diff options
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_nested.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/emulate-nested.c | 282 | ||||
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 6 | ||||
| -rw-r--r-- | arch/arm64/kvm/trace_arm.h | 26 |
5 files changed, 317 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 721680da1011..cb1c5c54cedd 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -988,6 +988,7 @@ int kvm_handle_cp10_id(struct kvm_vcpu *vcpu); void kvm_reset_sys_regs(struct kvm_vcpu *vcpu); int __init kvm_sys_reg_table_init(void); +int __init populate_nv_trap_config(void); bool lock_all_vcpus(struct kvm *kvm); void unlock_all_vcpus(struct kvm *kvm); diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 8fb67f032fd1..fa23cc9c2adc 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -11,6 +11,8 @@ static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu) test_bit(KVM_ARM_VCPU_HAS_EL2, vcpu->arch.features)); } +extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu); + struct sys_reg_params; struct sys_reg_desc; diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index b96662029fb1..d5837ed0077c 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -14,6 +14,288 @@ #include "trace.h" +enum trap_behaviour { + BEHAVE_HANDLE_LOCALLY = 0, + BEHAVE_FORWARD_READ = BIT(0), + BEHAVE_FORWARD_WRITE = BIT(1), + BEHAVE_FORWARD_ANY = BEHAVE_FORWARD_READ | BEHAVE_FORWARD_WRITE, +}; + +struct trap_bits { + const enum vcpu_sysreg index; + const enum trap_behaviour behaviour; + const u64 value; + const u64 mask; +}; + +/* Coarse Grained Trap definitions */ +enum cgt_group_id { + /* Indicates no coarse trap control */ + __RESERVED__, + + /* + * The first batch of IDs denote coarse trapping that are used + * on their own instead of being part of a combination of + * trap controls. + */ + + /* + * Anything after this point is a combination of coarse trap + * controls, which must all be evaluated to decide what to do. + */ + __MULTIPLE_CONTROL_BITS__, + + /* + * Anything after this point requires a callback evaluating a + * complex trap condition. Hopefully we'll never need this... + */ + __COMPLEX_CONDITIONS__, + + /* Must be last */ + __NR_CGT_GROUP_IDS__ +}; + +static const struct trap_bits coarse_trap_bits[] = { +}; + +#define MCB(id, ...) \ + [id - __MULTIPLE_CONTROL_BITS__] = \ + (const enum cgt_group_id[]){ \ + __VA_ARGS__, __RESERVED__ \ + } + +static const enum cgt_group_id *coarse_control_combo[] = { +}; + +typedef enum trap_behaviour (*complex_condition_check)(struct kvm_vcpu *); + +#define CCC(id, fn) \ + [id - __COMPLEX_CONDITIONS__] = fn + +static const complex_condition_check ccc[] = { +}; + +/* + * Bit assignment for the trap controls. We use a 64bit word with the + * following layout for each trapped sysreg: + * + * [9:0] enum cgt_group_id (10 bits) + * [62:10] Unused (53 bits) + * [63] RES0 - Must be zero, as lost on insertion in the xarray + */ +#define TC_CGT_BITS 10 + +union trap_config { + u64 val; + struct { + unsigned long cgt:TC_CGT_BITS; /* Coarse Grained Trap id */ + unsigned long unused:53; /* Unused, should be zero */ + unsigned long mbz:1; /* Must Be Zero */ + }; +}; + +struct encoding_to_trap_config { + const u32 encoding; + const u32 end; + const union trap_config tc; + const unsigned int line; +}; + +#define SR_RANGE_TRAP(sr_start, sr_end, trap_id) \ + { \ + .encoding = sr_start, \ + .end = sr_end, \ + .tc = { \ + .cgt = trap_id, \ + }, \ + .line = __LINE__, \ + } + +#define SR_TRAP(sr, trap_id) SR_RANGE_TRAP(sr, sr, trap_id) + +/* + * Map encoding to trap bits for exception reported with EC=0x18. + * These must only be evaluated when running a nested hypervisor, but + * that the current context is not a hypervisor context. When the + * trapped access matches one of the trap controls, the exception is + * re-injected in the nested hypervisor. + */ +static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = { +}; + +static DEFINE_XARRAY(sr_forward_xa); + +static union trap_config get_trap_config(u32 sysreg) +{ + return (union trap_config) { + .val = xa_to_value(xa_load(&sr_forward_xa, sysreg)), + }; +} + +static __init void print_nv_trap_error(const struct encoding_to_trap_config *tc, + const char *type, int err) +{ + kvm_err("%s line %d encoding range " + "(%d, %d, %d, %d, %d) - (%d, %d, %d, %d, %d) (err=%d)\n", + type, tc->line, + sys_reg_Op0(tc->encoding), sys_reg_Op1(tc->encoding), + sys_reg_CRn(tc->encoding), sys_reg_CRm(tc->encoding), + sys_reg_Op2(tc->encoding), + sys_reg_Op0(tc->end), sys_reg_Op1(tc->end), + sys_reg_CRn(tc->end), sys_reg_CRm(tc->end), + sys_reg_Op2(tc->end), + err); +} + +int __init populate_nv_trap_config(void) +{ + int ret = 0; + + BUILD_BUG_ON(sizeof(union trap_config) != sizeof(void *)); + BUILD_BUG_ON(__NR_CGT_GROUP_IDS__ > BIT(TC_CGT_BITS)); + + for (int i = 0; i < ARRAY_SIZE(encoding_to_cgt); i++) { + const struct encoding_to_trap_config *cgt = &encoding_to_cgt[i]; + void *prev; + + if (cgt->tc.val & BIT(63)) { + kvm_err("CGT[%d] has MBZ bit set\n", i); + ret = -EINVAL; + } + + if (cgt->encoding != cgt->end) { + prev = xa_store_range(&sr_forward_xa, + cgt->encoding, cgt->end, + xa_mk_value(cgt->tc.val), + GFP_KERNEL); + } else { + prev = xa_store(&sr_forward_xa, cgt->encoding, + xa_mk_value(cgt->tc.val), GFP_KERNEL); + if (prev && !xa_is_err(prev)) { + ret = -EINVAL; + print_nv_trap_error(cgt, "Duplicate CGT", ret); + } + } + + if (xa_is_err(prev)) { + ret = xa_err(prev); + print_nv_trap_error(cgt, "Failed CGT insertion", ret); + } + } + + kvm_info("nv: %ld coarse grained trap handlers\n", + ARRAY_SIZE(encoding_to_cgt)); + + for (int id = __MULTIPLE_CONTROL_BITS__; id < __COMPLEX_CONDITIONS__; id++) { + const enum cgt_group_id *cgids; + + cgids = coarse_control_combo[id - __MULTIPLE_CONTROL_BITS__]; + + for (int i = 0; cgids[i] != __RESERVED__; i++) { + if (cgids[i] >= __MULTIPLE_CONTROL_BITS__) { + kvm_err("Recursive MCB %d/%d\n", id, cgids[i]); + ret = -EINVAL; + } + } + } + + if (ret) + xa_destroy(&sr_forward_xa); + + return ret; +} + +static enum trap_behaviour get_behaviour(struct kvm_vcpu *vcpu, + const struct trap_bits *tb) +{ + enum trap_behaviour b = BEHAVE_HANDLE_LOCALLY; + u64 val; + + val = __vcpu_sys_reg(vcpu, tb->index); + if ((val & tb->mask) == tb->value) + b |= tb->behaviour; + + return b; +} + +static enum trap_behaviour __compute_trap_behaviour(struct kvm_vcpu *vcpu, + const enum cgt_group_id id, + enum trap_behaviour b) +{ + switch (id) { + const enum cgt_group_id *cgids; + + case __RESERVED__ ... __MULTIPLE_CONTROL_BITS__ - 1: + if (likely(id != __RESERVED__)) + b |= get_behaviour(vcpu, &coarse_trap_bits[id]); + break; + case __MULTIPLE_CONTROL_BITS__ ... __COMPLEX_CONDITIONS__ - 1: + /* Yes, this is recursive. Don't do anything stupid. */ + cgids = coarse_control_combo[id - __MULTIPLE_CONTROL_BITS__]; + for (int i = 0; cgids[i] != __RESERVED__; i++) + b |= __compute_trap_behaviour(vcpu, cgids[i], b); + break; + default: + if (ARRAY_SIZE(ccc)) + b |= ccc[id - __COMPLEX_CONDITIONS__](vcpu); + break; + } + + return b; +} + +static enum trap_behaviour compute_trap_behaviour(struct kvm_vcpu *vcpu, + const union trap_config tc) +{ + enum trap_behaviour b = BEHAVE_HANDLE_LOCALLY; + + return __compute_trap_behaviour(vcpu, tc.cgt, b); +} + +bool __check_nv_sr_forward(struct kvm_vcpu *vcpu) +{ + union trap_config tc; + enum trap_behaviour b; + bool is_read; + u32 sysreg; + u64 esr; + + if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu)) + return false; + + esr = kvm_vcpu_get_esr(vcpu); + sysreg = esr_sys64_to_sysreg(esr); + is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ; + + tc = get_trap_config(sysreg); + + /* + * A value of 0 for the whole entry means that we know nothing + * for this sysreg, and that it cannot be re-injected into the + * nested hypervisor. In this situation, let's cut it short. + * + * Note that ultimately, we could also make use of the xarray + * to store the index of the sysreg in the local descriptor + * array, avoiding another search... Hint, hint... + */ + if (!tc.val) + return false; + + b = compute_trap_behaviour(vcpu, tc); + + if (((b & BEHAVE_FORWARD_READ) && is_read) || + ((b & BEHAVE_FORWARD_WRITE) && !is_read)) + goto inject; + + return false; + +inject: + trace_kvm_forward_sysreg_trap(vcpu, sysreg, is_read); + + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return true; +} + static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) { u64 mode = spsr & PSR_MODE_MASK; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index f5baaa508926..9556896311db 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -3177,6 +3177,9 @@ int kvm_handle_sys_reg(struct kvm_vcpu *vcpu) trace_kvm_handle_sys_reg(esr); + if (__check_nv_sr_forward(vcpu)) + return 1; + params = esr_sys64_to_params(esr); params.regval = vcpu_get_reg(vcpu, Rt); @@ -3594,5 +3597,8 @@ int __init kvm_sys_reg_table_init(void) if (!first_idreg) return -EINVAL; + if (kvm_get_mode() == KVM_MODE_NV) + return populate_nv_trap_config(); + return 0; } diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h index 6ce5c025218d..8ad53104934d 100644 --- a/arch/arm64/kvm/trace_arm.h +++ b/arch/arm64/kvm/trace_arm.h @@ -364,6 +364,32 @@ TRACE_EVENT(kvm_inject_nested_exception, __entry->hcr_el2) ); +TRACE_EVENT(kvm_forward_sysreg_trap, + TP_PROTO(struct kvm_vcpu *vcpu, u32 sysreg, bool is_read), + TP_ARGS(vcpu, sysreg, is_read), + + TP_STRUCT__entry( + __field(u64, pc) + __field(u32, sysreg) + __field(bool, is_read) + ), + + TP_fast_assign( + __entry->pc = *vcpu_pc(vcpu); + __entry->sysreg = sysreg; + __entry->is_read = is_read; + ), + + TP_printk("%llx %c (%d,%d,%d,%d,%d)", + __entry->pc, + __entry->is_read ? 'R' : 'W', + sys_reg_Op0(__entry->sysreg), + sys_reg_Op1(__entry->sysreg), + sys_reg_CRn(__entry->sysreg), + sys_reg_CRm(__entry->sysreg), + sys_reg_Op2(__entry->sysreg)) +); + #endif /* _TRACE_ARM_ARM64_KVM_H */ #undef TRACE_INCLUDE_PATH |