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 7CEDFCA5FD2 for ; Thu, 1 Oct 2026 22:07:12 +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=yt0d7f0K7RTpFyUxmS5k853unes0VcTfu1z72WXMx1g=; b=uyqjD2Exn3gYWFdvh47wdWbYrl A1E7gxC7TRthb3wq36XrI6fbo5/euR1L9Lkaa+PiW0DJSTV/wfwMXQTvkhxWOTxQMcAJcYn2qgOXH R/o371AHXXZVglpViKMvt6ewbflBRzBXAgRkuoPegaMKh8dqE+zVKfGi9CcH0qfUr0ik7SEXUYVff BPKFOiOUTfX0XVBEBtfsCbd/leklAnCZJDxgtpBciNo+SINfzJFyRXbRRli73YZ/Zr2OYULQ2ruaG NPJxECTpS6aVEaFKI9RDaVrlhJG1i4gXLBFQ3YjHnYlEr2vKTnUWNovIFTfplqHS5ZBar5ZprDrYE Oer+uGnw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCOvi-0000000AK8b-1CN9; Thu, 01 Oct 2026 22:07:06 +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 1xCOvd-0000000AK5z-2LWL for linux-arm-kernel@lists.infradead.org; Thu, 01 Oct 2026 22:07:03 +0000 Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id D727420B7168; Thu, 1 Oct 2026 15:06:06 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D727420B7168 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1790892366; bh=yt0d7f0K7RTpFyUxmS5k853unes0VcTfu1z72WXMx1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GsI7nSMyUm9bkvwFV59pXbAzRZ1rtG+7DY7ghLfWUrh3Sw+ODLhNkYrcHrCNhDaz4 6f7RekhhHZ6erFXPQd+wY+Uu3gHrGfN1Ox0jhBEJPuNcuUW2xljC5TEQEXBf63ffn3 0IpNNNkuFMLcabLHq7wPHJn0iNDC+tgJfyUrmbkk= From: Kameron Carr To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, longli@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 v4 2/6] firmware: smccc: Detect hypervisor via RSI host call in CCA Realms Date: Thu, 1 Oct 2026 15:05:48 -0700 Message-ID: <20261001220552.1793471-3-kameroncarr@linux.microsoft.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20261001220552.1793471-1-kameroncarr@linux.microsoft.com> References: <20261001220552.1793471-1-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-20261001_150701_627317_720DE6E5 X-CRM114-Status: GOOD ( 12.29 ) 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 Modify arm_smccc_hypervisor_has_uuid() to check is_realm_world() and use rsi_host_call() to query the hypervisor vendor UUID when inside a Realm. The realm path is factored into a helper, arm_smccc_realm_get_hypervisor_uuid(), that owns a file-static rsi_host_call buffer (uuid_hc) serialized by a spinlock. The RSI-specific includes, file-static state and helper are guarded with CONFIG_ARM64 because does not exist on 32-bit ARM. For non-Realm environments, the existing arm_smccc_1_1_invoke() path is unchanged. Reviewed-by: Michael Kelley Signed-off-by: Kameron Carr --- drivers/firmware/smccc/smccc.c | 41 +++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c index afc2e4d..7e77170 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -14,6 +14,12 @@ #include +#ifdef CONFIG_ARM64 +#include +#include +#include +#endif + static u32 smccc_version = ARM_SMCCC_VERSION_1_0; static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE; @@ -69,12 +75,45 @@ s32 arm_smccc_get_soc_id_revision(void) } EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_revision); +#ifdef CONFIG_ARM64 +static struct rsi_host_call uuid_hc; +static DEFINE_SPINLOCK(uuid_hc_lock); + +/* + * Helper function to get the hypervisor UUID via an RsiHostCall. + */ +static void arm_smccc_realm_get_hypervisor_uuid(struct arm_smccc_res *res) +{ + guard(spinlock_irqsave)(&uuid_hc_lock); + + memset(&uuid_hc, 0, sizeof(uuid_hc)); + uuid_hc.gprs[0] = ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID; + + if (rsi_host_call(__pa_symbol(&uuid_hc)) != RSI_SUCCESS) { + res->a0 = SMCCC_RET_NOT_SUPPORTED; + return; + } + + res->a0 = uuid_hc.gprs[0]; + res->a1 = uuid_hc.gprs[1]; + res->a2 = uuid_hc.gprs[2]; + res->a3 = uuid_hc.gprs[3]; +} +#endif + bool arm_smccc_hypervisor_has_uuid(const uuid_t *hyp_uuid) { struct arm_smccc_res res = {}; uuid_t uuid; - arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res); +#ifdef CONFIG_ARM64 + if (is_realm_world()) + arm_smccc_realm_get_hypervisor_uuid(&res); + else +#endif + arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, + &res); + if (res.a0 == SMCCC_RET_NOT_SUPPORTED) return false; -- 2.45.4