crypto: ccp - Add support to enable CipherTextHiding on SNP_INIT_EX

To enable ciphertext hiding, it must be specified in the SNP_INIT_EX
command as part of SNP initialization.

Modify the sev_platform_init_args structure, which is used as input to
sev_platform_init(), to include a field that, when non-zero,
indicates that ciphertext hiding should be enabled and specifies the
maximum ASID that can be used for an SEV-SNP guest.

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Reviewed-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 58c9e040e9ac909e9c52694fafa663f6ff3948c1..334405461657d495e5257eb1b2083e1afabb7bd6 100644 (file)
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1186,7 +1186,7 @@ static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
        return 0;
 }
 
-static int __sev_snp_init_locked(int *error)
+static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
 {
        struct psp_device *psp = psp_master;
        struct sev_data_snp_init_ex data;
@@ -1247,6 +1247,12 @@ static int __sev_snp_init_locked(int *error)
                }
 
                memset(&data, 0, sizeof(data));
+
+               if (max_snp_asid) {
+                       data.ciphertext_hiding_en = 1;
+                       data.max_snp_asid = max_snp_asid;
+               }
+
                data.init_rmp = 1;
                data.list_paddr_en = 1;
                data.list_paddr = __psp_pa(snp_range_list);
@@ -1433,7 +1439,7 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
        if (sev->sev_plat_status.state == SEV_STATE_INIT)
                return 0;
 
-       rc = __sev_snp_init_locked(&args->error);
+       rc = __sev_snp_init_locked(&args->error, args->max_snp_asid);
        if (rc && rc != -ENODEV)
                return rc;
 
@@ -1516,7 +1522,7 @@ static int snp_move_to_init_state(struct sev_issue_cmd *argp, bool *shutdown_req
 {
        int error, rc;
 
-       rc = __sev_snp_init_locked(&error);
+       rc = __sev_snp_init_locked(&error, 0);
        if (rc) {
                argp->error = SEV_RET_INVALID_PLATFORM_STATE;
                return rc;

diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index d83185b4268b020828b1d368643c940b33e1ae32..e0dbcb4b4fd9a449d5142ae0326a69a188e3357f 100644 (file)
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -748,10 +748,13 @@ struct sev_data_snp_guest_request {
 struct sev_data_snp_init_ex {
        u32 init_rmp:1;
        u32 list_paddr_en:1;
-       u32 rsvd:30;
+       u32 rapl_dis:1;
+       u32 ciphertext_hiding_en:1;
+       u32 rsvd:28;
        u32 rsvd1;
        u64 list_paddr;
-       u8  rsvd2[48];
+       u16 max_snp_asid;
+       u8  rsvd2[46];
 } __packed;
 
 /**
@@ -800,10 +803,13 @@ struct sev_data_snp_shutdown_ex {
  * @probe: True if this is being called as part of CCP module probe, which
  *  will defer SEV_INIT/SEV_INIT_EX firmware initialization until needed
  *  unless psp_init_on_probe module param is set
+ * @max_snp_asid: When non-zero, enable ciphertext hiding and specify the
+ *  maximum ASID that can be used for an SEV-SNP guest.
  */
 struct sev_platform_init_args {
        int error;
        bool probe;
+       unsigned int max_snp_asid;
 };
 
 /**