| Message ID | 20171012182844.kjv5zab7o6fwwwdk@pd.tnic (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/12/17 1:28 PM, Borislav Petkov wrote: > On Fri, Oct 06, 2017 at 08:06:03PM -0500, Brijesh Singh wrote: >> The SEV_PEK_GEN command is used to generate a new Platform Endorsement >> Key (PEK). The command is defined in SEV spec section 5.6. >> >> Cc: Paolo Bonzini <pbonzini@redhat.com> >> Cc: "Radim Krčmář" <rkrcmar@redhat.com> >> Cc: Borislav Petkov <bp@suse.de> >> Cc: Herbert Xu <herbert@gondor.apana.org.au> >> Cc: Gary Hook <gary.hook@amd.com> >> Cc: Tom Lendacky <thomas.lendacky@amd.com> >> Cc: linux-crypto@vger.kernel.org >> Cc: kvm@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> --- >> drivers/crypto/ccp/psp-dev.c | 68 ++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 68 insertions(+) > Just small fixups. Worth noting is this: > > if (do_shutdown) > - sev_handle_cmd(SEV_CMD_SHUTDOWN, 0, NULL); > + ret = sev_do_cmd(SEV_CMD_SHUTDOWN, 0, NULL); > > I think we want to return the result of the *last* command > executed, which, in the do_shutdown=1 case is SEV_CMD_SHUTDOWN, not > SEV_CMD_PEK_GEN. Lets consider this scenario 1- platform is in uninit state, we transition it to INIT 2- PEK_GEN command failed 3- since we have transitioned the platform in INIT state hence we must call the shutdown otherwise we will leave the system in wrong state. The shutdown command will most probably succeed and we will look the ret value > --- > diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c > index d02f48e356e8..31045ea7e798 100644 > --- a/drivers/crypto/ccp/psp-dev.c > +++ b/drivers/crypto/ccp/psp-dev.c > @@ -211,7 +211,7 @@ static int sev_platform_get_state(int *state, int *error) > if (!data) > return -ENOMEM; > > - ret = sev_handle_cmd(SEV_CMD_PLATFORM_STATUS, data, error); > + ret = sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error); > if (!ret) > *state = data->state; > > @@ -228,7 +228,7 @@ static int sev_firmware_init(int *error) > if (!data) > return -ENOMEM; > > - rc = sev_handle_cmd(SEV_CMD_INIT, data, error); > + rc = sev_do_cmd(SEV_CMD_INIT, data, error); > > kfree(data); > return rc; > @@ -240,8 +240,8 @@ static int sev_ioctl_pek_gen(struct sev_issue_cmd *argp) > int ret, state; > > /* > - * PEK_GEN command can be issued only when firmware is in INIT state. > - * If firmware is in UNINIT state then we transition it in INIT state > + * The PEK_GEN command can be issued only when the firmware is in INIT > + * state. If it is in UNINIT state then we transition it in INIT state > * and issue the command. > */ > ret = sev_platform_get_state(&state, &argp->error); > @@ -258,10 +258,10 @@ static int sev_ioctl_pek_gen(struct sev_issue_cmd *argp) > do_shutdown = 1; > } > > - ret = sev_handle_cmd(SEV_CMD_PEK_GEN, 0, &argp->error); > + ret = sev_do_cmd(SEV_CMD_PEK_GEN, 0, &argp->error); > > if (do_shutdown) > - sev_handle_cmd(SEV_CMD_SHUTDOWN, 0, NULL); > + ret = sev_do_cmd(SEV_CMD_SHUTDOWN, 0, NULL); > > return ret; > } > @@ -291,10 +291,10 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) > ret = sev_ioctl_do_platform_status(&input); > break; > > - case SEV_PEK_GEN: { > + case SEV_PEK_GEN: > ret = sev_ioctl_pek_gen(&input); > break; > - } > + > default: > ret = -EINVAL; > goto out; >
On Thu, Oct 12, 2017 at 03:11:07PM -0500, Brijesh Singh wrote: > Lets consider this scenario > 1- platform is in uninit state, we transition it to INIT > 2- PEK_GEN command failed > 3- since we have transitioned the platform in INIT state hence we must > call the shutdown otherwise we will leave the system in wrong state. The > shutdown command will most probably succeed and we will look the ret value Sure but what do you do if the main command, i.e., PEK_GEN succeeds but the shutdown command fails? You probably should carve out the whole shutdown order in separate functions. I mean, the sequences do repeat in a couple of functions so you could do: ioctl: case <CMD>: init_platform() do_main_cmd() shutdown_platform() break; and this way you have everything nicely separated and retvals properly tracked... Hmmm?
On 10/12/17 3:21 PM, Borislav Petkov wrote: > On Thu, Oct 12, 2017 at 03:11:07PM -0500, Brijesh Singh wrote: >> Lets consider this scenario >> 1- platform is in uninit state, we transition it to INIT >> 2- PEK_GEN command failed >> 3- since we have transitioned the platform in INIT state hence we must >> call the shutdown otherwise we will leave the system in wrong state. The >> shutdown command will most probably succeed and we will look the ret value > Sure but what do you do if the main command, i.e., PEK_GEN succeeds but > the shutdown command fails? > > You probably should carve out the whole shutdown order in separate > functions. I mean, the sequences do repeat in a couple of functions so > you could do: > > ioctl: > > case <CMD>: > > init_platform() > do_main_cmd() > shutdown_platform() > break; > > and this way you have everything nicely separated and retvals properly > tracked... > > Hmmm? Some commands are allowed in INIT and WORKING, some in UINIT only, some WORKING, and others in all the state. We need to follow the platform state machine. I will see what I can do. thanks
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c index d02f48e356e8..31045ea7e798 100644 --- a/drivers/crypto/ccp/psp-dev.c +++ b/drivers/crypto/ccp/psp-dev.c @@ -211,7 +211,7 @@ static int sev_platform_get_state(int *state, int *error) if (!data) return -ENOMEM; - ret = sev_handle_cmd(SEV_CMD_PLATFORM_STATUS, data, error); + ret = sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error); if (!ret) *state = data->state; @@ -228,7 +228,7 @@ static int sev_firmware_init(int *error) if (!data) return -ENOMEM; - rc = sev_handle_cmd(SEV_CMD_INIT, data, error); + rc = sev_do_cmd(SEV_CMD_INIT, data, error); kfree(data); return rc; @@ -240,8 +240,8 @@ static int sev_ioctl_pek_gen(struct sev_issue_cmd *argp) int ret, state; /* - * PEK_GEN command can be issued only when firmware is in INIT state. - * If firmware is in UNINIT state then we transition it in INIT state + * The PEK_GEN command can be issued only when the firmware is in INIT + * state. If it is in UNINIT state then we transition it in INIT state * and issue the command. */ ret = sev_platform_get_state(&state, &argp->error); @@ -258,10 +258,10 @@ static int sev_ioctl_pek_gen(struct sev_issue_cmd *argp) do_shutdown = 1; } - ret = sev_handle_cmd(SEV_CMD_PEK_GEN, 0, &argp->error); + ret = sev_do_cmd(SEV_CMD_PEK_GEN, 0, &argp->error); if (do_shutdown) - sev_handle_cmd(SEV_CMD_SHUTDOWN, 0, NULL); + ret = sev_do_cmd(SEV_CMD_SHUTDOWN, 0, NULL); return ret; } @@ -291,10 +291,10 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) ret = sev_ioctl_do_platform_status(&input); break; - case SEV_PEK_GEN: { + case SEV_PEK_GEN: ret = sev_ioctl_pek_gen(&input); break; - } + default: ret = -EINVAL; goto out;