Emulating AT A12E[01] instructions involves two steps. First, do the stage-1 translation by reusing the existing AT emulation functions. Then do the stage-2 translation by walking the guest hypervisor's stage-2 page table in software. Record the translation result to PAR_EL1.
Signed-off-by: Jintack Lim <jintack....@linaro.org> --- arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/kvm/sys_regs.c | 99 ++++++++++++++++++++++++++++++++++++++-- 2 files changed, 96 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 3993703..e160895 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -111,6 +111,7 @@ #define VTCR_EL2_TG0_16K TCR_TG0_16K #define VTCR_EL2_TG0_64K TCR_TG0_64K #define VTCR_EL2_SH0_MASK TCR_SH0_MASK +#define VTCR_EL2_SH0_SHIFT TCR_SH0_SHIFT #define VTCR_EL2_SH0_INNER TCR_SH0_INNER #define VTCR_EL2_ORGN0_MASK TCR_ORGN0_MASK #define VTCR_EL2_ORGN0_WBWA TCR_ORGN0_WBWA diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index cb46db5..7950ee0 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1656,6 +1656,97 @@ static bool handle_s1e2(struct kvm_vcpu *vcpu, struct sys_reg_params *p, return true; } +static u64 setup_par_aborted(u32 esr) +{ + u64 par = 0; + + /* S [9]: fault in the stage 2 translation */ + par |= (1 << 9); + /* FST [6:1]: Fault status code */ + par |= (esr << 1); + /* F [0]: translation is aborted */ + par |= 1; + + return par; +} + +static u64 setup_par_completed(struct kvm_vcpu *vcpu, struct kvm_s2_trans *out) +{ + u64 par, vtcr_sh0; + + /* F [0]: Translation is completed successfully */ + par = 0; + /* ATTR [63:56] */ + par |= out->upper_attr; + /* PA [47:12] */ + par |= out->output & GENMASK_ULL(11, 0); + /* RES1 [11] */ + par |= (1UL << 11); + /* SH [8:7]: Shareability attribute */ + vtcr_sh0 = vcpu_sys_reg(vcpu, VTCR_EL2) & VTCR_EL2_SH0_MASK; + par |= (vtcr_sh0 >> VTCR_EL2_SH0_SHIFT) << 7; + + return par; +} + +static bool handle_s12(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r, bool write) +{ + u64 par, va; + u32 esr; + phys_addr_t ipa; + struct kvm_s2_trans out; + int ret; + + /* Do the stage-1 translation */ + handle_s1e01(vcpu, p, r); + par = vcpu_sys_reg(vcpu, PAR_EL1); + if (par & 1) { + /* The stage-1 translation aborted */ + return true; + } + + /* Do the stage-2 translation */ + va = p->regval; + ipa = (par & GENMASK_ULL(47, 12)) | (va & GENMASK_ULL(11, 0)); + out.esr = 0; + ret = kvm_walk_nested_s2(vcpu, ipa, &out); + if (ret < 0) + return false; + + /* Check if the stage-2 PTW is aborted */ + if (out.esr) { + esr = out.esr; + goto s2_trans_abort; + } + + /* Check the access permission */ + if ((!write && !out.readable) || (write && !out.writable)) { + esr = ESR_ELx_FSC_PERM; + esr |= out.level & 0x3; + goto s2_trans_abort; + } + + vcpu_sys_reg(vcpu, PAR_EL1) = setup_par_completed(vcpu, &out); + return true; + +s2_trans_abort: + vcpu_sys_reg(vcpu, PAR_EL1) = setup_par_aborted(esr); + return true; +} + +static bool handle_s12r(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + return handle_s12(vcpu, p, r, false); +} + +static bool handle_s12w(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + return handle_s12(vcpu, p, r, true); +} + /* * AT instruction emulation * @@ -1733,10 +1824,10 @@ static bool handle_s1e2(struct kvm_vcpu *vcpu, struct sys_reg_params *p, SYS_INSN_TO_DESC(AT_S1E1WP, handle_s1e01, NULL), SYS_INSN_TO_DESC(AT_S1E2R, handle_s1e2, NULL), SYS_INSN_TO_DESC(AT_S1E2W, handle_s1e2, NULL), - SYS_INSN_TO_DESC(AT_S12E1R, NULL, NULL), - SYS_INSN_TO_DESC(AT_S12E1W, NULL, NULL), - SYS_INSN_TO_DESC(AT_S12E0R, NULL, NULL), - SYS_INSN_TO_DESC(AT_S12E0W, NULL, NULL), + SYS_INSN_TO_DESC(AT_S12E1R, handle_s12r, NULL), + SYS_INSN_TO_DESC(AT_S12E1W, handle_s12w, NULL), + SYS_INSN_TO_DESC(AT_S12E0R, handle_s12r, NULL), + SYS_INSN_TO_DESC(AT_S12E0W, handle_s12w, NULL), SYS_INSN_TO_DESC(TLBI_IPAS2E1IS, NULL, NULL), SYS_INSN_TO_DESC(TLBI_IPAS2LE1IS, NULL, NULL), SYS_INSN_TO_DESC(TLBI_ALLE2IS, NULL, NULL), -- 1.9.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm