diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index b8357d6ecd47ef6766a0fe9fe5161f6447228c16..b63be696b776a7d764359cb990533871d910197d 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -128,8 +128,9 @@ struct snp_psc_desc {
struct psc_entry entries[VMGEXIT_PSC_MAX_ENTRY];
} __packed;
-/* Guest message request error code */
+/* 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
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index eb07d4435391bedc4db1a2d6483bda477c093bea..b44c487727d456e445a4ad53ddaff76d84e449b1 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -368,7 +368,6 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
{
struct resctrl_schema *s;
struct rdtgroup *rdtgrp;
- struct rdt_domain *dom;
struct rdt_resource *r;
char *tok, *resname;
int ret = 0;
@@ -397,10 +396,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
goto out;
}
- list_for_each_entry(s, &resctrl_schema_all, list) {
- list_for_each_entry(dom, &s->res->domains, list)
- memset(dom->staged_config, 0, sizeof(dom->staged_config));
- }
+ rdt_staged_configs_clear();
while ((tok = strsep(&buf, "\n")) != NULL) {
resname = strim(strsep(&tok, ":"));
@@ -445,6 +441,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
}
out:
+ rdt_staged_configs_clear();
rdtgroup_kn_unlock(of->kn);
cpus_read_unlock();
return ret ?: nbytes;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 8edecc5763d8e31313294145b7e0af8a6e477611..85ceaf9a31ac20099c86647b4958e4ca0f28fa6b 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -555,5 +555,6 @@ void __check_limbo(struct rdt_domain *d, bool force_free);
void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
void __init thread_throttle_mode_init(void);
void __init mbm_config_rftype_init(const char *config);
+void rdt_staged_configs_clear(void);
#endif /* _ASM_X86_RESCTRL_INTERNAL_H */
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 884b6e9a7e31c36281afe21b2f507f9b223781b2..6ad33f355861feab9a1f013ff82e026e9638044b 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -78,6 +78,19 @@ void rdt_last_cmd_printf(const char *fmt, ...)
va_end(ap);
}
+void rdt_staged_configs_clear(void)
+{
+ struct rdt_resource *r;
+ struct rdt_domain *dom;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ for_each_alloc_capable_rdt_resource(r) {
+ list_for_each_entry(dom, &r->domains, list)
+ memset(dom->staged_config, 0, sizeof(dom->staged_config));
+ }
+}
+
/*
* Trivial allocator for CLOSIDs. Since h/w only supports a small number,
* we can keep a bitmap of free CLOSIDs in a single integer.
@@ -3107,7 +3120,9 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
{
struct resctrl_schema *s;
struct rdt_resource *r;
- int ret;
+ int ret = 0;
+
+ rdt_staged_configs_clear();
list_for_each_entry(s, &resctrl_schema_all, list) {
r = s->res;
@@ -3119,20 +3134,22 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
} else {
ret = rdtgroup_init_cat(s, rdtgrp->closid);
if (ret < 0)
- return ret;
+ goto out;
}
ret = resctrl_arch_update_domains(r, rdtgrp->closid);
if (ret < 0) {
rdt_last_cmd_puts("Failed to initialize allocations\n");
- return ret;
+ goto out;
}
}
rdtgrp->mode = RDT_MODE_SHAREABLE;
- return 0;
+out:
+ rdt_staged_configs_clear();
+ return ret;
}
static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 679026a640efd8e2e87a03d3b5e57cf18de1a6dd..3f664ab277c4987ac57f41959a300f3a8f5c6439 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -2183,9 +2183,6 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
struct ghcb *ghcb;
int ret;
- if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
- return -ENODEV;
-
if (!fw_err)
return -EINVAL;
@@ -2212,15 +2209,26 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
if (ret)
goto e_put;
- if (ghcb->save.sw_exit_info_2) {
- /* Number of expected pages are returned in RBX */
- if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST &&
- ghcb->save.sw_exit_info_2 == SNP_GUEST_REQ_INVALID_LEN)
- input->data_npages = ghcb_get_rbx(ghcb);
+ *fw_err = ghcb->save.sw_exit_info_2;
+ switch (*fw_err) {
+ case 0:
+ break;
- *fw_err = ghcb->save.sw_exit_info_2;
+ case SNP_GUEST_REQ_ERR_BUSY:
+ ret = -EAGAIN;
+ break;
+ case SNP_GUEST_REQ_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);
+ ret = -ENOSPC;
+ break;
+ }
+ fallthrough;
+ default:
ret = -EIO;
+ break;
}
e_put:
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 88cccd65029dba414912656310c3e72313a4aa4b..c6efcf559d8821261cb1724bf45275101a351238 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -600,7 +600,8 @@ void __init sme_enable(struct boot_params *bp)
cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
((u64)bp->ext_cmd_line_ptr << 32));
- cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+ if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0)
+ return;
if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
sme_me_mask = me_mask;
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 7b4e9009f33559fe04a11c17af5433715b625893..46f1a8d558b0b28321b1f9312dd415df25f4f504 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -31,6 +31,9 @@
#define AAD_LEN 48
#define MSG_HDR_VER 1
+#define SNP_REQ_MAX_RETRY_DURATION (60*HZ)
+#define SNP_REQ_RETRY_DELAY (2*HZ)
+
struct snp_guest_crypto {
struct crypto_aead *tfm;
u8 *iv, *authtag;
@@ -318,26 +321,14 @@ 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, 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, __u64 *fw_err)
{
- unsigned long err;
- u64 seqno;
+ unsigned long err = 0xff, override_err = 0;
+ unsigned long req_start = jiffies;
+ unsigned int override_npages = 0;
int rc;
- /* Get message sequence and verify that its a non-zero */
- seqno = snp_get_msg_seqno(snp_dev);
- if (!seqno)
- return -EIO;
-
- memset(snp_dev->response, 0, sizeof(struct snp_guest_msg));
-
- /* Encrypt the userspace provided payload */
- rc = enc_payload(snp_dev, seqno, msg_ver, type, req_buf, req_sz);
- if (rc)
- return rc;
-
+retry_request:
/*
* Call firmware to process the request. In this function the encrypted
* message enters shared memory with the host. So after this call the
@@ -345,18 +336,24 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
* prevent reuse of the IV.
*/
rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err);
+ switch (rc) {
+ case -ENOSPC:
+ /*
+ * If the extended guest request fails due to having too
+ * small of a certificate data buffer, retry the same
+ * guest request without the extended data request in
+ * order to increment the sequence number and thus avoid
+ * IV reuse.
+ */
+ override_npages = snp_dev->input.data_npages;
+ exit_code = SVM_VMGEXIT_GUEST_REQUEST;
- /*
- * If the extended guest request fails due to having too small of a
- * certificate data buffer, retry the same guest request without the
- * extended data request in order to increment the sequence number
- * and thus avoid IV reuse.
- */
- if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST &&
- err == SNP_GUEST_REQ_INVALID_LEN) {
- const unsigned int certs_npages = snp_dev->input.data_npages;
-
- exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+ /*
+ * Override the error to inform callers the given extended
+ * request buffer size was too small and give the caller the
+ * required buffer size.
+ */
+ override_err = SNP_GUEST_REQ_INVALID_LEN;
/*
* If this call to the firmware succeeds, the sequence number can
@@ -366,15 +363,20 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
* of the VMPCK and the error code being propagated back to the
* user as an ioctl() return code.
*/
- rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err);
+ goto retry_request;
- /*
- * Override the error to inform callers the given extended
- * request buffer size was too small and give the caller the
- * required buffer size.
- */
- err = SNP_GUEST_REQ_INVALID_LEN;
- snp_dev->input.data_npages = certs_npages;
+ /*
+ * The host may return SNP_GUEST_REQ_ERR_EBUSY if the request has been
+ * throttled. Retry in the driver to avoid returning and reusing the
+ * message sequence number on a different message.
+ */
+ case -EAGAIN:
+ if (jiffies - req_start > SNP_REQ_MAX_RETRY_DURATION) {
+ rc = -ETIMEDOUT;
+ break;
+ }
+ schedule_timeout_killable(SNP_REQ_RETRY_DELAY);
+ goto retry_request;
}
/*
@@ -386,7 +388,10 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
snp_inc_msg_seqno(snp_dev);
if (fw_err)
- *fw_err = err;
+ *fw_err = override_err ?: err;
+
+ if (override_npages)
+ snp_dev->input.data_npages = override_npages;
/*
* If an extended guest request was issued and the supplied certificate
@@ -394,29 +399,49 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
* prevent IV reuse. If the standard request was successful, return -EIO
* back to the caller as would have originally been returned.
*/
- if (!rc && err == SNP_GUEST_REQ_INVALID_LEN)
+ 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)
+{
+ u64 seqno;
+ int rc;
+
+ /* Get message sequence and verify that its a non-zero */
+ seqno = snp_get_msg_seqno(snp_dev);
+ if (!seqno)
return -EIO;
+ memset(snp_dev->response, 0, sizeof(struct snp_guest_msg));
+
+ /* Encrypt the userspace provided payload */
+ rc = enc_payload(snp_dev, seqno, msg_ver, type, req_buf, req_sz);
+ if (rc)
+ return rc;
+
+ rc = __handle_guest_request(snp_dev, exit_code, fw_err);
if (rc) {
- dev_alert(snp_dev->dev,
- "Detected error from ASP request. rc: %d, fw_err: %llu\n",
- rc, *fw_err);
- goto disable_vmpck;
+ if (rc == -EIO && *fw_err == SNP_GUEST_REQ_INVALID_LEN)
+ return rc;
+
+ dev_alert(snp_dev->dev, "Detected error from ASP request. rc: %d, fw_err: %llu\n", rc, *fw_err);
+ snp_disable_vmpck(snp_dev);
+ return rc;
}
rc = verify_and_dec_payload(snp_dev, resp_buf, resp_sz);
if (rc) {
- dev_alert(snp_dev->dev,
- "Detected unexpected decode failure from ASP. rc: %d\n",
- rc);
- goto disable_vmpck;
+ dev_alert(snp_dev->dev, "Detected unexpected decode failure from ASP. rc: %d\n", rc);
+ snp_disable_vmpck(snp_dev);
+ return rc;
}
return 0;
-
-disable_vmpck:
- snp_disable_vmpck(snp_dev);
- return rc;
}
static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
@@ -703,6 +728,9 @@ static int __init sev_guest_probe(struct platform_device *pdev)
void __iomem *mapping;
int ret;
+ if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
+ return -ENODEV;
+
if (!dev->platform_data)
return -ENODEV;