[PATCH v2 08/13] vtpmmgr: Shutdown more gracefully

From: Jason Andryuk <jandryuk@gmail.com>
To: xen-devel@lists.xenproject.org
Cc: Jason Andryuk <jandryuk@gmail.com>,
	Daniel De Graaf <dgdegra@tycho.nsa.gov>,
	Quan Xu <quan.xu0@gmail.com>,
	Samuel Thibault <samuel.thibault@ens-lyon.org>,
	Samuel Thibault <samuel.thibaut@ens-lyon.org>
Subject: [PATCH v2 08/13] vtpmmgr: Shutdown more gracefully
Date: Thu,  6 May 2021 09:59:18 -0400	[thread overview]
Message-ID: <20210506135923.161427-9-jandryuk@gmail.com> (raw)
In-Reply-To: <20210506135923.161427-1-jandryuk@gmail.com>

vtpmmgr uses the default, weak app_shutdown, which immediately calls the
shutdown hypercall.  This short circuits the vtpmmgr clean up logic.  We
need to perform the clean up to actually Flush our key out of the tpm.

Setting do_shutdown is one step in that direction, but vtpmmgr will most
likely be waiting in tpmback_req_any.  We need to call shutdown_tpmback
to cancel the wait inside tpmback and perform the shutdown.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibaut@ens-lyon.org>
---
 stubdom/vtpmmgr/vtpmmgr.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/stubdom/vtpmmgr/vtpmmgr.c b/stubdom/vtpmmgr/vtpmmgr.c
index 9fddaa24f8..46ea018921 100644
--- a/stubdom/vtpmmgr/vtpmmgr.c
+++ b/stubdom/vtpmmgr/vtpmmgr.c
@@ -67,11 +67,21 @@ int hw_is_tpm2(void)
     return (hardware_version.hw_version == TPM2_HARDWARE) ? 1 : 0;
 }
 
+static int do_shutdown;
+
+void app_shutdown(unsigned int reason)
+{
+    printk("Shutdown requested: %d\n", reason);
+    do_shutdown = 1;
+
+    shutdown_tpmback();
+}
+
 void main_loop(void) {
    tpmcmd_t* tpmcmd;
    uint8_t respbuf[TCPA_MAX_BUFFER_LENGTH];
 
-   while(1) {
+   while (!do_shutdown) {
       /* Wait for requests from a vtpm */
       vtpmloginfo(VTPM_LOG_VTPM, "Waiting for commands from vTPM's:\n");
       if((tpmcmd = tpmback_req_any()) == NULL) {
-- 
2.30.2


