The ARMv8 architecture allows trapping of TLB maintenane instructions from EL0/EL1 to higher exception levels. On encountering a trappable TLB instruction in a guest, an exception is taken to EL2.
Add functionality to handle emulating the TLB instructions. Signed-off-by: Punit Agrawal <[email protected]> Cc: Christoffer Dall <[email protected]> Cc: Marc Zyngier <[email protected]> --- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/kvm/hyp/tlb.c | 146 +++++++++++++++++++++++++++++++++++++++ arch/arm64/kvm/sys_regs.c | 81 ++++++++++++++++++++++ arch/arm64/kvm/trace.h | 16 +++++ 4 files changed, 244 insertions(+) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 7561f63..1ac1cc3 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -49,6 +49,7 @@ extern char __kvm_hyp_vector[]; extern void __kvm_flush_vm_context(void); extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa); extern void __kvm_tlb_flush_vmid(struct kvm *kvm); +extern void __kvm_emulate_tlb_invalidate(struct kvm *kvm, u32 sysreg, u64 regval); extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c index 4cda100..e0a0309 100644 --- a/arch/arm64/kvm/hyp/tlb.c +++ b/arch/arm64/kvm/hyp/tlb.c @@ -78,3 +78,149 @@ static void __hyp_text __tlb_flush_vm_context(void) } __alias(__tlb_flush_vm_context) void __kvm_flush_vm_context(void); + +/* Intentionally empty functions */ +static void __hyp_text __switch_to_hyp_role_nvhe(void) { } +static void __hyp_text __switch_to_host_role_nvhe(void) { } + +static void __hyp_text __switch_to_hyp_role_vhe(void) +{ + u64 hcr = read_sysreg(hcr_el2); + + hcr &= ~HCR_TGE; + write_sysreg(hcr, hcr_el2); +} + +static void __hyp_text __switch_to_host_role_vhe(void) +{ + u64 hcr = read_sysreg(hcr_el2); + + hcr |= HCR_TGE; + write_sysreg(hcr, hcr_el2); +} + +static hyp_alternate_select(__switch_to_hyp_role, + __switch_to_hyp_role_nvhe, + __switch_to_hyp_role_vhe, + ARM64_HAS_VIRT_HOST_EXTN); + +static hyp_alternate_select(__switch_to_host_role, + __switch_to_host_role_nvhe, + __switch_to_host_role_vhe, + ARM64_HAS_VIRT_HOST_EXTN); + +static void __hyp_text __switch_to_guest_regime(struct kvm *kvm) +{ + write_sysreg(kvm->arch.vttbr, vttbr_el2); + __switch_to_hyp_role(); + isb(); +} + +static void __hyp_text __switch_to_host_regime(void) +{ + __switch_to_host_role(); + write_sysreg(0, vttbr_el2); +} + +/* + * AArch32 TLB maintenance instructions trapping to EL2 + */ +#define TLBIALLIS sys_reg(0, 0, 8, 3, 0) +#define TLBIMVAIS sys_reg(0, 0, 8, 3, 1) +#define TLBIASIDIS sys_reg(0, 0, 8, 3, 2) +#define TLBIMVAAIS sys_reg(0, 0, 8, 3, 3) +#define TLBIMVALIS sys_reg(0, 0, 8, 3, 5) +#define TLBIMVAALIS sys_reg(0, 0, 8, 3, 7) +#define ITLBIALL sys_reg(0, 0, 8, 5, 0) +#define ITLBIMVA sys_reg(0, 0, 8, 5, 1) +#define ITLBIASID sys_reg(0, 0, 8, 5, 2) +#define DTLBIALL sys_reg(0, 0, 8, 6, 0) +#define DTLBIMVA sys_reg(0, 0, 8, 6, 1) +#define DTLBIASID sys_reg(0, 0, 8, 6, 2) +#define TLBIALL sys_reg(0, 0, 8, 7, 0) +#define TLBIMVA sys_reg(0, 0, 8, 7, 1) +#define TLBIASID sys_reg(0, 0, 8, 7, 2) +#define TLBIMVAA sys_reg(0, 0, 8, 7, 3) +#define TLBIMVAL sys_reg(0, 0, 8, 7, 5) +#define TLBIMVAAL sys_reg(0, 0, 8, 7, 7) + +/* + * ARMv8 ARM: Table C5-4 TLB maintenance instructions + * (Ref: ARMv8 ARM C5.1 version: ARM DDI 0487A.j) + */ +#define TLBI_VMALLE1IS sys_reg(1, 0, 8, 3, 0) +#define TLBI_VAE1IS sys_reg(1, 0, 8, 3, 1) +#define TLBI_ASIDE1IS sys_reg(1, 0, 8, 3, 2) +#define TLBI_VAAE1IS sys_reg(1, 0, 8, 3, 3) +#define TLBI_VALE1IS sys_reg(1, 0, 8, 3, 5) +#define TLBI_VAALE1IS sys_reg(1, 0, 8, 3, 7) +#define TLBI_VMALLE1 sys_reg(1, 0, 8, 7, 0) +#define TLBI_VAE1 sys_reg(1, 0, 8, 7, 1) +#define TLBI_ASIDE1 sys_reg(1, 0, 8, 7, 2) +#define TLBI_VAAE1 sys_reg(1, 0, 8, 7, 3) +#define TLBI_VALE1 sys_reg(1, 0, 8, 7, 5) +#define TLBI_VAALE1 sys_reg(1, 0, 8, 7, 7) + +void __hyp_text +__kvm_emulate_tlb_invalidate(struct kvm *kvm, u32 sys_op, u64 regval) +{ + kvm = kern_hyp_va(kvm); + + /* + * Switch to the guest before performing any TLB operations to + * target the appropriate VMID + */ + __switch_to_guest_regime(kvm); + + /* + * TLB maintenance operations broadcast to inner-shareable + * domain when HCR_FB is set (default for KVM). + */ + switch (sys_op) { + case TLBIALL: + case TLBIALLIS: + case ITLBIALL: + case DTLBIALL: + case TLBI_VMALLE1: + case TLBI_VMALLE1IS: + __tlbi(vmalle1is); + break; + case TLBIMVA: + case TLBIMVAIS: + case ITLBIMVA: + case DTLBIMVA: + case TLBI_VAE1: + case TLBI_VAE1IS: + __tlbi(vae1is, regval); + break; + case TLBIASID: + case TLBIASIDIS: + case ITLBIASID: + case DTLBIASID: + case TLBI_ASIDE1: + case TLBI_ASIDE1IS: + __tlbi(aside1is, regval); + break; + case TLBIMVAA: + case TLBIMVAAIS: + case TLBI_VAAE1: + case TLBI_VAAE1IS: + __tlbi(vaae1is, regval); + break; + case TLBIMVAL: + case TLBIMVALIS: + case TLBI_VALE1: + case TLBI_VALE1IS: + __tlbi(vale1is, regval); + break; + case TLBIMVAAL: + case TLBIMVAALIS: + case TLBI_VAALE1: + case TLBI_VAALE1IS: + __tlbi(vaale1is, regval); + break; + } + isb(); + + __switch_to_host_regime(); +} diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b0b225c..ca0b80f 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -790,6 +790,18 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, return true; } +static bool emulate_tlb_invalidate(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u32 opcode = sys_reg(p->Op0, p->Op1, p->CRn, p->CRm, p->Op2); + + kvm_call_hyp(__kvm_emulate_tlb_invalidate, + vcpu->kvm, opcode, p->regval); + trace_kvm_tlb_invalidate(*vcpu_pc(vcpu), opcode); + + return true; +} + /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */ #define DBG_BCR_BVR_WCR_WVR_EL1(n) \ /* DBGBVRn_EL1 */ \ @@ -849,6 +861,35 @@ static const struct sys_reg_desc sys_reg_descs[] = { { Op0(0b01), Op1(0b000), CRn(0b0111), CRm(0b1110), Op2(0b010), access_dcsw }, + /* + * ARMv8 ARM: Table C5-4 TLB maintenance instructions + * (Ref: ARMv8 ARM C5.1 version: ARM DDI 0487A.j) + */ + /* TLBI VMALLE1IS */ + { Op0(1), Op1(0), CRn(8), CRm(3), Op2(0), emulate_tlb_invalidate }, + /* TLBI VAE1IS */ + { Op0(1), Op1(0), CRn(8), CRm(3), Op2(1), emulate_tlb_invalidate }, + /* TLBI ASIDE1IS */ + { Op0(1), Op1(0), CRn(8), CRm(3), Op2(2), emulate_tlb_invalidate }, + /* TLBI VAAE1IS */ + { Op0(1), Op1(0), CRn(8), CRm(3), Op2(3), emulate_tlb_invalidate }, + /* TLBI VALE1IS */ + { Op0(1), Op1(0), CRn(8), CRm(3), Op2(5), emulate_tlb_invalidate }, + /* TLBI VAALE1IS */ + { Op0(1), Op1(0), CRn(8), CRm(3), Op2(7), emulate_tlb_invalidate }, + /* TLBI VMALLE1 */ + { Op0(1), Op1(0), CRn(8), CRm(7), Op2(0), emulate_tlb_invalidate }, + /* TLBI VAE1 */ + { Op0(1), Op1(0), CRn(8), CRm(7), Op2(1), emulate_tlb_invalidate }, + /* TLBI ASIDE1 */ + { Op0(1), Op1(0), CRn(8), CRm(7), Op2(2), emulate_tlb_invalidate }, + /* TLBI VAAE1 */ + { Op0(1), Op1(0), CRn(8), CRm(7), Op2(3), emulate_tlb_invalidate }, + /* TLBI VALE1 */ + { Op0(1), Op1(0), CRn(8), CRm(7), Op2(5), emulate_tlb_invalidate }, + /* TLBI VAALE1 */ + { Op0(1), Op1(0), CRn(8), CRm(7), Op2(7), emulate_tlb_invalidate }, + DBG_BCR_BVR_WCR_WVR_EL1(0), DBG_BCR_BVR_WCR_WVR_EL1(1), /* MDCCINT_EL1 */ @@ -1337,6 +1378,46 @@ static const struct sys_reg_desc cp15_regs[] = { { Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw }, { Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw }, + /* + * TLB operations + */ + /* TLBIALLIS */ + { Op1( 0), CRn( 8), CRm( 3), Op2( 0), emulate_tlb_invalidate}, + /* TLBIMVAIS */ + { Op1( 0), CRn( 8), CRm( 3), Op2( 1), emulate_tlb_invalidate}, + /* TLBIASIDIS */ + { Op1( 0), CRn( 8), CRm( 3), Op2( 2), emulate_tlb_invalidate}, + /* TLBIMVAAIS */ + { Op1( 0), CRn( 8), CRm( 3), Op2( 3), emulate_tlb_invalidate}, + /* TLBIMVALIS */ + { Op1( 0), CRn( 8), CRm( 3), Op2( 5), emulate_tlb_invalidate}, + /* TLBIMVAALIS */ + { Op1( 0), CRn( 8), CRm( 3), Op2( 7), emulate_tlb_invalidate}, + /* ITLBIALL */ + { Op1( 0), CRn( 8), CRm( 5), Op2( 0), emulate_tlb_invalidate}, + /* ITLBIMVA */ + { Op1( 0), CRn( 8), CRm( 5), Op2( 1), emulate_tlb_invalidate}, + /* ITLBIASID */ + { Op1( 0), CRn( 8), CRm( 5), Op2( 2), emulate_tlb_invalidate}, + /* DTLBIALL */ + { Op1( 0), CRn( 8), CRm( 6), Op2( 0), emulate_tlb_invalidate}, + /* DTLBIMVA */ + { Op1( 0), CRn( 8), CRm( 6), Op2( 1), emulate_tlb_invalidate}, + /* DTLBIASID */ + { Op1( 0), CRn( 8), CRm( 6), Op2( 2), emulate_tlb_invalidate}, + /* TLBIALL */ + { Op1( 0), CRn( 8), CRm( 7), Op2( 0), emulate_tlb_invalidate}, + /* TLBIMVA */ + { Op1( 0), CRn( 8), CRm( 7), Op2( 1), emulate_tlb_invalidate}, + /* TLBIASID */ + { Op1( 0), CRn( 8), CRm( 7), Op2( 2), emulate_tlb_invalidate}, + /* TLBIMVAA */ + { Op1( 0), CRn( 8), CRm( 7), Op2( 3), emulate_tlb_invalidate}, + /* TLBIMVAL */ + { Op1( 0), CRn( 8), CRm( 7), Op2( 5), emulate_tlb_invalidate}, + /* TLBIMVAAL */ + { Op1( 0), CRn( 8), CRm( 7), Op2( 7), emulate_tlb_invalidate}, + /* PMU */ { Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmcr }, { Op1( 0), CRn( 9), CRm(12), Op2( 1), access_pmcnten }, diff --git a/arch/arm64/kvm/trace.h b/arch/arm64/kvm/trace.h index 7fb0008..c4d577f 100644 --- a/arch/arm64/kvm/trace.h +++ b/arch/arm64/kvm/trace.h @@ -166,6 +166,22 @@ TRACE_EVENT(kvm_set_guest_debug, TP_printk("vcpu: %p, flags: 0x%08x", __entry->vcpu, __entry->guest_debug) ); +TRACE_EVENT(kvm_tlb_invalidate, + TP_PROTO(unsigned long vcpu_pc, u32 opcode), + TP_ARGS(vcpu_pc, opcode), + + TP_STRUCT__entry( + __field(unsigned long, vcpu_pc) + __field(u32, opcode) + ), + + TP_fast_assign( + __entry->vcpu_pc = vcpu_pc; + __entry->opcode = opcode; + ), + + TP_printk("vcpu_pc=0x%16lx opcode=%08x", __entry->vcpu_pc, __entry->opcode) +); #endif /* _TRACE_ARM64_KVM_H */ -- 2.8.1
