From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7FDD165F05 for ; Fri, 30 Aug 2024 13:02:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725022924; cv=none; b=XfV3UcLLFU/SjK6T5LMFAIY4mjAQkmLlrix7Jmlt0XDRkZwaqhvUTdZe3OBpK2Tsd2M5IAhvq7zxmzfn4nO+Xuex2DIoqNW0TKfTkc/OyRo79WxtVpfcx9m8m8nRBVnOsJy/He6AXGiJWTJ5Tdi7y+9K/YxvH6TAZtMPc/0Qxu8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725022924; c=relaxed/simple; bh=fOFx+vCt8zSA57KmyUhuAyFmh0/KvJ1/VKXwh9l++u8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=q9y5ujScLg0OUIvaGeIxkmwuRihVmgUkEJWGHjbbWh05XXQPTgBAaWPxIqoddRO9QhxMarhs+KsYsoE45Eu8Mnxt20EdoNPr8gc2jl7DjOA+V5EBrxdcSaVx+dkCrOSPmBdqlnLigMJ4hxELTOQEcQ/ZhqycFVlf+xZiKlgKibw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GAHkh1qT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GAHkh1qT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAD05C4CEC7; Fri, 30 Aug 2024 13:02:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725022924; bh=fOFx+vCt8zSA57KmyUhuAyFmh0/KvJ1/VKXwh9l++u8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GAHkh1qTi7oYPE2zN8n3dhr38w5cisPWLPHf8zTV6iDTr+wsL/iBsDZ6ls1cgLSz5 IF1MXB85RhM1j7YqSwWQXzfQav9PWxOrGxbJYMgzeQwHgmCG/lvM0gezWsbpsRB3JW /OY9Z3P0QqWXjOgrcVsQ5itABnI5/d271z9CacTz+vsGUJHm5lFkqsPj0tF6TiIDu+ Q9FRhm7i0tJe9bdUnfdKuEjb3Z7awrFJHHBF/OaohVyBvW3dN8SFX618xBbje3ycq/ rChwaWsqw/jfyo2qs3LT0B3ds8FEwwoQJ5Me9r8a5NUMX8PDPuC6ubQ9qbdzMTpxkZ tQwX/Dj7SNoOw== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon , Sudeep Holla , Catalin Marinas , Lorenzo Pieralisi , Suzuki Poulose , Steven Price , Oliver Upton , Marc Zyngier , linux-coco@lists.linux.dev Subject: [PATCH v2 4/7] drivers/virt: pkvm: Hook up mem_encrypt API using pKVM hypercalls Date: Fri, 30 Aug 2024 14:01:47 +0100 Message-Id: <20240830130150.8568-5-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240830130150.8568-1-will@kernel.org> References: <20240830130150.8568-1-will@kernel.org> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If we detect the presence of pKVM's SHARE and UNSHARE hypercalls, then register a backend implementation of the mem_encrypt API so that things like DMA buffers can be shared appropriately with the host. Signed-off-by: Will Deacon --- Documentation/virt/kvm/arm/hypercalls.rst | 50 +++++++++++++++++ drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c | 55 +++++++++++++++++++ include/linux/arm-smccc.h | 14 +++++ 3 files changed, 119 insertions(+) diff --git a/Documentation/virt/kvm/arm/hypercalls.rst b/Documentation/virt/kvm/arm/hypercalls.rst index 16515eb42149..c42580e71bf8 100644 --- a/Documentation/virt/kvm/arm/hypercalls.rst +++ b/Documentation/virt/kvm/arm/hypercalls.rst @@ -66,3 +66,53 @@ Query the memory protection parameters for a pKVM protected virtual machine. | Return Values: | (int64) | R0 | ``INVALID_PARAMETER (-3)`` on error, else | | | | | memory protection granule in bytes | +---------------------+----------+----+---------------------------------------------+ + +``ARM_SMCCC_KVM_FUNC_MEM_SHARE`` +-------------------------------- + +Share a region of memory with the KVM host, granting it read, write and execute +permissions. The size of the region is equal to the memory protection granule +advertised by ``ARM_SMCCC_KVM_FUNC_HYP_MEMINFO``. + ++---------------------+-------------------------------------------------------------+ +| Presence: | Optional; pKVM protected guests only. | ++---------------------+-------------------------------------------------------------+ +| Calling convention: | HVC64 | ++---------------------+----------+--------------------------------------------------+ +| Function ID: | (uint32) | 0xC6000003 | ++---------------------+----------+----+---------------------------------------------+ +| Arguments: | (uint64) | R1 | Base IPA of memory region to share | +| +----------+----+---------------------------------------------+ +| | (uint64) | R2 | Reserved / Must be zero | +| +----------+----+---------------------------------------------+ +| | (uint64) | R3 | Reserved / Must be zero | ++---------------------+----------+----+---------------------------------------------+ +| Return Values: | (int64) | R0 | ``SUCCESS (0)`` | +| | | +---------------------------------------------+ +| | | | ``INVALID_PARAMETER (-3)`` | ++---------------------+----------+----+---------------------------------------------+ + +``ARM_SMCCC_KVM_FUNC_MEM_UNSHARE`` +---------------------------------- + +Revoke access permission from the KVM host to a memory region previously shared +with ``ARM_SMCCC_KVM_FUNC_MEM_SHARE``. The size of the region is equal to the +memory protection granule advertised by ``ARM_SMCCC_KVM_FUNC_HYP_MEMINFO``. + ++---------------------+-------------------------------------------------------------+ +| Presence: | Optional; pKVM protected guests only. | ++---------------------+-------------------------------------------------------------+ +| Calling convention: | HVC64 | ++---------------------+----------+--------------------------------------------------+ +| Function ID: | (uint32) | 0xC6000004 | ++---------------------+----------+----+---------------------------------------------+ +| Arguments: | (uint64) | R1 | Base IPA of memory region to unshare | +| +----------+----+---------------------------------------------+ +| | (uint64) | R2 | Reserved / Must be zero | +| +----------+----+---------------------------------------------+ +| | (uint64) | R3 | Reserved / Must be zero | ++---------------------+----------+----+---------------------------------------------+ +| Return Values: | (int64) | R0 | ``SUCCESS (0)`` | +| | | +---------------------------------------------+ +| | | | ``INVALID_PARAMETER (-3)`` | ++---------------------+----------+----+---------------------------------------------+ diff --git a/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c b/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c index a5148701d2f1..8256cf68fd76 100644 --- a/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c +++ b/drivers/virt/coco/pkvm-guest/arm-pkvm-guest.c @@ -9,18 +9,72 @@ #include #include +#include #include #include static size_t pkvm_granule; +static int arm_smccc_do_one_page(u32 func_id, phys_addr_t phys) +{ + phys_addr_t end = phys + PAGE_SIZE; + + while (phys < end) { + struct arm_smccc_res res; + + arm_smccc_1_1_invoke(func_id, phys, 0, 0, &res); + if (res.a0 != SMCCC_RET_SUCCESS) + return -EPERM; + + phys += pkvm_granule; + } + + return 0; +} + +static int __set_memory_range(u32 func_id, unsigned long start, int numpages) +{ + void *addr = (void *)start, *end = addr + numpages * PAGE_SIZE; + + while (addr < end) { + int err; + + err = arm_smccc_do_one_page(func_id, virt_to_phys(addr)); + if (err) + return err; + + addr += PAGE_SIZE; + } + + return 0; +} + +static int pkvm_set_memory_encrypted(unsigned long addr, int numpages) +{ + return __set_memory_range(ARM_SMCCC_VENDOR_HYP_KVM_MEM_UNSHARE_FUNC_ID, + addr, numpages); +} + +static int pkvm_set_memory_decrypted(unsigned long addr, int numpages) +{ + return __set_memory_range(ARM_SMCCC_VENDOR_HYP_KVM_MEM_SHARE_FUNC_ID, + addr, numpages); +} + +static const struct arm64_mem_crypt_ops pkvm_crypt_ops = { + .encrypt = pkvm_set_memory_encrypted, + .decrypt = pkvm_set_memory_decrypted, +}; + void pkvm_init_hyp_services(void) { int i; struct arm_smccc_res res; const u32 funcs[] = { ARM_SMCCC_KVM_FUNC_HYP_MEMINFO, + ARM_SMCCC_KVM_FUNC_MEM_SHARE, + ARM_SMCCC_KVM_FUNC_MEM_UNSHARE, }; for (i = 0; i < ARRAY_SIZE(funcs); ++i) { @@ -34,4 +88,5 @@ void pkvm_init_hyp_services(void) return; pkvm_granule = res.a0; + arm64_mem_crypt_ops_register(&pkvm_crypt_ops); } diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 16b6dcc54e02..9cb7c95920b0 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -116,6 +116,8 @@ #define ARM_SMCCC_KVM_FUNC_FEATURES 0 #define ARM_SMCCC_KVM_FUNC_PTP 1 #define ARM_SMCCC_KVM_FUNC_HYP_MEMINFO 2 +#define ARM_SMCCC_KVM_FUNC_MEM_SHARE 3 +#define ARM_SMCCC_KVM_FUNC_MEM_UNSHARE 4 #define ARM_SMCCC_KVM_FUNC_FEATURES_2 127 #define ARM_SMCCC_KVM_NUM_FUNCS 128 @@ -144,6 +146,18 @@ ARM_SMCCC_OWNER_VENDOR_HYP, \ ARM_SMCCC_KVM_FUNC_HYP_MEMINFO) +#define ARM_SMCCC_VENDOR_HYP_KVM_MEM_SHARE_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_MEM_SHARE) + +#define ARM_SMCCC_VENDOR_HYP_KVM_MEM_UNSHARE_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_MEM_UNSHARE) + /* ptp_kvm counter type ID */ #define KVM_PTP_VIRT_COUNTER 0 #define KVM_PTP_PHYS_COUNTER 1 -- 2.46.0.469.g59c65b2a67-goog