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author | Anup Patel <anup.patel@wdc.com> | 2021-09-27 14:40:05 +0300 |
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committer | Anup Patel <anup@brainfault.org> | 2021-10-04 13:19:57 +0300 |
commit | 34bde9d8b9e6e5249db3c07cf1ebfe75c23c671c (patch) | |
tree | ff74abdabe5103aae8533e738446e2b0df2be4c8 /arch/riscv/kvm/vcpu_switch.S | |
parent | 92ad82002c39ede73b397d17ba7ab9842517dbe5 (diff) | |
download | linux-34bde9d8b9e6e5249db3c07cf1ebfe75c23c671c.tar.xz |
RISC-V: KVM: Implement VCPU world-switch
This patch implements the VCPU world-switch for KVM RISC-V.
The KVM RISC-V world-switch (i.e. __kvm_riscv_switch_to()) mostly
switches general purpose registers, SSTATUS, STVEC, SSCRATCH and
HSTATUS CSRs. Other CSRs are switched via vcpu_load() and vcpu_put()
interface in kvm_arch_vcpu_load() and kvm_arch_vcpu_put() functions
respectively.
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>
Diffstat (limited to 'arch/riscv/kvm/vcpu_switch.S')
-rw-r--r-- | arch/riscv/kvm/vcpu_switch.S | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S new file mode 100644 index 000000000000..5174b025ff4e --- /dev/null +++ b/arch/riscv/kvm/vcpu_switch.S @@ -0,0 +1,203 @@ +/* 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> +#include <asm/asm-offsets.h> +#include <asm/csr.h> + + .text + .altmacro + .option norelax + +ENTRY(__kvm_riscv_switch_to) + /* Save Host GPRs (except A0 and T0-T6) */ + REG_S ra, (KVM_ARCH_HOST_RA)(a0) + REG_S sp, (KVM_ARCH_HOST_SP)(a0) + REG_S gp, (KVM_ARCH_HOST_GP)(a0) + REG_S tp, (KVM_ARCH_HOST_TP)(a0) + REG_S s0, (KVM_ARCH_HOST_S0)(a0) + REG_S s1, (KVM_ARCH_HOST_S1)(a0) + REG_S a1, (KVM_ARCH_HOST_A1)(a0) + REG_S a2, (KVM_ARCH_HOST_A2)(a0) + REG_S a3, (KVM_ARCH_HOST_A3)(a0) + REG_S a4, (KVM_ARCH_HOST_A4)(a0) + REG_S a5, (KVM_ARCH_HOST_A5)(a0) + REG_S a6, (KVM_ARCH_HOST_A6)(a0) + REG_S a7, (KVM_ARCH_HOST_A7)(a0) + REG_S s2, (KVM_ARCH_HOST_S2)(a0) + REG_S s3, (KVM_ARCH_HOST_S3)(a0) + REG_S s4, (KVM_ARCH_HOST_S4)(a0) + REG_S s5, (KVM_ARCH_HOST_S5)(a0) + REG_S s6, (KVM_ARCH_HOST_S6)(a0) + REG_S s7, (KVM_ARCH_HOST_S7)(a0) + REG_S s8, (KVM_ARCH_HOST_S8)(a0) + REG_S s9, (KVM_ARCH_HOST_S9)(a0) + REG_S s10, (KVM_ARCH_HOST_S10)(a0) + REG_S s11, (KVM_ARCH_HOST_S11)(a0) + + /* Save Host and Restore Guest SSTATUS */ + REG_L t0, (KVM_ARCH_GUEST_SSTATUS)(a0) + csrrw t0, CSR_SSTATUS, t0 + REG_S t0, (KVM_ARCH_HOST_SSTATUS)(a0) + + /* Save Host and Restore Guest HSTATUS */ + REG_L t1, (KVM_ARCH_GUEST_HSTATUS)(a0) + csrrw t1, CSR_HSTATUS, t1 + REG_S t1, (KVM_ARCH_HOST_HSTATUS)(a0) + + /* Save Host and Restore Guest SCOUNTEREN */ + REG_L t2, (KVM_ARCH_GUEST_SCOUNTEREN)(a0) + csrrw t2, CSR_SCOUNTEREN, t2 + REG_S t2, (KVM_ARCH_HOST_SCOUNTEREN)(a0) + + /* Save Host SSCRATCH and change it to struct kvm_vcpu_arch pointer */ + csrrw t3, CSR_SSCRATCH, a0 + REG_S t3, (KVM_ARCH_HOST_SSCRATCH)(a0) + + /* Save Host STVEC and change it to return path */ + la t4, __kvm_switch_return + csrrw t4, CSR_STVEC, t4 + REG_S t4, (KVM_ARCH_HOST_STVEC)(a0) + + /* Restore Guest SEPC */ + REG_L t0, (KVM_ARCH_GUEST_SEPC)(a0) + csrw CSR_SEPC, t0 + + /* Restore Guest GPRs (except A0) */ + REG_L ra, (KVM_ARCH_GUEST_RA)(a0) + REG_L sp, (KVM_ARCH_GUEST_SP)(a0) + REG_L gp, (KVM_ARCH_GUEST_GP)(a0) + REG_L tp, (KVM_ARCH_GUEST_TP)(a0) + REG_L t0, (KVM_ARCH_GUEST_T0)(a0) + REG_L t1, (KVM_ARCH_GUEST_T1)(a0) + REG_L t2, (KVM_ARCH_GUEST_T2)(a0) + REG_L s0, (KVM_ARCH_GUEST_S0)(a0) + REG_L s1, (KVM_ARCH_GUEST_S1)(a0) + REG_L a1, (KVM_ARCH_GUEST_A1)(a0) + REG_L a2, (KVM_ARCH_GUEST_A2)(a0) + REG_L a3, (KVM_ARCH_GUEST_A3)(a0) + REG_L a4, (KVM_ARCH_GUEST_A4)(a0) + REG_L a5, (KVM_ARCH_GUEST_A5)(a0) + REG_L a6, (KVM_ARCH_GUEST_A6)(a0) + REG_L a7, (KVM_ARCH_GUEST_A7)(a0) + REG_L s2, (KVM_ARCH_GUEST_S2)(a0) + REG_L s3, (KVM_ARCH_GUEST_S3)(a0) + REG_L s4, (KVM_ARCH_GUEST_S4)(a0) + REG_L s5, (KVM_ARCH_GUEST_S5)(a0) + REG_L s6, (KVM_ARCH_GUEST_S6)(a0) + REG_L s7, (KVM_ARCH_GUEST_S7)(a0) + REG_L s8, (KVM_ARCH_GUEST_S8)(a0) + REG_L s9, (KVM_ARCH_GUEST_S9)(a0) + REG_L s10, (KVM_ARCH_GUEST_S10)(a0) + REG_L s11, (KVM_ARCH_GUEST_S11)(a0) + REG_L t3, (KVM_ARCH_GUEST_T3)(a0) + REG_L t4, (KVM_ARCH_GUEST_T4)(a0) + REG_L t5, (KVM_ARCH_GUEST_T5)(a0) + REG_L t6, (KVM_ARCH_GUEST_T6)(a0) + + /* Restore Guest A0 */ + REG_L a0, (KVM_ARCH_GUEST_A0)(a0) + + /* Resume Guest */ + sret + + /* Back to Host */ + .align 2 +__kvm_switch_return: + /* Swap Guest A0 with SSCRATCH */ + csrrw a0, CSR_SSCRATCH, a0 + + /* Save Guest GPRs (except A0) */ + REG_S ra, (KVM_ARCH_GUEST_RA)(a0) + REG_S sp, (KVM_ARCH_GUEST_SP)(a0) + REG_S gp, (KVM_ARCH_GUEST_GP)(a0) + REG_S tp, (KVM_ARCH_GUEST_TP)(a0) + REG_S t0, (KVM_ARCH_GUEST_T0)(a0) + REG_S t1, (KVM_ARCH_GUEST_T1)(a0) + REG_S t2, (KVM_ARCH_GUEST_T2)(a0) + REG_S s0, (KVM_ARCH_GUEST_S0)(a0) + REG_S s1, (KVM_ARCH_GUEST_S1)(a0) + REG_S a1, (KVM_ARCH_GUEST_A1)(a0) + REG_S a2, (KVM_ARCH_GUEST_A2)(a0) + REG_S a3, (KVM_ARCH_GUEST_A3)(a0) + REG_S a4, (KVM_ARCH_GUEST_A4)(a0) + REG_S a5, (KVM_ARCH_GUEST_A5)(a0) + REG_S a6, (KVM_ARCH_GUEST_A6)(a0) + REG_S a7, (KVM_ARCH_GUEST_A7)(a0) + REG_S s2, (KVM_ARCH_GUEST_S2)(a0) + REG_S s3, (KVM_ARCH_GUEST_S3)(a0) + REG_S s4, (KVM_ARCH_GUEST_S4)(a0) + REG_S s5, (KVM_ARCH_GUEST_S5)(a0) + REG_S s6, (KVM_ARCH_GUEST_S6)(a0) + REG_S s7, (KVM_ARCH_GUEST_S7)(a0) + REG_S s8, (KVM_ARCH_GUEST_S8)(a0) + REG_S s9, (KVM_ARCH_GUEST_S9)(a0) + REG_S s10, (KVM_ARCH_GUEST_S10)(a0) + REG_S s11, (KVM_ARCH_GUEST_S11)(a0) + REG_S t3, (KVM_ARCH_GUEST_T3)(a0) + REG_S t4, (KVM_ARCH_GUEST_T4)(a0) + REG_S t5, (KVM_ARCH_GUEST_T5)(a0) + REG_S t6, (KVM_ARCH_GUEST_T6)(a0) + + /* Save Guest SEPC */ + csrr t0, CSR_SEPC + REG_S t0, (KVM_ARCH_GUEST_SEPC)(a0) + + /* Restore Host STVEC */ + REG_L t1, (KVM_ARCH_HOST_STVEC)(a0) + csrw CSR_STVEC, t1 + + /* Save Guest A0 and Restore Host SSCRATCH */ + REG_L t2, (KVM_ARCH_HOST_SSCRATCH)(a0) + csrrw t2, CSR_SSCRATCH, t2 + REG_S t2, (KVM_ARCH_GUEST_A0)(a0) + + /* Save Guest and Restore Host SCOUNTEREN */ + REG_L t3, (KVM_ARCH_HOST_SCOUNTEREN)(a0) + csrrw t3, CSR_SCOUNTEREN, t3 + REG_S t3, (KVM_ARCH_GUEST_SCOUNTEREN)(a0) + + /* Save Guest and Restore Host HSTATUS */ + REG_L t4, (KVM_ARCH_HOST_HSTATUS)(a0) + csrrw t4, CSR_HSTATUS, t4 + REG_S t4, (KVM_ARCH_GUEST_HSTATUS)(a0) + + /* Save Guest and Restore Host SSTATUS */ + REG_L t5, (KVM_ARCH_HOST_SSTATUS)(a0) + csrrw t5, CSR_SSTATUS, t5 + REG_S t5, (KVM_ARCH_GUEST_SSTATUS)(a0) + + /* Restore Host GPRs (except A0 and T0-T6) */ + REG_L ra, (KVM_ARCH_HOST_RA)(a0) + REG_L sp, (KVM_ARCH_HOST_SP)(a0) + REG_L gp, (KVM_ARCH_HOST_GP)(a0) + REG_L tp, (KVM_ARCH_HOST_TP)(a0) + REG_L s0, (KVM_ARCH_HOST_S0)(a0) + REG_L s1, (KVM_ARCH_HOST_S1)(a0) + REG_L a1, (KVM_ARCH_HOST_A1)(a0) + REG_L a2, (KVM_ARCH_HOST_A2)(a0) + REG_L a3, (KVM_ARCH_HOST_A3)(a0) + REG_L a4, (KVM_ARCH_HOST_A4)(a0) + REG_L a5, (KVM_ARCH_HOST_A5)(a0) + REG_L a6, (KVM_ARCH_HOST_A6)(a0) + REG_L a7, (KVM_ARCH_HOST_A7)(a0) + REG_L s2, (KVM_ARCH_HOST_S2)(a0) + REG_L s3, (KVM_ARCH_HOST_S3)(a0) + REG_L s4, (KVM_ARCH_HOST_S4)(a0) + REG_L s5, (KVM_ARCH_HOST_S5)(a0) + REG_L s6, (KVM_ARCH_HOST_S6)(a0) + REG_L s7, (KVM_ARCH_HOST_S7)(a0) + REG_L s8, (KVM_ARCH_HOST_S8)(a0) + REG_L s9, (KVM_ARCH_HOST_S9)(a0) + REG_L s10, (KVM_ARCH_HOST_S10)(a0) + REG_L s11, (KVM_ARCH_HOST_S11)(a0) + + /* Return to C code */ + ret +ENDPROC(__kvm_riscv_switch_to) |