From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=13.77.154.182 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793405680; b=XT0TcVQCPJHKv1QiiAzOTV6JKaqNU5yz+xjAfPYnELg+lquA1OYbDQ1LMdsRLDY3mhIb nz/Vs6MYDI1jaK9XjsFU6UUeVSY0HiJ5YXj5aesB+W8PRzcULgl1cY80eiZqef6f9hQjh Fz56X6BPC9q/X3CPaJtHziM3I0Qc46zFIKQ/KbSRRWTVLcUrcCQoZxsNpCU4kHdzxaDai XgYxFjZtQQEF6BcDNDaWVuA76tzBd+DrRP1hyAaQtYm/xVbgFEM8fDfWBb3kHQUTfKf9w 2ZfexGDYyKr1f4tPxFhnD4dtXBaj3mkoS3hWi/WfTDCf4dZFnR4j0dGSp2qgG6wA2ww== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793405680; h=DMARC-Filter:Received:DKIM-Filter:DKIM-Signature:From:To:Cc:Subject: Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Spam-Status:X-Spam-Checker-Version; bh=ZuhsC/k40xEzF9QkutlorSf7RKQMQyfgDBXyPj/af/8=; b=3tC1G+awvA5lUOEX+O2oPo6tEUzOhRYtKWUs5FP3wDTsmy1kt+CK6PzFqk/497iczFne w157gn6XnuhJEkqnfaTUI8O0IFlmFZEjDgElgcsSPDs+iWbuk5MpTH6A4f5jTXnW9iepO sE9asrylye0H4lOI4sAeStm1pbEp4WHN64Tw94Er+sERLYZaKDOgQH2tIYk1l6qvxpiX3 xeh0wC5+Lim7uzu40ys2dXRQndBvTfjGN5m48RSGzZEzwahM8GkQ9bQEY8pLOJY23u1Z/ xMF3BKn2BvzVg+bakB6SiK+JCQpH3oy4O9U2RksELXN6H8sZmXGCQAyZ+JfIqTidutw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass header.d=linux.microsoft.com header.i=@linux.microsoft.com header.a=rsa-sha256 header.s=default header.b=QbZev5HN; arc=none smtp.remote-ip=13.77.154.182 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B084E606A326; Sat, 31 Oct 2026 00:14:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org B084E606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.a=rsa-sha256 header.s=default header.b=QbZev5HN Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id 94F9920B7169; Fri, 30 Oct 2026 17:14:26 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 94F9920B7169 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1793405666; bh=ZuhsC/k40xEzF9QkutlorSf7RKQMQyfgDBXyPj/af/8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QbZev5HN9VxnKr5TP+oRbN+xtSD+Bog3G8XTFyWvRaLplHmS0cTaiDseJKdjkg8ot q6A2WpJUJtYId4bcSjUDrrbbC6mAmwDYrYCeRwhf2NoIQXqhEU9dV30fiLi8kA0Kiy dOkP2qnv9TUgI2SHsANOQ1rB7dJhtN/oNCO1nNvo= From: Kameron Carr To: decui@microsoft.com, haiyangz@microsoft.com, mhklinux@outlook.com, wei.liu@kernel.org Cc: arnd@arndb.de, catalin.marinas@arm.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, mark.rutland@arm.com, sudeep.holla@kernel.org, thuth@redhat.com, will@kernel.org Subject: [PATCH v6 3/6] arm64: hyperv: Add per-CPU RSI host call infrastructure for CCA Realms Date: Fri, 30 Oct 2026 17:14:09 -0700 Message-ID: <20261031001412.4150488-4-kameroncarr@linux.microsoft.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20261031001412.4150488-1-kameroncarr@linux.microsoft.com> References: <20261031001412.4150488-1-kameroncarr@linux.microsoft.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 | 27 +++++++++++++++++++++++++-- arch/arm64/include/asm/mshyperv.h | 4 ++++ 2 files changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index 82572c5..46ab2da 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -14,12 +14,16 @@ #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, @@ -110,6 +114,20 @@ 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); @@ -131,13 +149,13 @@ 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) @@ -150,6 +168,11 @@ 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