From: Steven Price <steven.price@arm.com>
To: kvm@vger.kernel.org, kvmarm@lists.linux.dev
Cc: Sami Mujawar <sami.mujawar@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
James Morse <james.morse@arm.com>,
Oliver Upton <oliver.upton@linux.dev>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Joey Gouly <joey.gouly@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Fuad Tabba <tabba@google.com>,
linux-coco@lists.linux.dev,
Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
Steven Price <steven.price@arm.com>
Subject: [PATCH v2 14/14] virt: arm-cca-guest: TSM_REPORT support for realms
Date: Fri, 12 Apr 2024 09:42:13 +0100 [thread overview]
Message-ID: <20240412084213.1733764-15-steven.price@arm.com> (raw)
In-Reply-To: <20240412084213.1733764-1-steven.price@arm.com>
From: Sami Mujawar <sami.mujawar@arm.com>
Introduce an arm-cca-guest driver that registers with
the configfs-tsm module to provide user interfaces for
retrieving an attestation token.
When a new report is requested the arm-cca-guest driver
invokes the appropriate RSI interfaces to query an
attestation token.
The steps to retrieve an attestation token are as follows:
1. Mount the configfs filesystem if not already mounted
mount -t configfs none /sys/kernel/config
2. Generate an attestation token
report=/sys/kernel/config/tsm/report/report0
mkdir $report
dd if=/dev/urandom bs=64 count=1 > $report/inblob
hexdump -C $report/outblob
rmdir $report
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
drivers/virt/coco/Kconfig | 2 +
drivers/virt/coco/Makefile | 1 +
drivers/virt/coco/arm-cca-guest/Kconfig | 11 +
drivers/virt/coco/arm-cca-guest/Makefile | 2 +
.../virt/coco/arm-cca-guest/arm-cca-guest.c | 208 ++++++++++++++++++
5 files changed, 224 insertions(+)
create mode 100644 drivers/virt/coco/arm-cca-guest/Kconfig
create mode 100644 drivers/virt/coco/arm-cca-guest/Makefile
create mode 100644 drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
diff --git a/drivers/virt/coco/Kconfig b/drivers/virt/coco/Kconfig
index 87d142c1f932..4fb69804b622 100644
--- a/drivers/virt/coco/Kconfig
+++ b/drivers/virt/coco/Kconfig
@@ -12,3 +12,5 @@ source "drivers/virt/coco/efi_secret/Kconfig"
source "drivers/virt/coco/sev-guest/Kconfig"
source "drivers/virt/coco/tdx-guest/Kconfig"
+
+source "drivers/virt/coco/arm-cca-guest/Kconfig"
diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile
index 18c1aba5edb7..a6228a1bf992 100644
--- a/drivers/virt/coco/Makefile
+++ b/drivers/virt/coco/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_TSM_REPORTS) += tsm.o
obj-$(CONFIG_EFI_SECRET) += efi_secret/
obj-$(CONFIG_SEV_GUEST) += sev-guest/
obj-$(CONFIG_INTEL_TDX_GUEST) += tdx-guest/
+obj-$(CONFIG_ARM_CCA_GUEST) += arm-cca-guest/
diff --git a/drivers/virt/coco/arm-cca-guest/Kconfig b/drivers/virt/coco/arm-cca-guest/Kconfig
new file mode 100644
index 000000000000..c4039c10dce2
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-guest/Kconfig
@@ -0,0 +1,11 @@
+config ARM_CCA_GUEST
+ tristate "Arm CCA Guest driver"
+ depends on ARM64
+ default m
+ select TSM_REPORTS
+ help
+ The driver provides userspace interface to request and
+ attestation report from the Realm Management Monitor(RMM).
+
+ If you choose 'M' here, this module will be called
+ realm-guest.
diff --git a/drivers/virt/coco/arm-cca-guest/Makefile b/drivers/virt/coco/arm-cca-guest/Makefile
new file mode 100644
index 000000000000..69eeba08e98a
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-guest/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ARM_CCA_GUEST) += arm-cca-guest.o
diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
new file mode 100644
index 000000000000..2c15ff162da0
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/cc_platform.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <linux/tsm.h>
+#include <linux/types.h>
+
+#include <asm/rsi.h>
+
+/**
+ * struct arm_cca_token_info - a descriptor for the token buffer.
+ * @granule: PA of the page to which the token will be written
+ * @offset: Offset within granule to start of buffer in bytes
+ * @len: Number of bytes of token data that was retrieved
+ * @result: result of rsi_attestation_token_continue operation
+ */
+struct arm_cca_token_info {
+ phys_addr_t granule;
+ unsigned long offset;
+ int result;
+};
+
+/**
+ * arm_cca_attestation_continue - Retrieve the attestation token data.
+ *
+ * @param: pointer to the arm_cca_token_info
+ *
+ * Attestation token generation is a long running operation and therefore
+ * the token data may not be retrieved in a single call. Moreover, the
+ * token retrieval operation must be requested on the same CPU on which the
+ * attestation token generation was initialised.
+ * This helper function is therefore scheduled on the same CPU multiple
+ * times until the entire token data is retrieved.
+ */
+static void arm_cca_attestation_continue(void *param)
+{
+ unsigned long len;
+ unsigned long size;
+ struct arm_cca_token_info *info;
+
+ if (!param)
+ return;
+
+ info = (struct arm_cca_token_info *)param;
+
+ size = GRANULE_SIZE - info->offset;
+ info->result = rsi_attestation_token_continue(info->granule,
+ info->offset, size, &len);
+ info->offset += len;
+}
+
+/**
+ * arm_cca_report_new - Generate a new attestation token.
+ *
+ * @report: pointer to the TSM report context information.
+ * @data: pointer to the context specific data for this module.
+ *
+ * Initialise the attestation token generation using the challenge data
+ * passed in the TSM decriptor. Allocate memory for the attestation token
+ * and schedule calls to retrieve the attestation token on the same CPU
+ * on which the attestation token generation was initialised.
+ *
+ * Return:
+ * * %0 - Attestation token generated successfully.
+ * * %-EINVAL - A parameter was not valid.
+ * * %-ENOMEM - Out of memory.
+ * * %-EFAULT - Failed to get IPA for memory page(s).
+ * * %A negative status code as returned by smp_call_function_single().
+ */
+static int arm_cca_report_new(struct tsm_report *report, void *data)
+{
+ int ret;
+ int cpu;
+ long max_size;
+ unsigned long token_size;
+ struct arm_cca_token_info info;
+ void *buf;
+ u8 *token __free(kvfree) = NULL;
+ struct tsm_desc *desc = &report->desc;
+
+ if (!report)
+ return -EINVAL;
+
+ if (desc->inblob_len < 32 || desc->inblob_len > 64)
+ return -EINVAL;
+
+ /*
+ * Get a CPU on which the attestation token generation will be
+ * scheduled and initialise the attestation token generation.
+ */
+ cpu = get_cpu();
+ max_size = rsi_attestation_token_init(desc->inblob, desc->inblob_len);
+ put_cpu();
+
+ if (max_size <= 0)
+ return -EINVAL;
+
+ /* Allocate outblob */
+ token = kvzalloc(max_size, GFP_KERNEL);
+ if (!token)
+ return -ENOMEM;
+
+ /*
+ * Since the outblob may not be physically contiguous, use a page
+ * to bounce the buffer from RMM.
+ */
+ buf = alloc_pages_exact(GRANULE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ /* Get the PA of the memory page(s) that were allocated. */
+ info.granule = (unsigned long)virt_to_phys(buf);
+
+ token_size = 0;
+ /* Loop until the token is ready or there is an error. */
+ do {
+ /* Retrieve one GRANULE_SIZE data per loop iteration. */
+ info.offset = 0;
+ do {
+ /*
+ * Schedule a call to retrieve a sub-granule chunk
+ * of data per loop iteration.
+ */
+ ret = smp_call_function_single(cpu,
+ arm_cca_attestation_continue,
+ (void *)&info, true);
+ if (ret != 0) {
+ token_size = 0;
+ goto exit_free_granule_page;
+ }
+
+ ret = info.result;
+ } while ((ret == RSI_INCOMPLETE) &&
+ (info.offset < GRANULE_SIZE));
+
+ /*
+ * Copy the retrieved token data from the granule
+ * to the token buffer, ensuring that the RMM doesn't
+ * overflow the buffer.
+ */
+ if (WARN_ON(token_size + info.offset > max_size))
+ break;
+ memcpy(&token[token_size], buf, info.offset);
+ token_size += info.offset;
+ } while (ret == RSI_INCOMPLETE);
+
+ if (ret != RSI_SUCCESS) {
+ ret = -ENXIO;
+ token_size = 0;
+ goto exit_free_granule_page;
+ }
+
+ report->outblob = no_free_ptr(token);
+exit_free_granule_page:
+ report->outblob_len = token_size;
+ free_pages_exact(buf, GRANULE_SIZE);
+ return ret;
+}
+
+static const struct tsm_ops arm_cca_tsm_ops = {
+ .name = KBUILD_MODNAME,
+ .report_new = arm_cca_report_new,
+};
+
+/**
+ * arm_cca_guest_init - Register with the Trusted Security Module (TSM)
+ * interface.
+ *
+ * Return:
+ * * %0 - Registered successfully with the TSM interface.
+ * * %-ENODEV - The execution context is not an Arm Realm.
+ * * %-EINVAL - A parameter was not valid.
+ * * %-EBUSY - Already registered.
+ */
+static int __init arm_cca_guest_init(void)
+{
+ int ret;
+
+ if (!is_realm_world())
+ return -ENODEV;
+
+ ret = tsm_register(&arm_cca_tsm_ops, NULL, &tsm_report_default_type);
+ if (ret < 0)
+ pr_err("Failed to register with TSM.\n");
+
+ return ret;
+}
+module_init(arm_cca_guest_init);
+
+/**
+ * arm_cca_guest_exit - unregister with the Trusted Security Module (TSM)
+ * interface.
+ */
+static void __exit arm_cca_guest_exit(void)
+{
+ tsm_unregister(&arm_cca_tsm_ops);
+}
+module_exit(arm_cca_guest_exit);
+
+MODULE_AUTHOR("Sami Mujawar <sami.mujawar@arm.com>");
+MODULE_DESCRIPTION("Arm CCA Guest TSM Driver.");
+MODULE_LICENSE("GPL");
--
2.34.1
next prev parent reply other threads:[~2024-04-12 8:42 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-12 8:40 [v2] Support for Arm CCA VMs on Linux Steven Price
2024-04-11 18:54 ` Itaru Kitayama
2024-04-15 8:14 ` Steven Price
2024-04-12 8:41 ` [PATCH v2 00/14] arm64: Support for running as a guest in Arm CCA Steven Price
2024-04-12 8:42 ` [PATCH v2 01/14] arm64: rsi: Add RSI definitions Steven Price
2024-04-12 8:42 ` [PATCH v2 02/14] arm64: Detect if in a realm and set RIPAS RAM Steven Price
2024-05-10 17:35 ` Catalin Marinas
2024-05-14 10:18 ` Suzuki K Poulose
2024-05-16 14:32 ` Catalin Marinas
2024-05-15 15:03 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 03/14] arm64: realm: Query IPA size from the RMM Steven Price
2024-05-13 14:03 ` Catalin Marinas
2024-05-16 15:13 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 04/14] arm64: Mark all I/O as non-secure shared Steven Price
2024-04-12 8:42 ` [PATCH v2 05/14] fixmap: Allow architecture overriding set_fixmap_io Steven Price
2024-04-12 8:42 ` [PATCH v2 06/14] arm64: Override set_fixmap_io Steven Price
2024-05-13 16:14 ` Catalin Marinas
2024-05-14 10:21 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 07/14] arm64: Make the PHYS_MASK_SHIFT dynamic Steven Price
2024-05-13 16:38 ` Catalin Marinas
2024-05-16 15:34 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 08/14] arm64: Enforce bounce buffers for realm DMA Steven Price
2024-05-13 16:56 ` Catalin Marinas
2024-04-12 8:42 ` [PATCH v2 09/14] arm64: Enable memory encrypt for Realms Steven Price
2024-04-15 3:13 ` kernel test robot
2024-04-25 13:42 ` Suzuki K Poulose
2024-04-25 15:52 ` Steven Price
2024-04-25 16:29 ` Suzuki K Poulose
2024-04-25 18:16 ` Emanuele Rocca
2024-05-14 18:00 ` Catalin Marinas
2024-05-15 10:47 ` Suzuki K Poulose
2024-05-16 7:48 ` Catalin Marinas
2024-05-16 9:06 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 10/14] arm64: Force device mappings to be non-secure shared Steven Price
2024-05-15 9:01 ` Catalin Marinas
2024-05-15 11:00 ` Suzuki K Poulose
2024-05-17 9:34 ` Catalin Marinas
2024-04-12 8:42 ` [PATCH v2 11/14] efi: arm64: Map Device with Prot Shared Steven Price
2024-04-12 8:42 ` [PATCH v2 12/14] arm64: realm: Support nonsecure ITS emulation shared Steven Price
2024-05-15 11:01 ` Catalin Marinas
2024-04-12 8:42 ` [PATCH v2 13/14] arm64: rsi: Interfaces to query attestation token Steven Price
2024-05-15 11:10 ` Catalin Marinas
2024-04-12 8:42 ` Steven Price [this message]
2024-04-24 13:06 ` [PATCH v2 14/14] virt: arm-cca-guest: TSM_REPORT support for realms Thomas Fossati
2024-04-24 13:27 ` Suzuki K Poulose
2024-04-24 13:19 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 00/43] arm64: Support for Arm CCA in KVM Steven Price
2024-04-12 8:42 ` [PATCH v2 01/43] KVM: Prepare for handling only shared mappings in mmu_notifier events Steven Price
2024-04-25 9:48 ` Fuad Tabba
2024-04-25 15:58 ` Steven Price
2024-04-25 22:56 ` Sean Christopherson
2024-04-12 8:42 ` [PATCH v2 02/43] kvm: arm64: pgtable: Track the number of pages in the entry level Steven Price
2024-04-12 8:42 ` [PATCH v2 03/43] kvm: arm64: Include kvm_emulate.h in kvm/arm_psci.h Steven Price
2024-04-12 8:42 ` [PATCH v2 04/43] arm64: RME: Handle Granule Protection Faults (GPFs) Steven Price
2024-04-16 11:17 ` Suzuki K Poulose
2024-04-18 13:17 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 05/43] arm64: RME: Add SMC definitions for calling the RMM Steven Price
2024-04-16 12:38 ` Suzuki K Poulose
2024-04-18 13:17 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 06/43] arm64: RME: Add wrappers for RMI calls Steven Price
2024-04-16 13:14 ` Suzuki K Poulose
2024-04-19 11:18 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 07/43] arm64: RME: Check for RME support at KVM init Steven Price
2024-04-16 13:30 ` Suzuki K Poulose
2024-04-22 15:39 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 08/43] arm64: RME: Define the user ABI Steven Price
2024-04-12 8:42 ` [PATCH v2 09/43] arm64: RME: ioctls to create and configure realms Steven Price
2024-04-17 9:51 ` Suzuki K Poulose
2024-04-22 16:33 ` Steven Price
2024-04-18 16:04 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 10/43] kvm: arm64: Expose debug HW register numbers for Realm Steven Price
2024-04-12 8:42 ` [PATCH v2 11/43] arm64: kvm: Allow passing machine type in KVM creation Steven Price
2024-04-17 10:20 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 12/43] arm64: RME: Keep a spare page delegated to the RMM Steven Price
2024-04-17 10:19 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 13/43] arm64: RME: RTT handling Steven Price
2024-04-17 13:37 ` Suzuki K Poulose
2024-04-24 10:59 ` Steven Price
2024-04-12 8:42 ` [PATCH v2 14/43] arm64: RME: Allocate/free RECs to match vCPUs Steven Price
2024-04-18 9:23 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 15/43] arm64: RME: Support for the VGIC in realms Steven Price
2024-04-12 8:42 ` [PATCH v2 16/43] KVM: arm64: Support timers in realm RECs Steven Price
2024-04-18 9:30 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 17/43] arm64: RME: Allow VMM to set RIPAS Steven Price
2024-04-19 9:34 ` Suzuki K Poulose
2024-04-19 10:20 ` Suzuki K Poulose
2024-05-01 15:47 ` Steven Price
2024-05-02 10:16 ` Suzuki K Poulose
2024-04-25 9:53 ` Fuad Tabba
2024-05-01 14:27 ` Jean-Philippe Brucker
2024-05-01 14:56 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 18/43] arm64: RME: Handle realm enter/exit Steven Price
2024-04-19 13:00 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 19/43] KVM: arm64: Handle realm MMIO emulation Steven Price
2024-04-12 8:42 ` [PATCH v2 20/43] arm64: RME: Allow populating initial contents Steven Price
2024-04-19 13:17 ` Suzuki K Poulose
2024-04-12 8:42 ` [PATCH v2 21/43] arm64: RME: Runtime faulting of memory Steven Price
2024-04-25 10:43 ` Fuad Tabba
2024-04-12 8:42 ` [PATCH v2 22/43] KVM: arm64: Handle realm VCPU load Steven Price
2024-04-12 8:42 ` [PATCH v2 23/43] KVM: arm64: Validate register access for a Realm VM Steven Price
2024-04-12 8:42 ` [PATCH v2 24/43] KVM: arm64: Handle Realm PSCI requests Steven Price
2024-04-12 8:42 ` [PATCH v2 25/43] KVM: arm64: WARN on injected undef exceptions Steven Price
2024-04-12 8:42 ` [PATCH v2 26/43] arm64: Don't expose stolen time for realm guests Steven Price
2024-04-12 8:42 ` [PATCH v2 27/43] arm64: rme: allow userspace to inject aborts Steven Price
2024-04-12 8:42 ` [PATCH v2 28/43] arm64: rme: support RSI_HOST_CALL Steven Price
2024-04-12 8:42 ` [PATCH v2 29/43] arm64: rme: Allow checking SVE on VM instance Steven Price
2024-04-12 8:42 ` [PATCH v2 30/43] arm64: RME: Always use 4k pages for realms Steven Price
2024-04-12 8:42 ` [PATCH v2 31/43] arm64: rme: Prevent Device mappings for Realms Steven Price
2024-04-12 8:42 ` [PATCH v2 32/43] arm_pmu: Provide a mechanism for disabling the physical IRQ Steven Price
2024-04-12 8:42 ` [PATCH v2 33/43] arm64: rme: Enable PMU support with a realm guest Steven Price
2024-04-13 23:44 ` kernel test robot
2024-04-18 16:06 ` Suzuki K Poulose
2024-04-12 8:43 ` [PATCH v2 34/43] kvm: rme: Hide KVM_CAP_READONLY_MEM for realm guests Steven Price
2024-04-12 8:43 ` [PATCH v2 35/43] arm64: RME: Propagate number of breakpoints and watchpoints to userspace Steven Price
2024-04-12 8:43 ` [PATCH v2 36/43] arm64: RME: Set breakpoint parameters through SET_ONE_REG Steven Price
2024-04-12 8:43 ` [PATCH v2 37/43] arm64: RME: Initialize PMCR.N with number counter supported by RMM Steven Price
2024-04-12 8:43 ` [PATCH v2 38/43] arm64: RME: Propagate max SVE vector length from RMM Steven Price
2024-04-12 8:43 ` [PATCH v2 39/43] arm64: RME: Configure max SVE vector length for a Realm Steven Price
2024-04-12 8:43 ` [PATCH v2 40/43] arm64: RME: Provide register list for unfinalized RME RECs Steven Price
2024-04-12 8:43 ` [PATCH v2 41/43] arm64: RME: Provide accurate register list Steven Price
2024-04-12 8:43 ` [PATCH v2 42/43] arm64: kvm: Expose support for private memory Steven Price
2024-04-25 14:44 ` Fuad Tabba
2024-04-12 8:43 ` [PATCH v2 43/43] KVM: arm64: Allow activating realms Steven Price
2024-04-12 16:52 ` [v2] Support for Arm CCA VMs on Linux Jean-Philippe Brucker
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