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-rw-r--r--Documentation/virt/coco/sev-guest.rst20
-rw-r--r--arch/x86/include/asm/sev-common.h4
-rw-r--r--arch/x86/include/asm/sev.h10
-rw-r--r--arch/x86/kernel/sev.c15
-rw-r--r--drivers/virt/coco/sev-guest/sev-guest.c72
-rw-r--r--include/uapi/linux/sev-guest.h18
6 files changed, 83 insertions, 56 deletions
diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst
index aa3e4c6a1f90..68b0d2363af8 100644
--- a/Documentation/virt/coco/sev-guest.rst
+++ b/Documentation/virt/coco/sev-guest.rst
@@ -37,11 +37,11 @@ along with a description:
the return value. General error numbers (-ENOMEM, -EINVAL)
are not detailed, but errors with specific meanings are.
-The guest ioctl should be issued on a file descriptor of the /dev/sev-guest device.
-The ioctl accepts struct snp_user_guest_request. The input and output structure is
-specified through the req_data and resp_data field respectively. If the ioctl fails
-to execute due to a firmware error, then fw_err code will be set. Otherwise, fw_err
-will be set to 0x00000000ffffffff, i.e., the lower 32-bits are -1.
+The guest ioctl should be issued on a file descriptor of the /dev/sev-guest
+device. The ioctl accepts struct snp_user_guest_request. The input and
+output structure is specified through the req_data and resp_data field
+respectively. If the ioctl fails to execute due to a firmware error, then
+the fw_error code will be set, otherwise fw_error will be set to -1.
The firmware checks that the message sequence counter is one greater than
the guests message sequence counter. If guest driver fails to increment message
@@ -57,8 +57,14 @@ counter (e.g. counter overflow), then -EIO will be returned.
__u64 req_data;
__u64 resp_data;
- /* firmware error code on failure (see psp-sev.h) */
- __u64 fw_err;
+ /* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */
+ union {
+ __u64 exitinfo2;
+ struct {
+ __u32 fw_error;
+ __u32 vmm_error;
+ };
+ };
};
2.1 SNP_GET_REPORT
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index b63be696b776..0759af9b1acf 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -128,10 +128,6 @@ struct snp_psc_desc {
struct psc_entry entries[VMGEXIT_PSC_MAX_ENTRY];
} __packed;
-/* Guest message request error codes */
-#define SNP_GUEST_REQ_INVALID_LEN BIT_ULL(32)
-#define SNP_GUEST_REQ_ERR_BUSY BIT_ULL(33)
-
#define GHCB_MSR_TERM_REQ 0x100
#define GHCB_MSR_TERM_REASON_SET_POS 12
#define GHCB_MSR_TERM_REASON_SET_MASK 0xf
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index ebc271bb6d8e..13dc2a9d23c1 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -9,6 +9,8 @@
#define __ASM_ENCRYPTED_STATE_H
#include <linux/types.h>
+#include <linux/sev-guest.h>
+
#include <asm/insn.h>
#include <asm/sev-common.h>
#include <asm/bootparam.h>
@@ -185,6 +187,9 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
return rc;
}
+
+struct snp_guest_request_ioctl;
+
void setup_ghcb(void);
void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
unsigned int npages);
@@ -196,7 +201,7 @@ void snp_set_memory_private(unsigned long vaddr, unsigned int 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, unsigned long *fw_err);
+int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
@@ -216,8 +221,7 @@ static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npag
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,
- unsigned long *fw_err)
+static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
{
return -ENOTTY;
}
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 3f664ab277c4..b031244d6d2d 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -22,6 +22,8 @@
#include <linux/efi.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/psp-sev.h>
+#include <uapi/linux/sev-guest.h>
#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
@@ -2175,7 +2177,7 @@ 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, unsigned long *fw_err)
+int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
{
struct ghcb_state state;
struct es_em_ctxt ctxt;
@@ -2183,8 +2185,7 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
struct ghcb *ghcb;
int ret;
- if (!fw_err)
- return -EINVAL;
+ rio->exitinfo2 = SEV_RET_NO_FW_CALL;
/*
* __sev_get_ghcb() needs to run with IRQs disabled because it is using
@@ -2209,16 +2210,16 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
if (ret)
goto e_put;
- *fw_err = ghcb->save.sw_exit_info_2;
- switch (*fw_err) {
+ rio->exitinfo2 = ghcb->save.sw_exit_info_2;
+ switch (rio->exitinfo2) {
case 0:
break;
- case SNP_GUEST_REQ_ERR_BUSY:
+ case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_BUSY):
ret = -EAGAIN;
break;
- case SNP_GUEST_REQ_INVALID_LEN:
+ 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);
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 0c7b47acba2a..97dbe715e96a 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -332,11 +332,12 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8
return __enc_payload(snp_dev, req, payload, sz);
}
-static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, __u64 *fw_err)
+static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
+ struct snp_guest_request_ioctl *rio)
{
- unsigned long err = 0xff, override_err = 0;
unsigned long req_start = jiffies;
unsigned int override_npages = 0;
+ u64 override_err = 0;
int rc;
retry_request:
@@ -346,7 +347,7 @@ retry_request:
* 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, &err);
+ rc = snp_issue_guest_request(exit_code, &snp_dev->input, rio);
switch (rc) {
case -ENOSPC:
/*
@@ -364,7 +365,7 @@ retry_request:
* request buffer size was too small and give the caller the
* required buffer size.
*/
- override_err = SNP_GUEST_REQ_INVALID_LEN;
+ override_err = SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN);
/*
* If this call to the firmware succeeds, the sequence number can
@@ -377,7 +378,7 @@ retry_request:
goto retry_request;
/*
- * The host may return SNP_GUEST_REQ_ERR_EBUSY if the request has been
+ * The host may return SNP_GUEST_VMM_ERR_BUSY if the request has been
* throttled. Retry in the driver to avoid returning and reusing the
* message sequence number on a different message.
*/
@@ -398,27 +399,29 @@ retry_request:
*/
snp_inc_msg_seqno(snp_dev);
- if (fw_err)
- *fw_err = override_err ?: err;
+ if (override_err) {
+ rio->exitinfo2 = override_err;
+
+ /*
+ * If an extended guest request was issued and the supplied certificate
+ * buffer was not large enough, a standard guest request was issued to
+ * prevent IV reuse. If the standard request was successful, return -EIO
+ * back to the caller as would have originally been returned.
+ */
+ if (!rc && override_err == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
+ rc = -EIO;
+ }
if (override_npages)
snp_dev->input.data_npages = override_npages;
- /*
- * If an extended guest request was issued and the supplied certificate
- * buffer was not large enough, a standard guest request was issued to
- * prevent IV reuse. If the standard request was successful, return -EIO
- * back to the caller as would have originally been returned.
- */
- if (!rc && override_err == SNP_GUEST_REQ_INVALID_LEN)
- return -EIO;
-
return rc;
}
-static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver,
- u8 type, void *req_buf, size_t req_sz, void *resp_buf,
- u32 resp_sz, __u64 *fw_err)
+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)
{
u64 seqno;
int rc;
@@ -432,7 +435,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
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, msg_ver, type, req_buf, req_sz);
+ rc = enc_payload(snp_dev, seqno, rio->msg_version, type, req_buf, req_sz);
if (rc)
return rc;
@@ -443,12 +446,16 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
memcpy(snp_dev->request, &snp_dev->secret_request,
sizeof(snp_dev->secret_request));
- rc = __handle_guest_request(snp_dev, exit_code, fw_err);
+ rc = __handle_guest_request(snp_dev, exit_code, rio);
if (rc) {
- if (rc == -EIO && *fw_err == SNP_GUEST_REQ_INVALID_LEN)
+ if (rc == -EIO &&
+ rio->exitinfo2 == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
return rc;
- dev_alert(snp_dev->dev, "Detected error from ASP request. rc: %d, fw_err: %llu\n", rc, *fw_err);
+ 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;
}
@@ -488,9 +495,9 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
if (!resp)
return -ENOMEM;
- rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version,
+ rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg,
SNP_MSG_REPORT_REQ, &req, sizeof(req), resp->data,
- resp_len, &arg->fw_err);
+ resp_len);
if (rc)
goto e_free;
@@ -528,9 +535,8 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req)))
return -EFAULT;
- rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version,
- SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len,
- &arg->fw_err);
+ rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg,
+ SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len);
if (rc)
return rc;
@@ -590,12 +596,12 @@ cmd:
return -ENOMEM;
snp_dev->input.data_npages = npages;
- ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg->msg_version,
+ 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, &arg->fw_err);
+ sizeof(req.data), resp->data, resp_len);
/* If certs length is invalid then copy the returned length */
- if (arg->fw_err == SNP_GUEST_REQ_INVALID_LEN) {
+ if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
req.certs_len = snp_dev->input.data_npages << PAGE_SHIFT;
if (copy_to_user((void __user *)arg->req_data, &req, sizeof(req)))
@@ -630,7 +636,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
if (copy_from_user(&input, argp, sizeof(input)))
return -EFAULT;
- input.fw_err = 0xff;
+ input.exitinfo2 = 0xff;
/* Message version must be non-zero */
if (!input.msg_version)
@@ -661,7 +667,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
mutex_unlock(&snp_cmd_mutex);
- if (input.fw_err && copy_to_user(argp, &input, sizeof(input)))
+ if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input)))
return -EFAULT;
return ret;
diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h
index 256aaeff7e65..2aa39112cf8d 100644
--- a/include/uapi/linux/sev-guest.h
+++ b/include/uapi/linux/sev-guest.h
@@ -52,8 +52,14 @@ struct snp_guest_request_ioctl {
__u64 req_data;
__u64 resp_data;
- /* firmware error code on failure (see psp-sev.h) */
- __u64 fw_err;
+ /* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */
+ union {
+ __u64 exitinfo2;
+ struct {
+ __u32 fw_error;
+ __u32 vmm_error;
+ };
+ };
};
struct snp_ext_report_req {
@@ -77,4 +83,12 @@ struct snp_ext_report_req {
/* Get SNP extended report as defined in the GHCB specification version 2. */
#define SNP_GET_EXT_REPORT _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x2, struct snp_guest_request_ioctl)
+/* Guest message request EXIT_INFO_2 constants */
+#define SNP_GUEST_FW_ERR_MASK GENMASK_ULL(31, 0)
+#define SNP_GUEST_VMM_ERR_SHIFT 32
+#define SNP_GUEST_VMM_ERR(x) (((u64)x) << SNP_GUEST_VMM_ERR_SHIFT)
+
+#define SNP_GUEST_VMM_ERR_INVALID_LEN 1
+#define SNP_GUEST_VMM_ERR_BUSY 2
+
#endif /* __UAPI_LINUX_SEV_GUEST_H_ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 08:56:02 +0100