Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 229 insertions, 1 deletions

diff --git a/drivers/virt/coco/tdx-guest/Kconfig b/drivers/virt/coco/tdx-guest/Kconfig
index 14246fc2fb..22dd59e194 100644
--- a/drivers/virt/coco/tdx-guest/Kconfig
+++ b/drivers/virt/coco/tdx-guest/Kconfig
@@ -1,6 +1,7 @@
 config TDX_GUEST_DRIVER
 	tristate "TDX Guest driver"
 	depends on INTEL_TDX_GUEST
+	select TSM_REPORTS
 	help
 	  The driver provides userspace interface to communicate with
 	  the TDX module to request the TDX guest details like attestation
diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c
index 5e44a0fa69..1253bf76b5 100644
--- a/drivers/virt/coco/tdx-guest/tdx-guest.c
+++ b/drivers/virt/coco/tdx-guest/tdx-guest.c
@@ -12,12 +12,60 @@
 #include <linux/mod_devicetable.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>
+#include <linux/set_memory.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/tsm.h>
+#include <linux/sizes.h>
 
 #include <uapi/linux/tdx-guest.h>
 
 #include <asm/cpu_device_id.h>
 #include <asm/tdx.h>
 
+/*
+ * Intel's SGX QE implementation generally uses Quote size less
+ * than 8K (2K Quote data + ~5K of certificate blob).
+ */
+#define GET_QUOTE_BUF_SIZE		SZ_8K
+
+#define GET_QUOTE_CMD_VER		1
+
+/* TDX GetQuote status codes */
+#define GET_QUOTE_SUCCESS		0
+#define GET_QUOTE_IN_FLIGHT		0xffffffffffffffff
+
+/* struct tdx_quote_buf: Format of Quote request buffer.
+ * @version: Quote format version, filled by TD.
+ * @status: Status code of Quote request, filled by VMM.
+ * @in_len: Length of TDREPORT, filled by TD.
+ * @out_len: Length of Quote data, filled by VMM.
+ * @data: Quote data on output or TDREPORT on input.
+ *
+ * More details of Quote request buffer can be found in TDX
+ * Guest-Host Communication Interface (GHCI) for Intel TDX 1.0,
+ * section titled "TDG.VP.VMCALL<GetQuote>"
+ */
+struct tdx_quote_buf {
+	u64 version;
+	u64 status;
+	u32 in_len;
+	u32 out_len;
+	u8 data[];
+};
+
+/* Quote data buffer */
+static void *quote_data;
+
+/* Lock to streamline quote requests */
+static DEFINE_MUTEX(quote_lock);
+
+/*
+ * GetQuote request timeout in seconds. Expect that 30 seconds
+ * is enough time for QE to respond to any Quote requests.
+ */
+static u32 getquote_timeout = 30;
+
 static long tdx_get_report0(struct tdx_report_req __user *req)
 {
 	u8 *reportdata, *tdreport;
@@ -53,6 +101,154 @@ out:
 	return ret;
 }
 
+static void free_quote_buf(void *buf)
+{
+	size_t len = PAGE_ALIGN(GET_QUOTE_BUF_SIZE);
+	unsigned int count = len >> PAGE_SHIFT;
+
+	if (set_memory_encrypted((unsigned long)buf, count)) {
+		pr_err("Failed to restore encryption mask for Quote buffer, leak it\n");
+		return;
+	}
+
+	free_pages_exact(buf, len);
+}
+
+static void *alloc_quote_buf(void)
+{
+	size_t len = PAGE_ALIGN(GET_QUOTE_BUF_SIZE);
+	unsigned int count = len >> PAGE_SHIFT;
+	void *addr;
+
+	addr = alloc_pages_exact(len, GFP_KERNEL | __GFP_ZERO);
+	if (!addr)
+		return NULL;
+
+	if (set_memory_decrypted((unsigned long)addr, count)) {
+		free_pages_exact(addr, len);
+		return NULL;
+	}
+
+	return addr;
+}
+
+/*
+ * wait_for_quote_completion() - Wait for Quote request completion
+ * @quote_buf: Address of Quote buffer.
+ * @timeout: Timeout in seconds to wait for the Quote generation.
+ *
+ * As per TDX GHCI v1.0 specification, sec titled "TDG.VP.VMCALL<GetQuote>",
+ * the status field in the Quote buffer will be set to GET_QUOTE_IN_FLIGHT
+ * while VMM processes the GetQuote request, and will change it to success
+ * or error code after processing is complete. So wait till the status
+ * changes from GET_QUOTE_IN_FLIGHT or the request being timed out.
+ */
+static int wait_for_quote_completion(struct tdx_quote_buf *quote_buf, u32 timeout)
+{
+	int i = 0;
+
+	/*
+	 * Quote requests usually take a few seconds to complete, so waking up
+	 * once per second to recheck the status is fine for this use case.
+	 */
+	while (quote_buf->status == GET_QUOTE_IN_FLIGHT && i++ < timeout) {
+		if (msleep_interruptible(MSEC_PER_SEC))
+			return -EINTR;
+	}
+
+	return (i == timeout) ? -ETIMEDOUT : 0;
+}
+
+static int tdx_report_new(struct tsm_report *report, void *data)
+{
+	u8 *buf, *reportdata = NULL, *tdreport = NULL;
+	struct tdx_quote_buf *quote_buf = quote_data;
+	struct tsm_desc *desc = &report->desc;
+	int ret;
+	u64 err;
+
+	/* TODO: switch to guard(mutex_intr) */
+	if (mutex_lock_interruptible(&quote_lock))
+		return -EINTR;
+
+	/*
+	 * If the previous request is timedout or interrupted, and the
+	 * Quote buf status is still in GET_QUOTE_IN_FLIGHT (owned by
+	 * VMM), don't permit any new request.
+	 */
+	if (quote_buf->status == GET_QUOTE_IN_FLIGHT) {
+		ret = -EBUSY;
+		goto done;
+	}
+
+	if (desc->inblob_len != TDX_REPORTDATA_LEN) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	reportdata = kmalloc(TDX_REPORTDATA_LEN, GFP_KERNEL);
+	if (!reportdata) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	tdreport = kzalloc(TDX_REPORT_LEN, GFP_KERNEL);
+	if (!tdreport) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	memcpy(reportdata, desc->inblob, desc->inblob_len);
+
+	/* Generate TDREPORT0 using "TDG.MR.REPORT" TDCALL */
+	ret = tdx_mcall_get_report0(reportdata, tdreport);
+	if (ret) {
+		pr_err("GetReport call failed\n");
+		goto done;
+	}
+
+	memset(quote_data, 0, GET_QUOTE_BUF_SIZE);
+
+	/* Update Quote buffer header */
+	quote_buf->version = GET_QUOTE_CMD_VER;
+	quote_buf->in_len = TDX_REPORT_LEN;
+
+	memcpy(quote_buf->data, tdreport, TDX_REPORT_LEN);
+
+	err = tdx_hcall_get_quote(quote_data, GET_QUOTE_BUF_SIZE);
+	if (err) {
+		pr_err("GetQuote hypercall failed, status:%llx\n", err);
+		ret = -EIO;
+		goto done;
+	}
+
+	ret = wait_for_quote_completion(quote_buf, getquote_timeout);
+	if (ret) {
+		pr_err("GetQuote request timedout\n");
+		goto done;
+	}
+
+	buf = kvmemdup(quote_buf->data, quote_buf->out_len, GFP_KERNEL);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	report->outblob = buf;
+	report->outblob_len = quote_buf->out_len;
+
+	/*
+	 * TODO: parse the PEM-formatted cert chain out of the quote buffer when
+	 * provided
+	 */
+done:
+	mutex_unlock(&quote_lock);
+	kfree(reportdata);
+	kfree(tdreport);
+
+	return ret;
+}
+
 static long tdx_guest_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg)
 {
@@ -82,17 +278,48 @@ static const struct x86_cpu_id tdx_guest_ids[] = {
 };
 MODULE_DEVICE_TABLE(x86cpu, tdx_guest_ids);
 
+static const struct tsm_ops tdx_tsm_ops = {
+	.name = KBUILD_MODNAME,
+	.report_new = tdx_report_new,
+};
+
 static int __init tdx_guest_init(void)
 {
+	int ret;
+
 	if (!x86_match_cpu(tdx_guest_ids))
 		return -ENODEV;
 
-	return misc_register(&tdx_misc_dev);
+	ret = misc_register(&tdx_misc_dev);
+	if (ret)
+		return ret;
+
+	quote_data = alloc_quote_buf();
+	if (!quote_data) {
+		pr_err("Failed to allocate Quote buffer\n");
+		ret = -ENOMEM;
+		goto free_misc;
+	}
+
+	ret = tsm_register(&tdx_tsm_ops, NULL, NULL);
+	if (ret)
+		goto free_quote;
+
+	return 0;
+
+free_quote:
+	free_quote_buf(quote_data);
+free_misc:
+	misc_deregister(&tdx_misc_dev);
+
+	return ret;
 }
 module_init(tdx_guest_init);
 
 static void __exit tdx_guest_exit(void)
 {
+	tsm_unregister(&tdx_tsm_ops);
+	free_quote_buf(quote_data);
 	misc_deregister(&tdx_misc_dev);
 }
 module_exit(tdx_guest_exit);