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Subject[Part2 PATCH v5.2 12.2/31] crypto: ccp: Add Secure Encrypted Virtualization (SEV) command support
Date
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@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
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
Make it as a second patch in the series (changes from 12.1 -> 12.2)

Changes since v5.1:
* text streamlining (from Boris)
* rename sev_handle_cmd -> sev_do_cmd (from Boris)
* PSP_P2CMSG needs arg eval (from Boris)
* use #ifdef instead of #if defined() (from Boris)

drivers/crypto/ccp/psp-dev.c | 251 +++++++++++++++++++++++++++++++++++++++++++
drivers/crypto/ccp/psp-dev.h | 16 +++
include/linux/psp-sev.h | 159 +++++++++++++++++++++++++++
3 files changed, 426 insertions(+)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index b5789f878560..175cb3c3b8ef 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -23,9 +23,16 @@
#include <linux/hw_random.h>
#include <linux/ccp.h>

+#include <uapi/linux/psp-sev.h>
+
#include "sp-dev.h"
#include "psp-dev.h"

+#define DEVICE_NAME "sev"
+
+static DEFINE_MUTEX(sev_cmd_mutex);
+static bool sev_fops_registered;
+
static struct psp_device *psp_alloc_struct(struct sp_device *sp)
{
struct device *dev = sp->dev;
@@ -45,9 +52,246 @@ 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 int 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);
+
+ return 0;
+}
+
+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_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(int cmd, void *data, int *psp_ret)
+{
+ unsigned int phys_lsb, phys_msb;
+ struct psp_device *psp;
+ unsigned int reg, ret;
+ struct sp_device *sp;
+
+ sp = sp_get_psp_master_device();
+ if (!sp)
+ return -ENODEV;
+
+ psp = sp->psp_data;
+ 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);
+
+ /* Only one command at a time... */
+ mutex_lock(&sev_cmd_mutex);
+
+ 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);
+
+ ret = sev_wait_cmd_ioc(psp, &reg);
+ if (ret)
+ goto unlock;
+
+ 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;
+ }
+
+unlock:
+ mutex_unlock(&sev_cmd_mutex);
+ print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
+ sev_cmd_buffer_len(cmd), false);
+ return ret;
+}
+
+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,
+};
+
+int sev_platform_init(struct sev_data_init *data, int *error)
+{
+ return sev_do_cmd(SEV_CMD_INIT, data, error);
+}
+EXPORT_SYMBOL_GPL(sev_platform_init);
+
+int sev_platform_shutdown(int *error)
+{
+ return sev_do_cmd(SEV_CMD_SHUTDOWN, 0, error);
+}
+EXPORT_SYMBOL_GPL(sev_platform_shutdown);
+
+int sev_platform_status(struct sev_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;
+ struct miscdevice *misc;
+ 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 (!sev_fops_registered) {
+
+ misc = devm_kzalloc(dev, sizeof(*misc), GFP_KERNEL);
+ if (!misc)
+ return -ENOMEM;
+
+ misc->minor = MISC_DYNAMIC_MINOR;
+ misc->name = DEVICE_NAME;
+ misc->fops = &sev_fops;
+
+ ret = misc_register(misc);
+ if (ret)
+ return ret;
+
+ sev_fops_registered = true;
+ psp->sev_misc = misc;
+ init_waitqueue_head(&psp->sev_int_queue);
+ dev_info(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 psp_device *psp)
+{
+ if (psp->sev_misc)
+ misc_deregister(psp->sev_misc);
+}
+
int psp_dev_init(struct sp_device *sp)
{
struct device *dev = sp->dev;
@@ -84,11 +328,17 @@ 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 +351,6 @@ void psp_dev_destroy(struct sp_device *sp)
{
struct psp_device *psp = sp->psp_data;

+ sev_exit(psp);
sp_free_psp_irq(sp, psp);
}
diff --git a/drivers/crypto/ccp/psp-dev.h b/drivers/crypto/ccp/psp-dev.h
index 55b7808367c3..7a781ec20684 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

@@ -54,6 +66,10 @@ struct psp_device {
struct sp_device *sp;

void __iomem *io_regs;
+
+ unsigned int sev_int_rcvd;
+ wait_queue_head_t sev_int_queue;
+ struct miscdevice *sev_misc;
};

#endif /* __PSP_DEV_H */
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 496375d7f6a9..5d562d49deac 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -512,4 +512,163 @@ 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
+ *
+ * @init: sev_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_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_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
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