From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
John Allen <john.allen@amd.com>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-kernel@vger.kernel.org, Borislav Petkov <bp@suse.de>
Subject: [PATCH 4/5] crypto: ccp: Use the stack for small SEV command buffers
Date: Fri, 2 Apr 2021 16:37:01 -0700 [thread overview]
Message-ID: <20210402233702.3291792-5-seanjc@google.com> (raw)
In-Reply-To: <20210402233702.3291792-1-seanjc@google.com>
For commands with small input/output buffers, use the local stack to
"allocate" the structures used to communicate with the PSP. Now that
__sev_do_cmd_locked() gracefully handles vmalloc'd buffers, there's no
reason to avoid using the stack, e.g. CONFIG_VMAP_STACK=y will just work.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
drivers/crypto/ccp/sev-dev.c | 122 ++++++++++++++---------------------
1 file changed, 47 insertions(+), 75 deletions(-)
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 6d5882290cfc..6a380d483fce 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -402,7 +402,7 @@ 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;
- struct sev_data_pek_csr *data;
+ struct sev_data_pek_csr data;
void __user *input_address;
void *blob = NULL;
int ret;
@@ -413,29 +413,24 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;
- data = kzalloc(sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
/* userspace wants to query CSR length */
- if (!input.address || !input.length)
+ if (!input.address || !input.length) {
+ data.address = 0;
+ data.len = 0;
goto cmd;
+ }
/* allocate a physically contiguous buffer to store the CSR blob */
input_address = (void __user *)input.address;
- if (input.length > SEV_FW_BLOB_MAX_SIZE) {
- ret = -EFAULT;
- goto e_free;
- }
+ if (input.length > SEV_FW_BLOB_MAX_SIZE)
+ return -EFAULT;
blob = kmalloc(input.length, GFP_KERNEL);
- if (!blob) {
- ret = -ENOMEM;
- goto e_free;
- }
+ if (!blob)
+ return -ENOMEM;
- data->address = __psp_pa(blob);
- data->len = input.length;
+ data.address = __psp_pa(blob);
+ data.len = input.length;
cmd:
if (sev->state == SEV_STATE_UNINIT) {
@@ -444,10 +439,10 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
goto e_free_blob;
}
- ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, data, &argp->error);
+ ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);
/* If we query the CSR length, FW responded with expected data. */
- input.length = data->len;
+ input.length = data.len;
if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
ret = -EFAULT;
@@ -461,8 +456,6 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
e_free_blob:
kfree(blob);
-e_free:
- kfree(data);
return ret;
}
@@ -594,7 +587,7 @@ 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;
+ struct sev_data_pek_cert_import data;
void *pek_blob, *oca_blob;
int ret;
@@ -604,19 +597,14 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;
- data = kzalloc(sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
/* copy PEK certificate blobs from userspace */
pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
- if (IS_ERR(pek_blob)) {
- ret = PTR_ERR(pek_blob);
- goto e_free;
- }
+ if (IS_ERR(pek_blob))
+ return PTR_ERR(pek_blob);
- data->pek_cert_address = __psp_pa(pek_blob);
- data->pek_cert_len = input.pek_cert_len;
+ data.reserved = 0;
+ data.pek_cert_address = __psp_pa(pek_blob);
+ data.pek_cert_len = input.pek_cert_len;
/* copy PEK certificate blobs from userspace */
oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
@@ -625,8 +613,8 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
goto e_free_pek;
}
- data->oca_cert_address = __psp_pa(oca_blob);
- data->oca_cert_len = input.oca_cert_len;
+ data.oca_cert_address = __psp_pa(oca_blob);
+ data.oca_cert_len = input.oca_cert_len;
/* If platform is not in INIT state then transition it to INIT */
if (sev->state != SEV_STATE_INIT) {
@@ -635,21 +623,19 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
goto e_free_oca;
}
- ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, data, &argp->error);
+ ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
e_free_oca:
kfree(oca_blob);
e_free_pek:
kfree(pek_blob);
-e_free:
- kfree(data);
return ret;
}
static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
{
struct sev_user_data_get_id2 input;
- struct sev_data_get_id *data;
+ struct sev_data_get_id data;
void __user *input_address;
void *id_blob = NULL;
int ret;
@@ -663,28 +649,25 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
input_address = (void __user *)input.address;
- data = kzalloc(sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
if (input.address && input.length) {
id_blob = kmalloc(input.length, GFP_KERNEL);
- if (!id_blob) {
- kfree(data);
+ if (!id_blob)
return -ENOMEM;
- }
- data->address = __psp_pa(id_blob);
- data->len = input.length;
+ data.address = __psp_pa(id_blob);
+ data.len = input.length;
+ } else {
+ data.address = 0;
+ data.len = 0;
}
- ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, data, &argp->error);
+ ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, &data, &argp->error);
/*
* Firmware will return the length of the ID value (either the minimum
* required length or the actual length written), return it to the user.
*/
- input.length = data->len;
+ input.length = data.len;
if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
ret = -EFAULT;
@@ -692,7 +675,7 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
}
if (id_blob) {
- if (copy_to_user(input_address, id_blob, data->len)) {
+ if (copy_to_user(input_address, id_blob, data.len)) {
ret = -EFAULT;
goto e_free;
}
@@ -700,7 +683,6 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
e_free:
kfree(id_blob);
- kfree(data);
return ret;
}
@@ -750,7 +732,7 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
struct sev_device *sev = psp_master->sev_data;
struct sev_user_data_pdh_cert_export input;
void *pdh_blob = NULL, *cert_blob = NULL;
- struct sev_data_pdh_cert_export *data;
+ struct sev_data_pdh_cert_export data;
void __user *input_cert_chain_address;
void __user *input_pdh_cert_address;
int ret;
@@ -768,9 +750,7 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;
- data = kzalloc(sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
+ memset(&data, 0, sizeof(data));
/* Userspace wants to query the certificate length. */
if (!input.pdh_cert_address ||
@@ -782,25 +762,19 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
input_cert_chain_address = (void __user *)input.cert_chain_address;
/* Allocate a physically contiguous buffer to store the PDH blob. */
- if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) {
- ret = -EFAULT;
- goto e_free;
- }
+ if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)
+ return -EFAULT;
/* Allocate a physically contiguous buffer to store the cert chain blob. */
- if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) {
- ret = -EFAULT;
- goto e_free;
- }
+ if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)
+ return -EFAULT;
pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);
- if (!pdh_blob) {
- ret = -ENOMEM;
- goto e_free;
- }
+ if (!pdh_blob)
+ return -ENOMEM;
- data->pdh_cert_address = __psp_pa(pdh_blob);
- data->pdh_cert_len = input.pdh_cert_len;
+ data.pdh_cert_address = __psp_pa(pdh_blob);
+ data.pdh_cert_len = input.pdh_cert_len;
cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);
if (!cert_blob) {
@@ -808,15 +782,15 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
goto e_free_pdh;
}
- data->cert_chain_address = __psp_pa(cert_blob);
- data->cert_chain_len = input.cert_chain_len;
+ data.cert_chain_address = __psp_pa(cert_blob);
+ data.cert_chain_len = input.cert_chain_len;
cmd:
- ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);
+ ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
/* If we query the length, FW responded with expected data. */
- input.cert_chain_len = data->cert_chain_len;
- input.pdh_cert_len = data->pdh_cert_len;
+ input.cert_chain_len = data.cert_chain_len;
+ input.pdh_cert_len = data.pdh_cert_len;
if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
ret = -EFAULT;
@@ -841,8 +815,6 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
kfree(cert_blob);
e_free_pdh:
kfree(pdh_blob);
-e_free:
- kfree(data);
return ret;
}
--
2.31.0.208.g409f899ff0-goog
next prev parent reply other threads:[~2021-04-02 23:37 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-02 23:36 [PATCH 0/5] ccp: KVM: SVM: Use stack for SEV command buffers Sean Christopherson
2021-04-02 23:36 ` [PATCH 1/5] crypto: ccp: Detect and reject vmalloc addresses destined for PSP Sean Christopherson
2021-04-04 6:31 ` Christophe Leroy
2021-04-02 23:36 ` [PATCH 2/5] crypto: ccp: Reject SEV commands with mismatching command buffer Sean Christopherson
2021-04-03 17:02 ` Christophe Leroy
2021-04-05 16:26 ` Tom Lendacky
2021-04-05 16:33 ` Sean Christopherson
2021-04-05 16:37 ` Tom Lendacky
2021-04-02 23:37 ` [PATCH 3/5] crypto: ccp: Play nice with vmalloc'd memory for SEV command structs Sean Christopherson
2021-04-03 17:05 ` Christophe Leroy
2021-04-03 17:13 ` Christophe Leroy
2021-04-04 6:48 ` Christophe Leroy
2021-04-05 15:06 ` Sean Christopherson
2021-04-05 16:01 ` Brijesh Singh
2021-04-02 23:37 ` Sean Christopherson [this message]
2021-04-02 23:37 ` [PATCH 5/5] KVM: SVM: Allocate SEV command structures on local stack Sean Christopherson
2021-04-04 19:54 ` [PATCH 0/5] ccp: KVM: SVM: Use stack for SEV command buffers Brijesh Singh
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