[RFC Part2 PATCH 11/30] crypto:ccp: provide APIs to issue SEV-SNP commands

From: Brijesh Singh
Date: Wed Mar 24 2021 - 13:06:36 EST


Provide the APIs for the hypervisor to manage an SEV-SNP guest. The
commands for SEV-SNP is defined in the SEV-SNP firmware specification.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
drivers/crypto/ccp/sev-dev.c | 41 +++++++++++++++++
include/linux/psp-sev.h | 85 ++++++++++++++++++++++++++++++++++++
2 files changed, 126 insertions(+)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 562501c43d8f..242c4775eb56 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1019,6 +1019,47 @@ int sev_guest_df_flush(int *error)
}
EXPORT_SYMBOL_GPL(sev_guest_df_flush);

+int sev_guest_snp_decommission(struct sev_data_snp_decommission *data, int *error)
+{
+ return sev_do_cmd(SEV_CMD_SNP_DECOMMISSION, data, error);
+}
+EXPORT_SYMBOL_GPL(sev_guest_snp_decommission);
+
+int sev_guest_snp_df_flush(int *error)
+{
+ return sev_do_cmd(SEV_CMD_SNP_DF_FLUSH, NULL, error);
+}
+EXPORT_SYMBOL_GPL(sev_guest_snp_df_flush);
+
+int sev_snp_reclaim(struct sev_data_snp_page_reclaim *data, int *error)
+{
+ return sev_do_cmd(SEV_CMD_SNP_PAGE_RECLAIM, data, error);
+}
+EXPORT_SYMBOL_GPL(sev_snp_reclaim);
+
+int sev_snp_unsmash(unsigned long paddr, int *error)
+{
+ struct sev_data_snp_page_unsmash *data;
+ int rc;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT);
+ if (!data)
+ return -ENOMEM;
+
+ data->paddr = paddr;
+ rc = sev_do_cmd(SEV_CMD_SNP_PAGE_UNSMASH, data, error);
+
+ kfree(data);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(sev_snp_unsmash);
+
+int sev_guest_snp_dbg_decrypt(struct sev_data_snp_dbg *data, int *error)
+{
+ return sev_do_cmd(SEV_CMD_SNP_DBG_DECRYPT, data, error);
+}
+EXPORT_SYMBOL_GPL(sev_guest_snp_dbg_decrypt);
+
static void sev_exit(struct kref *ref)
{
misc_deregister(&misc_dev->misc);
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index ec45c18c3b0a..32532df37446 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -821,6 +821,80 @@ int sev_guest_df_flush(int *error);
*/
int sev_guest_decommission(struct sev_data_decommission *data, int *error);

+/**
+ * sev_guest_df_flush - perform SNP 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_snp_df_flush(int *error);
+
+/**
+ * sev_guest_snp_decommission - perform SNP_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_snp_decommission(struct sev_data_snp_decommission *data, int *error);
+
+/**
+ * sev_snp_reclaim - perform SNP_PAGE_RECLAIM command
+ *
+ * @decommission: sev_snp_page_reclaim 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_snp_reclaim(struct sev_data_snp_page_reclaim *data, int *error);
+
+/**
+ * sev_snp_reclaim - perform SNP_PAGE_UNSMASH command
+ *
+ * @decommission: sev_snp_page_unmash 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_snp_unsmash(unsigned long paddr, int *error);
+
+/**
+ * sev_guest_snp_dbg_decrypt - perform SEV SNP_DBG_DECRYPT 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_snp_dbg_decrypt(struct sev_data_snp_dbg *data, int *error);
+
+
void *psp_copy_user_blob(u64 uaddr, u32 len);

#else /* !CONFIG_CRYPTO_DEV_SP_PSP */
@@ -848,6 +922,17 @@ sev_issue_cmd_external_user(struct file *filep, unsigned int id, void *data, int

static inline void *psp_copy_user_blob(u64 __user uaddr, u32 len) { return ERR_PTR(-EINVAL); }

+static inline int
+sev_guest_snp_decommission(struct sev_data_snp_decommission *data, int *error) { return -ENODEV; }
+
+static inline int sev_guest_snp_df_flush(int *error) { return -ENODEV; }
+
+static inline int sev_snp_reclaim(struct sev_data_snp_page_reclaim *data, int *error) { return -ENODEV; }
+
+static inline int sev_snp_unsmash(unsigned long paddr, int *error) { return -ENODEV; }
+
+static inline int sev_guest_snp_dbg_decrypt(struct sev_data_snp_dbg *data, int *error) { return -ENODEV; }
+
#endif /* CONFIG_CRYPTO_DEV_SP_PSP */

#endif /* __PSP_SEV_H__ */
--
2.17.1