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[Qemu-devel] [PATCH V13 7/7] Add fd parameter for TPM passthrough driver
From: |
Stefan Berger |
Subject: |
[Qemu-devel] [PATCH V13 7/7] Add fd parameter for TPM passthrough driver |
Date: |
Mon, 12 Dec 2011 14:12:16 -0500 |
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 <address@hidden>
---
v13:
- Only accepting a character device's file descriptor
v12:
- added documentation part
---
hw/tpm_passthrough.c | 73 +++++++++++++++++++++++++++++++++++++-------------
qemu-config.c | 5 +++
qemu-options.hx | 6 +++-
3 files changed, 64 insertions(+), 20 deletions(-)
diff --git a/hw/tpm_passthrough.c b/hw/tpm_passthrough.c
index f9cfe3d..57bb77a 100644
--- a/hw/tpm_passthrough.c
+++ b/hw/tpm_passthrough.c
@@ -361,33 +361,68 @@ static int tpm_passthrough_handle_device_opts(QemuOpts
*opts, TPMBackend *tb)
const char *value;
char buf[64];
int n;
+ struct stat statbuf;
- value = qemu_opt_get(opts, "path");
- if (!value) {
- value = TPM_PASSTHROUGH_DEFAULT_DEVICE;
- }
+ 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;
+ }
- n = snprintf(tb->s.tpm_pt->tpm_dev, sizeof(tb->s.tpm_pt->tpm_dev),
- "%s", value);
+ snprintf(buf, sizeof(buf), "fd=%d", tb->s.tpm_pt->tpm_fd);
- if (n >= sizeof(tb->s.tpm_pt->tpm_dev)) {
- error_report("TPM device path is too long.\n");
- goto err_exit;
- }
+ tb->parameters = g_strdup(buf);
- snprintf(buf, sizeof(buf), "path=%s", tb->s.tpm_pt->tpm_dev);
+ 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;
+ }
- tb->parameters = g_strdup(buf);
+ snprintf(buf, sizeof(buf), "path=%s", tb->s.tpm_pt->tpm_dev);
- if (tb->parameters == NULL) {
- return 1;
+ 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;
+ }
}
- 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 (fstat(tb->s.tpm_pt->tpm_fd, &statbuf) != 0) {
+ error_report("Cannot determine file descriptor type for TPM "
+ "device: %s", strerror(errno));
+ goto err_close_tpmdev;
+ }
+
+ /* only allow character devices for now */
+ if (!S_ISCHR(statbuf.st_mode)) {
+ error_report("TPM file descriptor is not a character device");
+ goto err_close_tpmdev;
}
if (tpm_passthrough_test_tpmdev(tb->s.tpm_pt->tpm_fd)) {
diff --git a/qemu-config.c b/qemu-config.c
index cc4c31d..e49f4d8 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -564,6 +564,11 @@ 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 */ }
},
};
diff --git a/qemu-options.hx b/qemu-options.hx
index 4916baf..7eca701 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1932,7 +1932,7 @@ Use ? to print all available TPM backend types.
qemu -tpmdev ?
@end example
address@hidden -tpmdev passthrough, address@hidden, address@hidden
address@hidden -tpmdev passthrough, address@hidden, address@hidden,
address@hidden
(Linux-host only) Enable access to the host's TPM using the passthrough
driver.
@@ -1941,6 +1941,10 @@ driver.
a Linux host this would be @code{/dev/tpm0}.
@option{path} is optional and by default @code{/dev/tpm0} is used.
address@hidden specifies the file descriptor of the host's TPM device.
address@hidden and @option{path} are mutually exclusive.
address@hidden is optional.
+
Some notes about using the host's TPM with the passthrough driver:
The TPM device accessed by the passthrough driver must not be
--
1.7.6.4
- [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, (continued)
- [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Stefan Berger, 2011/12/12
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Anthony Liguori, 2011/12/12
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Stefan Berger, 2011/12/12
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Paul Brook, 2011/12/12
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Stefan Berger, 2011/12/13
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Michael S. Tsirkin, 2011/12/13
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Anthony Liguori, 2011/12/13
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Stefan Berger, 2011/12/13
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Paul Brook, 2011/12/13
- Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option, Paul Brook, 2011/12/13
[Qemu-devel] [PATCH V13 7/7] Add fd parameter for TPM passthrough driver,
Stefan Berger <=
[Qemu-devel] [PATCH V13 1/7] Support for TPM command line options, Stefan Berger, 2011/12/12
[Qemu-devel] [PATCH V13 2/7] Add TPM (frontend) hardware interface (TPM TIS) to Qemu, Stefan Berger, 2011/12/12
[Qemu-devel] [PATCH V13 5/7] Add a TPM Passthrough backend driver implementation, Stefan Berger, 2011/12/12