Re: [PATCH v7 03/16] virt: sev-guest: Add SNP guest request structure

From: Nikunj A. Dadhania
Date: Wed Jan 31 2024 - 08:59:01 EST

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On 1/25/2024 5:29 PM, Borislav Petkov wrote:
> On Wed, Dec 20, 2023 at 08:43:45PM +0530, Nikunj A Dadhania wrote:
>> -int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
>> +int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input,
>> + struct snp_guest_request_ioctl *rio)
>> {
>> struct ghcb_state state;
>> struct es_em_ctxt ctxt;
>> unsigned long flags;
>> struct ghcb *ghcb;
>> + u64 exit_code;
>
> Silly local vars. Just use req->exit_code everywhere instead.
>
>> int ret;
>>
>> rio->exitinfo2 = SEV_RET_NO_FW_CALL;
>> + if (!req)
>> + return -EINVAL;
>
> Such tests are done under the variable which is assigned, not randomly.
>
> Also, what's the point in testing req? Will that ever be NULL? What are
> you actually protecting against here?
>
>> diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
>> index 469e10d9bf35..5cafbd1c42cb 100644
>> --- a/drivers/virt/coco/sev-guest/sev-guest.c
>> +++ b/drivers/virt/coco/sev-guest/sev-guest.c
>> @@ -27,8 +27,7 @@
>>
>> #include <asm/svm.h>
>> #include <asm/sev.h>
>> -
>> -#include "sev-guest.h"
>> +#include <asm/sev-guest.h>
>>
>> #define DEVICE_NAME "sev-guest"
>>
>> @@ -169,7 +168,7 @@ static struct aesgcm_ctx *snp_init_crypto(u8 *key, size_t keylen)
>> return ctx;
>> }
>>
>> -static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, void *payload, u32 sz)
>> +static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, struct snp_guest_req *guest_req)
>
> So we call the request everywhere "req". But you've called it
> "guest_req" here because...
>
>> {
>> struct snp_guest_msg *resp = &snp_dev->secret_response;
>> struct snp_guest_msg *req = &snp_dev->secret_request;
>
> ... there already is a "req" variable which is not a guest request thing
> but a guest message. So why don't you call it "req_msg" instead and the
> "resp" "resp_msg" so that it is clear what is what?
>
> And then you can call the actual request var "req" and then the code
> becomes more readable...
>
> ...
>
>> static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
>> {
>> struct snp_report_req *req = &snp_dev->req.report;
>> + struct snp_guest_req guest_req = {0};
>
> You have the same issue here.
>
> If we aim at calling the local vars in every function the same, the code
> becomes automatically much more readable.
>
> And so on...
>

Changed to "req" for all the guest request throughout the file. Other "req"
usage are renamed appropriately.

Subject: [PATCH] virt: sev-guest: Add SNP guest request structure

Add a snp_guest_req structure to simplify the function arguments. The
structure will be used to call the SNP Guest message request API
instead of passing a long list of parameters. Use "req" as variable name
for guest req throughout the file and rename other variables appropriately.

Update snp_issue_guest_request() prototype to include the new guest request
structure and move the prototype to sev_guest.h.

Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
Tested-by: Peter Gonda <pgonda@xxxxxxxxxx>
---
.../x86/include/asm}/sev-guest.h | 18 ++
arch/x86/include/asm/sev.h | 8 -
arch/x86/kernel/sev.c | 16 +-
drivers/virt/coco/sev-guest/sev-guest.c | 195 ++++++++++--------
4 files changed, 135 insertions(+), 102 deletions(-)
rename {drivers/virt/coco/sev-guest => arch/x86/include/asm}/sev-guest.h (78%)

diff --git a/drivers/virt/coco/sev-guest/sev-guest.h b/arch/x86/include/asm/sev-guest.h
similarity index 78%
rename from drivers/virt/coco/sev-guest/sev-guest.h
rename to arch/x86/include/asm/sev-guest.h
index ceb798a404d6..27cc15ad6131 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.h
+++ b/arch/x86/include/asm/sev-guest.h
@@ -63,4 +63,22 @@ struct snp_guest_msg {
u8 payload[4000];
} __packed;

+struct snp_guest_req {
+ void *req_buf;
+ size_t req_sz;
+
+ void *resp_buf;
+ size_t resp_sz;
+
+ void *data;
+ size_t data_npages;
+
+ u64 exit_code;
+ unsigned int vmpck_id;
+ u8 msg_version;
+ u8 msg_type;
+};
+
+int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input,
+ struct snp_guest_request_ioctl *rio);
#endif /* __VIRT_SEVGUEST_H__ */
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 5b4a1ce3d368..78465a8c7dc6 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -97,8 +97,6 @@ extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
struct snp_req_data {
unsigned long req_gpa;
unsigned long resp_gpa;
- unsigned long data_gpa;
- unsigned int data_npages;
};

struct sev_guest_platform_data {
@@ -209,7 +207,6 @@ void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
void __init __noreturn snp_abort(void);
-int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
void snp_accept_memory(phys_addr_t start, phys_addr_t end);
u64 snp_get_unsupported_features(u64 status);
u64 sev_get_status(void);
@@ -233,11 +230,6 @@ static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npa
static inline void snp_set_wakeup_secondary_cpu(void) { }
static inline bool snp_init(struct boot_params *bp) { return false; }
static inline void snp_abort(void) { }
-static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
-{
- return -ENOTTY;
-}
-
static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
static inline u64 sev_get_status(void) { return 0; }
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index c67285824e82..43ffd307731f 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -28,6 +28,7 @@
#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
#include <asm/sev.h>
+#include <asm/sev-guest.h>
#include <asm/insn-eval.h>
#include <asm/fpu/xcr.h>
#include <asm/processor.h>
@@ -2170,7 +2171,8 @@ static int __init init_sev_config(char *str)
}
__setup("sev=", init_sev_config);

-int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
+int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input,
+ struct snp_guest_request_ioctl *rio)
{
struct ghcb_state state;
struct es_em_ctxt ctxt;
@@ -2194,12 +2196,12 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct sn

vc_ghcb_invalidate(ghcb);

- if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
- ghcb_set_rax(ghcb, input->data_gpa);
- ghcb_set_rbx(ghcb, input->data_npages);
+ if (req->exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
+ ghcb_set_rax(ghcb, __pa(req->data));
+ ghcb_set_rbx(ghcb, req->data_npages);
}

- ret = sev_es_ghcb_hv_call(ghcb, &ctxt, exit_code, input->req_gpa, input->resp_gpa);
+ ret = sev_es_ghcb_hv_call(ghcb, &ctxt, req->exit_code, input->req_gpa, input->resp_gpa);
if (ret)
goto e_put;

@@ -2214,8 +2216,8 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct sn

case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN):
/* Number of expected pages are returned in RBX */
- if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
- input->data_npages = ghcb_get_rbx(ghcb);
+ if (req->exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
+ req->data_npages = ghcb_get_rbx(ghcb);
ret = -ENOSPC;
break;
}
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 0450c5383476..b6c8f70e936c 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -27,8 +27,7 @@

#include <asm/svm.h>
#include <asm/sev.h>
-
-#include "sev-guest.h"
+#include <asm/sev-guest.h>

#define DEVICE_NAME "sev-guest"

@@ -169,65 +168,64 @@ static struct aesgcm_ctx *snp_init_crypto(u8 *key, size_t keylen)
return ctx;
}

-static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, void *payload, u32 sz)
+static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, struct snp_guest_req *req)
{
- struct snp_guest_msg *resp = &snp_dev->secret_response;
- struct snp_guest_msg *req = &snp_dev->secret_request;
- struct snp_guest_msg_hdr *req_hdr = &req->hdr;
- struct snp_guest_msg_hdr *resp_hdr = &resp->hdr;
+ struct snp_guest_msg *resp_msg = &snp_dev->secret_response;
+ struct snp_guest_msg *req_msg = &snp_dev->secret_request;
+ struct snp_guest_msg_hdr *req_msg_hdr = &req_msg->hdr;
+ struct snp_guest_msg_hdr *resp_msg_hdr = &resp_msg->hdr;
struct aesgcm_ctx *ctx = snp_dev->ctx;
u8 iv[GCM_AES_IV_SIZE] = {};

pr_debug("response [seqno %lld type %d version %d sz %d]\n",
- resp_hdr->msg_seqno, resp_hdr->msg_type, resp_hdr->msg_version,
- resp_hdr->msg_sz);
+ resp_msg_hdr->msg_seqno, resp_msg_hdr->msg_type, resp_msg_hdr->msg_version,
+ resp_msg_hdr->msg_sz);

/* Copy response from shared memory to encrypted memory. */
- memcpy(resp, snp_dev->response, sizeof(*resp));
+ memcpy(resp_msg, snp_dev->response, sizeof(*resp_msg));

/* Verify that the sequence counter is incremented by 1 */
- if (unlikely(resp_hdr->msg_seqno != (req_hdr->msg_seqno + 1)))
+ if (unlikely(resp_msg_hdr->msg_seqno != (req_msg_hdr->msg_seqno + 1)))
return -EBADMSG;

/* Verify response message type and version number. */
- if (resp_hdr->msg_type != (req_hdr->msg_type + 1) ||
- resp_hdr->msg_version != req_hdr->msg_version)
+ if (resp_msg_hdr->msg_type != (req_msg_hdr->msg_type + 1) ||
+ resp_msg_hdr->msg_version != req_msg_hdr->msg_version)
return -EBADMSG;

/*
* If the message size is greater than our buffer length then return
* an error.
*/
- if (unlikely((resp_hdr->msg_sz + ctx->authsize) > sz))
+ if (unlikely((resp_msg_hdr->msg_sz + ctx->authsize) > req->resp_sz))
return -EBADMSG;

/* Decrypt the payload */
- memcpy(iv, &resp_hdr->msg_seqno, min(sizeof(iv), sizeof(resp_hdr->msg_seqno)));
- if (!aesgcm_decrypt(ctx, payload, resp->payload, resp_hdr->msg_sz,
- &resp_hdr->algo, AAD_LEN, iv, resp_hdr->authtag))
+ memcpy(iv, &resp_msg_hdr->msg_seqno, min(sizeof(iv), sizeof(resp_msg_hdr->msg_seqno)));
+ if (!aesgcm_decrypt(ctx, req->resp_buf, resp_msg->payload, resp_msg_hdr->msg_sz,
+ &resp_msg_hdr->algo, AAD_LEN, iv, resp_msg_hdr->authtag))
return -EBADMSG;

return 0;
}

-static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8 type,
- void *payload, size_t sz)
+static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, struct snp_guest_req *req)
{
- struct snp_guest_msg *req = &snp_dev->secret_request;
- struct snp_guest_msg_hdr *hdr = &req->hdr;
+ struct snp_guest_msg *msg = &snp_dev->secret_request;
+ struct snp_guest_msg_hdr *hdr = &msg->hdr;
struct aesgcm_ctx *ctx = snp_dev->ctx;
u8 iv[GCM_AES_IV_SIZE] = {};

- memset(req, 0, sizeof(*req));
+ memset(msg, 0, sizeof(*msg));

hdr->algo = SNP_AEAD_AES_256_GCM;
hdr->hdr_version = MSG_HDR_VER;
hdr->hdr_sz = sizeof(*hdr);
- hdr->msg_type = type;
- hdr->msg_version = version;
+ hdr->msg_type = req->msg_type;
+ hdr->msg_version = req->msg_version;
hdr->msg_seqno = seqno;
- hdr->msg_vmpck = vmpck_id;
- hdr->msg_sz = sz;
+ hdr->msg_vmpck = req->vmpck_id;
+ hdr->msg_sz = req->req_sz;

/* Verify the sequence number is non-zero */
if (!hdr->msg_seqno)
@@ -236,17 +234,17 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8
pr_debug("request [seqno %lld type %d version %d sz %d]\n",
hdr->msg_seqno, hdr->msg_type, hdr->msg_version, hdr->msg_sz);

- if (WARN_ON((sz + ctx->authsize) > sizeof(req->payload)))
+ if (WARN_ON((req->req_sz + ctx->authsize) > sizeof(msg->payload)))
return -EBADMSG;

memcpy(iv, &hdr->msg_seqno, min(sizeof(iv), sizeof(hdr->msg_seqno)));
- aesgcm_encrypt(ctx, req->payload, payload, sz, &hdr->algo, AAD_LEN,
- iv, hdr->authtag);
+ aesgcm_encrypt(ctx, msg->payload, req->req_buf, req->req_sz, &hdr->algo,
+ AAD_LEN, iv, hdr->authtag);

return 0;
}

-static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
+static int __handle_guest_request(struct snp_guest_dev *snp_dev, struct snp_guest_req *req,
struct snp_guest_request_ioctl *rio)
{
unsigned long req_start = jiffies;
@@ -261,7 +259,7 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
* sequence number must be incremented or the VMPCK must be deleted to
* prevent reuse of the IV.
*/
- rc = snp_issue_guest_request(exit_code, &snp_dev->input, rio);
+ rc = snp_issue_guest_request(req, &snp_dev->input, rio);
switch (rc) {
case -ENOSPC:
/*
@@ -271,8 +269,8 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
* order to increment the sequence number and thus avoid
* IV reuse.
*/
- override_npages = snp_dev->input.data_npages;
- exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+ override_npages = req->data_npages;
+ req->exit_code = SVM_VMGEXIT_GUEST_REQUEST;

/*
* Override the error to inform callers the given extended
@@ -327,15 +325,13 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
}

if (override_npages)
- snp_dev->input.data_npages = override_npages;
+ req->data_npages = override_npages;

return rc;
}

-static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
- struct snp_guest_request_ioctl *rio, u8 type,
- void *req_buf, size_t req_sz, void *resp_buf,
- u32 resp_sz)
+static int snp_send_guest_request(struct snp_guest_dev *snp_dev, struct snp_guest_req *req,
+ struct snp_guest_request_ioctl *rio)
{
u64 seqno;
int rc;
@@ -349,7 +345,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
memset(snp_dev->response, 0, sizeof(struct snp_guest_msg));

/* Encrypt the userspace provided payload in snp_dev->secret_request. */
- rc = enc_payload(snp_dev, seqno, rio->msg_version, type, req_buf, req_sz);
+ rc = enc_payload(snp_dev, seqno, req);
if (rc)
return rc;

@@ -360,7 +356,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
memcpy(snp_dev->request, &snp_dev->secret_request,
sizeof(snp_dev->secret_request));

- rc = __handle_guest_request(snp_dev, exit_code, rio);
+ rc = __handle_guest_request(snp_dev, req, rio);
if (rc) {
if (rc == -EIO &&
rio->exitinfo2 == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
@@ -369,12 +365,11 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
dev_alert(snp_dev->dev,
"Detected error from ASP request. rc: %d, exitinfo2: 0x%llx\n",
rc, rio->exitinfo2);
-
snp_disable_vmpck(snp_dev);
return rc;
}

- rc = verify_and_dec_payload(snp_dev, resp_buf, resp_sz);
+ rc = verify_and_dec_payload(snp_dev, req);
if (rc) {
dev_alert(snp_dev->dev, "Detected unexpected decode failure from ASP. rc: %d\n", rc);
snp_disable_vmpck(snp_dev);
@@ -391,8 +386,9 @@ struct snp_req_resp {

static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
{
- struct snp_report_req *req = &snp_dev->req.report;
- struct snp_report_resp *resp;
+ struct snp_report_req *report_req = &snp_dev->req.report;
+ struct snp_guest_req req = {0};
+ struct snp_report_resp *report_resp;
int rc, resp_len;

lockdep_assert_held(&snp_cmd_mutex);
@@ -400,7 +396,7 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
if (!arg->req_data || !arg->resp_data)
return -EINVAL;

- if (copy_from_user(req, (void __user *)arg->req_data, sizeof(*req)))
+ if (copy_from_user(report_req, (void __user *)arg->req_data, sizeof(*report_req)))
return -EFAULT;

/*
@@ -408,29 +404,37 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
* response payload. Make sure that it has enough space to cover the
* authtag.
*/
- resp_len = sizeof(resp->data) + snp_dev->ctx->authsize;
- resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
- if (!resp)
+ resp_len = sizeof(report_resp->data) + snp_dev->ctx->authsize;
+ report_resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
+ if (!report_resp)
return -ENOMEM;

- rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg,
- SNP_MSG_REPORT_REQ, req, sizeof(*req), resp->data,
- resp_len);
+ req.msg_version = arg->msg_version;
+ req.msg_type = SNP_MSG_REPORT_REQ;
+ req.vmpck_id = vmpck_id;
+ req.req_buf = report_req;
+ req.req_sz = sizeof(*report_req);
+ req.resp_buf = report_resp->data;
+ req.resp_sz = resp_len;
+ req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+
+ rc = snp_send_guest_request(snp_dev, &req, arg);
if (rc)
goto e_free;

- if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp)))
+ if (copy_to_user((void __user *)arg->resp_data, report_resp, sizeof(*report_resp)))
rc = -EFAULT;

e_free:
- kfree(resp);
+ kfree(report_resp);
return rc;
}

static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
{
- struct snp_derived_key_req *req = &snp_dev->req.derived_key;
- struct snp_derived_key_resp resp = {0};
+ struct snp_derived_key_req *derived_key_req = &snp_dev->req.derived_key;
+ struct snp_derived_key_resp derived_key_resp = {0};
+ struct snp_guest_req req = {0};
int rc, resp_len;
/* Response data is 64 bytes and max authsize for GCM is 16 bytes. */
u8 buf[64 + 16];
@@ -445,25 +449,34 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
* response payload. Make sure that it has enough space to cover the
* authtag.
*/
- resp_len = sizeof(resp.data) + snp_dev->ctx->authsize;
+ resp_len = sizeof(derived_key_resp.data) + snp_dev->ctx->authsize;
if (sizeof(buf) < resp_len)
return -ENOMEM;

- if (copy_from_user(req, (void __user *)arg->req_data, sizeof(*req)))
+ if (copy_from_user(derived_key_req, (void __user *)arg->req_data,
+ sizeof(*derived_key_req)))
return -EFAULT;

- rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg,
- SNP_MSG_KEY_REQ, req, sizeof(*req), buf, resp_len);
+ req.msg_version = arg->msg_version;
+ req.msg_type = SNP_MSG_KEY_REQ;
+ req.vmpck_id = vmpck_id;
+ req.req_buf = derived_key_req;
+ req.req_sz = sizeof(*derived_key_req);
+ req.resp_buf = buf;
+ req.resp_sz = resp_len;
+ req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+
+ rc = snp_send_guest_request(snp_dev, &req, arg);
if (rc)
return rc;

- memcpy(resp.data, buf, sizeof(resp.data));
- if (copy_to_user((void __user *)arg->resp_data, &resp, sizeof(resp)))
+ memcpy(derived_key_resp.data, buf, sizeof(derived_key_resp.data));
+ if (copy_to_user((void __user *)arg->resp_data, &derived_key_resp, sizeof(derived_key_resp)))
rc = -EFAULT;

/* The response buffer contains the sensitive data, explicitly clear it. */
memzero_explicit(buf, sizeof(buf));
- memzero_explicit(&resp, sizeof(resp));
+ memzero_explicit(&derived_key_resp, sizeof(derived_key_resp));
return rc;
}

@@ -471,32 +484,33 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
struct snp_req_resp *io)

{
- struct snp_ext_report_req *req = &snp_dev->req.ext_report;
- struct snp_report_resp *resp;
- int ret, npages = 0, resp_len;
+ struct snp_ext_report_req *report_req = &snp_dev->req.ext_report;
+ struct snp_guest_req req = {0};
+ struct snp_report_resp *report_resp;
sockptr_t certs_address;
+ int ret, resp_len;

lockdep_assert_held(&snp_cmd_mutex);

if (sockptr_is_null(io->req_data) || sockptr_is_null(io->resp_data))
return -EINVAL;

- if (copy_from_sockptr(req, io->req_data, sizeof(*req)))
+ if (copy_from_sockptr(report_req, io->req_data, sizeof(*report_req)))
return -EFAULT;

/* caller does not want certificate data */
- if (!req->certs_len || !req->certs_address)
+ if (!report_req->certs_len || !report_req->certs_address)
goto cmd;

- if (req->certs_len > SEV_FW_BLOB_MAX_SIZE ||
- !IS_ALIGNED(req->certs_len, PAGE_SIZE))
+ if (report_req->certs_len > SEV_FW_BLOB_MAX_SIZE ||
+ !IS_ALIGNED(report_req->certs_len, PAGE_SIZE))
return -EINVAL;

if (sockptr_is_kernel(io->resp_data)) {
- certs_address = KERNEL_SOCKPTR((void *)req->certs_address);
+ certs_address = KERNEL_SOCKPTR((void *)report_req->certs_address);
} else {
- certs_address = USER_SOCKPTR((void __user *)req->certs_address);
- if (!access_ok(certs_address.user, req->certs_len))
+ certs_address = USER_SOCKPTR((void __user *)report_req->certs_address);
+ if (!access_ok(certs_address.user, report_req->certs_len))
return -EFAULT;
}

@@ -506,45 +520,53 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
* the host. If host does not supply any certs in it, then copy
* zeros to indicate that certificate data was not provided.
*/
- memset(snp_dev->certs_data, 0, req->certs_len);
- npages = req->certs_len >> PAGE_SHIFT;
+ memset(snp_dev->certs_data, 0, report_req->certs_len);
+ req.data_npages = report_req->certs_len >> PAGE_SHIFT;
cmd:
/*
* The intermediate response buffer is used while decrypting the
* response payload. Make sure that it has enough space to cover the
* authtag.
*/
- resp_len = sizeof(resp->data) + snp_dev->ctx->authsize;
- resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
- if (!resp)
+ resp_len = sizeof(report_resp->data) + snp_dev->ctx->authsize;
+ report_resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
+ if (!report_resp)
return -ENOMEM;

- snp_dev->input.data_npages = npages;
- ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg,
- SNP_MSG_REPORT_REQ, &req->data,
- sizeof(req->data), resp->data, resp_len);
+ req.msg_version = arg->msg_version;
+ req.msg_type = SNP_MSG_REPORT_REQ;
+ req.vmpck_id = vmpck_id;
+ req.req_buf = &report_req->data;
+ req.req_sz = sizeof(report_req->data);
+ req.resp_buf = report_resp->data;
+ req.resp_sz = resp_len;
+ req.exit_code = SVM_VMGEXIT_EXT_GUEST_REQUEST;
+ req.data = snp_dev->certs_data;
+
+ ret = snp_send_guest_request(snp_dev, &req, arg);

/* If certs length is invalid then copy the returned length */
if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
- req->certs_len = snp_dev->input.data_npages << PAGE_SHIFT;
+ report_req->certs_len = req.data_npages << PAGE_SHIFT;

- if (copy_to_sockptr(io->req_data, req, sizeof(*req)))
+ if (copy_to_sockptr(io->req_data, report_req, sizeof(*report_req)))
ret = -EFAULT;
}

if (ret)
goto e_free;

- if (npages && copy_to_sockptr(certs_address, snp_dev->certs_data, req->certs_len)) {
+ if (req.data_npages && report_req->certs_len &&
+ copy_to_sockptr(certs_address, snp_dev->certs_data, report_req->certs_len)) {
ret = -EFAULT;
goto e_free;
}

- if (copy_to_sockptr(io->resp_data, resp, sizeof(*resp)))
+ if (copy_to_sockptr(io->resp_data, report_resp, sizeof(*report_resp)))
ret = -EFAULT;

e_free:
- kfree(resp);
+ kfree(report_resp);
return ret;
}

@@ -868,7 +890,6 @@ static int __init sev_guest_probe(struct platform_device *pdev)
/* initial the input address for guest request */
snp_dev->input.req_gpa = __pa(snp_dev->request);
snp_dev->input.resp_gpa = __pa(snp_dev->response);
- snp_dev->input.data_gpa = __pa(snp_dev->certs_data);

ret = tsm_register(&sev_tsm_ops, snp_dev, &tsm_report_extra_type);
if (ret)
--
2.34.1

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