[PATCH v1 08/11] KVM: arm64: Move the host hypercall interface to its own header
From: Fuad Tabba <fuad.tabba@linux.dev>
Date: 2026-07-20 16:14:25
Also in:
kvmarm, linux-arm-kernel, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Move the kvm_call_hyp() dispatch macros and pkvm_handle_t out of kvm_host.h into a new kvm_hcall.h, giving the host<->hyp hypercall interface a single home that subsequent patches build on to restore type-checking across the boundary. The only adjustment to the moved code is the checkpatch-mandated space in "while (0)". No functional change intended. Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev> --- arch/arm64/include/asm/kvm_hcall.h | 68 ++++++++++++++++++++++++++++++ arch/arm64/include/asm/kvm_host.h | 48 +-------------------- 2 files changed, 69 insertions(+), 47 deletions(-) create mode 100644 arch/arm64/include/asm/kvm_hcall.h
diff --git a/arch/arm64/include/asm/kvm_hcall.h b/arch/arm64/include/asm/kvm_hcall.h
new file mode 100644
index 0000000000000..d925b2c28a3d8
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_hcall.h@@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * The host<->hyp hypercall interface. + * + * Copyright (C) 2026 Google LLC + * Author: Fuad Tabba <fuad.tabba@linux.dev> + */ + +#ifndef __ARM64_KVM_HCALL_H__ +#define __ARM64_KVM_HCALL_H__ + +#include <linux/arm-smccc.h> +#include <linux/bug.h> +#include <linux/errno.h> +#include <linux/types.h> + +#include <asm/barrier.h> +#include <asm/kvm_asm.h> +#include <asm/virt.h> + +typedef u16 pkvm_handle_t; + +#ifndef __KVM_NVHE_HYPERVISOR__ +#define kvm_call_hyp_nvhe(f, ...) \ + ({ \ + struct arm_smccc_res res; \ + \ + arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(f), \ + ##__VA_ARGS__, &res); \ + if (WARN_ON(res.a0 != SMCCC_RET_SUCCESS)) \ + res.a1 = -EOPNOTSUPP; \ + \ + res.a1; \ + }) + +/* + * 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. + */ +#define kvm_call_hyp(f, ...) \ + do { \ + if (has_vhe()) { \ + f(__VA_ARGS__); \ + isb(); \ + } else { \ + kvm_call_hyp_nvhe(f, ##__VA_ARGS__); \ + } \ + } while (0) + +#define kvm_call_hyp_ret(f, ...) \ + ({ \ + typeof(f(__VA_ARGS__)) ret; \ + \ + if (has_vhe()) { \ + ret = f(__VA_ARGS__); \ + } else { \ + ret = kvm_call_hyp_nvhe(f, ##__VA_ARGS__); \ + } \ + \ + ret; \ + }) +#else /* __KVM_NVHE_HYPERVISOR__ */ +#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__) +#endif /* __KVM_NVHE_HYPERVISOR__ */ + +#endif /* __ARM64_KVM_HCALL_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index bae2c4f92ef5c..81d359ac7af14 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -27,6 +27,7 @@ #include <asm/fpsimd.h> #include <asm/kvm.h> #include <asm/kvm_asm.h> +#include <asm/kvm_hcall.h> #include <asm/vncr_mapping.h> #define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -251,8 +252,6 @@ struct kvm_smccc_features { unsigned long vendor_hyp_bmap_2; /* Function numbers 64-127 */ }; -typedef u16 pkvm_handle_t; - struct kvm_protected_vm { pkvm_handle_t handle; struct kvm_hyp_memcache teardown_mc;
@@ -1252,51 +1251,6 @@ void kvm_arm_resume_guest(struct kvm *kvm); #define vcpu_has_run_once(vcpu) (!!READ_ONCE((vcpu)->pid)) -#ifndef __KVM_NVHE_HYPERVISOR__ -#define kvm_call_hyp_nvhe(f, ...) \ - ({ \ - struct arm_smccc_res res; \ - \ - arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(f), \ - ##__VA_ARGS__, &res); \ - if (WARN_ON(res.a0 != SMCCC_RET_SUCCESS)) \ - res.a1 = -EOPNOTSUPP; \ - \ - res.a1; \ - }) - -/* - * 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. - */ -#define kvm_call_hyp(f, ...) \ - do { \ - if (has_vhe()) { \ - f(__VA_ARGS__); \ - isb(); \ - } else { \ - kvm_call_hyp_nvhe(f, ##__VA_ARGS__); \ - } \ - } while(0) - -#define kvm_call_hyp_ret(f, ...) \ - ({ \ - typeof(f(__VA_ARGS__)) ret; \ - \ - if (has_vhe()) { \ - ret = f(__VA_ARGS__); \ - } else { \ - ret = kvm_call_hyp_nvhe(f, ##__VA_ARGS__); \ - } \ - \ - ret; \ - }) -#else /* __KVM_NVHE_HYPERVISOR__ */ -#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__) -#endif /* __KVM_NVHE_HYPERVISOR__ */ - int handle_exit(struct kvm_vcpu *vcpu, int exception_index); void handle_exit_early(struct kvm_vcpu *vcpu, int exception_index);
--
2.39.5