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 090BFCA5FE6 for ; Fri, 2 Oct 2026 21:59:20 +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-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=b2GtJHBzDcmYlbHghwmtxMILKeFIMO+Ff8lGch7jV0Q=; b=1wJFd/gSKtP3TIYgWNckh60n1p ymPvE7s93iDl010t2jwSO8D57VkqJHPvgzIL6VHp7nR2lSbvfia9n1Bo18cpbdbx/ZkMxYa2AlSio FGPEG+6KRQceJH2OG7QdqHqZ8RVNlYnz3/rUEp8seQtHsriGM/Zj+vjmNmIHUS366p+LAZhhdGHyG jv/zM4IvBSv/FziCtb+2Z0Qow+RFbby2x8n5gGqOtoTwyGspBKxrJIhF81/idjU4/mXcAlGueRdkg MMH1ZM/e+wR/Mn+8Yxb3DBTJREuZ5mKbLicbTpPSGujs7vV6qJiGxSK/cnQpz88vmgcfloL4RJRY5 ZhoSr7xw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xClHS-0000000CZCM-1cOT; Fri, 02 Oct 2026 21:59:02 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xClHM-0000000CZ9A-2K9j for linux-arm-kernel@lists.infradead.org; Fri, 02 Oct 2026 21:58:57 +0000 Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id 2431820B7169; Fri, 2 Oct 2026 14:58:01 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2431820B7169 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1790978281; bh=b2GtJHBzDcmYlbHghwmtxMILKeFIMO+Ff8lGch7jV0Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bY/eCuPtmV+/cl9lGxAHg9mVkeIqewu+FwiHuWbNU6TkRDLg0RCJPMYgsbXZb9yZp 4roTg0N7pVxP5vzT5OM13fXad3Pj7EXUahyzKsH3VP8hc1VmmzPBaK+5db670FZy4p uPnx5WAkoFJIQIqLQPRQcDCGh4OYDFxdfbF01FHU= From: Kameron Carr To: haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, mhklinux@outlook.com Cc: catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, lpieralisi@kernel.org, sudeep.holla@kernel.org, arnd@arndb.de, thuth@redhat.com, linux-hyperv@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: [PATCH v5 3/6] arm64: hyperv: Add per-CPU RSI host call infrastructure for CCA Realms Date: Fri, 2 Oct 2026 14:57:22 -0700 Message-ID: <20261002215725.2015959-4-kameroncarr@linux.microsoft.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20261002215725.2015959-1-kameroncarr@linux.microsoft.com> References: <20261002215725.2015959-1-kameroncarr@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261002_145856_613684_93D9BB0E X-CRM114-Status: GOOD ( 15.35 ) 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 Arm CCA Realms cannot issue Hyper-V hypercalls via HVC; the guest must route them through the RSI_HOST_CALL interface, which takes the IPA of a per-CPU rsi_host_call structure as its argument. Add hv_hostcall_array as a per-CPU struct array and allocate it during hyperv_init(). The allocation is gated on is_realm_world() so non-Realm arm64 Hyper-V guests pay no memory cost. Reviewed-by: Michael Kelley Signed-off-by: Kameron Carr --- arch/arm64/hyperv/mshyperv.c | 28 ++++++++++++++++++++++++++-- arch/arm64/include/asm/mshyperv.h | 4 ++++ 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index 4fdc26a..b1657cf 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -11,14 +11,19 @@ #include #include +#include #include #include +#include #include #include #include static bool hyperv_initialized; +struct rsi_host_call *hv_hostcall_array; +EXPORT_SYMBOL_GPL(hv_hostcall_array); + int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) { hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, @@ -85,6 +90,20 @@ static int __init hyperv_init(void) if (!hyperv_detect_via_acpi() && !hyperv_detect_via_smccc()) return 0; + /* + * The RSI host-call buffers are only ever used when + * is_realm_world() is true. Skip the allocation on non-Realm + * guests. A single contiguous array of nr_cpu_ids entries is + * allocated; each CPU indexes into it by its processor ID. + */ + if (is_realm_world()) { + hv_hostcall_array = kcalloc(nr_cpu_ids, + sizeof(struct rsi_host_call), + GFP_KERNEL); + if (!hv_hostcall_array) + return -ENOMEM; + } + /* Setup the guest ID */ guest_id = hv_generate_guest_id(LINUX_VERSION_CODE); hv_set_vpreg(HV_REGISTER_GUEST_OS_ID, guest_id); @@ -106,13 +125,13 @@ static int __init hyperv_init(void) ret = hv_common_init(); if (ret) - return ret; + goto free_hostcall_mem; ret = cpuhp_setup_state(CPUHP_AP_HYPERV_ONLINE, "arm64/hyperv_init:online", hv_common_cpu_init, hv_common_cpu_die); if (ret < 0) { hv_common_free(); - return ret; + goto free_hostcall_mem; } if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID) @@ -125,6 +144,11 @@ static int __init hyperv_init(void) hyperv_initialized = true; return 0; + +free_hostcall_mem: + kfree(hv_hostcall_array); + hv_hostcall_array = NULL; + return ret; } early_initcall(hyperv_init); diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h index b721d31..aed0aa5 100644 --- a/arch/arm64/include/asm/mshyperv.h +++ b/arch/arm64/include/asm/mshyperv.h @@ -61,6 +61,10 @@ static inline u64 hv_get_non_nested_msr(unsigned int reg) ARM_SMCCC_OWNER_VENDOR_HYP, \ HV_SMCCC_FUNC_NUMBER) +/* Per-CPU-indexed RSI host call structures for CCA Realms */ +struct rsi_host_call; +extern struct rsi_host_call *hv_hostcall_array; + #include #endif -- 2.45.4