diff options
Diffstat (limited to 'arch/riscv/kvm/vcpu_switch.S')
| -rw-r--r-- | arch/riscv/kvm/vcpu_switch.S | 137 |
1 files changed, 87 insertions, 50 deletions
diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S index 0c26189aa01c..47686bcb21e0 100644 --- a/arch/riscv/kvm/vcpu_switch.S +++ b/arch/riscv/kvm/vcpu_switch.S @@ -11,11 +11,7 @@ #include <asm/asm-offsets.h> #include <asm/csr.h> - .text - .altmacro - .option norelax - -SYM_FUNC_START(__kvm_riscv_switch_to) +.macro SAVE_HOST_GPRS /* Save Host GPRs (except A0 and T0-T6) */ REG_S ra, (KVM_ARCH_HOST_RA)(a0) REG_S sp, (KVM_ARCH_HOST_SP)(a0) @@ -40,39 +36,33 @@ SYM_FUNC_START(__kvm_riscv_switch_to) REG_S s9, (KVM_ARCH_HOST_S9)(a0) REG_S s10, (KVM_ARCH_HOST_S10)(a0) REG_S s11, (KVM_ARCH_HOST_S11)(a0) +.endm +.macro SAVE_HOST_AND_RESTORE_GUEST_CSRS __resume_addr /* Load Guest CSR values */ REG_L t0, (KVM_ARCH_GUEST_SSTATUS)(a0) - REG_L t1, (KVM_ARCH_GUEST_HSTATUS)(a0) - REG_L t2, (KVM_ARCH_GUEST_SCOUNTEREN)(a0) - la t4, .Lkvm_switch_return - REG_L t5, (KVM_ARCH_GUEST_SEPC)(a0) + la t1, \__resume_addr + REG_L t2, (KVM_ARCH_GUEST_SEPC)(a0) /* Save Host and Restore Guest SSTATUS */ csrrw t0, CSR_SSTATUS, t0 - /* Save Host and Restore Guest HSTATUS */ - csrrw t1, CSR_HSTATUS, t1 - - /* Save Host and Restore Guest SCOUNTEREN */ - csrrw t2, CSR_SCOUNTEREN, t2 - /* Save Host STVEC and change it to return path */ - csrrw t4, CSR_STVEC, t4 + csrrw t1, CSR_STVEC, t1 + + /* Restore Guest SEPC */ + csrw CSR_SEPC, t2 /* Save Host SSCRATCH and change it to struct kvm_vcpu_arch pointer */ csrrw t3, CSR_SSCRATCH, a0 - /* Restore Guest SEPC */ - csrw CSR_SEPC, t5 - /* Store Host CSR values */ REG_S t0, (KVM_ARCH_HOST_SSTATUS)(a0) - REG_S t1, (KVM_ARCH_HOST_HSTATUS)(a0) - REG_S t2, (KVM_ARCH_HOST_SCOUNTEREN)(a0) + REG_S t1, (KVM_ARCH_HOST_STVEC)(a0) REG_S t3, (KVM_ARCH_HOST_SSCRATCH)(a0) - REG_S t4, (KVM_ARCH_HOST_STVEC)(a0) +.endm +.macro RESTORE_GUEST_GPRS /* Restore Guest GPRs (except A0) */ REG_L ra, (KVM_ARCH_GUEST_RA)(a0) REG_L sp, (KVM_ARCH_GUEST_SP)(a0) @@ -107,13 +97,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to) /* Restore Guest A0 */ REG_L a0, (KVM_ARCH_GUEST_A0)(a0) +.endm - /* Resume Guest */ - sret - - /* Back to Host */ - .align 2 -.Lkvm_switch_return: +.macro SAVE_GUEST_GPRS /* Swap Guest A0 with SSCRATCH */ csrrw a0, CSR_SSCRATCH, a0 @@ -148,39 +134,33 @@ SYM_FUNC_START(__kvm_riscv_switch_to) REG_S t4, (KVM_ARCH_GUEST_T4)(a0) REG_S t5, (KVM_ARCH_GUEST_T5)(a0) REG_S t6, (KVM_ARCH_GUEST_T6)(a0) +.endm +.macro SAVE_GUEST_AND_RESTORE_HOST_CSRS /* Load Host CSR values */ - REG_L t1, (KVM_ARCH_HOST_STVEC)(a0) - REG_L t2, (KVM_ARCH_HOST_SSCRATCH)(a0) - REG_L t3, (KVM_ARCH_HOST_SCOUNTEREN)(a0) - REG_L t4, (KVM_ARCH_HOST_HSTATUS)(a0) - REG_L t5, (KVM_ARCH_HOST_SSTATUS)(a0) - - /* Save Guest SEPC */ - csrr t0, CSR_SEPC + REG_L t0, (KVM_ARCH_HOST_STVEC)(a0) + REG_L t1, (KVM_ARCH_HOST_SSCRATCH)(a0) + REG_L t2, (KVM_ARCH_HOST_SSTATUS)(a0) /* Save Guest A0 and Restore Host SSCRATCH */ - csrrw t2, CSR_SSCRATCH, t2 + csrrw t1, CSR_SSCRATCH, t1 - /* Restore Host STVEC */ - csrw CSR_STVEC, t1 - - /* Save Guest and Restore Host SCOUNTEREN */ - csrrw t3, CSR_SCOUNTEREN, t3 + /* Save Guest SEPC */ + csrr t3, CSR_SEPC - /* Save Guest and Restore Host HSTATUS */ - csrrw t4, CSR_HSTATUS, t4 + /* Restore Host STVEC */ + csrw CSR_STVEC, t0 /* Save Guest and Restore Host SSTATUS */ - csrrw t5, CSR_SSTATUS, t5 + csrrw t2, CSR_SSTATUS, t2 /* Store Guest CSR values */ - REG_S t0, (KVM_ARCH_GUEST_SEPC)(a0) - REG_S t2, (KVM_ARCH_GUEST_A0)(a0) - REG_S t3, (KVM_ARCH_GUEST_SCOUNTEREN)(a0) - REG_S t4, (KVM_ARCH_GUEST_HSTATUS)(a0) - REG_S t5, (KVM_ARCH_GUEST_SSTATUS)(a0) + REG_S t1, (KVM_ARCH_GUEST_A0)(a0) + REG_S t2, (KVM_ARCH_GUEST_SSTATUS)(a0) + REG_S t3, (KVM_ARCH_GUEST_SEPC)(a0) +.endm +.macro RESTORE_HOST_GPRS /* Restore Host GPRs (except A0 and T0-T6) */ REG_L ra, (KVM_ARCH_HOST_RA)(a0) REG_L sp, (KVM_ARCH_HOST_SP)(a0) @@ -205,11 +185,68 @@ SYM_FUNC_START(__kvm_riscv_switch_to) REG_L s9, (KVM_ARCH_HOST_S9)(a0) REG_L s10, (KVM_ARCH_HOST_S10)(a0) REG_L s11, (KVM_ARCH_HOST_S11)(a0) +.endm + + .text + .altmacro + .option norelax + + /* + * Parameters: + * A0 <= Pointer to struct kvm_vcpu_arch + */ +SYM_FUNC_START(__kvm_riscv_switch_to) + SAVE_HOST_GPRS + + SAVE_HOST_AND_RESTORE_GUEST_CSRS .Lkvm_switch_return + + RESTORE_GUEST_GPRS + + /* Resume Guest using SRET */ + sret + + /* Back to Host */ + .align 2 +.Lkvm_switch_return: + SAVE_GUEST_GPRS + + SAVE_GUEST_AND_RESTORE_HOST_CSRS + + RESTORE_HOST_GPRS /* Return to C code */ ret SYM_FUNC_END(__kvm_riscv_switch_to) + /* + * Parameters: + * A0 <= Pointer to struct kvm_vcpu_arch + * A1 <= SBI extension ID + * A2 <= SBI function ID + */ +SYM_FUNC_START(__kvm_riscv_nacl_switch_to) + SAVE_HOST_GPRS + + SAVE_HOST_AND_RESTORE_GUEST_CSRS .Lkvm_nacl_switch_return + + /* Resume Guest using SBI nested acceleration */ + add a6, a2, zero + add a7, a1, zero + ecall + + /* Back to Host */ + .align 2 +.Lkvm_nacl_switch_return: + SAVE_GUEST_GPRS + + SAVE_GUEST_AND_RESTORE_HOST_CSRS + + RESTORE_HOST_GPRS + + /* Return to C code */ + ret +SYM_FUNC_END(__kvm_riscv_nacl_switch_to) + SYM_CODE_START(__kvm_riscv_unpriv_trap) /* * We assume that faulting unpriv load/store instruction is |