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-rw-r--r--arch/x86/coco/sev/Makefile3
-rw-r--r--arch/x86/coco/sev/core.c193
-rw-r--r--arch/x86/coco/sev/vc-handle.c9
3 files changed, 147 insertions, 58 deletions
diff --git a/arch/x86/coco/sev/Makefile b/arch/x86/coco/sev/Makefile
index db3255b979bd..342d79f0ab6a 100644
--- a/arch/x86/coco/sev/Makefile
+++ b/arch/x86/coco/sev/Makefile
@@ -5,5 +5,6 @@ obj-y += core.o sev-nmi.o vc-handle.o
# Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
UBSAN_SANITIZE_sev-nmi.o := n
-# GCC may fail to respect __no_sanitize_address when inlining
+# GCC may fail to respect __no_sanitize_address or __no_kcsan when inlining
KASAN_SANITIZE_sev-nmi.o := n
+KCSAN_SANITIZE_sev-nmi.o := n
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index b2569257acd3..fc59ce78c477 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -88,7 +88,7 @@ static const char * const sev_status_feat_names[] = {
*/
static u64 snp_tsc_scale __ro_after_init;
static u64 snp_tsc_offset __ro_after_init;
-static u64 snp_tsc_freq_khz __ro_after_init;
+static unsigned long snp_tsc_freq_khz __ro_after_init;
DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
@@ -869,12 +869,12 @@ static void *snp_alloc_vmsa_page(int cpu)
return page_address(p + 1);
}
-static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
+static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip, unsigned int cpu)
{
struct sev_es_save_area *cur_vmsa, *vmsa;
struct svsm_ca *caa;
u8 sipi_vector;
- int cpu, ret;
+ int ret;
u64 cr4;
/*
@@ -895,15 +895,6 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
/* Override start_ip with known protected guest start IP */
start_ip = real_mode_header->sev_es_trampoline_start;
-
- /* Find the logical CPU for the APIC ID */
- for_each_present_cpu(cpu) {
- if (arch_match_cpu_phys_id(cpu, apic_id))
- break;
- }
- if (cpu >= nr_cpu_ids)
- return -EINVAL;
-
cur_vmsa = per_cpu(sev_vmsa, cpu);
/*
@@ -1054,11 +1045,13 @@ int __init sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
* This is needed by the OVMF UEFI firmware which will use whatever it finds in
* the GHCB MSR as its GHCB to talk to the hypervisor. So make sure the per-cpu
* runtime GHCBs used by the kernel are also mapped in the EFI page-table.
+ *
+ * When running under SVSM the CA page is needed too, so map it as well.
*/
-int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
+int __init sev_es_efi_map_ghcbs_cas(pgd_t *pgd)
{
+ unsigned long address, pflags, pflags_enc;
struct sev_es_runtime_data *data;
- unsigned long address, pflags;
int cpu;
u64 pfn;
@@ -1066,6 +1059,7 @@ int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
return 0;
pflags = _PAGE_NX | _PAGE_RW;
+ pflags_enc = cc_mkenc(pflags);
for_each_possible_cpu(cpu) {
data = per_cpu(runtime_data, cpu);
@@ -1075,6 +1069,16 @@ int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags))
return 1;
+
+ if (snp_vmpl) {
+ address = per_cpu(svsm_caa_pa, cpu);
+ if (!address)
+ return 1;
+
+ pfn = address >> PAGE_SHIFT;
+ if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags_enc))
+ return 1;
+ }
}
return 0;
@@ -1398,16 +1402,16 @@ 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 = &req->input;
struct ghcb_state state;
struct es_em_ctxt ctxt;
unsigned long flags;
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
@@ -1432,8 +1436,8 @@ 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;
@@ -1462,11 +1466,74 @@ e_restore_irq:
return ret;
}
+/**
+ * snp_svsm_vtpm_probe() - Probe if SVSM provides a vTPM device
+ *
+ * Check that there is SVSM and that it supports at least TPM_SEND_COMMAND
+ * which is the only request used so far.
+ *
+ * Return: true if the platform provides a vTPM SVSM device, false otherwise.
+ */
+static bool snp_svsm_vtpm_probe(void)
+{
+ struct svsm_call call = {};
+
+ /* The vTPM device is available only if a SVSM is present */
+ if (!snp_vmpl)
+ return false;
+
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY);
+
+ if (svsm_perform_call_protocol(&call))
+ return false;
+
+ /* Check platform commands contains TPM_SEND_COMMAND - platform command 8 */
+ return call.rcx_out & BIT_ULL(8);
+}
+
+/**
+ * snp_svsm_vtpm_send_command() - Execute a vTPM operation on SVSM
+ * @buffer: A buffer used to both send the command and receive the response.
+ *
+ * Execute a SVSM_VTPM_CMD call as defined by
+ * "Secure VM Service Module for SEV-SNP Guests" Publication # 58019 Revision: 1.00
+ *
+ * All command request/response buffers have a common structure as specified by
+ * the following table:
+ * Byte Size     In/Out    Description
+ * Offset    (Bytes)
+ * 0x000     4          In        Platform command
+ *                         Out       Platform command response size
+ *
+ * Each command can build upon this common request/response structure to create
+ * a structure specific to the command. See include/linux/tpm_svsm.h for more
+ * details.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int snp_svsm_vtpm_send_command(u8 *buffer)
+{
+ struct svsm_call call = {};
+
+ call.caa = svsm_get_caa();
+ call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD);
+ call.rcx = __pa(buffer);
+
+ return svsm_perform_call_protocol(&call);
+}
+EXPORT_SYMBOL_GPL(snp_svsm_vtpm_send_command);
+
static struct platform_device sev_guest_device = {
.name = "sev-guest",
.id = -1,
};
+static struct platform_device tpm_svsm_device = {
+ .name = "tpm-svsm",
+ .id = -1,
+};
+
static int __init snp_init_platform_device(void)
{
if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
@@ -1475,7 +1542,11 @@ static int __init snp_init_platform_device(void)
if (platform_device_register(&sev_guest_device))
return -ENODEV;
- pr_info("SNP guest platform device initialized.\n");
+ if (snp_svsm_vtpm_probe() &&
+ platform_device_register(&tpm_svsm_device))
+ return -ENODEV;
+
+ pr_info("SNP guest platform devices initialized.\n");
return 0;
}
device_initcall(snp_init_platform_device);
@@ -1861,8 +1932,7 @@ 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;
@@ -1876,7 +1946,7 @@ retry_request:
* sequence number must be incremented or the VMPCK must be deleted to
* prevent reuse of the IV.
*/
- rc = snp_issue_guest_request(req, &req->input, rio);
+ rc = snp_issue_guest_request(req);
switch (rc) {
case -ENOSPC:
/*
@@ -1929,7 +1999,7 @@ retry_request:
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
@@ -1947,12 +2017,20 @@ retry_request:
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;
+ /*
+ * enc_payload() calls aesgcm_encrypt(), which can potentially offload to HW.
+ * The offload's DMA SG list of data to encrypt has to be in linear mapping.
+ */
+ if (!virt_addr_valid(req->req_buf) || !virt_addr_valid(req->resp_buf)) {
+ pr_warn("AES-GSM buffers must be in linear mapping");
+ return -EINVAL;
+ }
+
guard(mutex)(&snp_cmd_mutex);
/* Check if the VMPCK is not empty */
@@ -1985,14 +2063,14 @@ 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;
@@ -2011,11 +2089,10 @@ 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;
- struct snp_guest_req *req;
+ struct snp_guest_req req = {};
int rc = -ENOMEM;
tsc_req = kzalloc(sizeof(*tsc_req), GFP_KERNEL);
@@ -2031,32 +2108,24 @@ static int __init snp_get_tsc_info(void)
if (!tsc_resp)
goto e_free_tsc_req;
- req = kzalloc(sizeof(*req), GFP_KERNEL);
- 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_tsc_resp;
rc = snp_msg_init(mdesc, snp_vmpl);
if (rc)
goto e_free_mdesc;
- req->msg_version = MSG_HDR_VER;
- req->msg_type = SNP_MSG_TSC_INFO_REQ;
- req->vmpck_id = snp_vmpl;
- req->req_buf = tsc_req;
- req->req_sz = sizeof(*tsc_req);
- req->resp_buf = (void *)tsc_resp;
- req->resp_sz = sizeof(*tsc_resp) + AUTHTAG_LEN;
- req->exit_code = SVM_VMGEXIT_GUEST_REQUEST;
+ req.msg_version = MSG_HDR_VER;
+ req.msg_type = SNP_MSG_TSC_INFO_REQ;
+ req.vmpck_id = snp_vmpl;
+ req.req_buf = tsc_req;
+ req.req_sz = sizeof(*tsc_req);
+ req.resp_buf = (void *)tsc_resp;
+ 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;
@@ -2077,11 +2146,7 @@ e_request:
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:
+e_free_tsc_resp:
kfree(tsc_resp);
e_free_tsc_req:
kfree(tsc_req);
@@ -2109,15 +2174,31 @@ static unsigned long securetsc_get_tsc_khz(void)
void __init snp_secure_tsc_init(void)
{
- unsigned long long tsc_freq_mhz;
+ struct snp_secrets_page *secrets;
+ unsigned long tsc_freq_mhz;
+ void *mem;
if (!cc_platform_has(CC_ATTR_GUEST_SNP_SECURE_TSC))
return;
+ mem = early_memremap_encrypted(sev_secrets_pa, PAGE_SIZE);
+ if (!mem) {
+ pr_err("Unable to get TSC_FACTOR: failed to map the SNP secrets page.\n");
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECURE_TSC);
+ }
+
+ secrets = (__force struct snp_secrets_page *)mem;
+
setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
rdmsrq(MSR_AMD64_GUEST_TSC_FREQ, tsc_freq_mhz);
- snp_tsc_freq_khz = (unsigned long)(tsc_freq_mhz * 1000);
+
+ /* Extract the GUEST TSC MHZ from BIT[17:0], rest is reserved space */
+ tsc_freq_mhz &= GENMASK_ULL(17, 0);
+
+ snp_tsc_freq_khz = SNP_SCALE_TSC_FREQ(tsc_freq_mhz * 1000, secrets->tsc_factor);
x86_platform.calibrate_cpu = securetsc_get_tsc_khz;
x86_platform.calibrate_tsc = securetsc_get_tsc_khz;
+
+ early_memunmap(mem, PAGE_SIZE);
}
diff --git a/arch/x86/coco/sev/vc-handle.c b/arch/x86/coco/sev/vc-handle.c
index 0989d98da130..faf1fce89ed4 100644
--- a/arch/x86/coco/sev/vc-handle.c
+++ b/arch/x86/coco/sev/vc-handle.c
@@ -17,6 +17,7 @@
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/psp-sev.h>
+#include <linux/efi.h>
#include <uapi/linux/sev-guest.h>
#include <asm/init.h>
@@ -178,9 +179,15 @@ static enum es_result __vc_decode_kern_insn(struct es_em_ctxt *ctxt)
return ES_OK;
}
+/*
+ * User instruction decoding is also required for the EFI runtime. Even though
+ * the EFI runtime is running in kernel mode, it uses special EFI virtual
+ * address mappings that require the use of efi_mm to properly address and
+ * decode.
+ */
static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
{
- if (user_mode(ctxt->regs))
+ if (user_mode(ctxt->regs) || mm_is_efi(current->active_mm))
return __vc_decode_user_insn(ctxt);
else
return __vc_decode_kern_insn(ctxt);
generated by cgit (git 2.34.1) at 2025-07-31 10:16:02 +0000