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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>
2022-04-20RISC-V: KVM: Restrict the extensions that can be disabledAtish Patra
Currently, the config isa register allows us to disable all allowed single letter ISA extensions. It shouldn't be the case as vmm shouldn't be able to disable base extensions (imac). These extensions should always be enabled as long as they are enabled in the host ISA. Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org> Fixes: 92ad82002c39 ("RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls")
2022-04-20RISC-V: KVM: Remove 's' & 'u' as valid ISA extensionAtish Patra
There are no ISA extension defined as 's' & 'u' in RISC-V specifications. The misa register defines 's' & 'u' bit as Supervisor/User privilege mode enabled. But it should not appear in the ISA extension in the device tree. Remove those from the allowed ISA extension for kvm. Fixes: a33c72faf2d7 ("RISC-V: KVM: Implement VCPU create, init and destroy functions") Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-09RISC-V: KVM: include missing hwcap.h into vcpu_fpHeiko Stuebner
vcpu_fp uses the riscv_isa_extension mechanism which gets defined in hwcap.h but doesn't include that head file. While it seems to work in most cases, in certain conditions this can lead to build failures like ../arch/riscv/kvm/vcpu_fp.c: In function ‘kvm_riscv_vcpu_fp_reset’: ../arch/riscv/kvm/vcpu_fp.c:22:13: error: implicit declaration of function ‘riscv_isa_extension_available’ [-Werror=implicit-function-declaration] 22 | if (riscv_isa_extension_available(&isa, f) || | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../arch/riscv/kvm/vcpu_fp.c:22:49: error: ‘f’ undeclared (first use in this function) 22 | if (riscv_isa_extension_available(&isa, f) || Fix this by simply including the necessary header. Fixes: 0a86512dc113 ("RISC-V: KVM: Factor-out FP virtualization into separate sources") Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-09RISC-V: KVM: Don't clear hgatp CSR in kvm_arch_vcpu_put()Anup Patel
We might have RISC-V systems (such as QEMU) where VMID is not part of the TLB entry tag so these systems will have to flush all TLB entries upon any change in hgatp.VMID. Currently, we zero-out hgatp CSR in kvm_arch_vcpu_put() and we re-program hgatp CSR in kvm_arch_vcpu_load(). For above described systems, this will flush all TLB entries whenever VCPU exits to user-space hence reducing performance. This patch fixes above described performance issue by not clearing hgatp CSR in kvm_arch_vcpu_put(). Fixes: 34bde9d8b9e6 ("RISC-V: KVM: Implement VCPU world-switch") Cc: stable@vger.kernel.org Signed-off-by: Anup Patel <apatel@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11RISC-V: KVM: Implement SBI HSM suspend callAnup Patel
The SBI v0.3 specification extends SBI HSM extension by adding SBI HSM suspend call and related HART states. This patch extends the KVM RISC-V HSM implementation to provide KVM guest a minimal SBI HSM suspend call which is equivalent to a WFI instruction. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() functionAnup Patel
The wait for interrupt (WFI) instruction emulation can share the VCPU halt logic with SBI HSM suspend emulation so this patch adds a common kvm_riscv_vcpu_wfi() function 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>
2022-03-11RISC-V: Add SBI HSM suspend related definesAnup Patel
We add defines related to SBI HSM suspend call and also update HSM states naming as-per the latest SBI specification. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11RISC-V: KVM: Implement SBI v0.3 SRST extensionAnup Patel
The SBI v0.3 specification defines SRST (System Reset) extension which provides a standard poweroff and reboot interface. This patch implements SRST extension for the KVM Guest. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11RISC-V: KVM: Add common kvm_riscv_vcpu_sbi_system_reset() functionAnup Patel
We rename kvm_sbi_system_shutdown() to kvm_riscv_vcpu_sbi_system_reset() and move it to vcpu_sbi.c so that it can be shared by SBI v0.1 shutdown and SBI v0.3 SRST extension. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11RISC-V: KVM: Refine __kvm_riscv_switch_to() implementationVincent Chen
Kernel uses __kvm_riscv_switch_to() and __kvm_switch_return() to switch the context of host kernel and guest kernel. Several CSRs belonging to the context will be read and written during the context switch. To ensure atomic read-modify-write control of CSR and ordering of CSR accesses, some hardware blocks flush the pipeline when writing a CSR. In this circumstance, grouping CSR executions together as much as possible can reduce the performance impact of the pipeline. Therefore, this commit reorders the CSR instructions to enhance the context switch performance.. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Suggested-by: Hsinyi Lee <hsinyi.lee@sifive.com> Suggested-by: Fu-Ching Yang <fu-ching.yang@sifive.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11RISC-V: KVM: remove unneeded semicolonYang Li
Eliminate the following coccicheck warning: ./arch/riscv/kvm/vcpu_sbi_v01.c:117:2-3: Unneeded semicolon Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-02-05Merge tag 'kvmarm-fixes-5.17-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.17, take #2 - A couple of fixes when handling an exception while a SError has been delivered - Workaround for Cortex-A510's single-step[ erratum
2022-02-02RISC-V: KVM: Fix SBI implementation versionAnup Patel
The SBI implementation version returned by KVM RISC-V should be the Host Linux version code. Fixes: c62a76859723 ("RISC-V: KVM: Add SBI v0.2 base extension") Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-02-02RISC-V: KVM: make CY, TM, and IR counters accessible in VU modeMayuresh Chitale
Those applications that run in VU mode and access the time CSR cause a virtual instruction trap as Guest kernel currently does not initialize the scounteren CSR. To fix this, we should make CY, TM, and IR counters accessibile by default in VU mode (similar to OpenSBI). Fixes: a33c72faf2d73 ("RISC-V: KVM: Implement VCPU create, init and destroy functions") Cc: stable@vger.kernel.org Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-02-02kvm/riscv: rework guest entry logicMark Rutland
In kvm_arch_vcpu_ioctl_run() we enter an RCU extended quiescent state (EQS) by calling guest_enter_irqoff(), and unmask IRQs prior to exiting the EQS by calling guest_exit(). As the IRQ entry code will not wake RCU in this case, we may run the core IRQ code and IRQ handler without RCU watching, leading to various potential problems. Additionally, we do not inform lockdep or tracing that interrupts will be enabled during guest execution, which caan lead to misleading traces and warnings that interrupts have been enabled for overly-long periods. This patch fixes these issues by using the new timing and context entry/exit helpers to ensure that interrupts are handled during guest vtime but with RCU watching, with a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); Since instrumentation may make use of RCU, we must also ensure that no instrumented code is run during the EQS. I've split out the critical section into a new kvm_riscv_enter_exit_vcpu() helper which is marked noinstr. Fixes: 99cdc6c18c2d815e ("RISC-V: Add initial skeletal KVM support") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anup Patel <anup@brainfault.org> Cc: Atish Patra <atishp@atishpatra.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Tested-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-01-20RISC-V: Do not use cpumask data structure for hartid bitmapAtish Patra
Currently, SBI APIs accept a hartmask that is generated from struct cpumask. Cpumask data structure can hold upto NR_CPUs value. Thus, it is not the correct data structure for hartids as it can be higher than NR_CPUs for platforms with sparse or discontguous hartids. Remove all association between hartid mask and struct cpumask. Reviewed-by: Anup Patel <anup@brainfault.org> (For Linux RISC-V changes) Acked-by: Anup Patel <anup@brainfault.org> (For KVM RISC-V changes) Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-06KVM: RISC-V: Avoid spurious virtual interrupts after clearing hideleg CSRVincent Chen
When the last VM is terminated, the host kernel will invoke function hardware_disable_nolock() on each CPU to disable the related virtualization functions. Here, RISC-V currently only clears hideleg CSR and hedeleg CSR. This behavior will cause the host kernel to receive spurious interrupts if hvip CSR has pending interrupts and the corresponding enable bits in vsie CSR are asserted. To avoid it, hvip CSR and vsie CSR must be cleared before clearing hideleg CSR. Fixes: 99cdc6c18c2d ("RISC-V: Add initial skeletal KVM support") Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06RISC-V: KVM: Add VM capability to allow userspace get GPA bitsAnup Patel
The number of GPA bits supported for a RISC-V Guest/VM is based on the MMU mode used by the G-stage translation. The KVM RISC-V will detect and use the best possible MMU mode for the G-stage in kvm_arch_init(). We add a generic VM capability KVM_CAP_VM_GPA_BITS which can be used by the KVM userspace to get the number of GPA (guest physical address) bits supported for a Guest/VM. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-and-tested-by: Atish Patra <atishp@rivosinc.com>
2022-01-06RISC-V: KVM: Forward SBI experimental and vendor extensionsAnup Patel
The SBI experimental extension space is for temporary (or experimental) stuff whereas SBI vendor extension space is for hardware vendor specific stuff. Both these SBI extension spaces won't be standardized by the SBI specification so let's blindly forward such SBI calls to the userspace. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-and-tested-by: Atish Patra <atishp@rivosinc.com>
2022-01-06RISC-V: KVM: make kvm_riscv_vcpu_fp_clean() staticJisheng Zhang
There are no users outside vcpu_fp.c so make kvm_riscv_vcpu_fp_clean() static. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06RISC-V: KVM: Add SBI HSM extension in KVMAtish Patra
SBI HSM extension allows OS to start/stop harts any time. It also allows ordered booting of harts instead of random booting. Implement SBI HSM exntesion and designate the vcpu 0 as the boot vcpu id. All other non-zero non-booting vcpus should be brought up by the OS implementing HSM extension. If the guest OS doesn't implement HSM extension, only single vcpu will be available to OS. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2Atish Patra
The SBI v0.2 contains some of the improved versions of required v0.1 extensions such as remote fence, timer and IPI. This patch implements those extensions. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06RISC-V: KVM: Add SBI v0.2 base extensionAtish Patra
SBI v0.2 base extension defined to allow backward compatibility and probing of future extensions. This is also the only mandatory SBI extension that must be implemented by SBI implementors. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own fileAtish Patra
With SBI v0.2, there may be more SBI extensions in future. It makes more sense to group related extensions in separate files. Guest kernel will choose appropriate SBI version dynamically. Move the existing implementation to a separate file so that it can be removed in future without much conflict. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06RISC-V: KVM: Mark the existing SBI implementation as v0.1Atish Patra
The existing SBI specification impelementation follows v0.1 specification. The latest specification allows more scalability and performance improvements. Rename the existing implementation as v0.1 and provide a way to allow future extensions. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06KVM: RISC-V: Use common KVM implementation of MMU memory cachesSean Christopherson
Use common KVM's implementation of the MMU memory caches, which for all intents and purposes is semantically identical to RISC-V's version, the only difference being that the common implementation will fall back to an atomic allocation if there's a KVM bug that triggers a cache underflow. RISC-V appears to have based its MMU code on arm64 before the conversion to the common caches in commit c1a33aebe91d ("KVM: arm64: Use common KVM implementation of MMU memory caches"), despite having also copy-pasted the definition of KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE in kvm_types.h. Opportunistically drop the superfluous wrapper kvm_riscv_stage2_flush_cache(), whose name is very, very confusing as "cache flush" in the context of MMU code almost always refers to flushing hardware caches, not freeing unused software objects. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-12-09KVM: RISC-V: Use Makefile.kvm for common filesDavid Woodhouse
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211121125451.9489-6-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: Rename kvm_vcpu_block() => kvm_vcpu_halt()Sean Christopherson
Rename kvm_vcpu_block() to kvm_vcpu_halt() in preparation for splitting the actual "block" sequences into a separate helper (to be named kvm_vcpu_block()). x86 will use the standalone block-only path to handle non-halt cases where the vCPU is not runnable. Rename block_ns to halt_ns to match the new function name. No functional change intended. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: Stop passing kvm_userspace_memory_region to arch memslot hooksSean Christopherson
Drop the @mem param from kvm_arch_{prepare,commit}_memory_region() now that its use has been removed in all architectures. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <aa5ed3e62c27e881d0d8bc0acbc1572bc336dc19.1638817640.git.maciej.szmigiero@oracle.com>