[RFC 07/55] KVM: arm/arm64: Add virtual EL2 state emulation framework

Bandan Das
2017-06-01T20:05:49Z

Jintack Lim <jintack@cs.columbia.edu> writes:
...
> +/**
> + * kvm_arm_setup_shadow_state -- prepare shadow state based on emulated mode
> + * @vcpu: The VCPU pointer
> + */
> +void kvm_arm_setup_shadow_state(struct kvm_vcpu *vcpu)
> +{
> + struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
> +
> + ctxt->hw_pstate = *vcpu_cpsr(vcpu);
> + ctxt->hw_sys_regs = ctxt->sys_regs;
> + ctxt->hw_sp_el1 = ctxt->gp_regs.sp_el1;
> +}
> +
> +/**
> + * kvm_arm_restore_shadow_state -- write back shadow state from guest
> + * @vcpu: The VCPU pointer
> + */
> +void kvm_arm_restore_shadow_state(struct kvm_vcpu *vcpu)
> +{
> + struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
> +
> + *vcpu_cpsr(vcpu) = ctxt->hw_pstate;
> + ctxt->gp_regs.sp_el1 = ctxt->hw_sp_el1;
> +}
> +
> +void kvm_arm_init_cpu_context(kvm_cpu_context_t *cpu_ctxt)
> +{
> + cpu_ctxt->hw_sys_regs = &cpu_ctxt->sys_regs[0];
> +}

IIUC, the *_shadow_state() functions will set hw_* pointers to
either point to the "real" state or the shadow state to manage L2 ?
Maybe, it might make sense to make these function names a little more
generic since they are not dealing with setting the shadow state
alone.

> diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
> index 9341376..f2a1b32 100644
> --- a/arch/arm64/kvm/hyp/sysreg-sr.c
> +++ b/arch/arm64/kvm/hyp/sysreg-sr.c
> @@ -19,6 +19,7 @@
> #include <linux/kvm_host.h>
>
> #include <asm/kvm_asm.h>
> +#include <asm/kvm_emulate.h>
> #include <asm/kvm_hyp.h>
>
> /* Yes, this does nothing, on purpose */
> @@ -33,37 +34,41 @@ static void __hyp_text __sysreg_do_nothing(struct kvm_cpu_context *ctxt) { }
>
> static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
> {
> - ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
> - ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
> - ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
> - ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
> - ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
> + u64 *sys_regs = kern_hyp_va(ctxt->hw_sys_regs);
> +
> + sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
> + sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
> + sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
> + sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
> + sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
> ctxt->gp_regs.regs.sp = read_sysreg(sp_el0);
> ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
> - ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
> + ctxt->hw_pstate = read_sysreg_el2(spsr);
> }
>
> static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
> {
> - ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2);
> - ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
> - ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr);
> - ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr);
> - ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0);
> - ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1);
> - ctxt->sys_regs[TCR_EL1] = read_sysreg_el1(tcr);
> - ctxt->sys_regs[ESR_EL1] = read_sysreg_el1(esr);
> - ctxt->sys_regs[AFSR0_EL1] = read_sysreg_el1(afsr0);
> - ctxt->sys_regs[AFSR1_EL1] = read_sysreg_el1(afsr1);
> - ctxt->sys_regs[FAR_EL1] = read_sysreg_el1(far);
> - ctxt->sys_regs[MAIR_EL1] = read_sysreg_el1(mair);
> - ctxt->sys_regs[VBAR_EL1] = read_sysreg_el1(vbar);
> - ctxt->sys_regs[CONTEXTIDR_EL1] = read_sysreg_el1(contextidr);
> - ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
> - ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
> - ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
> -
> - ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
> + u64 *sys_regs = kern_hyp_va(ctxt->hw_sys_regs);
> +
> + sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2);
> + sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
> + sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr);
> + sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr);
> + sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0);
> + sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1);
> + sys_regs[TCR_EL1] = read_sysreg_el1(tcr);
> + sys_regs[ESR_EL1] = read_sysreg_el1(esr);
> + sys_regs[AFSR0_EL1] = read_sysreg_el1(afsr0);
> + sys_regs[AFSR1_EL1] = read_sysreg_el1(afsr1);
> + sys_regs[FAR_EL1] = read_sysreg_el1(far);
> + sys_regs[MAIR_EL1] = read_sysreg_el1(mair);
> + sys_regs[VBAR_EL1] = read_sysreg_el1(vbar);
> + sys_regs[CONTEXTIDR_EL1] = read_sysreg_el1(contextidr);
> + sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
> + sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
> + sys_regs[PAR_EL1] = read_sysreg(par_el1);
> +
> + ctxt->hw_sp_el1 = read_sysreg(sp_el1);
> ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
> ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
> }
> @@ -86,37 +91,41 @@ void __hyp_text __sysreg_save_guest_state(struct kvm_cpu_context *ctxt)
>
> static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
> {
> - write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
> - write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
> - write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
> - write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
> - write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
> + u64 *sys_regs = kern_hyp_va(ctxt->hw_sys_regs);
> +
> + write_sysreg(sys_regs[ACTLR_EL1], actlr_el1);
> + write_sysreg(sys_regs[TPIDR_EL0], tpidr_el0);
> + write_sysreg(sys_regs[TPIDRRO_EL0], tpidrro_el0);
> + write_sysreg(sys_regs[TPIDR_EL1], tpidr_el1);
> + write_sysreg(sys_regs[MDSCR_EL1], mdscr_el1);
> write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
> write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
> - write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
> + write_sysreg_el2(ctxt->hw_pstate, spsr);
> }
>
> static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
> {
> - write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
> - write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
> - write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr);
> - write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr);
> - write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], ttbr0);
> - write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], ttbr1);
> - write_sysreg_el1(ctxt->sys_regs[TCR_EL1], tcr);
> - write_sysreg_el1(ctxt->sys_regs[ESR_EL1], esr);
> - write_sysreg_el1(ctxt->sys_regs[AFSR0_EL1], afsr0);
> - write_sysreg_el1(ctxt->sys_regs[AFSR1_EL1], afsr1);
> - write_sysreg_el1(ctxt->sys_regs[FAR_EL1], far);
> - write_sysreg_el1(ctxt->sys_regs[MAIR_EL1], mair);
> - write_sysreg_el1(ctxt->sys_regs[VBAR_EL1], vbar);
> - write_sysreg_el1(ctxt->sys_regs[CONTEXTIDR_EL1],contextidr);
> - write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
> - write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
> - write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
> -
> - write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
> + u64 *sys_regs = kern_hyp_va(ctxt->hw_sys_regs);
> +
> + write_sysreg(sys_regs[MPIDR_EL1], vmpidr_el2);
> + write_sysreg(sys_regs[CSSELR_EL1], csselr_el1);
> + write_sysreg_el1(sys_regs[SCTLR_EL1], sctlr);
> + write_sysreg_el1(sys_regs[CPACR_EL1], cpacr);
> + write_sysreg_el1(sys_regs[TTBR0_EL1], ttbr0);
> + write_sysreg_el1(sys_regs[TTBR1_EL1], ttbr1);
> + write_sysreg_el1(sys_regs[TCR_EL1], tcr);
> + write_sysreg_el1(sys_regs[ESR_EL1], esr);
> + write_sysreg_el1(sys_regs[AFSR0_EL1], afsr0);
> + write_sysreg_el1(sys_regs[AFSR1_EL1], afsr1);
> + write_sysreg_el1(sys_regs[FAR_EL1], far);
> + write_sysreg_el1(sys_regs[MAIR_EL1], mair);
> + write_sysreg_el1(sys_regs[VBAR_EL1], vbar);
> + write_sysreg_el1(sys_regs[CONTEXTIDR_EL1], contextidr);
> + write_sysreg_el1(sys_regs[AMAIR_EL1], amair);
> + write_sysreg_el1(sys_regs[CNTKCTL_EL1], cntkctl);
> + write_sysreg(sys_regs[PAR_EL1], par_el1);
> +
> + write_sysreg(ctxt->hw_sp_el1, sp_el1);
> write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
> write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
> }