diff options
| -rw-r--r-- | arch/arm64/include/asm/esr.h | 12 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_emulate.h | 14 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 115 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_nested.h | 13 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_ptrauth.h | 21 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable-hwdef.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/arm.c | 91 | ||||
| -rw-r--r-- | arch/arm64/kvm/emulate-nested.c | 66 | ||||
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 13 | ||||
| -rw-r--r-- | arch/arm64/kvm/handle_exit.c | 36 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/debug-sr.h | 8 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 82 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/debug-sr.c | 8 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/psci-relay.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/setup.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/switch.c | 10 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/switch.c | 107 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 4 | ||||
| -rw-r--r-- | arch/arm64/kvm/nested.c | 8 | ||||
| -rw-r--r-- | arch/arm64/kvm/pauth.c | 206 | ||||
| -rw-r--r-- | arch/arm64/kvm/pmu.c | 2 |
23 files changed, 630 insertions, 196 deletions
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index 81606bf7d5ac..7abf09df7033 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -404,6 +404,18 @@ static inline bool esr_fsc_is_access_flag_fault(unsigned long esr) return (esr & ESR_ELx_FSC_TYPE) == ESR_ELx_FSC_ACCESS; } +/* Indicate whether ESR.EC==0x1A is for an ERETAx instruction */ +static inline bool esr_iss_is_eretax(unsigned long esr) +{ + return esr & ESR_ELx_ERET_ISS_ERET; +} + +/* Indicate which key is used for ERETAx (false: A-Key, true: B-Key) */ +static inline bool esr_iss_is_eretab(unsigned long esr) +{ + return esr & ESR_ELx_ERET_ISS_ERETA; +} + const char *esr_get_class_string(unsigned long esr); #endif /* __ASSEMBLY */ diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 975af30af31f..16ed1edc3780 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -125,16 +125,6 @@ static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 |= HCR_TWI; } -static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu) -{ - vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK); -} - -static inline void vcpu_ptrauth_disable(struct kvm_vcpu *vcpu) -{ - vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK); -} - static inline unsigned long vcpu_get_vsesr(struct kvm_vcpu *vcpu) { return vcpu->arch.vsesr_el2; @@ -588,7 +578,7 @@ static __always_inline u64 kvm_get_reset_cptr_el2(struct kvm_vcpu *vcpu) val = (CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN); if (!vcpu_has_sve(vcpu) || - (vcpu->arch.fp_state != FP_STATE_GUEST_OWNED)) + (*host_data_ptr(fp_owner) != FP_STATE_GUEST_OWNED)) val |= CPACR_EL1_ZEN_EL1EN | CPACR_EL1_ZEN_EL0EN; if (cpus_have_final_cap(ARM64_SME)) val |= CPACR_EL1_SMEN_EL1EN | CPACR_EL1_SMEN_EL0EN; @@ -596,7 +586,7 @@ static __always_inline u64 kvm_get_reset_cptr_el2(struct kvm_vcpu *vcpu) val = CPTR_NVHE_EL2_RES1; if (vcpu_has_sve(vcpu) && - (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)) + (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED)) val |= CPTR_EL2_TZ; if (cpus_have_final_cap(ARM64_SME)) val &= ~CPTR_EL2_TSM; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 9e8a496fb284..cdc0aad43d41 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -530,8 +530,42 @@ struct kvm_cpu_context { u64 *vncr_array; }; +/* + * This structure is instantiated on a per-CPU basis, and contains + * data that is: + * + * - tied to a single physical CPU, and + * - either have a lifetime that does not extend past vcpu_put() + * - or is an invariant for the lifetime of the system + * + * Use host_data_ptr(field) as a way to access a pointer to such a + * field. + */ struct kvm_host_data { struct kvm_cpu_context host_ctxt; + struct user_fpsimd_state *fpsimd_state; /* hyp VA */ + + /* Ownership of the FP regs */ + enum { + FP_STATE_FREE, + FP_STATE_HOST_OWNED, + FP_STATE_GUEST_OWNED, + } fp_owner; + + /* + * host_debug_state contains the host registers which are + * saved and restored during world switches. + */ + struct { + /* {Break,watch}point registers */ + struct kvm_guest_debug_arch regs; + /* Statistical profiling extension */ + u64 pmscr_el1; + /* Self-hosted trace */ + u64 trfcr_el1; + /* Values of trap registers for the host before guest entry. */ + u64 mdcr_el2; + } host_debug_state; }; struct kvm_host_psci_config { @@ -592,19 +626,9 @@ struct kvm_vcpu_arch { u64 mdcr_el2; u64 cptr_el2; - /* Values of trap registers for the host before guest entry. */ - u64 mdcr_el2_host; - /* Exception Information */ struct kvm_vcpu_fault_info fault; - /* Ownership of the FP regs */ - enum { - FP_STATE_FREE, - FP_STATE_HOST_OWNED, - FP_STATE_GUEST_OWNED, - } fp_state; - /* Configuration flags, set once and for all before the vcpu can run */ u8 cflags; @@ -627,11 +651,10 @@ struct kvm_vcpu_arch { * We maintain more than a single set of debug registers to support * debugging the guest from the host and to maintain separate host and * guest state during world switches. vcpu_debug_state are the debug - * registers of the vcpu as the guest sees them. host_debug_state are - * the host registers which are saved and restored during - * world switches. external_debug_state contains the debug - * values we want to debug the guest. This is set via the - * KVM_SET_GUEST_DEBUG ioctl. + * registers of the vcpu as the guest sees them. + * + * external_debug_state contains the debug values we want to debug the + * guest. This is set via the KVM_SET_GUEST_DEBUG ioctl. * * debug_ptr points to the set of debug registers that should be loaded * onto the hardware when running the guest. @@ -640,18 +663,8 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch vcpu_debug_state; struct kvm_guest_debug_arch external_debug_state; - struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ struct task_struct *parent_task; - struct { - /* {Break,watch}point registers */ - struct kvm_guest_debug_arch regs; - /* Statistical profiling extension */ - u64 pmscr_el1; - /* Self-hosted trace */ - u64 trfcr_el1; - } host_debug_state; - /* VGIC state */ struct vgic_cpu vgic_cpu; struct arch_timer_cpu timer_cpu; @@ -817,8 +830,6 @@ struct kvm_vcpu_arch { #define DEBUG_STATE_SAVE_SPE __vcpu_single_flag(iflags, BIT(5)) /* Save TRBE context if active */ #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) -/* vcpu running in HYP context */ -#define VCPU_HYP_CONTEXT __vcpu_single_flag(iflags, BIT(7)) /* SVE enabled for host EL0 */ #define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0)) @@ -896,7 +907,7 @@ struct kvm_vcpu_arch { * Don't bother with VNCR-based accesses in the nVHE code, it has no * business dealing with NV. */ -static inline u64 *__ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r) +static inline u64 *___ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r) { #if !defined (__KVM_NVHE_HYPERVISOR__) if (unlikely(cpus_have_final_cap(ARM64_HAS_NESTED_VIRT) && @@ -906,6 +917,13 @@ static inline u64 *__ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r) return (u64 *)&ctxt->sys_regs[r]; } +#define __ctxt_sys_reg(c,r) \ + ({ \ + BUILD_BUG_ON(__builtin_constant_p(r) && \ + (r) >= NR_SYS_REGS); \ + ___ctxt_sys_reg(c, r); \ + }) + #define ctxt_sys_reg(c,r) (*__ctxt_sys_reg(c,r)) u64 kvm_vcpu_sanitise_vncr_reg(const struct kvm_vcpu *, enum vcpu_sysreg); @@ -1168,6 +1186,32 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); DECLARE_KVM_HYP_PER_CPU(struct kvm_host_data, kvm_host_data); +/* + * How we access per-CPU host data depends on the where we access it from, + * and the mode we're in: + * + * - VHE and nVHE hypervisor bits use their locally defined instance + * + * - the rest of the kernel use either the VHE or nVHE one, depending on + * the mode we're running in. + * + * Unless we're in protected mode, fully deprivileged, and the nVHE + * per-CPU stuff is exclusively accessible to the protected EL2 code. + * In this case, the EL1 code uses the *VHE* data as its private state + * (which makes sense in a way as there shouldn't be any shared state + * between the host and the hypervisor). + * + * Yes, this is all totally trivial. Shoot me now. + */ +#if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__) +#define host_data_ptr(f) (&this_cpu_ptr(&kvm_host_data)->f) +#else +#define host_data_ptr(f) \ + (static_branch_unlikely(&kvm_protected_mode_initialized) ? \ + &this_cpu_ptr(&kvm_host_data)->f : \ + &this_cpu_ptr_hyp_sym(kvm_host_data)->f) +#endif + static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt) { /* The host's MPIDR is immutable, so let's set it up at boot time */ @@ -1331,4 +1375,19 @@ bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu); (get_idreg_field((kvm), id, fld) >= expand_field_sign(id, fld, min) && \ get_idreg_field((kvm), id, fld) <= expand_field_sign(id, fld, max)) +/* Check for a given level of PAuth support */ +#define kvm_has_pauth(k, l) \ + ({ \ + bool pa, pi, pa3; \ + \ + pa = kvm_has_feat((k), ID_AA64ISAR1_EL1, APA, l); \ + pa &= kvm_has_feat((k), ID_AA64ISAR1_EL1, GPA, IMP); \ + pi = kvm_has_feat((k), ID_AA64ISAR1_EL1, API, l); \ + pi &= kvm_has_feat((k), ID_AA64ISAR1_EL1, GPI, IMP); \ + pa3 = kvm_has_feat((k), ID_AA64ISAR2_EL1, APA3, l); \ + pa3 &= kvm_has_feat((k), ID_AA64ISAR2_EL1, GPA3, IMP); \ + \ + (pa + pi + pa3) == 1; \ + }) + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index c77d795556e1..5e0ab0596246 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -60,7 +60,20 @@ static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0) return ttbr0 & ~GENMASK_ULL(63, 48); } +extern bool forward_smc_trap(struct kvm_vcpu *vcpu); int kvm_init_nv_sysregs(struct kvm *kvm); +#ifdef CONFIG_ARM64_PTR_AUTH +bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr); +#else +static inline bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr) +{ + /* We really should never execute this... */ + WARN_ON_ONCE(1); + *elr = 0xbad9acc0debadbad; + return false; +} +#endif + #endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/include/asm/kvm_ptrauth.h b/arch/arm64/include/asm/kvm_ptrauth.h index 0cd0965255d2..d81bac256abc 100644 --- a/arch/arm64/include/asm/kvm_ptrauth.h +++ b/arch/arm64/include/asm/kvm_ptrauth.h @@ -99,5 +99,26 @@ alternative_else_nop_endif .macro ptrauth_switch_to_hyp g_ctxt, h_ctxt, reg1, reg2, reg3 .endm #endif /* CONFIG_ARM64_PTR_AUTH */ + +#else /* !__ASSEMBLY */ + +#define __ptrauth_save_key(ctxt, key) \ + do { \ + u64 __val; \ + __val = read_sysreg_s(SYS_ ## key ## KEYLO_EL1); \ + ctxt_sys_reg(ctxt, key ## KEYLO_EL1) = __val; \ + __val = read_sysreg_s(SYS_ ## key ## KEYHI_EL1); \ + ctxt_sys_reg(ctxt, key ## KEYHI_EL1) = __val; \ + } while(0) + +#define ptrauth_save_keys(ctxt) \ + do { \ + __ptrauth_save_key(ctxt, APIA); \ + __ptrauth_save_key(ctxt, APIB); \ + __ptrauth_save_key(ctxt, APDA); \ + __ptrauth_save_key(ctxt, APDB); \ + __ptrauth_save_key(ctxt, APGA); \ + } while(0) + #endif /* __ASSEMBLY__ */ #endif /* __ASM_KVM_PTRAUTH_H */ diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index ef207a0d4f0d..9943ff0af4c9 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -297,6 +297,7 @@ #define TCR_TBI1 (UL(1) << 38) #define TCR_HA (UL(1) << 39) #define TCR_HD (UL(1) << 40) +#define TCR_TBID0 (UL(1) << 51) #define TCR_TBID1 (UL(1) << 52) #define TCR_NFD0 (UL(1) << 53) #define TCR_NFD1 (UL(1) << 54) diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index c0c050e53157..04882b577575 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -23,6 +23,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ vgic/vgic-its.o vgic/vgic-debug.o kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o pmu.o +kvm-$(CONFIG_ARM64_PTR_AUTH) += pauth.o always-y := hyp_constants.h hyp-constants.s diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index c4a0a35e02c7..c93ac8a77c27 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -35,10 +35,11 @@ #include <asm/virt.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> #include <asm/kvm_mmu.h> #include <asm/kvm_nested.h> #include <asm/kvm_pkvm.h> -#include <asm/kvm_emulate.h> +#include <asm/kvm_ptrauth.h> #include <asm/sections.h> #include <kvm/arm_hypercalls.h> @@ -218,6 +219,40 @@ void kvm_arch_destroy_vm(struct kvm *kvm) kvm_arm_teardown_hypercalls(kvm); } +static bool kvm_has_full_ptr_auth(void) +{ + bool apa, gpa, api, gpi, apa3, gpa3; + u64 isar1, isar2, val; + + /* + * Check that: + * + * - both Address and Generic auth are implemented for a given + * algorithm (Q5, IMPDEF or Q3) + * - only a single algorithm is implemented. + */ + if (!system_has_full_ptr_auth()) + return false; + + isar1 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1); + isar2 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1); + + apa = !!FIELD_GET(ID_AA64ISAR1_EL1_APA_MASK, isar1); + val = FIELD_GET(ID_AA64ISAR1_EL1_GPA_MASK, isar1); + gpa = (val == ID_AA64ISAR1_EL1_GPA_IMP); + + api = !!FIELD_GET(ID_AA64ISAR1_EL1_API_MASK, isar1); + val = FIELD_GET(ID_AA64ISAR1_EL1_GPI_MASK, isar1); + gpi = (val == ID_AA64ISAR1_EL1_GPI_IMP); + + apa3 = !!FIELD_GET(ID_AA64ISAR2_EL1_APA3_MASK, isar2); + val = FIELD_GET(ID_AA64ISAR2_EL1_GPA3_MASK, isar2); + gpa3 = (val == ID_AA64ISAR2_EL1_GPA3_IMP); + + return (apa == gpa && api == gpi && apa3 == gpa3 && + (apa + api + apa3) == 1); +} + int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) { int r; @@ -311,7 +346,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) break; case KVM_CAP_ARM_PTRAUTH_ADDRESS: case KVM_CAP_ARM_PTRAUTH_GENERIC: - r = system_has_full_ptr_auth(); + r = kvm_has_full_ptr_auth(); break; case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE: if (kvm) @@ -378,12 +413,6 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO; - /* - * Default value for the FP state, will be overloaded at load - * time if we support FP (pretty likely) - */ - vcpu->arch.fp_state = FP_STATE_FREE; - /* Set up the timer */ kvm_timer_vcpu_init(vcpu); @@ -428,6 +457,44 @@ void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) } +static void vcpu_set_pauth_traps(struct kvm_vcpu *vcpu) +{ + if (vcpu_has_ptrauth(vcpu)) { + /* + * Either we're running running an L2 guest, and the API/APK + * bits come from L1's HCR_EL2, or API/APK are both set. + */ + if (unlikely(vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu))) { + u64 val; + + val = __vcpu_sys_reg(vcpu, HCR_EL2); + val &= (HCR_API | HCR_APK); + vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK); + vcpu->arch.hcr_el2 |= val; + } else { + vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK); + } + + /* + * Save the host keys if there is any chance for the guest + * to use pauth, as the entry code will reload the guest + * keys in that case. + * Protected mode is the exception to that rule, as the + * entry into the EL2 code eagerly switch back and forth + * between host and hyp keys (and kvm_hyp_ctxt is out of + * reach anyway). + */ + if (is_protected_kvm_enabled()) + return; + + if (vcpu->arch.hcr_el2 & (HCR_API | HCR_APK)) { + struct kvm_cpu_context *ctxt; + ctxt = this_cpu_ptr_hyp_sym(kvm_hyp_ctxt); + ptrauth_save_keys(ctxt); + } + } +} + void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { struct kvm_s2_mmu *mmu; @@ -466,8 +533,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) else vcpu_set_wfx_traps(vcpu); - if (vcpu_has_ptrauth(vcpu)) - vcpu_ptrauth_disable(vcpu); + vcpu_set_pauth_traps(vcpu); + kvm_arch_vcpu_load_debug_state_flags(vcpu); if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus)) @@ -1270,7 +1337,7 @@ static unsigned long system_supported_vcpu_features(void) if (!system_supports_sve()) clear_bit(KVM_ARM_VCPU_SVE, &features); - if (!system_has_full_ptr_auth()) { + if (!kvm_has_full_ptr_auth()) { clear_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, &features); clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features); } @@ -1971,7 +2038,7 @@ static void cpu_set_hyp_vector(void) static void cpu_hyp_init_context(void) { - kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt); + kvm_init_host_cpu_context(host_data_ptr(host_ctxt)); if (!is_kernel_in_hyp_mode()) cpu_init_hyp_mode(); diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index 4697ba41b3a9..72d733c74a38 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -2117,6 +2117,26 @@ inject: return true; } +static bool forward_traps(struct kvm_vcpu *vcpu, u64 control_bit) +{ + bool control_bit_set; + + if (!vcpu_has_nv(vcpu)) + return false; + + control_bit_set = __vcpu_sys_reg(vcpu, HCR_EL2) & control_bit; + if (!is_hyp_ctxt(vcpu) && control_bit_set) { + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return true; + } + return false; +} + +bool forward_smc_trap(struct kvm_vcpu *vcpu) +{ + return forward_traps(vcpu, HCR_TSC); +} + static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) { u64 mode = spsr & PSR_MODE_MASK; @@ -2152,37 +2172,39 @@ static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr) void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu) { - u64 spsr, elr, mode; - bool direct_eret; + u64 spsr, elr, esr; /* - * Going through the whole put/load motions is a waste of time - * if this is a VHE guest hypervisor returning to its own - * userspace, or the hypervisor performing a local exception - * return. No need to save/restore registers, no need to - * switch S2 MMU. Just do the canonical ERET. + * Forward this trap to the virtual EL2 if the virtual + * HCR_EL2.NV bit is set and this is coming from !EL2. */ - spsr = vcpu_read_sys_reg(vcpu, SPSR_EL2); - spsr = kvm_check_illegal_exception_return(vcpu, spsr); - - mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT); - - direct_eret = (mode == PSR_MODE_EL0t && - vcpu_el2_e2h_is_set(vcpu) && - vcpu_el2_tge_is_set(vcpu)); - direct_eret |= (mode == PSR_MODE_EL2h || mode == PSR_MODE_EL2t); - - if (direct_eret) { - *vcpu_pc(vcpu) = vcpu_read_sys_reg(vcpu, ELR_EL2); - *vcpu_cpsr(vcpu) = spsr; - trace_kvm_nested_eret(vcpu, *vcpu_pc(vcpu), spsr); + if (forward_traps(vcpu, HCR_NV)) return; + + /* Check for an ERETAx */ + esr = kvm_vcpu_get_esr(vcpu); + if (esr_iss_is_eretax(esr) && !kvm_auth_eretax(vcpu, &elr)) { + /* + * Oh no, ERETAx failed to authenticate. If we have + * FPACCOMBINE, deliver an exception right away. If we + * don't, then let the mangled ELR value trickle down the + * ERET handling, and the guest will have a little surprise. + */ + if (kvm_has_pauth(vcpu->kvm, FPACCOMBINE)) { + esr &= ESR_ELx_ERET_ISS_ERETA; + esr |= FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_FPAC); + kvm_inject_nested_sync(vcpu, esr); + return; + } } preempt_disable(); kvm_arch_vcpu_put(vcpu); - elr = __vcpu_sys_reg(vcpu, ELR_EL2); + spsr = __vcpu_sys_reg(vcpu, SPSR_EL2); + spsr = kvm_check_illegal_exception_return(vcpu, spsr); + if (!esr_iss_is_eretax(esr)) + elr = __vcpu_sys_reg(vcpu, ELR_EL2); trace_kvm_nested_eret(vcpu, elr, spsr); diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 826307e19e3a..7507dcc4e553 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -49,8 +49,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) if (ret) return ret; - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); - /* * We need to keep current's task_struct pinned until its data has been * unshared with the hypervisor to make sure it is not re-used by the @@ -86,7 +84,8 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) * guest in kvm_arch_vcpu_ctxflush_fp() and override this to * FP_STATE_FREE if the flag set. */ - vcpu->arch.fp_state = FP_STATE_HOST_OWNED; + *host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED; + *host_data_ptr(fpsimd_state) = kern_hyp_va(¤t->thread.uw.fpsimd_state); vcpu_clear_flag(vcpu, HOST_SVE_ENABLED); if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) @@ -110,7 +109,7 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) * been saved, this is very unlikely to happen. */ if (read_sysreg_s(SYS_SVCR) & (SVCR_SM_MASK | SVCR_ZA_MASK)) { - vcpu->arch.fp_state = FP_STATE_FREE; + *host_data_ptr(fp_owner) = FP_STATE_FREE; fpsimd_save_and_flush_cpu_state(); } } @@ -126,7 +125,7 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) { if (test_thread_flag(TIF_FOREIGN_FPSTATE)) - vcpu->arch.fp_state = FP_STATE_FREE; + *host_data_ptr(fp_owner) = FP_STATE_FREE; } /* @@ -142,7 +141,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) WARN_ON_ONCE(!irqs_disabled()); - if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) { + if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) { /* * Currently we do not support SME guests so SVCR is @@ -196,7 +195,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) isb(); } - if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) { + if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) { if (vcpu_has_sve(vcpu)) { __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 617ae6dea5d5..b037f0a0e27e 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -56,6 +56,13 @@ static int handle_hvc(struct kvm_vcpu *vcpu) static int handle_smc(struct kvm_vcpu *vcpu) { /* + * Forward this trapped smc instruction to the virtual EL2 if + * the guest has asked for it. + */ + if (forward_smc_trap(vcpu)) + return 1; + + /* * "If an SMC instruction executed at Non-secure EL1 is * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a * Trap exception, not a Secure Monitor Call exception [...]" @@ -207,19 +214,40 @@ static int handle_sve(struct kvm_vcpu *vcpu) } /* - * Guest usage of a ptrauth instruction (which the guest EL1 did not turn into - * a NOP). If we get here, it is that we didn't fixup ptrauth on exit, and all - * that we can do is give the guest an UNDEF. + * Two possibilities to handle a trapping ptrauth instruction: + * + * - Guest usage of a ptrauth instruction (which the guest EL1 did not + * turn into a NOP). If we get here, it is because we didn't enable + * ptrauth for the guest. This results in an UNDEF, as it isn't + * supposed to use ptrauth without being told it could. + * + * - Running an L2 NV guest while L1 has left HCR_EL2.API==0, and for + * which we reinject the exception into L1. + * + * Anything else is an emulation bug (hence the WARN_ON + UNDEF). */ static int kvm_handle_ptrauth(struct kvm_vcpu *vcpu) { + if (!vcpu_has_ptrauth(vcpu)) { + kvm_inject_undefined(vcpu); + return 1; + } + + if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) { + kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu)); + return 1; + } + + /* Really shouldn't be here! */ + WARN_ON_ONCE(1); kvm_inject_undefined(vcpu); return 1; } static int kvm_handle_eret(struct kvm_vcpu *vcpu) { - if (kvm_vcpu_get_esr(vcpu) & ESR_ELx_ERET_ISS_ERET) + if (esr_iss_is_eretax(kvm_vcpu_get_esr(vcpu)) && + !vcpu_has_ptrauth(vcpu)) return kvm_handle_ptrauth(vcpu); /* diff --git a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h index 961bbef104a6..d00093699aaf 100644 --- a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h @@ -135,9 +135,9 @@ static inline void __debug_switch_to_guest_common(struct kvm_vcpu *vcpu) if (!vcpu_get_flag(vcpu, DEBUG_DIRTY)) return; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); guest_ctxt = &vcpu->arch.ctxt; - host_dbg = &vcpu->arch.host_debug_state.regs; + host_dbg = host_data_ptr(host_debug_state.regs); guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr); __debug_save_state(host_dbg, host_ctxt); @@ -154,9 +154,9 @@ static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu) if (!vcpu_get_flag(vcpu, DEBUG_DIRTY)) return; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); guest_ctxt = &vcpu->arch.ctxt; - host_dbg = &vcpu->arch.host_debug_state.regs; + host_dbg = host_data_ptr(host_debug_state.regs); guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr); __debug_save_state(guest_dbg, guest_ctxt); diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index e3fcf8c4d5b4..61772bf1d3e6 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -27,6 +27,7 @@ #include <asm/kvm_hyp.h> #include <asm/kvm_mmu.h> #include <asm/kvm_nested.h> +#include <asm/kvm_ptrauth.h> #include <asm/fpsimd.h> #include <asm/debug-monitors.h> #include <asm/processor.h> @@ -42,7 +43,7 @@ extern struct kvm_exception_table_entry __stop___kvm_ex_table; /* Check whether the FP regs are owned by the guest */ static inline bool guest_owns_fp_regs(struct kvm_vcpu *vcpu) { - return vcpu->arch.fp_state == FP_STATE_GUEST_OWNED; + return *host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED; } /* Save the 32-bit only FPSIMD system register state */ @@ -155,7 +156,7 @@ static inline bool cpu_has_amu(void) static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu) { - struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt); struct kvm *kvm = kern_hyp_va(vcpu->kvm); CHECK_FGT_MASKS(HFGRTR_EL2); @@ -191,7 +192,7 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu) static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu) { - struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt); struct kvm *kvm = kern_hyp_va(vcpu->kvm); if (!cpus_have_final_cap(ARM64_HAS_FGT)) @@ -226,13 +227,13 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) write_sysreg(0, pmselr_el0); - hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + hctxt = host_data_ptr(host_ctxt); ctxt_sys_reg(hctxt, PMUSERENR_EL0) = read_sysreg(pmuserenr_el0); write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); vcpu_set_flag(vcpu, PMUSERENR_ON_CPU); } - vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2); + *host_data_ptr(host_debug_state.mdcr_el2) = read_sysreg(mdcr_el2); write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); if (cpus_have_final_cap(ARM64_HAS_HCX)) { @@ -254,13 +255,13 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) { - write_sysreg(vcpu->arch.mdcr_el2_host, mdcr_el2); + write_sysreg(*host_data_ptr(host_debug_state.mdcr_el2), mdcr_el2); write_sysreg(0, hstr_el2); if (kvm_arm_support_pmu_v3()) { struct kvm_cpu_context *hctxt; - hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + hctxt = host_data_ptr(host_ctxt); write_sysreg(ctxt_sys_reg(hctxt, PMUSERENR_EL0), pmuserenr_el0); vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU); } @@ -271,10 +272,8 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) __deactivate_traps_hfgxtr(vcpu); } -static inline void ___activate_traps(struct kvm_vcpu *vcpu) +static inline void ___activate_traps(struct kvm_vcpu *vcpu, u64 hcr) { - u64 hcr = vcpu->arch.hcr_el2; - if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM)) hcr |= HCR_TVM; @@ -376,8 +375,8 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) isb(); /* Write out the host state if it's in the registers */ - if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); + if (*host_data_ptr(fp_owner) == FP_STATE_HOST_OWNED) + __fpsimd_save_state(*host_data_ptr(fpsimd_state)); /* Restore the guest state */ if (sve_guest) @@ -389,7 +388,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) if (!(read_sysreg(hcr_el2) & HCR_RW)) write_sysreg(__vcpu_sys_reg(vcpu, FPEXC32_EL2), fpexc32_el2); - vcpu->arch.fp_state = FP_STATE_GUEST_OWNED; + *host_data_ptr(fp_owner) = FP_STATE_GUEST_OWNED; return true; } @@ -449,60 +448,6 @@ static inline bool handle_tx2_tvm(struct kvm_vcpu *vcpu) return true; } -static inline bool esr_is_ptrauth_trap(u64 esr) -{ - switch (esr_sys64_to_sysreg(esr)) { - case SYS_APIAKEYLO_EL1: - case SYS_APIAKEYHI_EL1: - case SYS_APIBKEYLO_EL1: - case SYS_APIBKEYHI_EL1: - case SYS_APDAKEYLO_EL1: - case SYS_APDAKEYHI_EL1: - case SYS_APDBKEYLO_EL1: - case SYS_APDBKEYHI_EL1: - case SYS_APGAKEYLO_EL1: - case SYS_APGAKEYHI_EL1: - return true; - } - - return false; -} - -#define __ptrauth_save_key(ctxt, key) \ - do { \ - u64 __val; \ - __val = read_sysreg_s(SYS_ ## key ## KEYLO_EL1); \ - ctxt_sys_reg(ctxt, key ## KEYLO_EL1) = __val; \ - __val = read_sysreg_s(SYS_ ## key ## KEYHI_EL1); \ - ctxt_sys_reg(ctxt, key ## KEYHI_EL1) = __val; \ -} while(0) - -DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); - -static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code) -{ - struct kvm_cpu_context *ctxt; - u64 val; - - if (!vcpu_has_ptrauth(vcpu)) - return false; - - ctxt = this_cpu_ptr(&kvm_hyp_ctxt); - __ptrauth_save_key(ctxt, APIA); - __ptrauth_save_key(ctxt, APIB); - __ptrauth_save_key(ctxt, APDA); - __ptrauth_save_key(ctxt, APDB); - __ptrauth_save_key(ctxt, APGA); - - vcpu_ptrauth_enable(vcpu); - - val = read_sysreg(hcr_el2); - val |= (HCR_API | HCR_APK); - write_sysreg(val, hcr_el2); - - return true; -} - static bool kvm_hyp_handle_cntpct(struct kvm_vcpu *vcpu) { struct arch_timer_context *ctxt; @@ -590,9 +535,6 @@ static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) __vgic_v3_perform_cpuif_access(vcpu) == 1) return true; - if (esr_is_ptrauth_trap(kvm_vcpu_get_esr(vcpu))) - return kvm_hyp_handle_ptrauth(vcpu, exit_code); - if (kvm_hyp_handle_cntpct(vcpu)) return true; diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c index 7746ea507b6f..53efda0235cf 100644 --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -83,10 +83,10 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) { /* Disable and flush SPE data generation */ if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) - __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); + __debug_save_spe(host_data_ptr(host_debug_state.pmscr_el1)); /* Disable and flush Self-Hosted Trace generation */ if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); + __debug_save_trace(host_data_ptr(host_debug_state.trfcr_el1)); } void __debug_switch_to_guest(struct kvm_vcpu *vcpu) @@ -97,9 +97,9 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu) void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) { if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) - __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); + __debug_restore_spe(*host_data_ptr(host_debug_state.pmscr_el1)); if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) - __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); + __debug_restore_trace(*host_data_ptr(host_debug_state.trfcr_el1)); } void __debug_switch_to_host(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 2385fd03ed87..26561c562f7a 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -39,10 +39,8 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.cptr_el2 = host_vcpu->arch.cptr_el2; hyp_vcpu->vcpu.arch.iflags = host_vcpu->arch.iflags; - hyp_vcpu->vcpu.arch.fp_state = host_vcpu->arch.fp_state; hyp_vcpu->vcpu.arch.debug_ptr = kern_hyp_va(host_vcpu->arch.debug_ptr); - hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state; hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2; @@ -64,7 +62,6 @@ static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) host_vcpu->arch.fault = hyp_vcpu->vcpu.arch.fault; host_vcpu->arch.iflags = hyp_vcpu->vcpu.arch.iflags; - host_vcpu->arch.fp_state = hyp_vcpu->vcpu.arch.fp_state; host_cpu_if->vgic_hcr = hyp_cpu_if->vgic_hcr; for (i = 0; i < hyp_cpu_if->used_lrs; ++i) diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c index d57bcb6ab94d..dfe8fe0f7eaf 100644 --- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c +++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c @@ -205,7 +205,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on) struct psci_boot_args *boot_args; struct kvm_cpu_context *host_ctxt; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); if (is_cpu_on) boot_args = this_cpu_ptr(&cpu_on_args); diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index bc58d1b515af..ae00dfa80801 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -257,8 +257,7 @@ static int fix_hyp_pgtable_refcnt(void) void __noreturn __pkvm_init_finalise(void) { - struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); - struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt; + struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt); unsigned long nr_pages, reserved_pages, pfn; int ret; diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index c50f8459e4fc..563604b55ea2 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -40,7 +40,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu) { u64 val; - ___activate_traps(vcpu); + ___activate_traps(vcpu, vcpu->arch.hcr_el2); __activate_traps_common(vcpu); val = vcpu->arch.cptr_el2; @@ -191,7 +191,6 @@ static const exit_handler_fn hyp_exit_handlers[] = { [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low, - [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, [ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops, }; @@ -203,7 +202,6 @@ static const exit_handler_fn pvm_exit_handlers[] = { [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low, - [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, [ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops, }; @@ -264,7 +262,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) pmr_sync(); } - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); host_ctxt->__hyp_running_vcpu = vcpu; guest_ctxt = &vcpu->arch.ctxt; @@ -337,7 +335,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu) __sysreg_restore_state_nvhe(host_ctxt); - if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) + if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) __fpsimd_save_fpexc32(vcpu); __debug_switch_to_host(vcpu); @@ -367,7 +365,7 @@ asmlinkage void __noreturn hyp_panic(void) struct kvm_cpu_context *host_ctxt; struct kvm_vcpu *vcpu; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); vcpu = host_ctxt->__hyp_running_vcpu; if (vcpu) { diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 1581df6aec87..23794589c52e 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -33,11 +33,43 @@ DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); +/* + * HCR_EL2 bits that the NV guest can freely change (no RES0/RES1 + * semantics, irrespective of the configuration), but that cannot be + * applied to the actual HW as things would otherwise break badly. + * + * - TGE: we want the guest to use EL1, which is incompatible with + * this bit being set + * + * - API/APK: they are already accounted for by vcpu_load(), and can + * only take effect across a load/put cycle (such as ERET) + */ +#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK) + +static u64 __compute_hcr(struct kvm_vcpu *vcpu) +{ + u64 hcr = vcpu->arch.hcr_el2; + + if (!vcpu_has_nv(vcpu)) + return hcr; + + if (is_hyp_ctxt(vcpu)) { + hcr |= HCR_NV | HCR_NV2 | HCR_AT | HCR_TTLB; + + if (!vcpu_el2_e2h_is_set(vcpu)) + hcr |= HCR_NV1; + + write_sysreg_s(vcpu->arch.ctxt.vncr_array, SYS_VNCR_EL2); + } + + return hcr | (__vcpu_sys_reg(vcpu, HCR_EL2) & ~NV_HCR_GUEST_EXCLUDE); +} + static void __activate_traps(struct kvm_vcpu *vcpu) { u64 val; - ___activate_traps(vcpu); + ___activate_traps(vcpu, __compute_hcr(vcpu)); if (has_cntpoff()) { struct timer_map map; @@ -162,6 +194,8 @@ static void __vcpu_put_deactivate_traps(struct kvm_vcpu *vcpu) void kvm_vcpu_load_vhe(struct kvm_vcpu *vcpu) { + host_data_ptr(host_ctxt)->__hyp_running_vcpu = vcpu; + __vcpu_load_switch_sysregs(vcpu); __vcpu_load_activate_traps(vcpu); __load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch); @@ -171,6 +205,61 @@ void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu) { __vcpu_put_deactivate_traps(vcpu); __vcpu_put_switch_sysregs(vcpu); + + host_data_ptr(host_ctxt)->__hyp_running_vcpu = NULL; +} + +static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code) +{ + u64 esr = kvm_vcpu_get_esr(vcpu); + u64 spsr, elr, mode; + + /* + * Going through the whole put/load motions is a waste of time + * if this is a VHE guest hypervisor returning to its own + * userspace, or the hypervisor performing a local exception + * return. No need to save/restore registers, no need to + * switch S2 MMU. Just do the canonical ERET. + * + * Unless the trap has to be forwarded further down the line, + * of course... + */ + if ((__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_NV) || + (__vcpu_sys_reg(vcpu, HFGITR_EL2) & HFGITR_EL2_ERET)) + return false; + + spsr = read_sysreg_el1(SYS_SPSR); + mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT); + + switch (mode) { + case PSR_MODE_EL0t: + if (!(vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu))) + return false; + break; + case PSR_MODE_EL2t: + mode = PSR_MODE_EL1t; + break; + case PSR_MODE_EL2h: + mode = PSR_MODE_EL1h; + break; + default: + return false; + } + + /* If ERETAx fails, take the slow path */ + if (esr_iss_is_eretax(esr)) { + if (!(vcpu_has_ptrauth(vcpu) && kvm_auth_eretax(vcpu, &elr))) + return false; + } else { + elr = read_sysreg_el1(SYS_ELR); + } + + spsr = (spsr & ~(PSR_MODE_MASK | PSR_MODE32_BIT)) | mode; + + write_sysreg_el2(spsr, SYS_SPSR); + write_sysreg_el2(elr, SYS_ELR); + + return true; } static const exit_handler_fn hyp_exit_handlers[] = { @@ -182,7 +271,7 @@ static const exit_handler_fn hyp_exit_handlers[] = { [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, [ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low, - [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, + [ESR_ELx_EC_ERET] = kvm_hyp_handle_eret, [ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops, }; @@ -197,7 +286,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) * If we were in HYP context on entry, adjust the PSTATE view * so that the usual helpers work correctly. */ - if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) { + if (vcpu_has_nv(vcpu) && (read_sysreg(hcr_el2) & HCR_NV)) { u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT); switch (mode) { @@ -221,8 +310,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt; u64 exit_code; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; - host_ctxt->__hyp_running_vcpu = vcpu; + host_ctxt = host_data_ptr(host_ctxt); guest_ctxt = &vcpu->arch.ctxt; sysreg_save_host_state_vhe(host_ctxt); @@ -240,11 +328,6 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) sysreg_restore_guest_state_vhe(guest_ctxt); __debug_switch_to_guest(vcpu); - if (is_hyp_ctxt(vcpu)) - vcpu_set_flag(vcpu, VCPU_HYP_CONTEXT); - else - vcpu_clear_flag(vcpu, VCPU_HYP_CONTEXT); - do { /* Jump in the fire! */ exit_code = __guest_enter(vcpu); @@ -258,7 +341,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) sysreg_restore_host_state_vhe(host_ctxt); - if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) + if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED) __fpsimd_save_fpexc32(vcpu); __debug_switch_to_host(vcpu); @@ -306,7 +389,7 @@ static void __hyp_call_panic(u64 spsr, u64 elr, u64 par) struct kvm_cpu_context *host_ctxt; struct kvm_vcpu *vcpu; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); vcpu = host_ctxt->__hyp_running_vcpu; __deactivate_traps(vcpu); diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c index a8b9ea496706..e12bd7d6d2dc 100644 --- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c @@ -67,7 +67,7 @@ void __vcpu_load_switch_sysregs(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; struct kvm_cpu_context *host_ctxt; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); __sysreg_save_user_state(host_ctxt); /* @@ -110,7 +110,7 @@ void __vcpu_put_switch_sysregs(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; struct kvm_cpu_context *host_ctxt; - host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt = host_data_ptr(host_ctxt); __sysreg_save_el1_state(guest_ctxt); __sysreg_save_user_state(guest_ctxt); diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index ced30c90521a..6813c7c7f00a 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -35,13 +35,9 @@ static u64 limit_nv_id_reg(u32 id, u64 val) break; case SYS_ID_AA64ISAR1_EL1: - /* Support everything but PtrAuth and Spec Invalidation */ + /* Support everything but Spec Invalidation */ val &= ~(GENMASK_ULL(63, 56) | - NV_FTR(ISAR1, SPECRES) | - NV_FTR(ISAR1, GPI) | - NV_FTR(ISAR1, GPA) | - NV_FTR(ISAR1, API) | - NV_FTR(ISAR1, APA)); + NV_FTR(ISAR1, SPECRES)); break; case SYS_ID_AA64PFR0_EL1: diff --git a/arch/arm64/kvm/pauth.c b/arch/arm64/kvm/pauth.c new file mode 100644 index 000000000000..d5eb3ae876be --- /dev/null +++ b/arch/arm64/kvm/pauth.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 - Google LLC + * Author: Marc Zyngier <maz@kernel.org> + * + * Primitive PAuth emulation for ERETAA/ERETAB. + * + * This code assumes that is is run from EL2, and that it is part of + * the emulation of ERETAx for a guest hypervisor. That's a lot of + * baked-in assumptions and shortcuts. + * + * Do no reuse for anything else! + */ + +#include <linux/kvm_host.h> + +#include <asm/gpr-num.h> +#include <asm/kvm_emulate.h> +#include <asm/pointer_auth.h> + +/* PACGA Xd, Xn, Xm */ +#define PACGA(d,n,m) \ + asm volatile(__DEFINE_ASM_GPR_NUMS \ + ".inst 0x9AC03000 |" \ + "(.L__gpr_num_%[Rd] << 0) |" \ + "(.L__gpr_num_%[Rn] << 5) |" \ + "(.L__gpr_num_%[Rm] << 16)\n" \ + : [Rd] "=r" ((d)) \ + : [Rn] "r" ((n)), [Rm] "r" ((m))) + +static u64 compute_pac(struct kvm_vcpu *vcpu, u64 ptr, + struct ptrauth_key ikey) +{ + struct ptrauth_key gkey; + u64 mod, pac = 0; + + preempt_disable(); + + if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU)) + mod = __vcpu_sys_reg(vcpu, SP_EL2); + else + mod = read_sysreg(sp_el1); + + gkey.lo = read_sysreg_s(SYS_APGAKEYLO_EL1); + gkey.hi = read_sysreg_s(SYS_APGAKEYHI_EL1); + + __ptrauth_key_install_nosync(APGA, ikey); + isb(); + + PACGA(pac, ptr, mod); + isb(); + + __ptrauth_key_install_nosync(APGA, gkey); + + preempt_enable(); + + /* PAC in the top 32bits */ + return pac; +} + +static bool effective_tbi(struct kvm_vcpu *vcpu, bool bit55) +{ + u64 tcr = vcpu_read_sys_reg(vcpu, TCR_EL2); + bool tbi, tbid; + + /* + * Since we are authenticating an instruction address, we have + * to take TBID into account. If E2H==0, ignore VA[55], as + * TCR_EL2 only has a single TBI/TBID. If VA[55] was set in + * this case, this is likely a guest bug... + */ + if (!vcpu_el2_e2h_is_set(vcpu)) { + tbi = tcr & BIT(20); + tbid = tcr & BIT(29); + } else if (bit55) { + tbi = tcr & TCR_TBI1; + tbid = tcr & TCR_TBID1; + } else { + tbi = tcr & TCR_TBI0; + tbid = tcr & TCR_TBID0; + } + + return tbi && !tbid; +} + +static int compute_bottom_pac(struct kvm_vcpu *vcpu, bool bit55) +{ + static const int maxtxsz = 39; // Revisit these two values once + static const int mintxsz = 16; // (if) we support TTST/LVA/LVA2 + u64 tcr = vcpu_read_sys_reg(vcpu, TCR_EL2); + int txsz; + + if (!vcpu_el2_e2h_is_set(vcpu) || !bit55) + txsz = FIELD_GET(TCR_T0SZ_MASK, tcr); + else + txsz = FIELD_GET(TCR_T1SZ_MASK, tcr); + + return 64 - clamp(txsz, mintxsz, maxtxsz); +} + +static u64 compute_pac_mask(struct kvm_vcpu *vcpu, bool bit55) +{ + int bottom_pac; + u64 mask; + + bottom_pac = compute_bottom_pac(vcpu, bit55); + + mask = GENMASK(54, bottom_pac); + if (!effective_tbi(vcpu, bit55)) + mask |= GENMASK(63, 56); + + return mask; +} + +static u64 to_canonical_addr(struct kvm_vcpu *vcpu, u64 ptr, u64 mask) +{ + bool bit55 = !!(ptr & BIT(55)); + + if (bit55) + return ptr | mask; + + return ptr & ~mask; +} + +static u64 corrupt_addr(struct kvm_vcpu *vcpu, u64 ptr) +{ + bool bit55 = !!(ptr & BIT(55)); + u64 mask, error_code; + int shift; + + if (effective_tbi(vcpu, bit55)) { + mask = GENMASK(54, 53); + shift = 53; + } else { + mask = GENMASK(62, 61); + shift = 61; + } + + if (esr_iss_is_eretab(kvm_vcpu_get_esr(vcpu))) + error_code = 2 << shift; + else + error_code = 1 << shift; + + ptr &= ~mask; + ptr |= error_code; + + return ptr; +} + +/* + * Authenticate an ERETAA/ERETAB instruction, returning true if the + * authentication succeeded and false otherwise. In all cases, *elr + * contains the VA to ERET to. Potential exception injection is left + * to the caller. + */ +bool kvm_auth_eretax(struct kvm_vcpu *vcpu, u64 *elr) +{ + u64 sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL2); + u64 esr = kvm_vcpu_get_esr(vcpu); + u64 ptr, cptr, pac, mask; + struct ptrauth_key ikey; + + *elr = ptr = vcpu_read_sys_reg(vcpu, ELR_EL2); + + /* We assume we're already in the context of an ERETAx */ + if (esr_iss_is_eretab(esr)) { + if (!(sctlr & SCTLR_EL1_EnIB)) + return true; + + ikey.lo = __vcpu_sys_reg(vcpu, APIBKEYLO_EL1); + ikey.hi = __vcpu_sys_reg(vcpu, APIBKEYHI_EL1); + } else { + if (!(sctlr & SCTLR_EL1_EnIA)) + return true; + + ikey.lo = __vcpu_sys_reg(vcpu, APIAKEYLO_EL1); + ikey.hi = __vcpu_sys_reg(vcpu, APIAKEYHI_EL1); + } + + mask = compute_pac_mask(vcpu, !!(ptr & BIT(55))); + cptr = to_canonical_addr(vcpu, ptr, mask); + + pac = compute_pac(vcpu, cptr, ikey); + + /* + * Slightly deviate from the pseudocode: if we have a PAC + * match with the signed pointer, then it must be good. + * Anything after this point is pure error handling. + */ + if ((pac & mask) == (ptr & mask)) { + *elr = cptr; + return true; + } + + /* + * Authentication failed, corrupt the canonical address if + * PAuth2 isn't implemented, or some XORing if it is. + */ + if (!kvm_has_pauth(vcpu->kvm, PAuth2)) + cptr = corrupt_addr(vcpu, cptr); + else + cptr = ptr ^ (pac & mask); + + *elr = cptr; + return false; +} diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c index a243934c5568..329819806096 100644 --- a/arch/arm64/kvm/pmu.c +++ b/arch/arm64/kvm/pmu.c @@ -232,7 +232,7 @@ bool kvm_set_pmuserenr(u64 val) if (!vcpu || !vcpu_get_flag(vcpu, PMUSERENR_ON_CPU)) return false; - hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + hctxt = host_data_ptr(host_ctxt); ctxt_sys_reg(hctxt, PMUSERENR_EL0) = val; return true; } |