From 9aba641b9ec2a9f443a6c666c054c5e98ef550b5 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Tue, 8 Jul 2025 10:25:10 -0700 Subject: [PATCH] KVM: arm64: nv: Respect exception routing rules for SEAs Synchronous external aborts are taken to EL2 if ELIsInHost() or HCR_EL2.TEA=1. Rework the SEA injection plumbing to respect the imposed routing of the guest hypervisor and opportunistically rephrase things to make their function a bit more obvious. Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20250708172532.1699409-6-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_emulate.h | 14 +++++++-- arch/arm64/kvm/emulate-nested.c | 10 +++++++ arch/arm64/kvm/guest.c | 5 ++-- arch/arm64/kvm/inject_fault.c | 45 +++++++++++----------------- arch/arm64/kvm/mmio.c | 6 ++-- arch/arm64/kvm/mmu.c | 15 +++------- 6 files changed, 48 insertions(+), 47 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 8ba991b4bcfde..3a27ed4de9ac1 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -46,15 +46,25 @@ void kvm_skip_instr32(struct kvm_vcpu *vcpu); void kvm_inject_undefined(struct kvm_vcpu *vcpu); void kvm_inject_vabt(struct kvm_vcpu *vcpu); -void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr); -void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr); +int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr); void kvm_inject_size_fault(struct kvm_vcpu *vcpu); +static inline int kvm_inject_sea_dabt(struct kvm_vcpu *vcpu, u64 addr) +{ + return kvm_inject_sea(vcpu, false, addr); +} + +static inline int kvm_inject_sea_iabt(struct kvm_vcpu *vcpu, u64 addr) +{ + return kvm_inject_sea(vcpu, true, addr); +} + void kvm_vcpu_wfi(struct kvm_vcpu *vcpu); void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu); int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2); int kvm_inject_nested_irq(struct kvm_vcpu *vcpu); +int kvm_inject_nested_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr); static inline void kvm_inject_nested_sve_trap(struct kvm_vcpu *vcpu) { diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index 1de4a9001d9d5..65a2471c5638f 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -2811,3 +2811,13 @@ int kvm_inject_nested_irq(struct kvm_vcpu *vcpu) /* esr_el2 value doesn't matter for exits due to irqs. */ return kvm_inject_nested(vcpu, 0, except_type_irq); } + +int kvm_inject_nested_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr) +{ + u64 esr = FIELD_PREP(ESR_ELx_EC_MASK, + iabt ? ESR_ELx_EC_IABT_LOW : ESR_ELx_EC_DABT_LOW); + esr |= ESR_ELx_FSC_EXTABT | ESR_ELx_IL; + + vcpu_write_sys_reg(vcpu, FAR_EL2, addr); + return kvm_inject_nested_sync(vcpu, esr); +} diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 2196979a24a32..8983a43fb45e9 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -839,6 +839,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, bool serror_pending = events->exception.serror_pending; bool has_esr = events->exception.serror_has_esr; bool ext_dabt_pending = events->exception.ext_dabt_pending; + int ret = 0; if (serror_pending && has_esr) { if (!cpus_have_final_cap(ARM64_HAS_RAS_EXTN)) @@ -853,9 +854,9 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, } if (ext_dabt_pending) - kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + ret = kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); - return 0; + return (ret < 0) ? ret : 0; } u32 __attribute_const__ kvm_target_cpu(void) diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index a640e839848e6..d9fa4046b6021 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c @@ -155,36 +155,28 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr) vcpu_write_sys_reg(vcpu, far, FAR_EL1); } -/** - * kvm_inject_dabt - inject a data abort into the guest - * @vcpu: The VCPU to receive the data abort - * @addr: The address to report in the DFAR - * - * It is assumed that this code is called from the VCPU thread and that the - * VCPU therefore is not currently executing guest code. - */ -void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr) +static void __kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr) { if (vcpu_el1_is_32bit(vcpu)) - inject_abt32(vcpu, false, addr); + inject_abt32(vcpu, iabt, addr); else - inject_abt64(vcpu, false, addr); + inject_abt64(vcpu, iabt, addr); } -/** - * kvm_inject_pabt - inject a prefetch abort into the guest - * @vcpu: The VCPU to receive the prefetch abort - * @addr: The address to report in the DFAR - * - * It is assumed that this code is called from the VCPU thread and that the - * VCPU therefore is not currently executing guest code. - */ -void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr) +static bool kvm_sea_target_is_el2(struct kvm_vcpu *vcpu) { - if (vcpu_el1_is_32bit(vcpu)) - inject_abt32(vcpu, true, addr); - else - inject_abt64(vcpu, true, addr); + return __vcpu_sys_reg(vcpu, HCR_EL2) & (HCR_TGE | HCR_TEA); +} + +int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr) +{ + lockdep_assert_held(&vcpu->mutex); + + if (is_nested_ctxt(vcpu) && kvm_sea_target_is_el2(vcpu)) + return kvm_inject_nested_sea(vcpu, iabt, addr); + + __kvm_inject_sea(vcpu, iabt, addr); + return 1; } void kvm_inject_size_fault(struct kvm_vcpu *vcpu) @@ -194,10 +186,7 @@ void kvm_inject_size_fault(struct kvm_vcpu *vcpu) addr = kvm_vcpu_get_fault_ipa(vcpu); addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); - if (kvm_vcpu_trap_is_iabt(vcpu)) - kvm_inject_pabt(vcpu, addr); - else - kvm_inject_dabt(vcpu, addr); + __kvm_inject_sea(vcpu, kvm_vcpu_trap_is_iabt(vcpu), addr); /* * If AArch64 or LPAE, set FSC to 0 to indicate an Address diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index ab365e839874e..573a6ade2f4e9 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -169,10 +169,8 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) trace_kvm_mmio_nisv(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu), kvm_vcpu_get_hfar(vcpu), fault_ipa); - if (vcpu_is_protected(vcpu)) { - kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); - return 1; - } + if (vcpu_is_protected(vcpu)) + return kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER, &vcpu->kvm->arch.flags)) { diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 2942ec92c5a4a..f05d70dd6d51d 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1836,11 +1836,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) if (fault_ipa >= BIT_ULL(VTCR_EL2_IPA(vcpu->arch.hw_mmu->vtcr))) { fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); - if (is_iabt) - kvm_inject_pabt(vcpu, fault_ipa); - else - kvm_inject_dabt(vcpu, fault_ipa); - return 1; + return kvm_inject_sea(vcpu, is_iabt, fault_ipa); } } @@ -1912,8 +1908,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) } if (kvm_vcpu_abt_iss1tw(vcpu)) { - kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); - ret = 1; + ret = kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); goto out_unlock; } @@ -1958,10 +1953,8 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) if (ret == 0) ret = 1; out: - if (ret == -ENOEXEC) { - kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); - ret = 1; - } + if (ret == -ENOEXEC) + ret = kvm_inject_sea_iabt(vcpu, kvm_vcpu_get_hfar(vcpu)); out_unlock: srcu_read_unlock(&vcpu->kvm->srcu, idx); return ret; -- 2.47.2