From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 47966C44502 for ; Mon, 6 Jul 2026 17:54:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=mMzZELxNMWkvZmpbYeYedfqqEOctYU5iyYuamj2u6LM=; b=zgL23xOgywKjA3HPpXR1Cae5Md 7MChXJFapDQQn7rqqX/QpTqJFr6Y7c6oo2reCaVc7RyAInewSeMjJgWoFbhveFwANhn5HeUYs0SyL h/y7JfZKbkJdYlr6IC+qzHmsD3T3BtgKUcH4zb1s1kv/S5x6wtUWT9gJNJSuHefQtzMQZkyA413OF TqKdnCcIMLd5oPFCEKaxGZsnHAEl2FI51pGRG2RyeTQCM28VJoEfDtY+YKkz+SJCzeGpA3KTV2VsD unSnUo7luo9zUJt9CVnWvnj4JQj+s8hDtuj9hcw+oD31w0MuOPEYrjV4Kk6CG/p2jNtQNgARUQOV+ FM0EZaQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgnWl-0000000DFla-2S7C; Mon, 06 Jul 2026 17:54:43 +0000 Received: from mail-wm1-x349.google.com ([2a00:1450:4864:20::349]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgnWZ-0000000DFbG-3jae for linux-arm-kernel@lists.infradead.org; Mon, 06 Jul 2026 17:54:37 +0000 Received: by mail-wm1-x349.google.com with SMTP id 5b1f17b1804b1-493c619bb52so23525385e9.1 for ; Mon, 06 Jul 2026 10:54:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783360470; x=1783965270; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=mMzZELxNMWkvZmpbYeYedfqqEOctYU5iyYuamj2u6LM=; b=C604P2a6qelUe5AzwRtKix45OWi4QRcBJE/b7Pd2tJjyg2YFvmW2vA44LdMtGnUW7m FBPgoYMHHy3Xo88jST3YJrtLHupyv0NWEe6Hq0V0Ug2d7PGXyYSijtxTtsnXa25W8WpC 6TmbZqTBBGMUlTQbywQRw2E07trW9mqcnGDO3B/fIGBNvsBVG89JERw2XbmeCk2YiE8I xL1Az6utqjsRfXO3H2ySxHsmicSlkMqTu9L9FQXWTjFtHQjrBMn5u0uF+N1eql646rVd 9DUrTi+/XJ9nGVVYJkBpDLazMxMDyntDd2bsKIpbAouArxVoAYFnstONrdMO7Hzqf4r6 ItLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783360470; x=1783965270; h=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; bh=mMzZELxNMWkvZmpbYeYedfqqEOctYU5iyYuamj2u6LM=; b=DJR4FU4NrG94q8WeAFkzkuHB71v0dfhEJnpfVfvMch4fhBOETTtwMGCO1Ba+N/BbqG MJJOFjD/RrUiVskLfsWUZdWeFbv2Rb+tdDnQ00wMDKLEYCfFPLSzx6Qqiv6/FTPZDlm3 ZbfSyf/JuQNu/Rpa8SZscLihOAbNu/m8VICw5razmtZeN0gMa4EukgQMDwNyWjkRMYvL XrWa0aWO3P4fo6qyJIQqZz8yLDqc/0knPTNfzPtjIL65GG/0awMMf1r6FxSGtJE0DWo9 TM4XyukRuh6R83FC0+Ygz2pP3SkIsg62FnubXIlEimuqK5NdhWZk3BhzMkqCM+wKOetB 6y5A== X-Gm-Message-State: AOJu0YyF9VKjA8oXsW+lTfcnycnB/U9JVJ6QCxY0AdSKZibikkV28NPX vTgsm81DsFgn+M2wvlFAlpLYBS6Pqa+KSs/ClRUrA0Z2y3UU2kHUtFF6sJTLJzEZp4xbEHqX+LJ QmLU5Jx0CpxKdnNaYAhe48w== X-Received: from wmhf18.prod.google.com ([2002:a7b:cc12:0:b0:492:4659:9cd8]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:19c6:b0:493:b03c:5650 with SMTP id 5b1f17b1804b1-493df06d8cdmr18355405e9.19.1783360469509; Mon, 06 Jul 2026 10:54:29 -0700 (PDT) Date: Mon, 6 Jul 2026 18:54:04 +0100 In-Reply-To: <20260706175415.2604046-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20260706175415.2604046-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.rc2.803.g1fd1e6609c-goog Message-ID: <20260706175415.2604046-8-vdonnefort@google.com> Subject: [PATCH v2 07/18] KVM: arm64: Add pkvm_hyp_req infrastructure From: Vincent Donnefort To: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kernel-team@android.com, qperret@google.com, tabba@google.com, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260706_105432_007468_01DF402D X-CRM114-Status: GOOD ( 18.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index 870f7870bb62..0be1469e7874 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -203,6 +203,95 @@ 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 e2c8714e8ccc..5ba8b81b8c6c 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); @@ -617,3 +620,25 @@ 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..4bf57c12e7de --- /dev/null +++ b/arch/arm64/kvm/trace_pkvm.h @@ -0,0 +1,37 @@ +/* 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_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: %u ret: %d", + __entry->type, __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.rc2.803.g1fd1e6609c-goog