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-rw-r--r--Documentation/admin-guide/hw-vuln/attack_vector_controls.rst2
-rw-r--r--Makefile2
-rw-r--r--arch/x86/boot/startup/sev-shared.c1
-rw-r--r--arch/x86/coco/sev/core.c2
-rw-r--r--arch/x86/coco/sev/vc-handle.c31
-rw-r--r--arch/x86/include/asm/cpuid.h8
-rw-r--r--arch/x86/kernel/cpu/bugs.c13
-rw-r--r--arch/x86/kernel/fpu/xstate.c19
-rw-r--r--drivers/virt/coco/sev-guest/sev-guest.c27
9 files changed, 54 insertions, 51 deletions
diff --git a/Documentation/admin-guide/hw-vuln/attack_vector_controls.rst b/Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
index b4de16f5ec44..6dd0800146f6 100644
--- a/Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
+++ b/Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
@@ -214,7 +214,7 @@ Spectre_v1 X
Spectre_v2 X X
Spectre_v2_user X X * (Note 1)
SRBDS X X X X
-SRSO X X
+SRSO X X X X
SSB (Note 4)
TAA X X X X * (Note 2)
TSA X X X X
diff --git a/Makefile b/Makefile
index 6bfe776bf3c5..d1adb78c3596 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
VERSION = 6
PATCHLEVEL = 17
SUBLEVEL = 0
-EXTRAVERSION = -rc1
+EXTRAVERSION = -rc2
NAME = Baby Opossum Posse
# *DOCUMENTATION*
diff --git a/arch/x86/boot/startup/sev-shared.c b/arch/x86/boot/startup/sev-shared.c
index ac7dfd21ddd4..a34cd19796f9 100644
--- a/arch/x86/boot/startup/sev-shared.c
+++ b/arch/x86/boot/startup/sev-shared.c
@@ -785,6 +785,7 @@ static void __head svsm_pval_4k_page(unsigned long paddr, bool validate)
pc->entry[0].page_size = RMP_PG_SIZE_4K;
pc->entry[0].action = validate;
pc->entry[0].ignore_cf = 0;
+ pc->entry[0].rsvd = 0;
pc->entry[0].pfn = paddr >> PAGE_SHIFT;
/* Protocol 0, Call ID 1 */
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 400a6ab75d45..14ef5908fb27 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -227,6 +227,7 @@ static u64 svsm_build_ca_from_pfn_range(u64 pfn, u64 pfn_end, bool action,
pe->page_size = RMP_PG_SIZE_4K;
pe->action = action;
pe->ignore_cf = 0;
+ pe->rsvd = 0;
pe->pfn = pfn;
pe++;
@@ -257,6 +258,7 @@ static int svsm_build_ca_from_psc_desc(struct snp_psc_desc *desc, unsigned int d
pe->page_size = e->pagesize ? RMP_PG_SIZE_2M : RMP_PG_SIZE_4K;
pe->action = e->operation == SNP_PAGE_STATE_PRIVATE;
pe->ignore_cf = 0;
+ pe->rsvd = 0;
pe->pfn = e->gfn;
pe++;
diff --git a/arch/x86/coco/sev/vc-handle.c b/arch/x86/coco/sev/vc-handle.c
index faf1fce89ed4..c3b4acbde0d8 100644
--- a/arch/x86/coco/sev/vc-handle.c
+++ b/arch/x86/coco/sev/vc-handle.c
@@ -371,29 +371,30 @@ static enum es_result __vc_handle_msr_caa(struct pt_regs *regs, bool write)
* executing with Secure TSC enabled, so special handling is required for
* accesses of MSR_IA32_TSC and MSR_AMD64_GUEST_TSC_FREQ.
*/
-static enum es_result __vc_handle_secure_tsc_msrs(struct pt_regs *regs, bool write)
+static enum es_result __vc_handle_secure_tsc_msrs(struct es_em_ctxt *ctxt, bool write)
{
+ struct pt_regs *regs = ctxt->regs;
u64 tsc;
/*
- * GUEST_TSC_FREQ should not be intercepted when Secure TSC is enabled.
- * Terminate the SNP guest when the interception is enabled.
+ * Writing to MSR_IA32_TSC can cause subsequent reads of the TSC to
+ * return undefined values, and GUEST_TSC_FREQ is read-only. Generate
+ * a #GP on all writes.
*/
- if (regs->cx == MSR_AMD64_GUEST_TSC_FREQ)
- return ES_VMM_ERROR;
+ if (write) {
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+ }
/*
- * Writes: Writing to MSR_IA32_TSC can cause subsequent reads of the TSC
- * to return undefined values, so ignore all writes.
- *
- * Reads: Reads of MSR_IA32_TSC should return the current TSC value, use
- * the value returned by rdtsc_ordered().
+ * GUEST_TSC_FREQ read should not be intercepted when Secure TSC is
+ * enabled. Terminate the guest if a read is attempted.
*/
- if (write) {
- WARN_ONCE(1, "TSC MSR writes are verboten!\n");
- return ES_OK;
- }
+ if (regs->cx == MSR_AMD64_GUEST_TSC_FREQ)
+ return ES_VMM_ERROR;
+ /* Reads of MSR_IA32_TSC should return the current TSC value. */
tsc = rdtsc_ordered();
regs->ax = lower_32_bits(tsc);
regs->dx = upper_32_bits(tsc);
@@ -416,7 +417,7 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
case MSR_IA32_TSC:
case MSR_AMD64_GUEST_TSC_FREQ:
if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
- return __vc_handle_secure_tsc_msrs(regs, write);
+ return __vc_handle_secure_tsc_msrs(ctxt, write);
break;
default:
break;
diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h
deleted file mode 100644
index d5749b25fa10..000000000000
--- a/arch/x86/include/asm/cpuid.h
+++ /dev/null
@@ -1,8 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-#ifndef _ASM_X86_CPUID_H
-#define _ASM_X86_CPUID_H
-
-#include <asm/cpuid/api.h>
-
-#endif /* _ASM_X86_CPUID_H */
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index b74bf937cd9f..2186a771b9fc 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -386,7 +386,6 @@ static bool __init should_mitigate_vuln(unsigned int bug)
case X86_BUG_SPECTRE_V2:
case X86_BUG_RETBLEED:
- case X86_BUG_SRSO:
case X86_BUG_L1TF:
case X86_BUG_ITS:
return cpu_attack_vector_mitigated(CPU_MITIGATE_USER_KERNEL) ||
@@ -3184,8 +3183,18 @@ static void __init srso_select_mitigation(void)
}
if (srso_mitigation == SRSO_MITIGATION_AUTO) {
- if (should_mitigate_vuln(X86_BUG_SRSO)) {
+ /*
+ * Use safe-RET if user->kernel or guest->host protection is
+ * required. Otherwise the 'microcode' mitigation is sufficient
+ * to protect the user->user and guest->guest vectors.
+ */
+ if (cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_HOST) ||
+ (cpu_attack_vector_mitigated(CPU_MITIGATE_USER_KERNEL) &&
+ !boot_cpu_has(X86_FEATURE_SRSO_USER_KERNEL_NO))) {
srso_mitigation = SRSO_MITIGATION_SAFE_RET;
+ } else if (cpu_attack_vector_mitigated(CPU_MITIGATE_USER_USER) ||
+ cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_GUEST)) {
+ srso_mitigation = SRSO_MITIGATION_MICROCODE;
} else {
srso_mitigation = SRSO_MITIGATION_NONE;
return;
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 12ed75c1b567..28e4fd65c9da 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1881,19 +1881,20 @@ long fpu_xstate_prctl(int option, unsigned long arg2)
#ifdef CONFIG_PROC_PID_ARCH_STATUS
/*
* Report the amount of time elapsed in millisecond since last AVX512
- * use in the task.
+ * use in the task. Report -1 if no AVX-512 usage.
*/
static void avx512_status(struct seq_file *m, struct task_struct *task)
{
- unsigned long timestamp = READ_ONCE(x86_task_fpu(task)->avx512_timestamp);
- long delta;
+ unsigned long timestamp;
+ long delta = -1;
- if (!timestamp) {
- /*
- * Report -1 if no AVX512 usage
- */
- delta = -1;
- } else {
+ /* AVX-512 usage is not tracked for kernel threads. Don't report anything. */
+ if (task->flags & (PF_KTHREAD | PF_USER_WORKER))
+ return;
+
+ timestamp = READ_ONCE(x86_task_fpu(task)->avx512_timestamp);
+
+ if (timestamp) {
delta = (long)(jiffies - timestamp);
/*
* Cap to LONG_MAX if time difference > LONG_MAX
diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index d2b3ae7113ab..b01ec99106cd 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -116,13 +116,11 @@ e_free:
static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg)
{
+ struct snp_derived_key_resp *derived_key_resp __free(kfree) = NULL;
struct snp_derived_key_req *derived_key_req __free(kfree) = NULL;
- struct snp_derived_key_resp derived_key_resp = {0};
struct snp_msg_desc *mdesc = snp_dev->msg_desc;
struct snp_guest_req req = {};
int rc, resp_len;
- /* Response data is 64 bytes and max authsize for GCM is 16 bytes. */
- u8 buf[64 + 16];
if (!arg->req_data || !arg->resp_data)
return -EINVAL;
@@ -132,8 +130,9 @@ 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(derived_key_resp.data) + mdesc->ctx->authsize;
- if (sizeof(buf) < resp_len)
+ resp_len = sizeof(derived_key_resp->data) + mdesc->ctx->authsize;
+ derived_key_resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT);
+ if (!derived_key_resp)
return -ENOMEM;
derived_key_req = kzalloc(sizeof(*derived_key_req), GFP_KERNEL_ACCOUNT);
@@ -149,23 +148,21 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
req.vmpck_id = mdesc->vmpck_id;
req.req_buf = derived_key_req;
req.req_sz = sizeof(*derived_key_req);
- req.resp_buf = buf;
+ req.resp_buf = derived_key_resp;
req.resp_sz = resp_len;
req.exit_code = SVM_VMGEXIT_GUEST_REQUEST;
rc = snp_send_guest_request(mdesc, &req);
arg->exitinfo2 = req.exitinfo2;
- if (rc)
- return rc;
-
- 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;
+ if (!rc) {
+ if (copy_to_user((void __user *)arg->resp_data, derived_key_resp,
+ sizeof(derived_key_resp->data)))
+ rc = -EFAULT;
+ }
/* The response buffer contains the sensitive data, explicitly clear it. */
- memzero_explicit(buf, sizeof(buf));
- memzero_explicit(&derived_key_resp, sizeof(derived_key_resp));
+ memzero_explicit(derived_key_resp, sizeof(*derived_key_resp));
+
return rc;
}
generated by cgit (git 2.34.1) at 2025-08-18 07:17:01 +0000