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path: root/arch/riscv/kvm/tlb.c
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2022-10-02RISC-V: KVM: Use Svinval for local TLB maintenance when availableAnup Patel1-12/+48
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 hfence encodingsAndrew Jones1-112/+17
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>
2022-05-20RISC-V: KVM: Cleanup stale TLB entries when host CPU changesAnup Patel1-0/+23
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 Patel1-1/+226
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 Patel1-0/+213
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>