| Message ID | 20231117080747.3643990-12-Shyam-sundar.S-k@amd.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce PMF Smart PC Solution Builder Feature | expand |
On Fri, 17 Nov 2023, Shyam Sundar S K wrote: > A policy binary is OS agnostic, and the same policies are expected to work > across the OSes. At times it becomes difficult to debug when the policies > inside the policy binaries starts to misbehave. Add a way to sideload such > policies independently to debug them via a debugfs entry. > > Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> > --- > diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c > index 5f10e5c6335e..f73663c629fe 100644 > --- a/drivers/platform/x86/amd/pmf/tee-if.c > +++ b/drivers/platform/x86/amd/pmf/tee-if.c > +#ifdef CONFIG_AMD_PMF_DEBUG > +static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf, > + size_t length, loff_t *pos) > +{ > + struct amd_pmf_dev *dev = filp->private_data; > + int ret; > + > + /* Policy binary size cannot exceed POLICY_BUF_MAX_SZ */ > + if (length > POLICY_BUF_MAX_SZ || length == 0) > + return -EINVAL; > + > + dev->policy_sz = length; > + if (copy_from_user(dev->policy_buf, buf, dev->policy_sz)) > + return -EFAULT; > + > + ret = amd_pmf_start_policy_engine(dev); Is this call safe against concurrent invocations from two racing writes? Other than that, this change looked fine. > + if (ret) > + return -EINVAL; > + > + return length; > +}
Hi Ilpo, On 11/21/2023 5:47 PM, Ilpo Järvinen wrote: > On Fri, 17 Nov 2023, Shyam Sundar S K wrote: > >> A policy binary is OS agnostic, and the same policies are expected to work >> across the OSes. At times it becomes difficult to debug when the policies >> inside the policy binaries starts to misbehave. Add a way to sideload such >> policies independently to debug them via a debugfs entry. >> >> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> >> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> >> --- > >> diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c >> index 5f10e5c6335e..f73663c629fe 100644 >> --- a/drivers/platform/x86/amd/pmf/tee-if.c >> +++ b/drivers/platform/x86/amd/pmf/tee-if.c > >> +#ifdef CONFIG_AMD_PMF_DEBUG >> +static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf, >> + size_t length, loff_t *pos) >> +{ >> + struct amd_pmf_dev *dev = filp->private_data; >> + int ret; >> + >> + /* Policy binary size cannot exceed POLICY_BUF_MAX_SZ */ >> + if (length > POLICY_BUF_MAX_SZ || length == 0) >> + return -EINVAL; >> + >> + dev->policy_sz = length; >> + if (copy_from_user(dev->policy_buf, buf, dev->policy_sz)) >> + return -EFAULT; >> + >> + ret = amd_pmf_start_policy_engine(dev); > > Is this call safe against concurrent invocations from two racing writes? > > Other than that, this change looked fine. This path gets enabled only when CONFIG_AMD_PMF_DEBUG option is enabled. Also when enabled, did not observe anything really unusual (like races). So I have retained the same code in v6. Kindly take a look. Thanks, Shyam > >> + if (ret) >> + return -EINVAL; >> + >> + return length; >> +} > >
diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h index 593930519039..8712299ad52b 100644 --- a/drivers/platform/x86/amd/pmf/pmf.h +++ b/drivers/platform/x86/amd/pmf/pmf.h @@ -219,6 +219,7 @@ struct amd_pmf_dev { bool cnqf_supported; struct notifier_block pwr_src_notifier; /* Smart PC solution builder */ + struct dentry *esbin; unsigned char *policy_buf; u32 policy_sz; struct tee_context *tee_ctx; diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c index 5f10e5c6335e..f73663c629fe 100644 --- a/drivers/platform/x86/amd/pmf/tee-if.c +++ b/drivers/platform/x86/amd/pmf/tee-if.c @@ -8,6 +8,7 @@ * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> */ +#include <linux/debugfs.h> #include <linux/tee_drv.h> #include <linux/uuid.h> #include "pmf.h" @@ -16,9 +17,14 @@ /* Policy binary actions sampling frequency (in ms) */ static int pb_actions_ms = MSEC_PER_SEC; +/* Sideload policy binaries to debug policy failures */ +static bool pb_side_load; + #ifdef CONFIG_AMD_PMF_DEBUG module_param(pb_actions_ms, int, 0644); MODULE_PARM_DESC(pb_actions_ms, "Policy binary actions sampling frequency (default = 1000ms)"); +module_param(pb_side_load, bool, 0444); +MODULE_PARM_DESC(pb_side_load, "Sideload policy binaries debug policy failures"); #endif static const uuid_t amd_pmf_ta_uuid = UUID_INIT(0x6fd93b77, 0x3fb8, 0x524d, @@ -269,6 +275,48 @@ static int amd_pmf_start_policy_engine(struct amd_pmf_dev *dev) return 0; } +#ifdef CONFIG_AMD_PMF_DEBUG +static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf, + size_t length, loff_t *pos) +{ + struct amd_pmf_dev *dev = filp->private_data; + int ret; + + /* Policy binary size cannot exceed POLICY_BUF_MAX_SZ */ + if (length > POLICY_BUF_MAX_SZ || length == 0) + return -EINVAL; + + dev->policy_sz = length; + if (copy_from_user(dev->policy_buf, buf, dev->policy_sz)) + return -EFAULT; + + ret = amd_pmf_start_policy_engine(dev); + if (ret) + return -EINVAL; + + return length; +} + +static const struct file_operations pb_fops = { + .write = amd_pmf_get_pb_data, + .open = simple_open, +}; + +static void amd_pmf_open_pb(struct amd_pmf_dev *dev, struct dentry *debugfs_root) +{ + dev->esbin = debugfs_create_dir("pb", debugfs_root); + debugfs_create_file("update_policy", 0644, dev->esbin, dev, &pb_fops); +} + +static void amd_pmf_remove_pb(struct amd_pmf_dev *dev) +{ + debugfs_remove_recursive(dev->esbin); +} +#else +static void amd_pmf_open_pb(struct amd_pmf_dev *dev, struct dentry *debugfs_root) {} +static void amd_pmf_remove_pb(struct amd_pmf_dev *dev) {} +#endif + static int amd_pmf_get_bios_buffer(struct amd_pmf_dev *dev) { dev->policy_buf = kzalloc(dev->policy_sz, GFP_KERNEL); @@ -281,6 +329,9 @@ static int amd_pmf_get_bios_buffer(struct amd_pmf_dev *dev) memcpy(dev->policy_buf, dev->policy_base, dev->policy_sz); + if (pb_side_load) + amd_pmf_open_pb(dev, dev->dbgfs_dir); + return amd_pmf_start_policy_engine(dev); } @@ -382,6 +433,9 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev) void amd_pmf_deinit_smart_pc(struct amd_pmf_dev *dev) { + if (pb_side_load) + amd_pmf_remove_pb(dev); + kfree(dev->prev_data); kfree(dev->policy_buf); cancel_delayed_work_sync(&dev->pb_work);