cache now specify its capacity at runtime, since the cache struct itself no longer has a fixed capacity known at compile time. To protect against someone accidentally defining a kvm_mmu_memory_cache struct directly (without the extra storage), this commit includes a WARN_ON() in kvm_mmu_topup_memory_cache(). In order to support different capacities, this commit changes the objects pointer array to be dynamically allocated the first time the cache is topped-up. While here, opportunistically clean up the stack-allocated kvm_mmu_memory_cache structs in riscv and arm64 to use designated initializers. No functional change intended. Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20220516232138.1783324-22-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-09RISC-V: KVM: fix typos in commentsJulia Lawall
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Introduce ISA extension registerAtish Patra
Currently, there is no provision for vmm (qemu-kvm or kvmtool) to query about multiple-letter ISA extensions. The config register is only used for base single letter ISA extensions. A new ISA extension register is added that will allow the vmm to query about any ISA extension one at a time. It is enabled for both single letter or multi-letter ISA extensions. The ISA extension register is useful to if the vmm requires to retrieve/set single extension while the config register should be used if all the base ISA extension required to retrieve or set. For any multi-letter ISA extensions, the new register interface must be used. Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Cleanup stale TLB entries when host CPU changesAnup Patel
On RISC-V platforms with hardware VMID support, we share same VMID for all VCPUs of a particular Guest/VM. This means we might have stale G-stage TLB entries on the current Host CPU due to some other VCPU of the same Guest which ran previously on the current Host CPU. To cleanup stale TLB entries, we simply flush all G-stage TLB entries by VMID whenever underlying Host CPU changes for a VCPU. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Add remote HFENCE functions based on VCPU requestsAnup Patel
The generic KVM has support for VCPU requests which can be used to do arch-specific work in the run-loop. We introduce remote HFENCE functions which will internally use VCPU requests instead of host SBI calls. Advantages of doing remote HFENCEs as VCPU requests are: 1) Multiple VCPUs of a Guest may be running on different Host CPUs so it is not always possible to determine the Host CPU mask for doing Host SBI call. For example, when VCPU X wants to do HFENCE on VCPU Y, it is possible that VCPU Y is blocked or in user-space (i.e. vcpu->cpu < 0). 2) To support nested virtualization, we will be having a separate shadow G-stage for each VCPU and a common host G-stage for the entire Guest/VM. The VCPU requests based remote HFENCEs helps us easily synchronize the common host G-stage and shadow G-stage of each VCPU without any additional IPI calls. This is also a preparatory patch for upcoming nested virtualization support where we will be having a shadow G-stage page table for each Guest VCPU. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Introduce range based local HFENCE functionsAnup Patel
Various __kvm_riscv_hfence_xyz() functions implemented in the kvm/tlb.S are equivalent to corresponding HFENCE.GVMA instructions and we don't have range based local HFENCE functions. This patch provides complete set of local HFENCE functions which supports range based TLB invalidation and supports HFENCE.VVMA based functions. This is also a preparatory patch for upcoming Svinval support in KVM RISC-V. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Treat SBI HFENCE calls as NOPsAnup Patel
We should treat SBI HFENCE calls as NOPs until nested virtualization is supported by KVM RISC-V. This will help us test booting a hypervisor under KVM RISC-V. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Add Sv57x4 mode support for G-stageAnup Patel
Latest QEMU supports G-stage Sv57x4 mode so this patch extends KVM RISC-V G-stage handling to detect and use Sv57x4 mode when available. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20RISC-V: KVM: Use G-stage name for hypervisor page tableAnup Patel
The two-stage address translation defined by the RISC-V privileged specification defines: VS-stage (guest virtual address to guest physical address) programmed by the Guest OS and G-stage (guest physical addree to host physical address) programmed by the hypervisor. To align with above terminology, we replace "stage2" with "gstage" and "Stage2" with "G-stage" name everywhere in KVM RISC-V sources. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-29Merge branch 'kvm-fixes-for-5.18-rc5' into HEADPaolo Bonzini
Fixes for (relatively) old bugs, to be merged in both the -rc and next development trees: * Fix potential races when walking host page table * Fix bad user ABI for KVM_EXIT_SYSTEM_EVENT * Fix shadow page table leak when KVM runs nested
2022-04-29KVM: fix bad user ABI for KVM_EXIT_SYSTEM_EVENTPaolo Bonzini
When KVM_EXIT_SYSTEM_EVENT was introduced, it included a flags member that at the time was unused. Unfortunately this extensibility mechanism has several issues: - x86 is not writing the member, so it would not be possible to use it on x86 except for new events - the member is not aligned to 64 bits, so the definition of the uAPI struct is incorrect for 32- on 64-bit userspace. This is a problem for RISC-V, which supports CONFIG_KVM_COMPAT, but fortunately usage of flags was only introduced in 5.18. Since padding has to be introduced, place a new field in there that tells if the flags field is valid. To allow further extensibility, in fact, change flags to an array of 16 values, and store how many of the values are valid. The availability of the new ndata field is tied to a system capability; all architectures are changed to fill in the field. To avoid breaking compilation of userspace that was using the flags field, provide a userspace-only union to overlap flags with data[0]. The new field is placed at the same offset for both 32- and 64-bit userspace. Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Peter Gonda <pgonda@google.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reported-by: kernel test robot <lkp@intel.com> Message-Id: <20220422103013.34832-1-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abusedSean Christopherson
Add wrappers to acquire/release KVM's SRCU lock when stashing the index in vcpu->src_idx, along with rudimentary detection of illegal usage, e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx. Because the SRCU index is (currently) either 0 or 1, illegal nesting bugs can go unnoticed for quite some time and only cause problems when the nested lock happens to get a different index. Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will likely yell so loudly that it will bring the kernel to its knees. Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Fabiano Rosas <farosas@linux.ibm.com> Message-Id: <20220415004343.2203171-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copySean Christopherson
Use the generic kvm_vcpu's srcu_idx instead of using an indentical field in RISC-V's version of kvm_vcpu_arch. Generic KVM very intentionally does not touch vcpu->srcu_idx, i.e. there's zero chance of running afoul of common code. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220415004343.2203171-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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