From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (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 8046143B6DB for ; Mon, 20 Jul 2026 17:15:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784567733; cv=none; b=rSMuYl4gizb0PWQjxBpL7YICYEINYvqP9q6BG/euaTtChKPXgluko9zR2k0cmLO3JRNl0r+wycN0tKVovavYrscj/RlUTz5/zpR0bdgPZ9nQVv2ZvkIDi9ZDbyj+oC2w0COktn4ZI/Hwryw1MB9kL+tDLJIq+S44yvs1FTMt260= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784567733; c=relaxed/simple; bh=KWjY7KEwm5mrqMvkaXjHCkfstVbsKNxqid61ShSpXAQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=f4NGA5rWVjdCXnwi66GecGpEdXvO9OOTuju4SX8gRAngfZ52LabhtJdYC5VIVw7wYTLro2HAgYahfnflRZ+dnQyerywgYMiyalMUUu8b+ii89FEvhveKSfgNiwqczZ7tIQ270a7UuhWkOLvKUGCYPFbc2OI1fvnidkHnirUI5mo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ULXYvC3u; arc=none smtp.client-ip=209.85.221.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ULXYvC3u" Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-47f7039fa59so1405174f8f.1 for ; Mon, 20 Jul 2026 10:15:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784567725; x=1785172525; darn=lists.linux.dev; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=9EDcUHf3Kk99Ex6b5W7LiX0AGyNeBjN/Qnlhy4ronBE=; b=ULXYvC3uVtg5WWXs3ij7JUoO8fuVOwPECnSS5JXS3ojU2jHv4Ia0W4DLK2zp2o6UX0 S9e+OMfIM2M2yRtdupM4daoWHtbKrHJ/ci8h3kj1HG7+MIypa74SCx2EXxWYHNwHduDA US+t6tZKiSQpz2fYOPt49gtta7edAYbuwb9C5e87aNf/hofNpGjMBWwGHjvqVfxmV3gq onNx65ywFP9GMJAThQHhMnagDymVu03Wx1Tj1UX25+W8ZysvumEI31jY88jlS4WW6q9M ZH+HcVhjCde9kuv8V3hm+ZEpyZlVH75yVwvZtwR5gaIJkf1DOQh2BaokXfuBaC8Bv1kI lBZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784567725; x=1785172525; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=9EDcUHf3Kk99Ex6b5W7LiX0AGyNeBjN/Qnlhy4ronBE=; b=KO/LcNUbNlALoD44hLmyS1al7LvNhgQi8ImYK7AHtkEUFXIyocoHl4yNw/xf3lsW1h nC03Cq7XGyOhCY6ZRSHPRTp9r68carBzsGdNJtqQx5GVg6hs3s7tE9dJlDvWslJNVrvf pV/TzB2jOe6nFZtieVgrC905nQVfcKuVSSjniELsWgYViJ/aYHE1VgUD50bYXpSxtlom hoEusc+nJzHbOjDPBiRpoJJCAju4IjXuwomKyoB0SXEl9KydeA9lASkbQ/GA/Vfom2Eh bbFlgJNd/MFuCKEmk+wXRNvnqkzpeKc/yZJZ+fXZLQoWSuXdMAG5sL6Njc9Vwy7d+sas 9ElQ== X-Forwarded-Encrypted: i=1; AHgh+RoTHP6a7e9TRSpx6Gxn0iw6ythetATL1C2ens/4SsH6q9EKIKLFgFeCaf97c+fRDgIT9Uk70jU=@lists.linux.dev X-Gm-Message-State: AOJu0YyISPTfmORKy4Xe972lCIIXp9I7IhQobCxU7Au99unpivoLQax5 XCPCfxKbMaj6ADw2wHXGnLFiD2R3BwU2fr81Gcosv1A9sePYNDtu4RLtdhmQMD5ihQtuQTbZHTM trig+Uylpyf+S2YqKzx21Ow== X-Received: from wrbgl14-n1.prod.google.com ([2002:a05:6000:298e:10b0:47a:28e:de6a]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:4696:b0:46e:8226:96b1 with SMTP id ffacd0b85a97d-47f62337b71mr11435453f8f.42.1784567725343; Mon, 20 Jul 2026 10:15:25 -0700 (PDT) Date: Mon, 20 Jul 2026 18:15:02 +0100 In-Reply-To: <20260720171513.1415357-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260720171513.1415357-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog Message-ID: <20260720171513.1415357-7-vdonnefort@google.com> Subject: [PATCH v3 06/17] KVM: arm64: Add pkvm_hyp_req infrastructure From: Vincent Donnefort To: maz@kernel.org, oupton@kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, kernel-team@android.com, tabba@google.com, qperret@google.com, Vincent Donnefort , Fuad Tabba Content-Type: text/plain; charset="UTF-8" Introduce a struct pkvm_hyp_req to enable the pKVM hypervisor to request resources from the host. Provide serialisation helpers to transport these requests via SMCCC registers (starting from a2): pkvm_hyp_req_to_smccc() to encode into the SMCCC args. smccc_to_pkvm_hyp_req() to decode them. When the hypervisor raises a request, the host must handle it and retry the HVC. To automate this sequence, introduce the pkvm_call_hyp_req() macro. This intercepts pending requests, invokes the handler and retries the HVC. Additionally, introduce a trace event to track the handling of these requests. Signed-off-by: Vincent Donnefort Reviewed-by: Fuad Tabba diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index 74fedd9c5ff0..6c2497047f8d 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -199,6 +199,95 @@ struct pkvm_mapping { u64 __subtree_last; /* Internal member for interval tree */ }; +enum pkvm_hyp_req_type { + PKVM_HYP_NO_REQ = 0, + __PKVM_HYP_REQ_TYPE_MAX, +}; + +#define PKVM_HYP_REQ_SMCCC_ARG_SIZE_MAX \ + (sizeof(struct arm_smccc_res) - offsetof(struct arm_smccc_res, a2) - 1) + +struct pkvm_hyp_req { + u8 type; + union { + struct { + u32 nr_pages; + } mem; + struct { + /* Helper for SMCCC encoding/decoding */ + u8 args[PKVM_HYP_REQ_SMCCC_ARG_SIZE_MAX]; + } args; + }; +}; + +static inline size_t pkvm_hyp_req_arg_size(u8 type) +{ + switch (type) { + case PKVM_HYP_NO_REQ: + return 0; + default: + WARN_ON(1); + } + + return 0; +} + +/* Encode the pending pkvm_hyp_req type into the SMCCC args */ +static inline void +pkvm_hyp_req_to_smccc(struct kvm_cpu_context *host_ctxt, struct pkvm_hyp_req *req) +{ + u8 *dst, type = req->type; + size_t size; + + if (type == PKVM_HYP_NO_REQ || type >= __PKVM_HYP_REQ_TYPE_MAX) { + host_ctxt->regs.regs[2] = 0; + return; + } + + size = pkvm_hyp_req_arg_size(type); + if (WARN_ON(size > PKVM_HYP_REQ_SMCCC_ARG_SIZE_MAX)) + return; + + dst = (u8 *)&host_ctxt->regs.regs[2]; + *dst = type; + + memcpy(dst + 1, &req->args, size); +} + +/* Return true if a pkvm_hyp_req has been decoded from the SMCCC args */ +static inline bool smccc_to_pkvm_hyp_req(struct pkvm_hyp_req *req, struct arm_smccc_res *res) +{ + u8 *src = (u8 *)res + offsetof(struct arm_smccc_res, a2); + u8 type = *src; + + if (type == PKVM_HYP_NO_REQ || type >= __PKVM_HYP_REQ_TYPE_MAX) + return false; + + req->type = type; + memcpy(&req->args, src + 1, pkvm_hyp_req_arg_size(type)); + + return true; +} + +int __pkvm_handle_smccc_req(struct arm_smccc_res *res); + +#define pkvm_call_hyp_req(f, ...) \ +({ \ + struct arm_smccc_res __res; \ + int __ret; \ + do { \ + __ret = -1; \ + arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(f), ##__VA_ARGS__, &__res); \ + if (WARN_ON(__res.a0 != SMCCC_RET_SUCCESS)) \ + break; \ + __ret = __res.a1; \ + if (!__ret) \ + break; \ + __ret = __pkvm_handle_smccc_req(&__res); \ + } while (!__ret); \ + __ret; \ +}) + int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, struct kvm_pgtable_mm_ops *mm_ops); void pkvm_pgtable_stage2_destroy_range(struct kvm_pgtable *pgt, diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index d2681da0b629..a626978dc91f 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -16,6 +16,9 @@ #include "hyp_constants.h" +#define CREATE_TRACE_POINTS +#include "trace_pkvm.h" + DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory); @@ -590,3 +593,25 @@ bool pkvm_force_reclaim_guest_page(phys_addr_t phys) return !ret || ret == -EAGAIN; } + +static int pkvm_handle_hyp_req(struct pkvm_hyp_req *req) +{ + int ret = -EINVAL; + + switch (req->type) { + } + + trace_kvm_handle_pkvm_hyp_req(req, ret); + + return ret; +} + +int __pkvm_handle_smccc_req(struct arm_smccc_res *res) +{ + struct pkvm_hyp_req req; + + if (smccc_to_pkvm_hyp_req(&req, res)) + return pkvm_handle_hyp_req(&req); + + return res->a1; +} diff --git a/arch/arm64/kvm/trace_pkvm.h b/arch/arm64/kvm/trace_pkvm.h new file mode 100644 index 000000000000..3966c111e3ad --- /dev/null +++ b/arch/arm64/kvm/trace_pkvm.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#if !defined(_TRACE_PKVM_ARM64_KVM_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PKVM_ARM64_KVM_H + +#include +#include + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM kvm + +TRACE_DEFINE_ENUM(PKVM_HYP_NO_REQ); + +#define PKVM_HYP_REQ_TYPES \ + { PKVM_HYP_NO_REQ, "NO_REQ" } + +TRACE_EVENT(kvm_handle_pkvm_hyp_req, + TP_PROTO(struct pkvm_hyp_req *req, int ret), + TP_ARGS(req, ret), + + TP_STRUCT__entry( + __field(u8, type) + __field(int, ret) + ), + + TP_fast_assign( + __entry->type = req->type; + __entry->ret = ret; + ), + + TP_printk("type: %s ret: %d", + __print_symbolic(__entry->type, PKVM_HYP_REQ_TYPES), + __entry->ret) +); + +#endif /* _TRACE_PKVM_ARM64_KVM_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace_pkvm + +/* This part must be outside protection */ +#include -- 2.55.0.229.g6434b31f56-goog