From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B8F8B49250F; Tue, 9 Jun 2026 18:10:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781028651; cv=none; b=UnEqCJhL7Mc9VsZluqsbi3jNZcPkUXyDzAZf488hXMfjN4iH4q6kWRiO5UxSNV4VXqiE5oPtCZm0eziNrOAuUKnq8zwoqnkq5wXEX1KKhrbUVt3TR+gB0nhSq7CCRwiKUtmQcMKerK+M4arA1YNe4Vl1kp9PmqAzXpLc1WzR1c8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781028651; c=relaxed/simple; bh=YvrRnYgFRPT3pktew9Oa0h+yh61Hi+hMc8epaXZyJlE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F34NGVuuh0W6Y0K1hsbcWO62zxm5uEzKmkgSF/GXkpPTZ+qypS371Cyf4/Ng+4amNEtvWYadXKf3QPj+GQ7/dMsOOqcDVv24pXGauu5W3W95JWn30jye2pCgFfF3RhNQhP6NjJyX5+q6pMGQTyd327t/k7wFSTD/J/DJ5t0ZAMI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=IuJ7iNid; arc=none smtp.client-ip=13.77.154.182 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) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="IuJ7iNid" 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> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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