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 59F65CD8CB2 for ; Tue, 9 Jun 2026 18:11:07 +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=LXjuMPLiwcUPBnoVBmjBz90akqs1/NsjpF4nPTQDs60=; b=oE5L4LlY8v1+inrilXJTlO19g+ C8nNCsm4gm3ZBxhkDIAoT+OrMiiMhoz1w1SBP34Mr57KvglSlY7uSOqrudG4xGG8AdaZhgQRDRHY7 vgU0o6LWN4TPyW0VLMJu/FyFzwZB1qY4UKZ5HDJoXWF9fbIKPV2E8NF1krRYlXGC3AQVG1MCmCdjF dHbiqXnunqsH9Bnol5KT7y6xcBYyjdAKufKRRmZq/HkWfgJxKa68K0cy60+IKxmpFCWW7XGAXmMBC FFj7Qmykhy8B6/3WUrefrZGe4Vq/KOGXipn8pHADcFtS2jRH4eNHOTsm4ZfpypTWU5kIvW8s5IfPn dU/fbCRQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wX0uf-00000006AiX-3os9; Tue, 09 Jun 2026 18:10:57 +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 1wX0uZ-00000006Af6-2hbs for linux-arm-kernel@lists.infradead.org; Tue, 09 Jun 2026 18:10:55 +0000 Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id B8A8B20B716B; Tue, 9 Jun 2026 11:10:31 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B8A8B20B716B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1781028631; bh=LXjuMPLiwcUPBnoVBmjBz90akqs1/NsjpF4nPTQDs60=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kyhASEOUvE/IbNTFtEIoIwOO4oVBCy7JHK1FGlbHBcMHtE+XMROVJtryqwUVL93nR 1rxfA/3AVUM/K9uTWljEEDsMY+W4111e7dDeo8z5HblTwAUcRZTlGomeOvHqewPjGW 2nyKhXowSnbFoNzCQg9WwOSel5xgFrgFgxkT0aHM= From: Kameron Carr To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, longli@microsoft.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, mhklinux@outlook.com Subject: [RFC PATCH 2/6] firmware: smccc: Detect hypervisor via RSI host call in CCA Realms Date: Tue, 9 Jun 2026 11:10:26 -0700 Message-ID: <20260609181030.2378391-3-kameroncarr@linux.microsoft.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20260609181030.2378391-1-kameroncarr@linux.microsoft.com> References: <20260609181030.2378391-1-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-20260609_111051_711747_6797D95F X-CRM114-Status: GOOD ( 12.36 ) 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. 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 bdee057db2fd3..6b465e65472b0 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -12,6 +12,12 @@ #include #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; @@ -67,12 +73,45 @@ 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 bool 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) + return false; + + res->a0 = uuid_hc.gprs[0]; + res->a1 = uuid_hc.gprs[1]; + res->a2 = uuid_hc.gprs[2]; + res->a3 = uuid_hc.gprs[3]; + return true; +} +#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()) { + if (!arm_smccc_realm_get_hypervisor_uuid(&res)) + return false; + } 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