On Fri, Jul 19, 2024 at 9:09 AM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote: > > Break down the __kvm_riscv_switch_to() function into macros so that > these macros can be later re-used by SBI NACL extension based low-level > switch function. > > Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx> > --- > arch/riscv/kvm/vcpu_switch.S | 52 +++++++++++++++++++++++++++--------- > 1 file changed, 40 insertions(+), 12 deletions(-) > > diff --git a/arch/riscv/kvm/vcpu_switch.S b/arch/riscv/kvm/vcpu_switch.S > index 3f8cbc21a644..9f13e5ce6a18 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) > @@ -40,10 +36,12 @@ 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) > - la t1, .Lkvm_switch_return > + la t1, \__resume_addr > REG_L t2, (KVM_ARCH_GUEST_SEPC)(a0) > > /* Save Host and Restore Guest SSTATUS */ > @@ -62,7 +60,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to) > REG_S t0, (KVM_ARCH_HOST_SSTATUS)(a0) > REG_S t1, (KVM_ARCH_HOST_STVEC)(a0) > REG_S t3, (KVM_ARCH_HOST_SSCRATCH)(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) > @@ -97,13 +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 > > @@ -138,7 +134,9 @@ 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 t0, (KVM_ARCH_HOST_STVEC)(a0) > REG_L t1, (KVM_ARCH_HOST_SSCRATCH)(a0) > @@ -160,7 +158,9 @@ SYM_FUNC_START(__kvm_riscv_switch_to) > 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) > @@ -185,6 +185,34 @@ 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 > -- > 2.34.1 > Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx> -- Regards, Atish
