[RFC PATCH v1 31/38] coco: guest: arm64: Add support for fetching interface report and certificate chain from host

["Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>]

Fetch interface report and certificate chain from the host using RHI calls.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 arch/arm64/include/asm/rsi_cmds.h        |   9 ++
 arch/arm64/include/asm/rsi_smc.h         |   6 ++
 drivers/virt/coco/arm-cca-guest/rsi-da.c | 131 +++++++++++++++++++++++
 drivers/virt/coco/arm-cca-guest/rsi-da.h |   5 +
 4 files changed, 151 insertions(+)

diff --git a/arch/arm64/include/asm/rsi_cmds.h b/arch/arm64/include/asm/rsi_cmds.h
index 1d76f7d37cb6..18fc4e1ce577 100644
--- a/arch/arm64/include/asm/rsi_cmds.h
+++ b/arch/arm64/include/asm/rsi_cmds.h
@@ -219,4 +219,13 @@ static inline unsigned long __rsi_rdev_get_interface_report(unsigned long vdev_i
 	return res.a0;
 }
 
+static inline unsigned long rsi_host_call(phys_addr_t addr)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RSI_HOST_CALL, addr, &res);
+
+	return res.a0;
+}
+
 #endif /* __ASM_RSI_CMDS_H */
diff --git a/arch/arm64/include/asm/rsi_smc.h b/arch/arm64/include/asm/rsi_smc.h
index 6afcccee2ae7..1d762fe3777b 100644
--- a/arch/arm64/include/asm/rsi_smc.h
+++ b/arch/arm64/include/asm/rsi_smc.h
@@ -183,6 +183,12 @@ struct realm_config {
  */
 #define SMC_RSI_IPA_STATE_GET			SMC_RSI_FID(0x198)
 
+struct rsi_host_call {
+	u16 imm;
+	u8 padding[6];
+	u64 gprs[31];
+};
+
 /*
  * Make a Host call.
  *
diff --git a/drivers/virt/coco/arm-cca-guest/rsi-da.c b/drivers/virt/coco/arm-cca-guest/rsi-da.c
index 28ec946df1e2..47b379318e7c 100644
--- a/drivers/virt/coco/arm-cca-guest/rsi-da.c
+++ b/drivers/virt/coco/arm-cca-guest/rsi-da.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/pci.h>
+#include <linux/mem_encrypt.h>
 #include <asm/rsi_cmds.h>
 
 #include "rsi-da.h"
@@ -50,6 +51,121 @@ rsi_rdev_get_interface_report(struct pci_dev *pdev, unsigned long vdev_id,
 	return RSI_SUCCESS;
 }
 
+static long rhi_get_report(int vdev_id, int da_object_type, void **report, int *report_size)
+{
+	int ret, enc_ret = 0;
+	int nr_pages;
+	int max_data_len;
+	void *data_buf_shared, *data_buf_private;
+	struct rsi_host_call *rhicall;
+
+	rhicall = kmalloc(sizeof(struct rsi_host_call), GFP_KERNEL);
+	if (!rhicall)
+		return -ENOMEM;
+
+	rhicall->imm = 0;
+	rhicall->gprs[0] = RHI_DA_FEATURES;
+
+	ret = rsi_host_call(virt_to_phys(rhicall));
+	if (ret != RSI_SUCCESS) {
+		ret =  -EIO;
+		goto err_out;
+	}
+
+	if (rhicall->gprs[0] != 0x3) {
+		ret =  -EIO;
+		goto err_out;
+	}
+
+	rhicall->imm = 0;
+	rhicall->gprs[0] = RHI_DA_OBJECT_SIZE;
+	rhicall->gprs[1] = vdev_id;
+	rhicall->gprs[2] = da_object_type;
+
+	ret = rsi_host_call(virt_to_phys(rhicall));
+	if (ret != RSI_SUCCESS) {
+		ret =  -EIO;
+		goto err_out;
+	}
+	if (rhicall->gprs[0] != RHI_DA_SUCCESS) {
+		ret =  -EIO;
+		goto err_out;
+	}
+	max_data_len = rhicall->gprs[1];
+	*report_size = max_data_len;
+
+	/*
+	 * We need to share this memory with hypervisor.
+	 * So it should be multiple of sharing unit.
+	 */
+	max_data_len = ALIGN(max_data_len, PAGE_SIZE);
+	nr_pages = max_data_len >> PAGE_SHIFT;
+
+	if (!max_data_len || nr_pages > MAX_ORDER_NR_PAGES) {
+		ret = -ENOMEM;
+		goto err_out;
+	}
+
+	/*
+	 * We need to share this memory with hypervisor.
+	 * So it should be multiple of sharing unit.
+	 */
+	data_buf_shared = (void *)__get_free_pages(GFP_KERNEL, get_order(max_data_len));
+	if (!data_buf_shared) {
+		ret =  -ENOMEM;
+		goto err_out;
+	}
+
+	data_buf_private = kmalloc(*report_size, GFP_KERNEL);
+	if (!data_buf_private) {
+		ret =  -ENOMEM;
+		goto err_private_alloc;
+	}
+
+	ret = set_memory_decrypted((unsigned long)data_buf_shared, nr_pages);
+	if (ret) {
+		ret =  -EIO;
+		goto err_decrypt;
+	}
+
+	rhicall->imm = 0;
+	rhicall->gprs[0] = RHI_DA_OBJECT_READ;
+	rhicall->gprs[1] = vdev_id;
+	rhicall->gprs[2] = da_object_type;
+	rhicall->gprs[3] = 0; /* offset within the data buffer */
+	rhicall->gprs[4] = max_data_len;
+	rhicall->gprs[5] = virt_to_phys(data_buf_shared);
+	ret = rsi_host_call(virt_to_phys(rhicall));
+	if (ret != RSI_SUCCESS || rhicall->gprs[0] != RHI_DA_SUCCESS) {
+		ret =  -EIO;
+		goto err_rhi_call;
+	}
+
+	memcpy(data_buf_private, data_buf_shared, *report_size);
+	enc_ret = set_memory_encrypted((unsigned long)data_buf_shared, nr_pages);
+	if (!enc_ret)
+		/* If we fail to mark it encrypted don't free it back */
+		free_pages((unsigned long)data_buf_shared, get_order(max_data_len));
+
+	*report = data_buf_private;
+	kfree(rhicall);
+	return 0;
+
+err_rhi_call:
+	enc_ret = set_memory_encrypted((unsigned long)data_buf_shared, nr_pages);
+err_decrypt:
+	kfree(data_buf_private);
+err_private_alloc:
+	if (!enc_ret)
+		/* If we fail to mark it encrypted don't free it back */
+		free_pages((unsigned long)data_buf_shared, get_order(max_data_len));
+err_out:
+	*report = NULL;
+	*report_size = 0;
+	kfree(rhicall);
+	return ret;
+}
+
 int rsi_device_lock(struct pci_dev *pdev)
 {
 	unsigned long ret;
@@ -82,5 +198,20 @@ int rsi_device_lock(struct pci_dev *pdev)
 		return -EOPNOTSUPP;
 	}
 
+	/* Now make a host call to copy the interface report to guest. */
+	ret = rhi_get_report(vdev_id, RHI_DA_OBJECT_INTERFACE_REPORT,
+			     &dsm->interface_report, &dsm->interface_report_size);
+	if (ret) {
+		pci_err(pdev, "failed to get interface report from the host (%lu)\n", ret);
+		return -EIO;
+	}
+
+	ret = rhi_get_report(vdev_id, RHI_DA_OBJECT_CERTIFICATE,
+			     &dsm->certificate, &dsm->certificate_size);
+	if (ret) {
+		pci_err(pdev, "failed to get device certificate from the host (%lu)\n", ret);
+		return -EIO;
+	}
+
 	return ret;
 }
diff --git a/drivers/virt/coco/arm-cca-guest/rsi-da.h b/drivers/virt/coco/arm-cca-guest/rsi-da.h
index f12430c7d792..bd565785ff4b 100644
--- a/drivers/virt/coco/arm-cca-guest/rsi-da.h
+++ b/drivers/virt/coco/arm-cca-guest/rsi-da.h
@@ -9,10 +9,15 @@
 #include <linux/pci.h>
 #include <linux/pci-tsm.h>
 #include <asm/rsi_smc.h>
+#include <asm/rhi.h>
 
 struct cca_guest_dsc {
 	struct pci_tsm_pf0 pci;
 	unsigned long instance_id;
+	void *interface_report;
+	int interface_report_size;
+	void *certificate;
+	int certificate_size;
 };
 
 static inline struct cca_guest_dsc *to_cca_guest_dsc(struct pci_dev *pdev)
-- 
2.43.0