From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-56.mta0.migadu.com [91.218.175.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 730A03A8745 for ; Tue, 1 Sep 2026 14:04:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788271456; cv=none; b=f7HavhRz5Z6ojlN16Q/GrrBBXXYg0dxenpOU2b8OPTOAk2BKySsQEKJAaxHXC0A/jNEsg2E1bhj63QOhf269fFJbZwgIxrCCLRmWzAMVfmDtoqetoHiBczlOHxHRp90ZNC904nFyRaKHJaJJQ1fjmQpUuanmmG2ZzDeWAGNF9qA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788271456; c=relaxed/simple; bh=a7xyJsByfTivb0jMyL/MYZ2UZcV+uOUY1idBfcRftu4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=O3pm8IY/Hb3gpZrXlHcM1kcjmpIqU+a70UKIjMeg8Nx8DWmb0UCkSqMiqoRu46wq/kiwUdTV0tUUYkVDx/YFvMAsXgLAwRYwWljQEu/oZIcoNXj/ySOh+ljeJZ6BOpbkpSiYiTEN4lYVThSPq7vwY1fa9crfIVx1a7ePdLiDVto= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=GARZ1cPB; arc=none smtp.client-ip=91.218.175.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="GARZ1cPB" X-Envelope-To: linux-trace-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=a7xyJsByfTivb0jMyL/MYZ2UZcV+uOUY1idBfcRftu4=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788271452; v=1; x=1788876252; b=GARZ1cPBmUbca8YJVU2llykvwYYmZV2kdJC3LotkyHKKPsC2SKkz4JW7YOv4p05CzSkFHCBH TiPsJhKmq4Zi0wyRTaaVZ1dOUsU6cwf757lur9Jy1hPTsHq2M8fvxLxQm1QfvMxM4moeZgLegXU APdetnTWBl5W8+wMtvmo3xW8= X-Envelope-To: linux-trace-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 4f38c450b1d7d3f9; Tue, 01 Sep 2026 14:04:11 +0000 X-Mizu-Trace-ID: 4f38c450b1d7d3f9 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Will Deacon , Steven Rostedt , Masami Hiramatsu , Alexandru Elisei , Vincent Donnefort , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Quentin Perret , Ard Biesheuvel , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Fuad Tabba , Fuad Tabba Subject: [PATCH v4 09/11] KVM: arm64: Type-check hypercall arguments at the caller Date: Tue, 1 Sep 2026 15:03:24 +0100 Message-Id: <20260901140326.3812068-10-fuad.tabba@linux.dev> In-Reply-To: <20260901140326.3812068-1-fuad.tabba@linux.dev> References: <20260901140326.3812068-1-fuad.tabba@linux.dev> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit kvm_call_hyp_nvhe() reduces its target to an SMCCC function number, so the compiler never sees a callable: arguments that are wrong in number, type or order are silently marshalled into registers. The kvm_call_hyp() wrappers only catch this on the VHE branch, and the pKVM-only hypercalls have no such branch. Declare each hypercall's signature once in kvm_hcall.h and generate a typed stub from it, in the mold of the syscall wrappers. Make kvm_call_hyp_nvhe() resolve to the stub so every caller is checked against the declared signature; a stale or mistyped call now fails to compile. The stubs inline to the same SMCCC call the untyped macro used to make: the compiled callers are unchanged, apart from hypercall returns now being tested at their declared width. The stage-2 protection arguments are declared u64 rather than enum kvm_pgtable_prot, as kvm_pgtable.h includes linux/kvm_host.h and the enum cannot be completed here. Assisted-by: Antigravity:gemini-3.1-pro Reviewed-by: Marc Zyngier Signed-off-by: Fuad Tabba --- arch/arm64/include/asm/kvm_hcall.h | 153 ++++++++++++++++++++++++++++- arch/arm64/kvm/hyp_trace.c | 2 +- 2 files changed, 153 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/kvm_hcall.h b/arch/arm64/include/asm/kvm_hcall.h index d925b2c28a3d8..c2efcb89e6e70 100644 --- a/arch/arm64/include/asm/kvm_hcall.h +++ b/arch/arm64/include/asm/kvm_hcall.h @@ -9,6 +9,7 @@ #ifndef __ARM64_KVM_HCALL_H__ #define __ARM64_KVM_HCALL_H__ +#include #include #include #include @@ -16,12 +17,37 @@ #include #include +#include #include typedef u16 pkvm_handle_t; +struct kvm; +struct kvm_s2_mmu; +struct kvm_vcpu; +struct vgic_v3_cpu_if; +struct vgic_v5_cpu_if; + +/* + * Hypercall signatures are declared as (type, name) argument pairs. + * __KVM_HCALL_MAP() applies a macro to each pair, in the mold of __MAP() + * in . The ladder is indexed by list entries, two per + * argument; __KVM_HCALL_MAP_N() takes that count explicitly. + */ +#define __KVM_HCALL_MAP2(m, t, a, ...) m(t, a) +#define __KVM_HCALL_MAP4(m, t, a, ...) m(t, a), __KVM_HCALL_MAP2(m, __VA_ARGS__) +#define __KVM_HCALL_MAP6(m, t, a, ...) m(t, a), __KVM_HCALL_MAP4(m, __VA_ARGS__) +#define __KVM_HCALL_MAP8(m, t, a, ...) m(t, a), __KVM_HCALL_MAP6(m, __VA_ARGS__) +#define __KVM_HCALL_MAP10(m, t, a, ...) m(t, a), __KVM_HCALL_MAP8(m, __VA_ARGS__) +#define __KVM_HCALL_MAP12(m, t, a, ...) m(t, a), __KVM_HCALL_MAP10(m, __VA_ARGS__) +#define __KVM_HCALL_MAP_N(n, m, ...) CONCATENATE(__KVM_HCALL_MAP, n)(m, __VA_ARGS__) +#define __KVM_HCALL_MAP(m, ...) __KVM_HCALL_MAP_N(COUNT_ARGS(__VA_ARGS__), m, __VA_ARGS__) + +#define __KVM_HCALL_DECL(t, a) t a +#define __KVM_HCALL_ARGS(t, a) a + #ifndef __KVM_NVHE_HYPERVISOR__ -#define kvm_call_hyp_nvhe(f, ...) \ +#define __kvm_call_hyp_nvhe(f, ...) \ ({ \ struct arm_smccc_res res; \ \ @@ -33,6 +59,29 @@ typedef u16 pkvm_handle_t; res.a1; \ }) +/* + * Generate a typed stub for each declared hypercall. kvm_call_hyp_nvhe() + * resolves to the stub, so a call with the wrong argument count or types + * fails to compile instead of being silently truncated to an SMCCC function + * number and a pile of registers. The stub inlines to the same SMCCC call + * the untyped macro used to make. + */ +#define DECLARE_KVM_HOST_HCALL(ret, name, ...) \ + static __always_inline \ + ret nvhe_hvc_##name(__KVM_HCALL_MAP(__KVM_HCALL_DECL, __VA_ARGS__)) \ + { \ + return (ret)__kvm_call_hyp_nvhe(name, \ + __KVM_HCALL_MAP(__KVM_HCALL_ARGS, __VA_ARGS__));\ + } + +#define DECLARE_KVM_HOST_HCALL0(ret, name) \ + static __always_inline ret nvhe_hvc_##name(void) \ + { \ + return (ret)__kvm_call_hyp_nvhe(name); \ + } + +#define kvm_call_hyp_nvhe(f, ...) nvhe_hvc_##f(__VA_ARGS__) + /* * The isb() below is there to guarantee the same behaviour on VHE as on !VHE, * where the eret to EL1 acts as a context synchronization event. @@ -63,6 +112,108 @@ typedef u16 pkvm_handle_t; #define kvm_call_hyp(f, ...) f(__VA_ARGS__) #define kvm_call_hyp_ret(f, ...) f(__VA_ARGS__) #define kvm_call_hyp_nvhe(f, ...) f(__VA_ARGS__) + +#define DECLARE_KVM_HOST_HCALL(ret, name, ...) +#define DECLARE_KVM_HOST_HCALL0(ret, name) #endif /* __KVM_NVHE_HYPERVISOR__ */ +/* Hypercalls that are unavailable once pKVM has finalised. */ +DECLARE_KVM_HOST_HCALL(int, __pkvm_init, + phys_addr_t, phys, unsigned long, size, + unsigned long *, per_cpu_base, u32, hyp_va_bits) +DECLARE_KVM_HOST_HCALL(ulong, __pkvm_create_private_mapping, + phys_addr_t, phys, size_t, size, u64, prot) +DECLARE_KVM_HOST_HCALL(int, __pkvm_cpu_set_vector, + enum arm64_hyp_spectre_vector, slot) +DECLARE_KVM_HOST_HCALL0(void, __kvm_enable_ssbs) +DECLARE_KVM_HOST_HCALL0(void, __vgic_v3_init_lrs) +DECLARE_KVM_HOST_HCALL0(u64, __vgic_v3_get_gic_config) + +DECLARE_KVM_HOST_HCALL0(int, __pkvm_prot_finalize) + +/* Hypercalls that are always available and common to [nh]VHE/pKVM. */ +DECLARE_KVM_HOST_HCALL(void, __kvm_adjust_pc, + struct kvm_vcpu *, vcpu) +DECLARE_KVM_HOST_HCALL(int, __kvm_vcpu_run, + struct kvm_vcpu *, vcpu) +DECLARE_KVM_HOST_HCALL0(void, __kvm_flush_vm_context) +DECLARE_KVM_HOST_HCALL(void, __kvm_tlb_flush_vmid_ipa, + struct kvm_s2_mmu *, mmu, phys_addr_t, ipa, int, level) +DECLARE_KVM_HOST_HCALL(void, __kvm_tlb_flush_vmid_ipa_nsh, + struct kvm_s2_mmu *, mmu, phys_addr_t, ipa, int, level) +DECLARE_KVM_HOST_HCALL(void, __kvm_tlb_flush_vmid, + struct kvm_s2_mmu *, mmu) +DECLARE_KVM_HOST_HCALL(void, __kvm_tlb_flush_vmid_range, + struct kvm_s2_mmu *, mmu, phys_addr_t, start, unsigned long, pages) +DECLARE_KVM_HOST_HCALL(void, __kvm_flush_cpu_context, + struct kvm_s2_mmu *, mmu) +DECLARE_KVM_HOST_HCALL(void, __kvm_timer_set_cntvoff, + u64, cntvoff) +DECLARE_KVM_HOST_HCALL(int, __tracing_load, + void *, desc_hva, size_t, desc_size) +DECLARE_KVM_HOST_HCALL0(void, __tracing_unload) +DECLARE_KVM_HOST_HCALL(int, __tracing_enable, + bool, enable) +DECLARE_KVM_HOST_HCALL(int, __tracing_swap_reader, + unsigned int, cpu) +DECLARE_KVM_HOST_HCALL(void, __tracing_update_clock, + u32, mult, u32, shift, u64, epoch_ns, u64, epoch_cyc) +DECLARE_KVM_HOST_HCALL(int, __tracing_reset, + unsigned int, cpu) +DECLARE_KVM_HOST_HCALL(int, __tracing_enable_event, + unsigned short, id, bool, enable) +DECLARE_KVM_HOST_HCALL(void, __tracing_write_event, + u64, id) +DECLARE_KVM_HOST_HCALL(void, __vgic_v3_save_aprs, + struct vgic_v3_cpu_if *, cpu_if) +DECLARE_KVM_HOST_HCALL(void, __vgic_v3_restore_vmcr_aprs, + struct vgic_v3_cpu_if *, cpu_if) +DECLARE_KVM_HOST_HCALL(void, __vgic_v5_save_apr, + struct vgic_v5_cpu_if *, cpu_if) +DECLARE_KVM_HOST_HCALL(void, __vgic_v5_restore_vmcr_apr, + struct vgic_v5_cpu_if *, cpu_if) + +/* Hypercalls that are available only when pKVM has finalised. */ +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_share_hyp, + u64, pfn) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_unshare_hyp, + u64, pfn) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_donate_guest, + u64, pfn, u64, gfn) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_share_guest, + u64, pfn, u64, gfn, u64, nr_pages, u64, prot) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_unshare_guest, + pkvm_handle_t, handle, u64, gfn, u64, nr_pages) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_relax_perms_guest, + u64, gfn, u64, prot) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_wrprotect_guest, + pkvm_handle_t, handle, u64, gfn, u64, nr_pages) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_test_clear_young_guest, + pkvm_handle_t, handle, u64, gfn, u64, nr_pages, bool, mkold) +DECLARE_KVM_HOST_HCALL(int, __pkvm_host_mkyoung_guest, + u64, gfn) +DECLARE_KVM_HOST_HCALL0(int, __pkvm_reserve_vm) +DECLARE_KVM_HOST_HCALL(void, __pkvm_unreserve_vm, + pkvm_handle_t, handle) +DECLARE_KVM_HOST_HCALL(int, __pkvm_init_vm, + struct kvm *, host_kvm, void *, vm_hva, void *, pgd_hva) +DECLARE_KVM_HOST_HCALL(int, __pkvm_init_vcpu, + pkvm_handle_t, handle, struct kvm_vcpu *, host_vcpu, + void *, vcpu_hva) +DECLARE_KVM_HOST_HCALL0(int, __pkvm_vcpu_in_poison_fault) +DECLARE_KVM_HOST_HCALL(int, __pkvm_force_reclaim_guest_page, + phys_addr_t, phys) +DECLARE_KVM_HOST_HCALL(int, __pkvm_reclaim_dying_guest_page, + pkvm_handle_t, handle, u64, gfn) +DECLARE_KVM_HOST_HCALL(int, __pkvm_start_teardown_vm, + pkvm_handle_t, handle) +DECLARE_KVM_HOST_HCALL(int, __pkvm_finalize_teardown_vm, + pkvm_handle_t, handle) +DECLARE_KVM_HOST_HCALL(void, __pkvm_vcpu_load, + pkvm_handle_t, handle, unsigned int, vcpu_idx, u64, hcr_el2) +DECLARE_KVM_HOST_HCALL0(void, __pkvm_vcpu_put) +DECLARE_KVM_HOST_HCALL0(void, __pkvm_vcpu_sync_state) +DECLARE_KVM_HOST_HCALL(void, __pkvm_tlb_flush_vmid, + pkvm_handle_t, handle) + #endif /* __ARM64_KVM_HCALL_H__ */ diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c index 9644c424819b7..44937e257375a 100644 --- a/arch/arm64/kvm/hyp_trace.c +++ b/arch/arm64/kvm/hyp_trace.c @@ -269,7 +269,7 @@ static struct trace_buffer_desc *hyp_trace_load(unsigned long size, void *priv) if (ret) goto err_free_buffer; - ret = kvm_call_hyp_nvhe(__tracing_load, (unsigned long)desc, desc_size); + ret = kvm_call_hyp_nvhe(__tracing_load, desc, desc_size); if (ret) goto err_unload_pages; -- 2.39.5