From: Brijesh Singh <[email protected]>
Add support to decrypt guest encrypted memory. These API interfaces can
be used for example to dump VMCBs on SNP guest exit.
Signed-off-by: Brijesh Singh <[email protected]>
Signed-off-by: Ashish Kalra <[email protected]>
[mdr: minor commit fixups]
Signed-off-by: Michael Roth <[email protected]>
---
drivers/crypto/ccp/sev-dev.c | 33 +++++++++++++++++++++++++++++++++
include/linux/psp-sev.h | 21 ++++++++++++++++++++-
2 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index d4f13e5a8dde..052190bdb8a6 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -2017,6 +2017,39 @@ int sev_guest_df_flush(int *error)
}
EXPORT_SYMBOL_GPL(sev_guest_df_flush);
+int snp_guest_dbg_decrypt_page(u64 gctx_pfn, u64 src_pfn, u64 dst_pfn, int *error)
+{
+ struct sev_data_snp_dbg data = {0};
+ struct sev_device *sev;
+ int ret;
+
+ if (!psp_master || !psp_master->sev_data)
+ return -ENODEV;
+
+ sev = psp_master->sev_data;
+
+ if (!sev->snp_initialized)
+ return -EINVAL;
+
+ data.gctx_paddr = sme_me_mask | (gctx_pfn << PAGE_SHIFT);
+ data.src_addr = sme_me_mask | (src_pfn << PAGE_SHIFT);
+ data.dst_addr = sme_me_mask | (dst_pfn << PAGE_SHIFT);
+ data.len = PAGE_SIZE;
+
+ /* The destination page must be in the firmware state. */
+ if (rmp_mark_pages_firmware(data.dst_addr, 1, false))
+ return -EIO;
+
+ ret = sev_do_cmd(SEV_CMD_SNP_DBG_DECRYPT, &data, error);
+
+ /* Restore the page state */
+ if (snp_reclaim_pages(data.dst_addr, 1, false))
+ ret = -EIO;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snp_guest_dbg_decrypt_page);
+
int snp_guest_ext_guest_request(struct sev_data_snp_guest_request *data,
unsigned long vaddr, unsigned long *npages, unsigned long *fw_err)
{
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 81bafc049eca..a1e6624540f3 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -913,13 +913,27 @@ int sev_guest_decommission(struct sev_data_decommission *data, int *error);
* @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_do_cmd(int cmd, void *data, int *psp_ret);
+
+/**
+ * snp_guest_dbg_decrypt_page - 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_do_cmd(int cmd, void *data, int *psp_ret);
+int snp_guest_dbg_decrypt_page(u64 gctx_pfn, u64 src_pfn, u64 dst_pfn, int *error);
void *psp_copy_user_blob(u64 uaddr, u32 len);
void *snp_alloc_firmware_page(gfp_t mask);
@@ -987,6 +1001,11 @@ static inline void *psp_copy_user_blob(u64 __user uaddr, u32 len) { return ERR_P
void snp_mark_pages_offline(unsigned long pfn, unsigned int npages) {}
+static inline int snp_guest_dbg_decrypt_page(u64 gctx_pfn, u64 src_pfn, u64 dst_pfn, int *error)
+{
+ return -ENODEV;
+}
+
static inline void *snp_alloc_firmware_page(gfp_t mask)
{
return NULL;
--
2.25.1