From: Anup Patel anup.patel@wdc.com
euleros inclusion category: feature bugzilla: NA CVE: NA
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.
Link: https://gitee.com/openeuler/kernel/issues/I1RR1Y 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 Signed-off-by: Mingwang Li limingwang@huawei.com Reviewed-by: Yifei Jiang jiangyifei@huawei.com Signed-off-by: Xie XiuQi xiexiuqi@huawei.com --- arch/riscv/include/asm/kvm_host.h | 9 +- arch/riscv/kernel/asm-offsets.c | 76 ++++++++++++ arch/riscv/kvm/Makefile | 2 +- arch/riscv/kvm/vcpu.c | 30 ++++- arch/riscv/kvm/vcpu_switch.S | 194 ++++++++++++++++++++++++++++++ 5 files changed, 307 insertions(+), 4 deletions(-) create mode 100644 arch/riscv/kvm/vcpu_switch.S
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 7dc52559b4fc..3a8f7b5eafd6 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -120,6 +120,13 @@ struct kvm_vcpu_arch { /* ISA feature bits (similar to MISA) */ unsigned long isa;
+ /* SSCRATCH and STVEC of Host */ + unsigned long host_sscratch; + unsigned long host_stvec; + + /* CPU context of Host */ + struct kvm_cpu_context host_context; + /* CPU context of Guest VCPU */ struct kvm_cpu_context guest_context;
@@ -169,7 +176,7 @@ int kvm_riscv_vcpu_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_cpu_trap *trap);
-static inline void __kvm_riscv_switch_to(struct kvm_vcpu_arch *vcpu_arch) {} +void __kvm_riscv_switch_to(struct kvm_vcpu_arch *vcpu_arch);
int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq); int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq); diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c index 07cb9c10de4e..3a230882b91e 100644 --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -7,7 +7,9 @@ #define GENERATING_ASM_OFFSETS
#include <linux/kbuild.h> +#include <linux/mm.h> #include <linux/sched.h> +#include <asm/kvm_host.h> #include <asm/thread_info.h> #include <asm/ptrace.h>
@@ -109,6 +111,80 @@ void asm_offsets(void) OFFSET(PT_BADADDR, pt_regs, badaddr); OFFSET(PT_CAUSE, pt_regs, cause);
+ OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero); + OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra); + OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp); + OFFSET(KVM_ARCH_GUEST_GP, kvm_vcpu_arch, guest_context.gp); + OFFSET(KVM_ARCH_GUEST_TP, kvm_vcpu_arch, guest_context.tp); + OFFSET(KVM_ARCH_GUEST_T0, kvm_vcpu_arch, guest_context.t0); + OFFSET(KVM_ARCH_GUEST_T1, kvm_vcpu_arch, guest_context.t1); + OFFSET(KVM_ARCH_GUEST_T2, kvm_vcpu_arch, guest_context.t2); + OFFSET(KVM_ARCH_GUEST_S0, kvm_vcpu_arch, guest_context.s0); + OFFSET(KVM_ARCH_GUEST_S1, kvm_vcpu_arch, guest_context.s1); + OFFSET(KVM_ARCH_GUEST_A0, kvm_vcpu_arch, guest_context.a0); + OFFSET(KVM_ARCH_GUEST_A1, kvm_vcpu_arch, guest_context.a1); + OFFSET(KVM_ARCH_GUEST_A2, kvm_vcpu_arch, guest_context.a2); + OFFSET(KVM_ARCH_GUEST_A3, kvm_vcpu_arch, guest_context.a3); + OFFSET(KVM_ARCH_GUEST_A4, kvm_vcpu_arch, guest_context.a4); + OFFSET(KVM_ARCH_GUEST_A5, kvm_vcpu_arch, guest_context.a5); + OFFSET(KVM_ARCH_GUEST_A6, kvm_vcpu_arch, guest_context.a6); + OFFSET(KVM_ARCH_GUEST_A7, kvm_vcpu_arch, guest_context.a7); + OFFSET(KVM_ARCH_GUEST_S2, kvm_vcpu_arch, guest_context.s2); + OFFSET(KVM_ARCH_GUEST_S3, kvm_vcpu_arch, guest_context.s3); + OFFSET(KVM_ARCH_GUEST_S4, kvm_vcpu_arch, guest_context.s4); + OFFSET(KVM_ARCH_GUEST_S5, kvm_vcpu_arch, guest_context.s5); + OFFSET(KVM_ARCH_GUEST_S6, kvm_vcpu_arch, guest_context.s6); + OFFSET(KVM_ARCH_GUEST_S7, kvm_vcpu_arch, guest_context.s7); + OFFSET(KVM_ARCH_GUEST_S8, kvm_vcpu_arch, guest_context.s8); + OFFSET(KVM_ARCH_GUEST_S9, kvm_vcpu_arch, guest_context.s9); + OFFSET(KVM_ARCH_GUEST_S10, kvm_vcpu_arch, guest_context.s10); + OFFSET(KVM_ARCH_GUEST_S11, kvm_vcpu_arch, guest_context.s11); + OFFSET(KVM_ARCH_GUEST_T3, kvm_vcpu_arch, guest_context.t3); + OFFSET(KVM_ARCH_GUEST_T4, kvm_vcpu_arch, guest_context.t4); + OFFSET(KVM_ARCH_GUEST_T5, kvm_vcpu_arch, guest_context.t5); + OFFSET(KVM_ARCH_GUEST_T6, kvm_vcpu_arch, guest_context.t6); + OFFSET(KVM_ARCH_GUEST_SEPC, kvm_vcpu_arch, guest_context.sepc); + OFFSET(KVM_ARCH_GUEST_SSTATUS, kvm_vcpu_arch, guest_context.sstatus); + OFFSET(KVM_ARCH_GUEST_HSTATUS, kvm_vcpu_arch, guest_context.hstatus); + + OFFSET(KVM_ARCH_HOST_ZERO, kvm_vcpu_arch, host_context.zero); + OFFSET(KVM_ARCH_HOST_RA, kvm_vcpu_arch, host_context.ra); + OFFSET(KVM_ARCH_HOST_SP, kvm_vcpu_arch, host_context.sp); + OFFSET(KVM_ARCH_HOST_GP, kvm_vcpu_arch, host_context.gp); + OFFSET(KVM_ARCH_HOST_TP, kvm_vcpu_arch, host_context.tp); + OFFSET(KVM_ARCH_HOST_T0, kvm_vcpu_arch, host_context.t0); + OFFSET(KVM_ARCH_HOST_T1, kvm_vcpu_arch, host_context.t1); + OFFSET(KVM_ARCH_HOST_T2, kvm_vcpu_arch, host_context.t2); + OFFSET(KVM_ARCH_HOST_S0, kvm_vcpu_arch, host_context.s0); + OFFSET(KVM_ARCH_HOST_S1, kvm_vcpu_arch, host_context.s1); + OFFSET(KVM_ARCH_HOST_A0, kvm_vcpu_arch, host_context.a0); + OFFSET(KVM_ARCH_HOST_A1, kvm_vcpu_arch, host_context.a1); + OFFSET(KVM_ARCH_HOST_A2, kvm_vcpu_arch, host_context.a2); + OFFSET(KVM_ARCH_HOST_A3, kvm_vcpu_arch, host_context.a3); + OFFSET(KVM_ARCH_HOST_A4, kvm_vcpu_arch, host_context.a4); + OFFSET(KVM_ARCH_HOST_A5, kvm_vcpu_arch, host_context.a5); + OFFSET(KVM_ARCH_HOST_A6, kvm_vcpu_arch, host_context.a6); + OFFSET(KVM_ARCH_HOST_A7, kvm_vcpu_arch, host_context.a7); + OFFSET(KVM_ARCH_HOST_S2, kvm_vcpu_arch, host_context.s2); + OFFSET(KVM_ARCH_HOST_S3, kvm_vcpu_arch, host_context.s3); + OFFSET(KVM_ARCH_HOST_S4, kvm_vcpu_arch, host_context.s4); + OFFSET(KVM_ARCH_HOST_S5, kvm_vcpu_arch, host_context.s5); + OFFSET(KVM_ARCH_HOST_S6, kvm_vcpu_arch, host_context.s6); + OFFSET(KVM_ARCH_HOST_S7, kvm_vcpu_arch, host_context.s7); + OFFSET(KVM_ARCH_HOST_S8, kvm_vcpu_arch, host_context.s8); + OFFSET(KVM_ARCH_HOST_S9, kvm_vcpu_arch, host_context.s9); + OFFSET(KVM_ARCH_HOST_S10, kvm_vcpu_arch, host_context.s10); + OFFSET(KVM_ARCH_HOST_S11, kvm_vcpu_arch, host_context.s11); + OFFSET(KVM_ARCH_HOST_T3, kvm_vcpu_arch, host_context.t3); + OFFSET(KVM_ARCH_HOST_T4, kvm_vcpu_arch, host_context.t4); + OFFSET(KVM_ARCH_HOST_T5, kvm_vcpu_arch, host_context.t5); + OFFSET(KVM_ARCH_HOST_T6, kvm_vcpu_arch, host_context.t6); + OFFSET(KVM_ARCH_HOST_SEPC, kvm_vcpu_arch, host_context.sepc); + OFFSET(KVM_ARCH_HOST_SSTATUS, kvm_vcpu_arch, host_context.sstatus); + OFFSET(KVM_ARCH_HOST_HSTATUS, kvm_vcpu_arch, host_context.hstatus); + OFFSET(KVM_ARCH_HOST_SSCRATCH, kvm_vcpu_arch, host_sscratch); + OFFSET(KVM_ARCH_HOST_STVEC, kvm_vcpu_arch, host_stvec); + /* * THREAD_{F,X}* might be larger than a S-type offset can handle, but * these are used in performance-sensitive assembly so we can't resort diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index 37b5a59d4f4f..845579273727 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -8,6 +8,6 @@ ccflags-y := -Ivirt/kvm -Iarch/riscv/kvm
kvm-objs := $(common-objs-y)
-kvm-objs += main.o vm.o mmu.o vcpu.o vcpu_exit.o +kvm-objs += main.o vm.o mmu.o vcpu.o vcpu_exit.o vcpu_switch.o
obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 1a692ac4a6f3..faa6f9673691 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -580,14 +580,40 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { - /* TODO: */ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + csr_write(CSR_VSSTATUS, csr->vsstatus); + csr_write(CSR_HIE, csr->hie); + csr_write(CSR_VSTVEC, csr->vstvec); + csr_write(CSR_VSSCRATCH, csr->vsscratch); + csr_write(CSR_VSEPC, csr->vsepc); + csr_write(CSR_VSCAUSE, csr->vscause); + csr_write(CSR_VSTVAL, csr->vstval); + csr_write(CSR_HVIP, csr->hvip); + csr_write(CSR_VSATP, csr->vsatp);
kvm_riscv_stage2_update_hgatp(vcpu); + + vcpu->cpu = cpu; }
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { - /* TODO: */ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + + vcpu->cpu = -1; + + csr_write(CSR_HGATP, 0); + + csr->vsstatus = csr_read(CSR_VSSTATUS); + csr->hie = csr_read(CSR_HIE); + csr->vstvec = csr_read(CSR_VSTVEC); + csr->vsscratch = csr_read(CSR_VSSCRATCH); + csr->vsepc = csr_read(CSR_VSEPC); + csr->vscause = csr_read(CSR_VSCAUSE); + csr->vstval = csr_read(CSR_VSTVAL); + csr->hvip = csr_read(CSR_HVIP); + csr->vsatp = csr_read(CSR_VSATP); }
static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu) diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S new file mode 100644 index 000000000000..e1a17df1b379 --- /dev/null +++ b/arch/riscv/kvm/vcpu_switch.S @@ -0,0 +1,194 @@ +/* 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 SSTATUS, HSTATUS, SCRATCH and STVEC */ + csrr t0, CSR_SSTATUS + REG_S t0, (KVM_ARCH_HOST_SSTATUS)(a0) + csrr t1, CSR_HSTATUS + REG_S t1, (KVM_ARCH_HOST_HSTATUS)(a0) + csrr t2, CSR_SSCRATCH + REG_S t2, (KVM_ARCH_HOST_SSCRATCH)(a0) + csrr t3, CSR_STVEC + REG_S t3, (KVM_ARCH_HOST_STVEC)(a0) + + /* Change Host exception vector to return path */ + la t4, __kvm_switch_return + csrw CSR_STVEC, t4 + + /* Restore Guest HSTATUS, SSTATUS and SEPC */ + REG_L t4, (KVM_ARCH_GUEST_SEPC)(a0) + csrw CSR_SEPC, t4 + REG_L t5, (KVM_ARCH_GUEST_SSTATUS)(a0) + csrw CSR_SSTATUS, t5 + REG_L t6, (KVM_ARCH_GUEST_HSTATUS)(a0) + csrw CSR_HSTATUS, t6 + + /* 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) + + /* Save Host A0 in SSCRATCH */ + csrw CSR_SSCRATCH, 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 A0 */ + csrr t0, CSR_SSCRATCH + REG_S t0, (KVM_ARCH_GUEST_A0)(a0) + + /* Save Guest HSTATUS, SSTATUS, and SEPC */ + csrr t0, CSR_SEPC + REG_S t0, (KVM_ARCH_GUEST_SEPC)(a0) + csrr t1, CSR_SSTATUS + REG_S t1, (KVM_ARCH_GUEST_SSTATUS)(a0) + csrr t2, CSR_HSTATUS + REG_S t2, (KVM_ARCH_GUEST_HSTATUS)(a0) + + /* Restore Host SSTATUS, HSTATUS, SCRATCH and STVEC */ + REG_L t3, (KVM_ARCH_HOST_SSTATUS)(a0) + csrw CSR_SSTATUS, t3 + REG_L t4, (KVM_ARCH_HOST_HSTATUS)(a0) + csrw CSR_HSTATUS, t4 + REG_L t5, (KVM_ARCH_HOST_SSCRATCH)(a0) + csrw CSR_SSCRATCH, t5 + REG_L t6, (KVM_ARCH_HOST_STVEC)(a0) + csrw CSR_STVEC, t6 + + /* 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)