AMD's new Secure Encrypted Virtualization (SEV) feature allows the memory contents of virtual machines to be transparently encrypted with a key unique to the VM. The programming and management of the encryption keys are handled by the AMD Secure Processor (AMD-SP) which exposes the commands for these tasks. The complete spec is available at: http://support.amd.com/TechDocs/55766_SEV-KM%20API_Specification.pdf Extend the AMD-SP driver to provide the following support: - an in-kernel API to communicate with the SEV firmware. The API can be used by the hypervisor to create encryption context for a SEV guest. - a userspace IOCTL to manage the platform certificates. Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Gary Hook <gary.hook@xxxxxxx> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx> Cc: linux-crypto@xxxxxxxxxxxxxxx Cc: kvm@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Improvements-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx> --- Boris, I have tried to minimize the INIT -> SHUTDOWN transition by keeping state information in sev_state variable. Since we INIT the platform during the modprobe time hence we no longer need the kref count and init mutex. Here are list of changes. Changes since v6: * Add functions to init and shutdown firmware during modprobe * Add sev_state variable in psp_device to keep track of the INIT and SHUTDOWN state * Don't allow caller to shutdown the FW because SHUTDOWN will be done during the module removal. * Drop the fw_init_mutex and init_refcount because we no longer allow apps to INIT and UINIT the platform drivers/crypto/ccp/psp-dev.c | 360 +++++++++++++++++++++++++++++++++++++++++++ drivers/crypto/ccp/psp-dev.h | 22 +++ drivers/crypto/ccp/sp-dev.c | 9 ++ drivers/crypto/ccp/sp-dev.h | 4 + include/linux/psp-sev.h | 158 +++++++++++++++++++ 5 files changed, 553 insertions(+) diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c index b5789f878560..060f57ac08b3 100644 --- a/drivers/crypto/ccp/psp-dev.c +++ b/drivers/crypto/ccp/psp-dev.c @@ -26,6 +26,15 @@ #include "sp-dev.h" #include "psp-dev.h" +#define DEVICE_NAME "sev" + +static DEFINE_MUTEX(sev_cmd_mutex); +static struct sev_misc_dev *misc_dev; +static struct psp_device *psp_master; + +static int sev_platform_shutdown_locked(int *error); +static int sev_platform_init_locked(struct sev_data_init *data, int *error); + static struct psp_device *psp_alloc_struct(struct sp_device *sp) { struct device *dev = sp->dev; @@ -45,9 +54,304 @@ static struct psp_device *psp_alloc_struct(struct sp_device *sp) static irqreturn_t psp_irq_handler(int irq, void *data) { + struct psp_device *psp = data; + unsigned int status; + int reg; + + /* Read the interrupt status: */ + status = ioread32(psp->io_regs + PSP_P2CMSG_INTSTS); + + /* Check if it is command completion: */ + if (!(status & BIT(PSP_CMD_COMPLETE_REG))) + goto done; + + /* Check if it is SEV command completion: */ + reg = ioread32(psp->io_regs + PSP_CMDRESP); + if (reg & PSP_CMDRESP_RESP) { + psp->sev_int_rcvd = 1; + wake_up(&psp->sev_int_queue); + } + +done: + /* Clear the interrupt status by writing the same value we read. */ + iowrite32(status, psp->io_regs + PSP_P2CMSG_INTSTS); + return IRQ_HANDLED; } +static void sev_wait_cmd_ioc(struct psp_device *psp, unsigned int *reg) +{ + psp->sev_int_rcvd = 0; + + wait_event(psp->sev_int_queue, psp->sev_int_rcvd); + *reg = ioread32(psp->io_regs + PSP_CMDRESP); +} + +static int sev_cmd_buffer_len(int cmd) +{ + switch (cmd) { + case SEV_CMD_INIT: return sizeof(struct sev_data_init); + case SEV_CMD_PLATFORM_STATUS: return sizeof(struct sev_user_data_status); + case SEV_CMD_PEK_CSR: return sizeof(struct sev_data_pek_csr); + case SEV_CMD_PEK_CERT_IMPORT: return sizeof(struct sev_data_pek_cert_import); + case SEV_CMD_PDH_CERT_EXPORT: return sizeof(struct sev_data_pdh_cert_export); + case SEV_CMD_LAUNCH_START: return sizeof(struct sev_data_launch_start); + case SEV_CMD_LAUNCH_UPDATE_DATA: return sizeof(struct sev_data_launch_update_data); + case SEV_CMD_LAUNCH_UPDATE_VMSA: return sizeof(struct sev_data_launch_update_vmsa); + case SEV_CMD_LAUNCH_FINISH: return sizeof(struct sev_data_launch_finish); + case SEV_CMD_LAUNCH_MEASURE: return sizeof(struct sev_data_launch_measure); + case SEV_CMD_ACTIVATE: return sizeof(struct sev_data_activate); + case SEV_CMD_DEACTIVATE: return sizeof(struct sev_data_deactivate); + case SEV_CMD_DECOMMISSION: return sizeof(struct sev_data_decommission); + case SEV_CMD_GUEST_STATUS: return sizeof(struct sev_data_guest_status); + case SEV_CMD_DBG_DECRYPT: return sizeof(struct sev_data_dbg); + case SEV_CMD_DBG_ENCRYPT: return sizeof(struct sev_data_dbg); + case SEV_CMD_SEND_START: return sizeof(struct sev_data_send_start); + case SEV_CMD_SEND_UPDATE_DATA: return sizeof(struct sev_data_send_update_data); + case SEV_CMD_SEND_UPDATE_VMSA: return sizeof(struct sev_data_send_update_vmsa); + case SEV_CMD_SEND_FINISH: return sizeof(struct sev_data_send_finish); + case SEV_CMD_RECEIVE_START: return sizeof(struct sev_data_receive_start); + case SEV_CMD_RECEIVE_FINISH: return sizeof(struct sev_data_receive_finish); + case SEV_CMD_RECEIVE_UPDATE_DATA: return sizeof(struct sev_data_receive_update_data); + case SEV_CMD_RECEIVE_UPDATE_VMSA: return sizeof(struct sev_data_receive_update_vmsa); + case SEV_CMD_LAUNCH_UPDATE_SECRET: return sizeof(struct sev_data_launch_secret); + default: return 0; + } + + return 0; +} + +static int sev_do_cmd_locked(int cmd, void *data, int *psp_ret) +{ + struct psp_device *psp = psp_master; + unsigned int phys_lsb, phys_msb; + unsigned int reg, ret = 0; + + if (!psp) + return -ENODEV; + + /* Get the physical address of the command buffer */ + phys_lsb = data ? lower_32_bits(__psp_pa(data)) : 0; + phys_msb = data ? upper_32_bits(__psp_pa(data)) : 0; + + dev_dbg(psp->dev, "sev command id %#x buffer 0x%08x%08x\n", + cmd, phys_msb, phys_lsb); + + print_hex_dump_debug("(in): ", DUMP_PREFIX_OFFSET, 16, 2, data, + sev_cmd_buffer_len(cmd), false); + + iowrite32(phys_lsb, psp->io_regs + PSP_CMDBUFF_ADDR_LO); + iowrite32(phys_msb, psp->io_regs + PSP_CMDBUFF_ADDR_HI); + + reg = cmd; + reg <<= PSP_CMDRESP_CMD_SHIFT; + reg |= PSP_CMDRESP_IOC; + iowrite32(reg, psp->io_regs + PSP_CMDRESP); + + /* wait for command completion */ + sev_wait_cmd_ioc(psp, ®); + + if (psp_ret) + *psp_ret = reg & PSP_CMDRESP_ERR_MASK; + + if (reg & PSP_CMDRESP_ERR_MASK) { + dev_dbg(psp->dev, "sev command %#x failed (%#010x)\n", + cmd, reg & PSP_CMDRESP_ERR_MASK); + ret = -EIO; + } + + print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data, + sev_cmd_buffer_len(cmd), false); + + return ret; +} + +static int sev_do_cmd(int cmd, void *data, int *psp_ret) +{ + int rc; + + mutex_lock(&sev_cmd_mutex); + rc = sev_do_cmd_locked(cmd, data, psp_ret); + mutex_unlock(&sev_cmd_mutex); + + return rc; +} + +static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) +{ + return -ENOTTY; +} + +static const struct file_operations sev_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = sev_ioctl, +}; + +static int sev_platform_init_locked(struct sev_data_init *data, int *error) +{ + struct psp_device *psp = psp_master; + struct sev_data_init *input = NULL; + int rc = 0; + + if (!psp) + return -ENODEV; + + if (psp->sev_state == SEV_STATE_INIT) + return 0; + + if (!data) { + input = kzalloc(sizeof(*input), GFP_KERNEL); + if (!input) + return -ENOMEM; + + data = input; + } + + rc = sev_do_cmd_locked(SEV_CMD_INIT, data, error); + if (rc) + goto e_free; + + psp->sev_state = SEV_STATE_INIT; + dev_dbg(psp->dev, "SEV firmware intialized\n"); + +e_free: + kfree(input); + return rc; +} + +int sev_platform_init(struct sev_data_init *data, int *error) +{ + int rc; + + mutex_lock(&sev_cmd_mutex); + rc = sev_platform_init_locked(data, error); + mutex_unlock(&sev_cmd_mutex); + + return rc; +} +EXPORT_SYMBOL_GPL(sev_platform_init); + +static int sev_platform_shutdown_locked(int *error) +{ + int ret; + + ret = sev_do_cmd_locked(SEV_CMD_SHUTDOWN, 0, error); + if (ret) + return ret; + + psp_master->sev_state = SEV_STATE_UNINIT; + dev_dbg(psp_master->dev, "SEV firmware shutdown\n"); + + return ret; +} + +int sev_platform_shutdown(int *error) +{ + if (error) + *error = 0; + + return 0; +} +EXPORT_SYMBOL_GPL(sev_platform_shutdown); + +int sev_platform_status(struct sev_user_data_status *data, int *error) +{ + return sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error); +} +EXPORT_SYMBOL_GPL(sev_platform_status); + +int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd, + void *data, int *error) +{ + if (!filep || filep->f_op != &sev_fops) + return -EBADF; + + return sev_do_cmd(cmd, data, error); +} +EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user); + +int sev_guest_deactivate(struct sev_data_deactivate *data, int *error) +{ + return sev_do_cmd(SEV_CMD_DEACTIVATE, data, error); +} +EXPORT_SYMBOL_GPL(sev_guest_deactivate); + +int sev_guest_activate(struct sev_data_activate *data, int *error) +{ + return sev_do_cmd(SEV_CMD_ACTIVATE, data, error); +} +EXPORT_SYMBOL_GPL(sev_guest_activate); + +int sev_guest_decommission(struct sev_data_decommission *data, int *error) +{ + return sev_do_cmd(SEV_CMD_DECOMMISSION, data, error); +} +EXPORT_SYMBOL_GPL(sev_guest_decommission); + +int sev_guest_df_flush(int *error) +{ + return sev_do_cmd(SEV_CMD_DF_FLUSH, 0, error); +} +EXPORT_SYMBOL_GPL(sev_guest_df_flush); + +static int sev_ops_init(struct psp_device *psp) +{ + struct device *dev = psp->dev; + int ret; + + /* + * SEV feature support can be detected on multiple devices but the SEV + * FW commands must be issued on the master. During probe, we do not + * know the master hence we create /dev/sev on the first device probe. + * sev_do_cmd() finds the right master device to which to issue the + * command to the firmware. + */ + if (!misc_dev) { + struct miscdevice *misc; + + misc_dev = devm_kzalloc(dev, sizeof(*misc_dev), GFP_KERNEL); + if (!misc_dev) + return -ENOMEM; + + misc = &misc_dev->misc; + misc->minor = MISC_DYNAMIC_MINOR; + misc->name = DEVICE_NAME; + misc->fops = &sev_fops; + + ret = misc_register(misc); + if (ret) + return ret; + + kref_init(&misc_dev->refcount); + } else { + kref_get(&misc_dev->refcount); + } + + init_waitqueue_head(&psp->sev_int_queue); + psp->sev_misc = misc_dev; + dev_dbg(dev, "registered SEV device\n"); + + return 0; +} + +static int sev_init(struct psp_device *psp) +{ + /* Check if device supports SEV feature */ + if (!(ioread32(psp->io_regs + PSP_FEATURE_REG) & 1)) { + dev_dbg(psp->dev, "device does not support SEV\n"); + return 1; + } + + return sev_ops_init(psp); +} + +static void sev_exit(struct kref *ref) +{ + struct sev_misc_dev *misc_dev = container_of(ref, struct sev_misc_dev, refcount); + + misc_deregister(&misc_dev->misc); +} + int psp_dev_init(struct sp_device *sp) { struct device *dev = sp->dev; @@ -84,11 +388,17 @@ int psp_dev_init(struct sp_device *sp) if (sp->set_psp_master_device) sp->set_psp_master_device(sp); + ret = sev_init(psp); + if (ret) + goto e_irq; + /* Enable interrupt */ iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTEN); return 0; +e_irq: + sp_free_psp_irq(psp->sp, psp); e_err: sp->psp_data = NULL; @@ -101,5 +411,55 @@ void psp_dev_destroy(struct sp_device *sp) { struct psp_device *psp = sp->psp_data; + if (psp->sev_misc) + kref_put(&misc_dev->refcount, sev_exit); + sp_free_psp_irq(sp, psp); } + +void psp_pci_init(void) +{ + struct sev_user_data_status *data; + struct sp_device *sp; + int error, rc; + + sp = sp_get_psp_master_device(); + if (!sp) + return; + + psp_master = sp->psp_data; + + /* Initialize the platform */ + rc = sev_platform_init(NULL, &error); + if (rc) { + dev_err(sp->dev, "SEV: failed to INIT error %#x\n", error); + return; + } + + /* Display SEV firmware version */ + data = kzalloc(sizeof (*data), GFP_KERNEL); + if (!data) + return; + + rc = sev_platform_status(data, &error); + if (rc) { + dev_err(sp->dev, "SEV: failed to get status error %#x\n", error); + goto e_free; + } + + dev_info(sp->dev, "SEV API:%d.%d build:%d\n", + data->api_major, data->api_minor, data->build); + +e_free: + kfree(data); +} + +void psp_pci_exit(void) +{ + if (!psp_master) + return; + + mutex_lock(&sev_cmd_mutex); + sev_platform_shutdown_locked(NULL); + mutex_unlock(&sev_cmd_mutex); +} diff --git a/drivers/crypto/ccp/psp-dev.h b/drivers/crypto/ccp/psp-dev.h index 55b7808367c3..98889b721904 100644 --- a/drivers/crypto/ccp/psp-dev.h +++ b/drivers/crypto/ccp/psp-dev.h @@ -25,9 +25,21 @@ #include <linux/interrupt.h> #include <linux/irqreturn.h> #include <linux/dmaengine.h> +#include <linux/psp-sev.h> +#include <linux/miscdevice.h> #include "sp-dev.h" +#define PSP_C2PMSG(_num) ((_num) << 2) +#define PSP_CMDRESP PSP_C2PMSG(32) +#define PSP_CMDBUFF_ADDR_LO PSP_C2PMSG(56) +#define PSP_CMDBUFF_ADDR_HI PSP_C2PMSG(57) +#define PSP_FEATURE_REG PSP_C2PMSG(63) + +#define PSP_P2CMSG(_num) ((_num) << 2) +#define PSP_CMD_COMPLETE_REG 1 +#define PSP_CMD_COMPLETE PSP_P2CMSG(PSP_CMD_COMPLETE_REG) + #define PSP_P2CMSG_INTEN 0x0110 #define PSP_P2CMSG_INTSTS 0x0114 @@ -44,6 +56,11 @@ #define MAX_PSP_NAME_LEN 16 +struct sev_misc_dev { + struct kref refcount; + struct miscdevice misc; +}; + struct psp_device { struct list_head entry; @@ -54,6 +71,11 @@ struct psp_device { struct sp_device *sp; void __iomem *io_regs; + + int sev_state; + unsigned int sev_int_rcvd; + wait_queue_head_t sev_int_queue; + struct sev_misc_dev *sev_misc; }; #endif /* __PSP_DEV_H */ diff --git a/drivers/crypto/ccp/sp-dev.c b/drivers/crypto/ccp/sp-dev.c index cf101c039c8f..eb0da6572720 100644 --- a/drivers/crypto/ccp/sp-dev.c +++ b/drivers/crypto/ccp/sp-dev.c @@ -272,6 +272,10 @@ static int __init sp_mod_init(void) if (ret) return ret; +#ifdef CONFIG_CRYPTO_DEV_SP_PSP + psp_pci_init(); +#endif + return 0; #endif @@ -291,6 +295,11 @@ static int __init sp_mod_init(void) static void __exit sp_mod_exit(void) { #ifdef CONFIG_X86 + +#ifdef CONFIG_CRYPTO_DEV_SP_PSP + psp_pci_exit(); +#endif + sp_pci_exit(); #endif diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h index 909cf3e436b4..acb197b66ced 100644 --- a/drivers/crypto/ccp/sp-dev.h +++ b/drivers/crypto/ccp/sp-dev.h @@ -143,12 +143,16 @@ static inline int ccp_dev_resume(struct sp_device *sp) #ifdef CONFIG_CRYPTO_DEV_SP_PSP int psp_dev_init(struct sp_device *sp); +void psp_pci_init(void); void psp_dev_destroy(struct sp_device *sp); +void psp_pci_exit(void); #else /* !CONFIG_CRYPTO_DEV_SP_PSP */ static inline int psp_dev_init(struct sp_device *sp) { return 0; } +static inline void psp_pci_init(void) { } static inline void psp_dev_destroy(struct sp_device *sp) { } +static inline void psp_pci_exit(void) { } #endif /* CONFIG_CRYPTO_DEV_SP_PSP */ diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h index 15bda519538e..7ddce7dec464 100644 --- a/include/linux/psp-sev.h +++ b/include/linux/psp-sev.h @@ -491,4 +491,162 @@ struct sev_data_dbg { u32 len; /* In */ } __packed; +#ifdef CONFIG_CRYPTO_DEV_SP_PSP + +/** + * sev_platform_init - perform SEV INIT command + * + * @init: sev_data_init structure to be processed + * @error: SEV command return code + * + * Returns: + * 0 if the SEV successfully processed the command + * -%ENODEV if the SEV device is not available + * -%ENOTSUPP if the SEV does not support SEV + * -%ETIMEDOUT if the SEV command timed out + * -%EIO if the SEV returned a non-zero return code + */ +int sev_platform_init(struct sev_data_init *init, int *error); + +/** + * sev_platform_shutdown - perform SEV SHUTDOWN command + * @error: SEV command return code + * + * Returns: + * 0 if the SEV successfully processed the command + * -%ENODEV if the SEV device is not available + * -%ENOTSUPP if the SEV does not support SEV + * -%ETIMEDOUT if the SEV command timed out + * -%EIO if the SEV returned a non-zero return code + */ +int sev_platform_shutdown(int *error); + +/** + * sev_platform_status - perform SEV PLATFORM_STATUS command + * + * @status: sev_user_data_status structure to be processed + * @error: SEV command return code + * + * Returns: + * 0 if the SEV successfully processed the command + * -%ENODEV if the SEV device is not available + * -%ENOTSUPP if the SEV does not support SEV + * -%ETIMEDOUT if the SEV command timed out + * -%EIO if the SEV returned a non-zero return code + */ +int sev_platform_status(struct sev_user_data_status *status, int *error); + +/** + * sev_issue_cmd_external_user - issue SEV command by other driver with a file + * handle. + * + * This function can be used by other drivers to issue a SEV command on + * behalf of userspace. The caller must pass a valid SEV file descriptor + * so that we know that it has access to SEV device. + * + * @filep - SEV device file pointer + * @cmd - command to issue + * @data - command buffer + * @error: SEV command return code + * + * Returns: + * 0 if the SEV successfully processed the command + * -%ENODEV if the SEV device is not available + * -%ENOTSUPP if the SEV does not support SEV + * -%ETIMEDOUT if the SEV command timed out + * -%EIO if the SEV returned a non-zero return code + * -%EINVAL if the SEV file descriptor is not valid + */ +int sev_issue_cmd_external_user(struct file *filep, unsigned int id, + void *data, int *error); + +/** + * sev_guest_deactivate - perform SEV DEACTIVATE command + * + * @deactivate: sev_data_deactivate structure to be processed + * @sev_ret: sev command return code + * + * Returns: + * 0 if the sev successfully processed the command + * -%ENODEV if the sev device is not available + * -%ENOTSUPP if the sev does not support SEV + * -%ETIMEDOUT if the sev command timed out + * -%EIO if the sev returned a non-zero return code + */ +int sev_guest_deactivate(struct sev_data_deactivate *data, int *error); + +/** + * sev_guest_activate - perform SEV ACTIVATE command + * + * @activate: sev_data_activate structure to be processed + * @sev_ret: sev command return code + * + * Returns: + * 0 if the sev successfully processed the command + * -%ENODEV if the sev device is not available + * -%ENOTSUPP if the sev does not support SEV + * -%ETIMEDOUT if the sev command timed out + * -%EIO if the sev returned a non-zero return code + */ +int sev_guest_activate(struct sev_data_activate *data, int *error); + +/** + * sev_guest_df_flush - perform SEV DF_FLUSH command + * + * @sev_ret: sev command return code + * + * Returns: + * 0 if the sev successfully processed the command + * -%ENODEV if the sev device is not available + * -%ENOTSUPP if the sev does not support SEV + * -%ETIMEDOUT if the sev command timed out + * -%EIO if the sev returned a non-zero return code + */ +int sev_guest_df_flush(int *error); + +/** + * sev_guest_decommission - perform SEV DECOMMISSION command + * + * @decommission: sev_data_decommission structure to be processed + * @sev_ret: sev command return code + * + * Returns: + * 0 if the sev successfully processed the command + * -%ENODEV if the sev device is not available + * -%ENOTSUPP if the sev does not support SEV + * -%ETIMEDOUT if the sev command timed out + * -%EIO if the sev returned a non-zero return code + */ +int sev_guest_decommission(struct sev_data_decommission *data, int *error); + +#else /* !CONFIG_CRYPTO_DEV_SP_PSP */ + +static inline int +sev_platform_status(struct sev_user_data_status *status, int *error) { return -ENODEV; } + +static inline int +sev_platform_init(struct sev_data_init *init, int *error) { return -ENODEV; } + +static inline int sev_platform_shutdown(int *error) { return -ENODEV; } + +static inline int +sev_guest_deactivate(struct sev_data_deactivate *data, int *error) { return -ENODEV; } + +static inline int +sev_guest_decommission(struct sev_data_decommission *data, int *error) { return -ENODEV; } + +static inline int +sev_guest_activate(struct sev_data_activate *data, int *error) { return -ENODEV; } + +static inline int sev_guest_df_flush(int *error) { return -ENODEV; } + +static inline int +sev_issue_cmd_external_user(struct file *filep, + unsigned int id, void *data, int *error) +{ + return -ENODEV; +} + +#endif /* CONFIG_CRYPTO_DEV_SP_PSP */ + #endif /* __PSP_SEV_H__ */ -- 2.9.5
