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[Qemu-devel] [PATCH v2 5/5] tpm: tpm_passthrough: Fail startup if FE buf
From: |
Stefan Berger |
Subject: |
[Qemu-devel] [PATCH v2 5/5] tpm: tpm_passthrough: Fail startup if FE buffer size < BE buffer size |
Date: |
Wed, 8 Nov 2017 14:01:59 -0500 |
If the requested buffer size of the frontend is smaller than the fixed
buffer size of the host's TPM, fail the startup_tpm() interface function,
which will make the device unusable. We fail it because the backend TPM
could produce larger packets than what the frontend could pass to the OS.
The current combination of TIS frontend and either passthrough or emulator
backend will not lead to this case since the TIS can support any size of
buffer.
Signed-off-by: Stefan Berger <address@hidden>
---
hw/tpm/tpm_passthrough.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/hw/tpm/tpm_passthrough.c b/hw/tpm/tpm_passthrough.c
index 886af9e..487aae2 100644
--- a/hw/tpm/tpm_passthrough.c
+++ b/hw/tpm/tpm_passthrough.c
@@ -304,6 +304,20 @@ static TPMBackend *tpm_passthrough_create(QemuOpts *opts)
return TPM_BACKEND(obj);
}
+static int tpm_passthrough_startup_tpm(TPMBackend *tb, size_t buffersize)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ if (buffersize && buffersize < tpm_pt->tpm_buffersize) {
+ error_report("Requested buffer size of %zu is smaller than host TPM's "
+ "fixed buffer size of %zu",
+ buffersize, tpm_pt->tpm_buffersize);
+ return -1;
+ }
+
+ return 0;
+}
+
static TpmTypeOptions *tpm_passthrough_get_tpm_options(TPMBackend *tb)
{
TpmTypeOptions *options = g_new0(TpmTypeOptions, 1);
@@ -362,6 +376,7 @@ static void tpm_passthrough_class_init(ObjectClass *klass,
void *data)
tbc->opts = tpm_passthrough_cmdline_opts;
tbc->desc = "Passthrough TPM backend driver";
tbc->create = tpm_passthrough_create;
+ tbc->startup_tpm = tpm_passthrough_startup_tpm;
tbc->reset = tpm_passthrough_reset;
tbc->cancel_cmd = tpm_passthrough_cancel_cmd;
tbc->get_tpm_established_flag = tpm_passthrough_get_tpm_established_flag;
--
2.5.5
- [Qemu-devel] [PATCH v2 0/5] tpm: Match frontend and backend buffer sizes (not 2.11), Stefan Berger, 2017/11/08
- [Qemu-devel] [PATCH v2 1/5] tpm: Move getting TPM buffer size to backends, Stefan Berger, 2017/11/08
- [Qemu-devel] [PATCH v2 3/5] tpm: tpm_passthrough: Read the buffer size from the host device, Stefan Berger, 2017/11/08
- [Qemu-devel] [PATCH v2 2/5] tpm: pull tpm_util_request() out of tpm_util_test(), Stefan Berger, 2017/11/08
- [Qemu-devel] [PATCH v2 5/5] tpm: tpm_passthrough: Fail startup if FE buffer size < BE buffer size,
Stefan Berger <=
- [Qemu-devel] [PATCH v2 4/5] tpm: tpm_emulator: get and set buffer size of device, Stefan Berger, 2017/11/08
- Re: [Qemu-devel] [PATCH v2 0/5] tpm: Match frontend and backend buffer sizes (not 2.11), Marc-André Lureau, 2017/11/09