Enable the passing of a file descriptor via fd=<..> to access the host's
TPM device using the TPM passthrough driver.
Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com>
---
hw/tpm_passthrough.c | 74
+++++++++++++++++++++++++++++++++------------------
qemu-config.c | 5 +++
2 files changed, 53 insertions(+), 26 deletions(-)
Index: qemu-git.pt/qemu-config.c
===================================================================
--- qemu-git.pt.orig/qemu-config.c
+++ qemu-git.pt/qemu-config.c
@@ -523,6 +523,11 @@ static QemuOptsList qemu_tpmdev_opts = {
.type = QEMU_OPT_STRING,
.help = "Persistent storage for TPM state",
},
+ {
+ .name = "fd",
+ .type = QEMU_OPT_STRING,
+ .help = "Filedescriptor for accessing the TPM",
+ },
{ /* end of list */ }
},
};
Index: qemu-git.pt/hw/tpm_passthrough.c
===================================================================
--- qemu-git.pt.orig/hw/tpm_passthrough.c
+++ qemu-git.pt/hw/tpm_passthrough.c
@@ -356,32 +356,54 @@ static int tpm_passthrough_handle_device
char buf[64];
int n;
- value = qemu_opt_get(opts, "path");
- if (!value) {
- value = TPM_PASSTHROUGH_DEFAULT_DEVICE;
- }
-
- n = snprintf(tb->s.tpm_pt->tpm_dev, sizeof(tb->s.tpm_pt->tpm_dev),
- "%s", value);
-
- if (n >= sizeof(tb->s.tpm_pt->tpm_dev)) {
- error_report("TPM device path is too long.\n");
- goto err_exit;
- }
-
- snprintf(buf, sizeof(buf), "path=%s", tb->s.tpm_pt->tpm_dev);
-
- tb->parameters = g_strdup(buf);
-
- if (tb->parameters == NULL) {
- return 1;
- }
-
- tb->s.tpm_pt->tpm_fd = open(tb->s.tpm_pt->tpm_dev, O_RDWR);
- if (tb->s.tpm_pt->tpm_fd < 0) {
- error_report("Cannot access TPM device using '%s'.\n",
- tb->s.tpm_pt->tpm_dev);
- goto err_exit;
+ value = qemu_opt_get(opts, "fd");
+ if (value) {
+ if (qemu_opt_get(opts, "path")) {
+ error_report("fd= is invalid with path=");
+ return -1;
+ }
+
+ tb->s.tpm_pt->tpm_fd = qemu_parse_fd(value);
+ if (tb->s.tpm_pt->tpm_fd < 0) {
+ error_report("Illegal file descriptor for TPM device.\n");
+ return -1;
+ }
+
+ snprintf(buf, sizeof(buf), "fd=%d", tb->s.tpm_pt->tpm_fd);
+
+ tb->parameters = g_strdup(buf);
+
+ if (tb->parameters == NULL) {
+ goto err_close_tpmdev;
+ }
+ } else {
+ value = qemu_opt_get(opts, "path");
+ if (!value) {
+ value = TPM_PASSTHROUGH_DEFAULT_DEVICE;
+ }
+
+ n = snprintf(tb->s.tpm_pt->tpm_dev, sizeof(tb->s.tpm_pt->tpm_dev),
+ "%s", value);
+
+ if (n >= sizeof(tb->s.tpm_pt->tpm_dev)) {
+ error_report("TPM device path is too long.\n");
+ goto err_exit;
+ }
+
+ snprintf(buf, sizeof(buf), "path=%s", tb->s.tpm_pt->tpm_dev);
+
+ tb->parameters = g_strdup(buf);
+
+ if (tb->parameters == NULL) {
+ return 1;
+ }
+
+ tb->s.tpm_pt->tpm_fd = open(tb->s.tpm_pt->tpm_dev, O_RDWR);
+ if (tb->s.tpm_pt->tpm_fd < 0) {
+ error_report("Cannot access TPM device using '%s'.\n",
+ tb->s.tpm_pt->tpm_dev);
+ goto err_exit;
+ }
}
if (tpm_passthrough_test_tpmdev(tb->s.tpm_pt->tpm_fd)) {