Move initializing SEV/SNP functionality to KVM

From: Ashish Kalra <[email protected]>

Move dev_info and dev_err messages related to SEV/SNP initialization and shutdown into __sev_platform_init_locked(), __sev_snp_init_locked() and __sev_platform_shutdown_locked(), __sev_snp_shutdown_locked() so that they don't need to be issued from callers.

This allows both _sev_platform_init_locked() and various SEV/SNP ioctls to call __sev_platform_init_locked(), __sev_snp_init_locked() and __sev_platform_shutdown_locked(), __sev_snp_shutdown_locked() for implicit SEV/SNP initialization and shutdown without additionally printing any errors/success messages.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 39 +++++++++++++++++++++++++++---------
 1 file changed, 30 insertions(+), 9 deletions(-)

drivers/crypto/ccp/sev-dev.c +0 -0

index 2e87ca0e292a..8f5c474b9d1c 100644

drivers/crypto/ccp/sev-dev.c +9 -2

 		return rc;
+	}
 
 	/* Prepare for first SNP guest launch after INIT. */
 	wbinvd_on_all_cpus();
 	rc = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, error);
-	if (rc)
+	if (rc) {
+		dev_err(sev->dev, "SEV-SNP: SNP_DF_FLUSH failed rc %d, error %#x\n",
+			rc, *error);
 		return rc;
+	}
 
 	sev->snp_initialized = true;
 	dev_dbg(sev->dev, "SEV-SNP firmware initialized\n");
 
+	dev_info(sev->dev, "SEV-SNP API:%d.%d build:%d\n", sev->api_major,
+		 sev->api_minor, sev->build);
+
 	sev_es_tmr_size = SNP_TMR_SIZE;
 
-	return rc;
+	return 0;
 }
 
 static void __sev_platform_init_handle_tmr(struct sev_device *sev)

drivers/crypto/ccp/sev-dev.c +9 -2

 		return rc;
+	}
 
 	sev->state = SEV_STATE_INIT;
 
 	/* Prepare for first SEV guest launch after INIT */
 	wbinvd_on_all_cpus();
 	rc = __sev_do_cmd_locked(SEV_CMD_DF_FLUSH, NULL, error);
-	if (rc)
+	if (rc) {
+		dev_err(sev->dev, "SEV: DF_FLUSH failed %#x, rc %d\n",
+			*error, rc);
 		return rc;
+	}
 
 	dev_dbg(sev->dev, "SEV firmware initialized\n");
 

@@ -1367,8 +1384,11 @@ static int __sev_platform_shutdown_locked(int *error)
 		return 0;
 
 	ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
-	if (ret)
+	if (ret) {
+		dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
+			*error, ret);
 		return ret;
+	}
 
 	sev->state = SEV_STATE_UNINIT;
 	dev_dbg(sev->dev, "SEV firmware shutdown\n");

drivers/crypto/ccp/sev-dev.c +2 -1

 			return ret;
 		}
 		/* reissue the shutdown command */

@@ -1692,7 +1712,8 @@ static int __sev_snp_shutdown_locked(int *error, bool panic)
 					  error);
 	}
 	if (ret) {
-		dev_err(sev->dev, "SEV-SNP firmware shutdown failed\n");
+		dev_err(sev->dev, "SEV-SNP firmware shutdown failed, rc %d, error %#x\n",
+			ret, *error);
 		return ret;
 	}
 

From: Ashish Kalra <[email protected]>

Modify the behavior of implicit SEV initialization in some of the SEV ioctls to do both SEV initialization and shutdown and add implicit SNP initialization and shutdown to some of the SNP ioctls so that the change of SEV/SNP platform initialization not being done during PSP driver probe time does not break userspace tools such as sevtool, etc.

Prior to this patch, SEV has always been initialized before these ioctls as SEV initialization is done as part of PSP module probe, but now with SEV initialization being moved to KVM module load instead of PSP driver probe, the implied SEV INIT actually makes sense and gets used and additionally to maintain SEV platform state consistency before and after the ioctl SEV shutdown needs to be done after the firmware call.

It is important to do SEV Shutdown here with the SEV/SNP initialization moving to KVM, an implicit SEV INIT here as part of the SEV ioctls not followed with SEV Shutdown will cause SEV to remain in INIT state and then a future SNP INIT in KVM module load will fail.

Similarly, prior to this patch, SNP has always been initialized before these ioctls as SNP initialization is done as part of PSP module probe, therefore, to keep a consistent behavior, SNP init needs to be done here implicitly as part of these ioctls followed with SNP shutdown before returning from the ioctl to maintain the consistent platform state before and after the ioctl.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 117 ++++++++++++++++++++++++++++-------
 1 file changed, 93 insertions(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +2 -1

index 8f5c474b9d1c..b06f43eb18f7 100644
@@ -1461,7 +1461,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
-       int rc;
+       bool shutdown_required = false;
+       int rc, error;
 
        if (!writable)
                return -EPERM;

@@ -1470,19 +1471,26 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
                rc = __sev_platform_init_locked(&argp->error);

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return rc;
 }
 
 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_csr input;
+       bool shutdown_required = false;
        struct sev_data_pek_csr data;
        void __user *input_address;
        void *blob = NULL;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1513,6 +1521,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_blob;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);

drivers/crypto/ccp/sev-dev.c +3 -1

+
        kfree(blob);
        return ret;
 }

@@ -1747,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import data;
+       bool shutdown_required = false;
        void *pek_blob, *oca_blob;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1780,11 +1793,15 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);

drivers/crypto/ccp/sev-dev.c +3 -11

+
        kfree(oca_blob);
 e_free_pek:
        kfree(pek_blob);

@@ -1901,17 +1918,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        struct sev_data_pdh_cert_export data;
        void __user *input_cert_chain_address;
        void __user *input_pdh_cert_address;
-       int ret;
-
-       /* If platform is not in INIT state then transition it to INIT. */
-       if (sev->state != SEV_STATE_INIT) {
-               if (!writable)
-                       return -EPERM;
-
-               ret = __sev_platform_init_locked(&argp->error);
-               if (ret)
-                       return ret;
-       }
+       bool shutdown_required = false;
+       int ret, error;
 
        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

drivers/crypto/ccp/sev-dev.c +5 -0

+               if (ret)
+                       goto e_free_cert;
+               shutdown_required = true;
+       }
+
        ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
 
        /* If we query the length, FW responded with expected data. */

drivers/crypto/ccp/sev-dev.c +4 -2

+
        kfree(cert_blob);
 e_free_pdh:
        kfree(pdh_blob);

@@ -1987,12 +2008,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
 {
        struct sev_device *sev = psp_master->sev_data;
+       bool shutdown_required = false;
        struct sev_data_snp_addr buf;
        struct page *status_page;
+       int ret, error;
        void *data;
-       int ret;
 
-       if (!sev->snp_initialized || !argp->data)
+       if (!argp->data)
                return -EINVAL;
 
        status_page = alloc_page(GFP_KERNEL_ACCOUNT);

drivers/crypto/ccp/sev-dev.c +8 -0

+               if (ret)
+                       goto cleanup;
+               shutdown_required = true;
+       }
+
        /*
         * Firmware expects status page to be in firmware-owned state, otherwise
         * it will report firmware error code INVALID_PAGE_STATE (0x1A).

@@ -2029,6 +2058,9 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
                ret = -EFAULT;
 
 cleanup:
+       if (shutdown_required)
+               __sev_snp_shutdown_locked(&error, false);
+
        __free_pages(status_page, 0);
        return ret;
 }

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return ret;
 }
 
 static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_snp_config config;
+       bool shutdown_required = false;
+       int ret, error;
 
-       if (!sev->snp_initialized || !argp->data)
+       if (!argp->data)
                return -EINVAL;
 
        if (!writable)

drivers/crypto/ccp/sev-dev.c +14 -2

+               if (ret)
+                       return ret;
+               shutdown_required = true;
+       }
+
+       ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
+
+       if (shutdown_required)
+               __sev_snp_shutdown_locked(&error, false);
+
+       return ret;
 }
 
 static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_snp_vlek_load input;
+       bool shutdown_required = false;
+       int ret, error;
        void *blob;
-       int ret;
 
-       if (!sev->snp_initialized || !argp->data)
+       if (!argp->data)
                return -EINVAL;
 
        if (!writable)

drivers/crypto/ccp/sev-dev.c +2 -1

+
+cleanup:
        kfree(blob);
 
        return ret;
--

2.34.1

Quoted 56 lines · Ashish Kalra

From: Ashish Kalra <[email protected]>

Modify the behavior of implicit SEV initialization in some of the SEV ioctls to do both SEV initialization and shutdown and add implicit SNP initialization and shutdown to some of the SNP ioctls so that the change of SEV/SNP platform initialization not being done during PSP driver probe time does not break userspace tools such as sevtool, etc.

Prior to this patch, SEV has always been initialized before these ioctls as SEV initialization is done as part of PSP module probe, but now with SEV initialization being moved to KVM module load instead of PSP driver probe, the implied SEV INIT actually makes sense and gets used and additionally to maintain SEV platform state consistency before and after the ioctl SEV shutdown needs to be done after the firmware call.

It is important to do SEV Shutdown here with the SEV/SNP initialization moving to KVM, an implicit SEV INIT here as part of the SEV ioctls not followed with SEV Shutdown will cause SEV to remain in INIT state and then a future SNP INIT in KVM module load will fail.

Similarly, prior to this patch, SNP has always been initialized before these ioctls as SNP initialization is done as part of PSP module probe, therefore, to keep a consistent behavior, SNP init needs to be done here implicitly as part of these ioctls followed with SNP shutdown before returning from the ioctl to maintain the consistent platform state before and after the ioctl.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 117 ++++++++++++++++++++++++++++-------
 1 file changed, 93 insertions(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +3 -1

index 8f5c474b9d1c..b06f43eb18f7 100644
@@ -1461,7 +1461,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
-       int rc;
+       bool shutdown_required = false;
+       int rc, error;
 
        if (!writable)
                return -EPERM;

@@ -1470,19 +1471,26 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
                rc = __sev_platform_init_locked(&argp->error);
                if (rc)
                        return rc;
+               shutdown_required = true;
        }
 

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr · line 1480

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +4 -1

-       return __sev_do_cmd_locked(cmd, NULL, &argp->error);
+       rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
+
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

This error is discarded. Is that by design? If so, It'd be better to call this ignored_error.

Quoted 28 lines

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return rc;
 }
 
 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_csr input;
+       bool shutdown_required = false;
        struct sev_data_pek_csr data;
        void __user *input_address;
        void *blob = NULL;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1513,6 +1521,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_blob;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);

@@ -1531,6 +1540,9 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
        }
 

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) · line 1544

Quoted 3 lines

drivers/crypto/ccp/sev-dev.c +2 -0

 e_free_blob:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Another discarded error. This function is called in different locations in sev-dev.c with and without checking the result, which seems problematic.

Quoted 18 lines

drivers/crypto/ccp/sev-dev.c +3 -1

+
        kfree(blob);
        return ret;
 }

@@ -1747,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import data;
+       bool shutdown_required = false;
        void *pek_blob, *oca_blob;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1780,11 +1793,15 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) · line 1803

Quoted 10 lines

drivers/crypto/ccp/sev-dev.c +3 -0

                if (ret)
                        goto e_free_oca;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
 
 e_free_oca:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Again.

Quoted 27 lines

drivers/crypto/ccp/sev-dev.c +3 -11

+
        kfree(oca_blob);
 e_free_pek:
        kfree(pek_blob);

@@ -1901,17 +1918,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        struct sev_data_pdh_cert_export data;
        void __user *input_cert_chain_address;
        void __user *input_pdh_cert_address;
-       int ret;
-
-       /* If platform is not in INIT state then transition it to INIT. */
-       if (sev->state != SEV_STATE_INIT) {
-               if (!writable)
-                       return -EPERM;
-
-               ret = __sev_platform_init_locked(&argp->error);
-               if (ret)
-                       return ret;
-       }
+       bool shutdown_required = false;
+       int ret, error;
 
        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

@@ -1952,6 +1960,16 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        data.cert_chain_len = input.cert_chain_len;
 

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) · line 1967

Quoted 6 lines

drivers/crypto/ccp/sev-dev.c +5 -0

 cmd:
+       /* If platform is not in INIT state then transition it to INIT. */
+       if (sev->state != SEV_STATE_INIT) {
+               if (!writable)
+                       goto e_free_cert;
+               ret = __sev_platform_init_locked(&argp->error);

Using argp->error for init instead of the ioctl-requested command means that the user will have difficulty distinguishing which process is at fault, no?

Quoted 9 lines

drivers/crypto/ccp/sev-dev.c +5 -0

+               if (ret)
+                       goto e_free_cert;
+               shutdown_required = true;
+       }
+
        ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
 
        /* If we query the length, FW responded with expected data. */

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) · line 2000

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +2 -0

@@ -1978,6 +1996,9 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        }
 
 e_free_cert:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Again.

Quoted 21 lines

drivers/crypto/ccp/sev-dev.c +4 -2

+
        kfree(cert_blob);
 e_free_pdh:
        kfree(pdh_blob);

@@ -1987,12 +2008,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
 {
        struct sev_device *sev = psp_master->sev_data;
+       bool shutdown_required = false;
        struct sev_data_snp_addr buf;
        struct page *status_page;
+       int ret, error;
        void *data;
-       int ret;
 
-       if (!sev->snp_initialized || !argp->data)
+       if (!argp->data)
                return -EINVAL;
 
        status_page = alloc_page(GFP_KERNEL_ACCOUNT);

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp) · line 2027

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +2 -0

@@ -2001,6 +2023,13 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
 
        data = page_address(status_page);
 
+       if (!sev->snp_initialized) {
+               ret = __sev_snp_init_locked(&argp->error);

Error provenance confusion.

Quoted 19 lines

drivers/crypto/ccp/sev-dev.c +8 -0

+               if (ret)
+                       goto cleanup;
+               shutdown_required = true;
+       }
+
        /*
         * Firmware expects status page to be in firmware-owned state, otherwise
         * it will report firmware error code INVALID_PAGE_STATE (0x1A).

@@ -2029,6 +2058,9 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
                ret = -EFAULT;
 
 cleanup:
+       if (shutdown_required)
+               __sev_snp_shutdown_locked(&error, false);
+
        __free_pages(status_page, 0);
        return ret;
 }

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp) · line 2076

Quoted 10 lines

drivers/crypto/ccp/sev-dev.c +4 -2

@@ -2037,21 +2069,34 @@ static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_data_snp_commit buf;
+       bool shutdown_required = false;
+       int ret, error;
 
-       if (!sev->snp_initialized)
-               return -EINVAL;
+       if (!sev->snp_initialized) {
+               ret = __sev_snp_init_locked(&argp->error);

Error provenance confusion.

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp) · line 2087

Quoted 12 lines

drivers/crypto/ccp/sev-dev.c +8 -1

+               if (ret)
+                       return ret;
+               shutdown_required = true;
+       }
 
        buf.len = sizeof(buf);
 
-       return __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
+       ret = __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
+
+       if (shutdown_required)
+               __sev_snp_shutdown_locked(&error, false);

Again.

Quoted 17 lines

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return ret;
 }
 
 static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_snp_config config;
+       bool shutdown_required = false;
+       int ret, error;
 
-       if (!sev->snp_initialized || !argp->data)
+       if (!argp->data)
                return -EINVAL;
 
        if (!writable)

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable · line 2109

Quoted 6 lines

drivers/crypto/ccp/sev-dev.c +2 -1

@@ -2060,17 +2105,30 @@ static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable
        if (copy_from_user(&config, (void __user *)argp->data, sizeof(config)))
                return -EFAULT;
 
-       return __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
+       if (!sev->snp_initialized) {
+               ret = __sev_snp_init_locked(&argp->error);

Error provenance problem again.

Quoted 28 lines

drivers/crypto/ccp/sev-dev.c +14 -2

+               if (ret)
+                       return ret;
+               shutdown_required = true;
+       }
+
+       ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
+
+       if (shutdown_required)
+               __sev_snp_shutdown_locked(&error, false);
+
+       return ret;
 }
 
 static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_snp_vlek_load input;
+       bool shutdown_required = false;
+       int ret, error;
        void *blob;
-       int ret;
 
-       if (!sev->snp_initialized || !argp->data)
+       if (!argp->data)
                return -EINVAL;
 
        if (!writable)

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable) · line 2151

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +2 -0

@@ -2089,8 +2147,19 @@ static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
 
        input.vlek_wrapped_address = __psp_pa(blob);
 
+       if (!sev->snp_initialized) {
+               ret = __sev_snp_init_locked(&argp->error);

Error provenance confusion.

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable) · line 2160

Quoted 9 lines

drivers/crypto/ccp/sev-dev.c +7 -0

+               if (ret)
+                       goto cleanup;
+               shutdown_required = true;
+       }
+
        ret = __sev_do_cmd_locked(SEV_CMD_SNP_VLEK_LOAD, &input, &argp->error);
 
+       if (shutdown_required)
+               __sev_snp_shutdown_locked(&error, false);

Again.

Quoted 8 lines

drivers/crypto/ccp/sev-dev.c +2 -1

+
+cleanup:
        kfree(blob);
 
        return ret;
--

2.34.1

Hello Dionna,

Quoted 57 lines · Dionna Amalie Glaze

Quoted 56 lines · Ashish Kalra

From: Ashish Kalra <[email protected]>

Modify the behavior of implicit SEV initialization in some of the SEV ioctls to do both SEV initialization and shutdown and add implicit SNP initialization and shutdown to some of the SNP ioctls so that the change of SEV/SNP platform initialization not being done during PSP driver probe time does not break userspace tools such as sevtool, etc.

Prior to this patch, SEV has always been initialized before these ioctls as SEV initialization is done as part of PSP module probe, but now with SEV initialization being moved to KVM module load instead of PSP driver probe, the implied SEV INIT actually makes sense and gets used and additionally to maintain SEV platform state consistency before and after the ioctl SEV shutdown needs to be done after the firmware call.

It is important to do SEV Shutdown here with the SEV/SNP initialization moving to KVM, an implicit SEV INIT here as part of the SEV ioctls not followed with SEV Shutdown will cause SEV to remain in INIT state and then a future SNP INIT in KVM module load will fail.

Similarly, prior to this patch, SNP has always been initialized before these ioctls as SNP initialization is done as part of PSP module probe, therefore, to keep a consistent behavior, SNP init needs to be done here implicitly as part of these ioctls followed with SNP shutdown before returning from the ioctl to maintain the consistent platform state before and after the ioctl.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 117 ++++++++++++++++++++++++++++-------
 1 file changed, 93 insertions(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +3 -1

index 8f5c474b9d1c..b06f43eb18f7 100644
@@ -1461,7 +1461,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
-       int rc;
+       bool shutdown_required = false;
+       int rc, error;
 
        if (!writable)
                return -EPERM;

@@ -1470,19 +1471,26 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
                rc = __sev_platform_init_locked(&argp->error);
                if (rc)
                        return rc;
+               shutdown_required = true;
        }
 

Quoted 9 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr · line 1480

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +4 -1

-       return __sev_do_cmd_locked(cmd, NULL, &argp->error);
+       rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
+
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

This error is discarded. Is that by design? If so, It'd be better to call this ignored_error.

This is by design, we cannot overwrite the error for the original command being issued here which in this case is do_pek_pdh_gen, hence we use a local error for the shutdown command. And __sev_platform_shutdown_locked() has it's own error logging code, so it will be printing the error message for the shutdown command failure, so the shutdown error is not eventually being ignored, that error log will assist in any inconsistent SEV/SNP platform state and subsequent errors.

Quoted 28 lines

Quoted 28 lines

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return rc;
 }
 
 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_csr input;
+       bool shutdown_required = false;
        struct sev_data_pek_csr data;
        void __user *input_address;
        void *blob = NULL;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1513,6 +1521,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_blob;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);

@@ -1531,6 +1540,9 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
        }
 

Quoted 7 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) · line 1544

Quoted 3 lines

drivers/crypto/ccp/sev-dev.c +2 -0

 e_free_blob:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Another discarded error. This function is called in different locations in sev-dev.c with and without checking the result, which seems problematic.

Not really, if shutdown fails for any reason, the error is printed. The return value here reflects the value of the original command/function. The command/ioctl could have succeeded but the shutdown failed, hence, shutdown error is printed, but the return value reflects that the ioctl succeeded.

Additionally, in case of INIT before the command is issued, the command may have failed without the SEV state being in INIT state, hence the error for the INIT command failure is returned back from the ioctl.

Quoted 58 lines

Quoted 18 lines

drivers/crypto/ccp/sev-dev.c +3 -1

+
        kfree(blob);
        return ret;
 }

@@ -1747,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import data;
+       bool shutdown_required = false;
        void *pek_blob, *oca_blob;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1780,11 +1793,15 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) · line 1803

Quoted 10 lines

drivers/crypto/ccp/sev-dev.c +3 -0

                if (ret)
                        goto e_free_oca;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
 
 e_free_oca:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Again.

Quoted 27 lines

drivers/crypto/ccp/sev-dev.c +3 -11

+
        kfree(oca_blob);
 e_free_pek:
        kfree(pek_blob);

@@ -1901,17 +1918,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        struct sev_data_pdh_cert_export data;
        void __user *input_cert_chain_address;
        void __user *input_pdh_cert_address;
-       int ret;
-
-       /* If platform is not in INIT state then transition it to INIT. */
-       if (sev->state != SEV_STATE_INIT) {
-               if (!writable)
-                       return -EPERM;
-
-               ret = __sev_platform_init_locked(&argp->error);
-               if (ret)
-                       return ret;
-       }
+       bool shutdown_required = false;
+       int ret, error;
 
        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

@@ -1952,6 +1960,16 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        data.cert_chain_len = input.cert_chain_len;
 

Quoted 11 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) · line 1967

Quoted 6 lines

drivers/crypto/ccp/sev-dev.c +5 -0

 cmd:
+       /* If platform is not in INIT state then transition it to INIT. */
+       if (sev->state != SEV_STATE_INIT) {
+               if (!writable)
+                       goto e_free_cert;
+               ret = __sev_platform_init_locked(&argp->error);

Using argp->error for init instead of the ioctl-requested command means that the user will have difficulty distinguishing which process is at fault, no?

Not really, in case the SEV command has still not been issued, argp->error is still usable and returned back to the caller (no need to use a local error here), we are not overwriting the argp->error used for the original command/ioctl here.

Quoted 193 lines · Ashish

Hello Dionna,

Quoted 57 lines · Dionna Amalie Glaze

Quoted 56 lines · Ashish Kalra

From: Ashish Kalra <[email protected]>

Modify the behavior of implicit SEV initialization in some of the SEV ioctls to do both SEV initialization and shutdown and add implicit SNP initialization and shutdown to some of the SNP ioctls so that the change of SEV/SNP platform initialization not being done during PSP driver probe time does not break userspace tools such as sevtool, etc.

Prior to this patch, SEV has always been initialized before these ioctls as SEV initialization is done as part of PSP module probe, but now with SEV initialization being moved to KVM module load instead of PSP driver probe, the implied SEV INIT actually makes sense and gets used and additionally to maintain SEV platform state consistency before and after the ioctl SEV shutdown needs to be done after the firmware call.

It is important to do SEV Shutdown here with the SEV/SNP initialization moving to KVM, an implicit SEV INIT here as part of the SEV ioctls not followed with SEV Shutdown will cause SEV to remain in INIT state and then a future SNP INIT in KVM module load will fail.

Similarly, prior to this patch, SNP has always been initialized before these ioctls as SNP initialization is done as part of PSP module probe, therefore, to keep a consistent behavior, SNP init needs to be done here implicitly as part of these ioctls followed with SNP shutdown before returning from the ioctl to maintain the consistent platform state before and after the ioctl.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 117 ++++++++++++++++++++++++++++-------
 1 file changed, 93 insertions(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +3 -1

index 8f5c474b9d1c..b06f43eb18f7 100644
@@ -1461,7 +1461,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
-       int rc;
+       bool shutdown_required = false;
+       int rc, error;
 
        if (!writable)
                return -EPERM;

@@ -1470,19 +1471,26 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
                rc = __sev_platform_init_locked(&argp->error);
                if (rc)
                        return rc;
+               shutdown_required = true;
        }
 

Quoted 9 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr · line 1480

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +4 -1

-       return __sev_do_cmd_locked(cmd, NULL, &argp->error);
+       rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
+
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

This error is discarded. Is that by design? If so, It'd be better to call this ignored_error.

This is by design, we cannot overwrite the error for the original command being issued here which in this case is do_pek_pdh_gen, hence we use a local error for the shutdown command. And __sev_platform_shutdown_locked() has it's own error logging code, so it will be printing the error message for the shutdown command failure, so the shutdown error is not eventually being ignored, that error log will assist in any inconsistent SEV/SNP platform state and subsequent errors.

Quoted 28 lines

Quoted 28 lines

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return rc;
 }
 
 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_csr input;
+       bool shutdown_required = false;
        struct sev_data_pek_csr data;
        void __user *input_address;
        void *blob = NULL;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1513,6 +1521,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_blob;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);

@@ -1531,6 +1540,9 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
        }
 

Quoted 7 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) · line 1544

Quoted 3 lines

drivers/crypto/ccp/sev-dev.c +2 -0

 e_free_blob:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Another discarded error. This function is called in different locations in sev-dev.c with and without checking the result, which seems problematic.

Not really, if shutdown fails for any reason, the error is printed. The return value here reflects the value of the original command/function. The command/ioctl could have succeeded but the shutdown failed, hence, shutdown error is printed, but the return value reflects that the ioctl succeeded.

Additionally, in case of INIT before the command is issued, the command may have failed without the SEV state being in INIT state, hence the error for the INIT command failure is returned back from the ioctl.

Quoted 58 lines

Quoted 18 lines

drivers/crypto/ccp/sev-dev.c +3 -1

+
        kfree(blob);
        return ret;
 }

@@ -1747,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import data;
+       bool shutdown_required = false;
        void *pek_blob, *oca_blob;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1780,11 +1793,15 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) · line 1803

Quoted 10 lines

drivers/crypto/ccp/sev-dev.c +3 -0

                if (ret)
                        goto e_free_oca;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
 
 e_free_oca:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Again.

Quoted 27 lines

drivers/crypto/ccp/sev-dev.c +3 -11

+
        kfree(oca_blob);
 e_free_pek:
        kfree(pek_blob);

@@ -1901,17 +1918,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        struct sev_data_pdh_cert_export data;
        void __user *input_cert_chain_address;
        void __user *input_pdh_cert_address;
-       int ret;
-
-       /* If platform is not in INIT state then transition it to INIT. */
-       if (sev->state != SEV_STATE_INIT) {
-               if (!writable)
-                       return -EPERM;
-
-               ret = __sev_platform_init_locked(&argp->error);
-               if (ret)
-                       return ret;
-       }
+       bool shutdown_required = false;
+       int ret, error;
 
        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

@@ -1952,6 +1960,16 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        data.cert_chain_len = input.cert_chain_len;
 

Quoted 11 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) · line 1967

Quoted 6 lines

drivers/crypto/ccp/sev-dev.c +5 -0

 cmd:
+       /* If platform is not in INIT state then transition it to INIT. */
+       if (sev->state != SEV_STATE_INIT) {
+               if (!writable)
+                       goto e_free_cert;
+               ret = __sev_platform_init_locked(&argp->error);

Using argp->error for init instead of the ioctl-requested command means that the user will have difficulty distinguishing which process is at fault, no?

Quoted 4 lines

Not really, in case the SEV command has still not been issued, argp->error is still usable and returned back to the caller (no need to use a local error here), we are not overwriting the argp->error used for the original command/ioctl here.

I mean in the case that argp->error is set to a value shared by the command and init, it's hard to know what the problem was. I'd like to ensure that the documentation is updated to reflect that (in this case) if PDH_CERT_EXPORT returns INVALID_PLATFORM_STATE, then it's because the platform was not in PSTATE.UNINIT state. The new behavior of initializing when you need to now means that you should have ruled out INVALID_PLATFORM_STATE as a possible value from PDH_EXPORT_CERT. Same for SNP_CONFIG.

There is not a 1-to-1 mapping between the ioctl commands and the SEV commands now, so I think you need extra documentation to clarify the new error space for at least pdh_export and set_config

SNP_PLATFORM_STATUS, VLEK_LOAD, and SNP_COMMIT appear to not necessarily have a provenance confusion after looking closer.

Quoted 208 lines · Dionna Amalie Glaze

Quoted 193 lines · Ashish

Hello Dionna,

Quoted 57 lines · Dionna Amalie Glaze

Quoted 56 lines · Ashish Kalra

From: Ashish Kalra <[email protected]>

Modify the behavior of implicit SEV initialization in some of the SEV ioctls to do both SEV initialization and shutdown and add implicit SNP initialization and shutdown to some of the SNP ioctls so that the change of SEV/SNP platform initialization not being done during PSP driver probe time does not break userspace tools such as sevtool, etc.

Prior to this patch, SEV has always been initialized before these ioctls as SEV initialization is done as part of PSP module probe, but now with SEV initialization being moved to KVM module load instead of PSP driver probe, the implied SEV INIT actually makes sense and gets used and additionally to maintain SEV platform state consistency before and after the ioctl SEV shutdown needs to be done after the firmware call.

It is important to do SEV Shutdown here with the SEV/SNP initialization moving to KVM, an implicit SEV INIT here as part of the SEV ioctls not followed with SEV Shutdown will cause SEV to remain in INIT state and then a future SNP INIT in KVM module load will fail.

Similarly, prior to this patch, SNP has always been initialized before these ioctls as SNP initialization is done as part of PSP module probe, therefore, to keep a consistent behavior, SNP init needs to be done here implicitly as part of these ioctls followed with SNP shutdown before returning from the ioctl to maintain the consistent platform state before and after the ioctl.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 117 ++++++++++++++++++++++++++++-------
 1 file changed, 93 insertions(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +3 -1

index 8f5c474b9d1c..b06f43eb18f7 100644
@@ -1461,7 +1461,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
-       int rc;
+       bool shutdown_required = false;
+       int rc, error;
 
        if (!writable)
                return -EPERM;

@@ -1470,19 +1471,26 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
                rc = __sev_platform_init_locked(&argp->error);
                if (rc)
                        return rc;
+               shutdown_required = true;
        }
 

Quoted 9 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr · line 1480

Quoted 5 lines

drivers/crypto/ccp/sev-dev.c +4 -1

-       return __sev_do_cmd_locked(cmd, NULL, &argp->error);
+       rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
+
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

This error is discarded. Is that by design? If so, It'd be better to call this ignored_error.

This is by design, we cannot overwrite the error for the original command being issued here which in this case is do_pek_pdh_gen, hence we use a local error for the shutdown command. And __sev_platform_shutdown_locked() has it's own error logging code, so it will be printing the error message for the shutdown command failure, so the shutdown error is not eventually being ignored, that error log will assist in any inconsistent SEV/SNP platform state and subsequent errors.

Quoted 28 lines

Quoted 28 lines

drivers/crypto/ccp/sev-dev.c +5 -1

+
+       return rc;
 }
 
 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 {
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_csr input;
+       bool shutdown_required = false;
        struct sev_data_pek_csr data;
        void __user *input_address;
        void *blob = NULL;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1513,6 +1521,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_blob;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);

@@ -1531,6 +1540,9 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
        }
 

Quoted 7 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable) · line 1544

Quoted 3 lines

drivers/crypto/ccp/sev-dev.c +2 -0

 e_free_blob:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Another discarded error. This function is called in different locations in sev-dev.c with and without checking the result, which seems problematic.

Not really, if shutdown fails for any reason, the error is printed. The return value here reflects the value of the original command/function. The command/ioctl could have succeeded but the shutdown failed, hence, shutdown error is printed, but the return value reflects that the ioctl succeeded.

Additionally, in case of INIT before the command is issued, the command may have failed without the SEV state being in INIT state, hence the error for the INIT command failure is returned back from the ioctl.

Quoted 58 lines

Quoted 18 lines

drivers/crypto/ccp/sev-dev.c +3 -1

+
        kfree(blob);
        return ret;
 }

@@ -1747,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import data;
+       bool shutdown_required = false;
        void *pek_blob, *oca_blob;
-       int ret;
+       int ret, error;
 
        if (!writable)
                return -EPERM;

@@ -1780,11 +1793,15 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
                ret = __sev_platform_init_locked(&argp->error);

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable) · line 1803

Quoted 10 lines

drivers/crypto/ccp/sev-dev.c +3 -0

                if (ret)
                        goto e_free_oca;
+               shutdown_required = true;
        }
 
        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
 
 e_free_oca:
+       if (shutdown_required)
+               __sev_platform_shutdown_locked(&error);

Again.

Quoted 27 lines

drivers/crypto/ccp/sev-dev.c +3 -11

+
        kfree(oca_blob);
 e_free_pek:
        kfree(pek_blob);

@@ -1901,17 +1918,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        struct sev_data_pdh_cert_export data;
        void __user *input_cert_chain_address;
        void __user *input_pdh_cert_address;
-       int ret;
-
-       /* If platform is not in INIT state then transition it to INIT. */
-       if (sev->state != SEV_STATE_INIT) {
-               if (!writable)
-                       return -EPERM;
-
-               ret = __sev_platform_init_locked(&argp->error);
-               if (ret)
-                       return ret;
-       }
+       bool shutdown_required = false;
+       int ret, error;
 
        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

@@ -1952,6 +1960,16 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
        data.cert_chain_len = input.cert_chain_len;
 

Quoted 11 lines

drivers/crypto/ccp/sev-dev.c static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) · line 1967

Quoted 6 lines

drivers/crypto/ccp/sev-dev.c +5 -0

 cmd:
+       /* If platform is not in INIT state then transition it to INIT. */
+       if (sev->state != SEV_STATE_INIT) {
+               if (!writable)
+                       goto e_free_cert;
+               ret = __sev_platform_init_locked(&argp->error);

Using argp->error for init instead of the ioctl-requested command means that the user will have difficulty distinguishing which process is at fault, no?

Quoted 4 lines

Not really, in case the SEV command has still not been issued, argp->error is still usable and returned back to the caller (no need to use a local error here), we are not overwriting the argp->error used for the original command/ioctl here.

I mean in the case that argp->error is set to a value shared by the command and init, it's hard to know what the problem was. I'd like to ensure that the documentation is updated to reflect that (in this case) if PDH_CERT_EXPORT returns INVALID_PLATFORM_STATE, then it's because the platform was not in PSTATE.UNINIT state. The new behavior of initializing when you need to now means that you should have ruled out INVALID_PLATFORM_STATE as a possible value from PDH_EXPORT_CERT. Same for SNP_CONFIG.

Quoted 8 lines

There is not a 1-to-1 mapping between the ioctl commands and the SEV commands now, so I think you need extra documentation to clarify the new error space for at least pdh_export and set_config

SNP_PLATFORM_STATUS, VLEK_LOAD, and SNP_COMMIT appear to not necessarily have a provenance confusion after looking closer.

I am more of less trying to match the current behavior of sev_ioctl_do_pek_import() or sev_ioctl_do_pdh_export().

All this is implementation specific handling so we can't update SEV/SNP firmware API specs documentation for this new error space, this is not a firmware specific return code.

But to maintain 1-to-1 mapping between the ioctl commands and the SEV/SNP commands, i think it will be better to handle this INIT in the same way as SHUTDOWN, which is to use a local error for INIT and in case of implicit INIT failures, let the error logs from __sev_platform_init_locked() OR __sev_snp_init_locked() be printed and always return INVALID_PLATFORM_STATE as error back to the caller.

Thanks,
Ashish

From: Ashish Kalra <[email protected]>

When SEV-SNP is enabled the TMR needs to be 2MB aligned and 2MB sized, ensure that TMR size is reset back to default when SNP is shutdown as SNP initialization and shutdown as part of some SNP ioctls may leave TMR size modified and cause subsequent SEV only initialization to fail.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 3 +++
 1 file changed, 3 insertions(+)

drivers/crypto/ccp/sev-dev.c +3 -1

index b06f43eb18f7..be8a84ce24c7 100644
@@ -1751,6 +1751,9 @@ static int __sev_snp_shutdown_locked(int *error, bool panic)
        sev->snp_initialized = false;
        dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
 
+       /* Reset TMR size back to default */
+       sev_es_tmr_size = SEV_TMR_SIZE;
+
        return ret;
 }
 
--

2.34.1

From: Ashish Kalra <[email protected]>

When SEV-SNP is enabled the TMR needs to be 2MB aligned and 2MB sized, ensure that TMR size is reset back to default when SNP is shutdown as SNP initialization and shutdown as part of some SNP ioctls may leave TMR size modified and cause subsequent SEV only initialization to fail.

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 3 +++
 1 file changed, 3 insertions(+)

drivers/crypto/ccp/sev-dev.c +3 -0

index b06f43eb18f7..be8a84ce24c7 100644
@@ -1751,6 +1751,9 @@ static int __sev_snp_shutdown_locked(int *error, bool panic)
 	sev->snp_initialized = false;
 	dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
 
+	/* Reset TMR size back to default */
+	sev_es_tmr_size = SEV_TMR_SIZE;
+
 	return ret;
 }
 

From: Ashish Kalra <[email protected]>

Register the SNP panic notifier if and only if SNP is actually initialized and deregistering the notifier when shutting down

SNP in PSP driver when KVM module is unloaded.

Currently the SNP panic notifier is being registered

irrespective of SNP being enabled/initialized and with this

change the SNP panic notifier is registered only if SNP support is enabled and initialized.

Reviewed-by Dionna Glaze <[email protected]>

Reviewed-by Alexey Kardashevskiy <[email protected]>

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

drivers/crypto/ccp/sev-dev.c +13 -9

index be8a84ce24c7..582304638319 100644
@@ -109,6 +109,13 @@ static void *sev_init_ex_buffer;
  */
 static struct sev_data_range_list *snp_range_list;
 
+static int snp_shutdown_on_panic(struct notifier_block *nb,
+				 unsigned long reason, void *arg);
+
+static struct notifier_block snp_panic_notifier = {
+	.notifier_call = snp_shutdown_on_panic,
+};
+
 static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
 {
 	struct sev_device *sev = psp_master->sev_data;

@@ -1197,6 +1204,9 @@ static int __sev_snp_init_locked(int *error)
 	dev_info(sev->dev, "SEV-SNP API:%d.%d build:%d\n", sev->api_major,
 		 sev->api_minor, sev->build);
 
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &snp_panic_notifier);
+
 	sev_es_tmr_size = SNP_TMR_SIZE;
 
 	return 0;

@@ -1751,6 +1761,9 @@ static int __sev_snp_shutdown_locked(int *error, bool panic)
 	sev->snp_initialized = false;
 	dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
 
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+					 &snp_panic_notifier);
+
 	/* Reset TMR size back to default */
 	sev_es_tmr_size = SEV_TMR_SIZE;
 

@@ -2466,10 +2479,6 @@ static int snp_shutdown_on_panic(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
-static struct notifier_block snp_panic_notifier = {
-	.notifier_call = snp_shutdown_on_panic,
-};
-
 int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd,
 				void *data, int *error)
 {

@@ -2518,8 +2527,6 @@ void sev_pci_init(void)
 	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
 		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
 
-	atomic_notifier_chain_register(&panic_notifier_list,
-				       &snp_panic_notifier);
 	return;
 
 err:

@@ -2536,7 +2543,4 @@ void sev_pci_exit(void)
 		return;
 
 	sev_firmware_shutdown(sev);
-
-	atomic_notifier_chain_unregister(&panic_notifier_list,
-					 &snp_panic_notifier);
 }

From: Ashish Kalra <[email protected]>

Add new API interface to do SEV/SNP platform shutdown when KVM module is unloaded.

Reviewed-by Dionna Glaze <[email protected]>

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 13 +++++++++++++
 include/linux/psp-sev.h      |  3 +++
 2 files changed, 16 insertions(+)

drivers/crypto/ccp/sev-dev.c +0 -0

index 582304638319..f0f3e6d29200 100644
@@ -2445,6 +2445,19 @@ static void sev_firmware_shutdown(struct sev_device *sev)
 	mutex_unlock(&sev_cmd_mutex);
 }
 

drivers/crypto/ccp/sev-dev.c +3 -0

+}
+EXPORT_SYMBOL_GPL(sev_platform_shutdown);
+
 void sev_dev_destroy(struct psp_device *psp)
 {
 	struct sev_device *sev = psp->sev_data;

include/linux/psp-sev.h +3 -0

index f3cad182d4ef..0b3a36bdaa90 100644
@@ -954,6 +954,7 @@ int sev_do_cmd(int cmd, void *data, int *psp_ret);
 void *psp_copy_user_blob(u64 uaddr, u32 len);
 void *snp_alloc_firmware_page(gfp_t mask);
 void snp_free_firmware_page(void *addr);
+void sev_platform_shutdown(void);
 
 #else	/* !CONFIG_CRYPTO_DEV_SP_PSP */
 

@@ -988,6 +989,8 @@ static inline void *snp_alloc_firmware_page(gfp_t mask)
 
 static inline void snp_free_firmware_page(void *addr) { }
 
+static inline void sev_platform_shutdown(void) { }
+
 #endif	/* CONFIG_CRYPTO_DEV_SP_PSP */
 
 #endif	/* __PSP_SEV_H__ */

From: Ashish Kalra <[email protected]>

Move platform initialization of SEV/SNP from PSP driver probe time to

KVM module load time so that KVM can do SEV/SNP platform initialization explicitly if it actually wants to use SEV/SNP functionality.

Add support for KVM to explicitly call into the PSP driver at load time

to initialize SEV/SNP by default but this behavior can be altered with KVM

module parameters to not do SEV/SNP platform initialization at module load time if required. Additionally SEV/SNP platform shutdown is invoked during

KVM module unload time.

Suggested-by Sean Christopherson <[email protected]>

Signed-off-by Ashish Kalra <[email protected]>

---
 arch/x86/kvm/svm/sev.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

arch/x86/kvm/svm/sev.c +1 -0

index 74525651770a..213d4c15a9da 100644
@@ -2933,6 +2933,7 @@ void __init sev_set_cpu_caps(void)
 void __init sev_hardware_setup(void)
 {
 	unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
+	struct sev_platform_init_args init_args = {0};
 	bool sev_snp_supported = false;
 	bool sev_es_supported = false;
 	bool sev_supported = false;

@@ -3059,6 +3060,17 @@ void __init sev_hardware_setup(void)
 	sev_supported_vmsa_features = 0;
 	if (sev_es_debug_swap_enabled)

arch/x86/kvm/svm/sev.c +5 -0

+	init_args.probe = true;
+	sev_platform_init(&init_args);
 }
 
 void sev_hardware_unsetup(void)

@@ -3074,6 +3086,9 @@ void sev_hardware_unsetup(void)
 
 	misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
 	misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
+
+	/* Do SEV and SNP Shutdown */
+	sev_platform_shutdown();
 }
 
 int sev_cpu_init(struct svm_cpu_data *sd)

From: Ashish Kalra <[email protected]>

SNP initialization is forced during PSP driver probe purely because SNP can't be initialized if VMs are running. But the only in-tree user of SEV/SNP functionality is KVM, and KVM depends on PSP driver for the same. Forcing SEV/SNP initialization because a hypervisor could be running legacy non-confidential VMs make no sense.

This patch removes SEV/SNP initialization from the PSP driver probe time and moves the requirement to initialize SEV/SNP functionality to KVM if it wants to use SEV/SNP.

Suggested-by Sean Christopherson <[email protected]>

Reviewed-by Alexey Kardashevskiy <[email protected]>

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +0 -3

index f0f3e6d29200..99a663dbc2b6 100644
@@ -1346,18 +1346,13 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
 	if (sev->state == SEV_STATE_INIT)
 		return 0;
 
-	/*
-	 * Legacy guests cannot be running while SNP_INIT(_EX) is executing,
-	 * so perform SEV-SNP initialization at probe time.

drivers/crypto/ccp/sev-dev.c +0 -12

 	}
 
 	/* Defer legacy SEV/SEV-ES support if allowed by caller/module. */

@@ -2505,9 +2500,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
 void sev_pci_init(void)
 {
 	struct sev_device *sev = psp_master->sev_data;
-	struct sev_platform_init_args args = {0};
 	u8 api_major, api_minor, build;
-	int rc;
 
 	if (!sev)
 		return;

@@ -2530,16 +2523,6 @@ void sev_pci_init(void)
 			 api_major, api_minor, build,
 			 sev->api_major, sev->api_minor, sev->build);
 
-	/* Initialize the platform */
-	args.probe = true;
-	rc = sev_platform_init(&args);
-	if (rc)
-		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
-			args.error, rc);
-
-	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
-		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
-
 	return;
 
 err:

drivers/crypto/ccp/sev-dev.c +0 -0

 }

Quoted 27 lines · Ashish Kalra

From: Ashish Kalra <[email protected]>

SNP initialization is forced during PSP driver probe purely because SNP can't be initialized if VMs are running. But the only in-tree user of SEV/SNP functionality is KVM, and KVM depends on PSP driver for the same. Forcing SEV/SNP initialization because a hypervisor could be running legacy non-confidential VMs make no sense.

This patch removes SEV/SNP initialization from the PSP driver probe time and moves the requirement to initialize SEV/SNP functionality to KVM if it wants to use SEV/SNP.

Suggested-by Sean Christopherson <[email protected]>

Reviewed-by Alexey Kardashevskiy <[email protected]>

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +0 -0

index f0f3e6d29200..99a663dbc2b6 100644
@@ -1346,18 +1346,13 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
 	if (sev->state == SEV_STATE_INIT)
 		return 0;
 

drivers/crypto/ccp/sev-dev.c static int _sev_platform_init_locked(struct sev_platform_init_args *args) · line 1355

Quoted 13 lines

drivers/crypto/ccp/sev-dev.c +1 -6

-	/*
-	 * Legacy guests cannot be running while SNP_INIT(_EX) is executing,
-	 * so perform SEV-SNP initialization at probe time.
-	 */
 	rc = __sev_snp_init_locked(&args->error);
 	if (rc && rc != -ENODEV) {
 		/*
 		 * Don't abort the probe if SNP INIT failed,
 		 * continue to initialize the legacy SEV firmware.
 		 */
-		dev_err(sev->dev, "SEV-SNP: failed to INIT rc %d, error %#x\n",
-			rc, args->error);
+		dev_err(sev->dev, "SEV-SNP: failed to INIT, continue SEV INIT\n");

Please don't remove the error information.

Quoted 32 lines

drivers/crypto/ccp/sev-dev.c +0 -12

 	}
 
 	/* Defer legacy SEV/SEV-ES support if allowed by caller/module. */

@@ -2505,9 +2500,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
 void sev_pci_init(void)
 {
 	struct sev_device *sev = psp_master->sev_data;
-	struct sev_platform_init_args args = {0};
 	u8 api_major, api_minor, build;
-	int rc;
 
 	if (!sev)
 		return;

@@ -2530,16 +2523,6 @@ void sev_pci_init(void)
 			 api_major, api_minor, build,
 			 sev->api_major, sev->api_minor, sev->build);
 
-	/* Initialize the platform */
-	args.probe = true;
-	rc = sev_platform_init(&args);
-	if (rc)
-		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
-			args.error, rc);
-
-	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
-		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
-
 	return;
 
 err:

@@ -2550,10 +2533,4 @@ void sev_pci_init(void)
 

drivers/crypto/ccp/sev-dev.c void sev_pci_init(void) · line 2558

Quoted 8 lines

drivers/crypto/ccp/sev-dev.c +0 -6

 void sev_pci_exit(void)
 {
-	struct sev_device *sev = psp_master->sev_data;
-
-	if (!sev)
-		return;
-
-	sev_firmware_shutdown(sev);

Should this remain? If there's a bug in KVM that somehow skips the shutdown call, then SEV will remain initialized. I think the path is safe to call a second time.

Hello Tom,

Quoted 28 lines · Tom Lendacky

Quoted 27 lines · Ashish Kalra

From: Ashish Kalra <[email protected]>

SNP initialization is forced during PSP driver probe purely because SNP can't be initialized if VMs are running. But the only in-tree user of SEV/SNP functionality is KVM, and KVM depends on PSP driver for the same. Forcing SEV/SNP initialization because a hypervisor could be running legacy non-confidential VMs make no sense.

This patch removes SEV/SNP initialization from the PSP driver probe time and moves the requirement to initialize SEV/SNP functionality to KVM if it wants to use SEV/SNP.

Suggested-by Sean Christopherson <[email protected]>

Reviewed-by Alexey Kardashevskiy <[email protected]>

Signed-off-by Ashish Kalra <[email protected]>

---
 drivers/crypto/ccp/sev-dev.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

drivers/crypto/ccp/sev-dev.c +0 -0

index f0f3e6d29200..99a663dbc2b6 100644
@@ -1346,18 +1346,13 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
 	if (sev->state == SEV_STATE_INIT)
 		return 0;
 

Quoted 16 lines

drivers/crypto/ccp/sev-dev.c static int _sev_platform_init_locked(struct sev_platform_init_args *args) · line 1355

Quoted 13 lines

drivers/crypto/ccp/sev-dev.c +1 -6

-	/*
-	 * Legacy guests cannot be running while SNP_INIT(_EX) is executing,
-	 * so perform SEV-SNP initialization at probe time.
-	 */
 	rc = __sev_snp_init_locked(&args->error);
 	if (rc && rc != -ENODEV) {
 		/*
 		 * Don't abort the probe if SNP INIT failed,
 		 * continue to initialize the legacy SEV firmware.
 		 */
-		dev_err(sev->dev, "SEV-SNP: failed to INIT rc %d, error %#x\n",
-			rc, args->error);
+		dev_err(sev->dev, "SEV-SNP: failed to INIT, continue SEV INIT\n");

Please don't remove the error information.

The error(s) are already being printed in __sev_snp_init_locked() otherwise the same error will be printed twice, hence removing it here.

Quoted 33 lines

Quoted 33 lines

drivers/crypto/ccp/sev-dev.c +0 -12

 	}
 
 	/* Defer legacy SEV/SEV-ES support if allowed by caller/module. */

@@ -2505,9 +2500,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
 void sev_pci_init(void)
 {
 	struct sev_device *sev = psp_master->sev_data;
-	struct sev_platform_init_args args = {0};
 	u8 api_major, api_minor, build;
-	int rc;
 
 	if (!sev)
 		return;

@@ -2530,16 +2523,6 @@ void sev_pci_init(void)
 			 api_major, api_minor, build,
 			 sev->api_major, sev->api_minor, sev->build);
 
-	/* Initialize the platform */
-	args.probe = true;
-	rc = sev_platform_init(&args);
-	if (rc)
-		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
-			args.error, rc);
-
-	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
-		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);
-
 	return;
 
 err:

@@ -2550,10 +2533,4 @@ void sev_pci_init(void)
 

Quoted 12 lines

drivers/crypto/ccp/sev-dev.c void sev_pci_init(void) · line 2558

Quoted 8 lines

drivers/crypto/ccp/sev-dev.c +0 -6

 void sev_pci_exit(void)
 {
-	struct sev_device *sev = psp_master->sev_data;
-
-	if (!sev)
-		return;
-
-	sev_firmware_shutdown(sev);

Should this remain? If there's a bug in KVM that somehow skips the shutdown call, then SEV will remain initialized. I think the path is safe to call a second time.

Ok.

Thanks,
Ashish