Anup Patel fd7bb4a251 RISC-V: KVM: Implement VMID allocator
We implement a simple VMID allocator for Guests/VMs which:
1. Detects number of VMID bits at boot-time
2. Uses atomic number to track VMID version and increments
   VMID version whenever we run-out of VMIDs
3. Flushes Guest TLBs on all host CPUs whenever we run-out
   of VMIDs
4. Force updates HW Stage2 VMID for each Guest VCPU whenever
   VMID changes using VCPU request KVM_REQ_UPDATE_HGATP

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-04 16:01:04 +05:30

75 lines
1.5 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#include <linux/linkage.h>
#include <asm/asm.h>
.text
.altmacro
.option norelax
/*
* Instruction encoding of hfence.gvma is:
* HFENCE.GVMA rs1, rs2
* HFENCE.GVMA zero, rs2
* HFENCE.GVMA rs1
* HFENCE.GVMA
*
* rs1!=zero and rs2!=zero ==> HFENCE.GVMA rs1, rs2
* rs1==zero and rs2!=zero ==> HFENCE.GVMA zero, rs2
* rs1!=zero and rs2==zero ==> HFENCE.GVMA rs1
* rs1==zero and rs2==zero ==> HFENCE.GVMA
*
* Instruction encoding of HFENCE.GVMA is:
* 0110001 rs2(5) rs1(5) 000 00000 1110011
*/
ENTRY(__kvm_riscv_hfence_gvma_vmid_gpa)
/*
* rs1 = a0 (GPA)
* rs2 = a1 (VMID)
* HFENCE.GVMA a0, a1
* 0110001 01011 01010 000 00000 1110011
*/
.word 0x62b50073
ret
ENDPROC(__kvm_riscv_hfence_gvma_vmid_gpa)
ENTRY(__kvm_riscv_hfence_gvma_vmid)
/*
* rs1 = zero
* rs2 = a0 (VMID)
* HFENCE.GVMA zero, a0
* 0110001 01010 00000 000 00000 1110011
*/
.word 0x62a00073
ret
ENDPROC(__kvm_riscv_hfence_gvma_vmid)
ENTRY(__kvm_riscv_hfence_gvma_gpa)
/*
* rs1 = a0 (GPA)
* rs2 = zero
* HFENCE.GVMA a0
* 0110001 00000 01010 000 00000 1110011
*/
.word 0x62050073
ret
ENDPROC(__kvm_riscv_hfence_gvma_gpa)
ENTRY(__kvm_riscv_hfence_gvma_all)
/*
* rs1 = zero
* rs2 = zero
* HFENCE.GVMA
* 0110001 00000 00000 000 00000 1110011
*/
.word 0x62000073
ret
ENDPROC(__kvm_riscv_hfence_gvma_all)