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 1CA48CD98CA for ; Tue, 9 Jun 2026 18:11:04 +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=xGLsNEvgsOokSRt2P87m8r94Kd1xZNQ7RfME0Rovs8A=; b=xX22IR1o+b86m2jFiE9WHzNn/B NnB4KeSXO0aS11EeGhYxuMU6jYyQcvqwjZ4Et82GJfygSGgEkRNjqO6Q2b4YbnepVc5TbilHkL+4W jzNtivUTVd9Vz++BVb3fEW+dVwpVWe2OsVtOfLdzd0m7zaBQQNkN8W5nDvDvy2N1AqM0c3KLJRXID TX9S7yCfo4TjNDgKpo3R575xWLmz5nWt5lr0lum1LgN4X7M7QvzjNrX6au7ECvGzN6XzPT0iPKC+I HB25ZxPTKwFdoJ2Mk/B3jD76qMWZNoH/eW5+dWW24QT0CMuBq1XG4n/YKoPJHmvmPJTdS9PiKDc48 Djh97vtw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wX0ue-00000006AhS-3Zsj; Tue, 09 Jun 2026 18:10:56 +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-00000006Aer-0TBO for linux-arm-kernel@lists.infradead.org; Tue, 09 Jun 2026 18:10:54 +0000 Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id E9F1920B716C; Tue, 9 Jun 2026 11:10:32 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com E9F1920B716C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1781028633; bh=xGLsNEvgsOokSRt2P87m8r94Kd1xZNQ7RfME0Rovs8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IuJ7iNidMDVBOuCO1DnLihoOhHsa1FexmfVhEgCgDclLZQeFgjqnmqHew9RRny7cS qGwc/8OlCSOjyJ/XT6gajMFqGMP9fs+W65XCLqG+ccLlksEtnVT3kUjcxuEXZbVHF0 5qHaQ0oosmF9RpFqsWrvFdqwnxH0Dm5xNHGGdxTY= 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 4/6] Drivers: hv: Mark shared memory as decrypted for CCA Realms Date: Tue, 9 Jun 2026 11:10:28 -0700 Message-ID: <20260609181030.2378391-5-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_235129_B5DD45FC X-CRM114-Status: GOOD ( 11.54 ) 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 In hv_common_cpu_init(), the per-CPU hypercall input/output pages need to be marked as decrypted (shared) for confidential VM isolation types. This is already done for SNP and TDX isolation; extend the same handling to Arm CCA Realm guests so that the host hypervisor can access the shared hypercall buffers. is_realm_world() is only declared in arch/arm64/include/asm/rsi.h, so using it directly in the arch-neutral drivers/hv/hv_common.c would break the x86 build. Introduce a Hyper-V-specific helper following the established hv_isolation_type_snp() / hv_isolation_type_tdx() pattern. On architectures other than arm64 the weak default keeps the existing behaviour. Signed-off-by: Kameron Carr --- arch/arm64/hyperv/mshyperv.c | 5 +++++ drivers/hv/hv_common.c | 9 ++++++++- include/asm-generic/mshyperv.h | 1 + 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index 08fec82691683..b595b2b9bdbbb 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -208,3 +208,8 @@ bool hv_is_hyperv_initialized(void) return hyperv_initialized; } EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); + +bool hv_isolation_type_cca(void) +{ + return is_realm_world(); +} diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 6b67ac6167891..010c7d98b5de1 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -499,7 +499,8 @@ int hv_common_cpu_init(unsigned int cpu) } if (!ms_hyperv.paravisor_present && - (hv_isolation_type_snp() || hv_isolation_type_tdx())) { + (hv_isolation_type_snp() || hv_isolation_type_tdx() || + hv_isolation_type_cca())) { ret = set_memory_decrypted((unsigned long)mem, pgcount); if (ret) { /* It may be unsafe to free 'mem' */ @@ -666,6 +667,12 @@ bool __weak hv_isolation_type_tdx(void) } EXPORT_SYMBOL_GPL(hv_isolation_type_tdx); +bool __weak hv_isolation_type_cca(void) +{ + return false; +} +EXPORT_SYMBOL_GPL(hv_isolation_type_cca); + void __weak hv_setup_vmbus_handler(void (*handler)(void)) { } diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index bf601d67cecb9..1fa79abce743c 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -79,6 +79,7 @@ u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); bool hv_isolation_type_snp(void); bool hv_isolation_type_tdx(void); +bool hv_isolation_type_cca(void); /* * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), -- 2.45.4