[PATCH 1/4] virt: sev-guest: Contain snp_guest_request_ioctl in sev-guest

[Alexey Kardashevskiy <aik@amd.com>]

SNP Guest Request only uses exitinfo2 which is a return value from GHCB,
has meaning beyond ioctl and therefore belongs to snp_guest_req.

Move exitinfo2 to snp_guest_req, remove snp_guest_request_ioctl from
the SEV platform code.

No functional change intended.

Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
---

Not passing exitinfo2 as a parameter as it's been mentioned on v2:

===
having a struct request which collects all fields you need to pass down or return to callers is the RightThing(tm) to do.
===
---
 arch/x86/include/asm/sev.h              | 10 +++---
 arch/x86/coco/sev/core.c                | 36 +++++++-------------
 drivers/virt/coco/sev-guest/sev-guest.c |  9 +++--
 3 files changed, 23 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 13a88a4b52a0..db233a03f472 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -231,6 +231,7 @@ struct snp_guest_req {
 	size_t resp_sz;
 
 	u64 exit_code;
+	u64 exitinfo2;
 	unsigned int vmpck_id;
 	u8 msg_version;
 	u8 msg_type;
@@ -486,8 +487,6 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
 	return rc;
 }
 
-struct snp_guest_request_ioctl;
-
 void setup_ghcb(void);
 void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
 				  unsigned long npages);
@@ -513,8 +512,7 @@ void snp_kexec_begin(void);
 int snp_msg_init(struct snp_msg_desc *mdesc, int vmpck_id);
 struct snp_msg_desc *snp_msg_alloc(void);
 void snp_msg_free(struct snp_msg_desc *mdesc);
-int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req,
-			   struct snp_guest_request_ioctl *rio);
+int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req);
 
 int snp_svsm_vtpm_send_command(u8 *buffer);
 
@@ -565,8 +563,8 @@ static inline void snp_kexec_begin(void) { }
 static inline int snp_msg_init(struct snp_msg_desc *mdesc, int vmpck_id) { return -1; }
 static inline struct snp_msg_desc *snp_msg_alloc(void) { return NULL; }
 static inline void snp_msg_free(struct snp_msg_desc *mdesc) { }
-static inline int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req,
-					 struct snp_guest_request_ioctl *rio) { return -ENODEV; }
+static inline int snp_send_guest_request(struct snp_msg_desc *mdesc,
+					 struct snp_guest_req *req) { return -ENODEV; }
 static inline int snp_svsm_vtpm_send_command(u8 *buffer) { return -ENODEV; }
 static inline void __init snp_secure_tsc_prepare(void) { }
 static inline void __init snp_secure_tsc_init(void) { }
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 5b145446e991..7a49c896feb4 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -1322,8 +1322,7 @@ int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call,
 }
 EXPORT_SYMBOL_GPL(snp_issue_svsm_attest_req);
 
-static int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input,
-				   struct snp_guest_request_ioctl *rio)
+static int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_data *input)
 {
 	struct ghcb_state state;
 	struct es_em_ctxt ctxt;
@@ -1331,7 +1330,7 @@ static int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_dat
 	struct ghcb *ghcb;
 	int ret;
 
-	rio->exitinfo2 = SEV_RET_NO_FW_CALL;
+	req->exitinfo2 = SEV_RET_NO_FW_CALL;
 
 	/*
 	 * __sev_get_ghcb() needs to run with IRQs disabled because it is using
@@ -1356,8 +1355,8 @@ static int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_dat
 	if (ret)
 		goto e_put;
 
-	rio->exitinfo2 = ghcb->save.sw_exit_info_2;
-	switch (rio->exitinfo2) {
+	req->exitinfo2 = ghcb->save.sw_exit_info_2;
+	switch (req->exitinfo2) {
 	case 0:
 		break;
 
@@ -1852,8 +1851,7 @@ static int enc_payload(struct snp_msg_desc *mdesc, u64 seqno, struct snp_guest_r
 	return 0;
 }
 
-static int __handle_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req,
-				  struct snp_guest_request_ioctl *rio)
+static int __handle_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req)
 {
 	unsigned long req_start = jiffies;
 	unsigned int override_npages = 0;
@@ -1867,7 +1865,7 @@ static int __handle_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_r
 	 * sequence number must be incremented or the VMPCK must be deleted to
 	 * prevent reuse of the IV.
 	 */
-	rc = snp_issue_guest_request(req, &req->input, rio);
+	rc = snp_issue_guest_request(req, &req->input);
 	switch (rc) {
 	case -ENOSPC:
 		/*
@@ -1920,7 +1918,7 @@ static int __handle_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_r
 	snp_inc_msg_seqno(mdesc);
 
 	if (override_err) {
-		rio->exitinfo2 = override_err;
+		req->exitinfo2 = override_err;
 
 		/*
 		 * If an extended guest request was issued and the supplied certificate
@@ -1938,8 +1936,7 @@ static int __handle_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_r
 	return rc;
 }
 
-int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req,
-			   struct snp_guest_request_ioctl *rio)
+int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req)
 {
 	u64 seqno;
 	int rc;
@@ -1976,14 +1973,14 @@ int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req
 	req->input.resp_gpa = __pa(mdesc->response);
 	req->input.data_gpa = req->certs_data ? __pa(req->certs_data) : 0;
 
-	rc = __handle_guest_request(mdesc, req, rio);
+	rc = __handle_guest_request(mdesc, req);
 	if (rc) {
 		if (rc == -EIO &&
-		    rio->exitinfo2 == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
+		    req->exitinfo2 == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
 			return rc;
 
 		pr_alert("Detected error from ASP request. rc: %d, exitinfo2: 0x%llx\n",
-			 rc, rio->exitinfo2);
+			 rc, req->exitinfo2);
 
 		snp_disable_vmpck(mdesc);
 		return rc;
@@ -2002,7 +1999,6 @@ EXPORT_SYMBOL_GPL(snp_send_guest_request);
 
 static int __init snp_get_tsc_info(void)
 {
-	struct snp_guest_request_ioctl *rio;
 	struct snp_tsc_info_resp *tsc_resp;
 	struct snp_tsc_info_req *tsc_req;
 	struct snp_msg_desc *mdesc;
@@ -2026,13 +2022,9 @@ static int __init snp_get_tsc_info(void)
 	if (!req)
 		goto e_free_tsc_resp;
 
-	rio = kzalloc(sizeof(*rio), GFP_KERNEL);
-	if (!rio)
-		goto e_free_req;
-
 	mdesc = snp_msg_alloc();
 	if (IS_ERR_OR_NULL(mdesc))
-		goto e_free_rio;
+		goto e_free_req;
 
 	rc = snp_msg_init(mdesc, snp_vmpl);
 	if (rc)
@@ -2047,7 +2039,7 @@ static int __init snp_get_tsc_info(void)
 	req->resp_sz = sizeof(*tsc_resp) + AUTHTAG_LEN;
 	req->exit_code = SVM_VMGEXIT_GUEST_REQUEST;
 
-	rc = snp_send_guest_request(mdesc, req, rio);
+	rc = snp_send_guest_request(mdesc, req);
 	if (rc)
 		goto e_request;
 
@@ -2068,8 +2060,6 @@ static int __init snp_get_tsc_info(void)
 	memzero_explicit(tsc_resp, sizeof(*tsc_resp) + AUTHTAG_LEN);
 e_free_mdesc:
 	snp_msg_free(mdesc);
-e_free_rio:
-	kfree(rio);
 e_free_req:
 	kfree(req);
  e_free_tsc_resp:
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index cf3fb61f4d5b..b18504398619 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -101,7 +101,8 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
 	req.resp_sz = resp_len;
 	req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
 
-	rc = snp_send_guest_request(mdesc, &req, arg);
+	rc = snp_send_guest_request(mdesc, &req);
+	arg->exitinfo2 = req.exitinfo2;
 	if (rc)
 		goto e_free;
 
@@ -152,7 +153,8 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
 	req.resp_sz = resp_len;
 	req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
 
-	rc = snp_send_guest_request(mdesc, &req, arg);
+	rc = snp_send_guest_request(mdesc, &req);
+	arg->exitinfo2 = req.exitinfo2;
 	if (rc)
 		return rc;
 
@@ -249,7 +251,8 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
 	req.resp_sz = resp_len;
 	req.exit_code = SVM_VMGEXIT_EXT_GUEST_REQUEST;
 
-	ret = snp_send_guest_request(mdesc, &req, arg);
+	ret = snp_send_guest_request(mdesc, &req);
+	arg->exitinfo2 = req.exitinfo2;
 
 	/* If certs length is invalid then copy the returned length */
 	if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
-- 
2.49.0