mirror of
https://github.com/torvalds/linux.git
synced 2024-09-20 15:03:04 +00:00
* Mitigate RFDS vulnerability
-----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmXvZgoACgkQaDWVMHDJ krC2Eg//aZKBp97/DSzRqXKDwJzVUr0sGJ9cii0gVT1sI+1U6ZZCh/roVH4xOT5/ HqtOOnQ+X0mwUx2VG3Yv2VPI7VW68sJ3/y9D8R4tnMEsyQ4CmDw96Pre3NyKr/Av jmW7SK94fOkpNFJOMk3zpk7GtRUlCsVkS1P61dOmMYduguhel/V20rWlx83BgnAY Rf/c3rBjqe8Ri3rzBP5icY/d6OgwoafuhME31DD/j6oKOh+EoQBvA4urj46yMTMX /mrK7hCm/wqwuOOvgGbo7sfZNBLCYy3SZ3EyF4beDERhPF1DaSvCwOULpGVJroqu SelFsKXAtEbYrDgsan+MYlx3bQv43q7PbHska1gjkH91plO4nAsssPr5VsusUKmT sq8jyBaauZb40oLOSgooL4RqAHrfs8q5695Ouwh/DB/XovMezUI1N/BkpGFmqpJI o2xH9P5q520pkB8pFhN9TbRuFSGe/dbWC24QTq1DUajo3M3RwcwX6ua9hoAKLtDF pCV5DNcVcXHD3Cxp0M5dQ5JEAiCnW+ZpUWgxPQamGDNW5PEvjDmFwql2uWw/qOuW lkheOIffq8ejUBQFbN8VXfIzzeeKQNFiIcViaqGITjIwhqdHAzVi28OuIGwtdh3g ywLzSC8yvyzgKrNBgtFMr3ucKN0FoPxpBro253xt2H7w8srXW64= =5V9t -----END PGP SIGNATURE----- Merge tag 'rfds-for-linus-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 RFDS mitigation from Dave Hansen: "RFDS is a CPU vulnerability that may allow a malicious userspace to infer stale register values from kernel space. Kernel registers can have all kinds of secrets in them so the mitigation is basically to wait until the kernel is about to return to userspace and has user values in the registers. At that point there is little chance of kernel secrets ending up in the registers and the microarchitectural state can be cleared. This leverages some recent robustness fixes for the existing MDS vulnerability. Both MDS and RFDS use the VERW instruction for mitigation" * tag 'rfds-for-linus-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: KVM/x86: Export RFDS_NO and RFDS_CLEAR to guests x86/rfds: Mitigate Register File Data Sampling (RFDS) Documentation/hw-vuln: Add documentation for RFDS x86/mmio: Disable KVM mitigation when X86_FEATURE_CLEAR_CPU_BUF is set
This commit is contained in:
Linus Torvalds
commit
0e33cf955f
|
|
@ -516,6 +516,7 @@ What: /sys/devices/system/cpu/vulnerabilities
|
|||
/sys/devices/system/cpu/vulnerabilities/mds
|
||||
/sys/devices/system/cpu/vulnerabilities/meltdown
|
||||
/sys/devices/system/cpu/vulnerabilities/mmio_stale_data
|
||||
/sys/devices/system/cpu/vulnerabilities/reg_file_data_sampling
|
||||
/sys/devices/system/cpu/vulnerabilities/retbleed
|
||||
/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
|
||||
/sys/devices/system/cpu/vulnerabilities/spectre_v1
|
||||
|
|
|
|||
|
|
@ -21,3 +21,4 @@ are configurable at compile, boot or run time.
|
|||
cross-thread-rsb
|
||||
srso
|
||||
gather_data_sampling
|
||||
reg-file-data-sampling
|
||||
|
|
|
|||
104
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
Normal file
104
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
Normal file
|
|
@ -0,0 +1,104 @@
|
|||
==================================
|
||||
Register File Data Sampling (RFDS)
|
||||
==================================
|
||||
|
||||
Register File Data Sampling (RFDS) is a microarchitectural vulnerability that
|
||||
only affects Intel Atom parts(also branded as E-cores). RFDS may allow
|
||||
a malicious actor to infer data values previously used in floating point
|
||||
registers, vector registers, or integer registers. RFDS does not provide the
|
||||
ability to choose which data is inferred. CVE-2023-28746 is assigned to RFDS.
|
||||
|
||||
Affected Processors
|
||||
===================
|
||||
Below is the list of affected Intel processors [#f1]_:
|
||||
|
||||
=================== ============
|
||||
Common name Family_Model
|
||||
=================== ============
|
||||
ATOM_GOLDMONT 06_5CH
|
||||
ATOM_GOLDMONT_D 06_5FH
|
||||
ATOM_GOLDMONT_PLUS 06_7AH
|
||||
ATOM_TREMONT_D 06_86H
|
||||
ATOM_TREMONT 06_96H
|
||||
ALDERLAKE 06_97H
|
||||
ALDERLAKE_L 06_9AH
|
||||
ATOM_TREMONT_L 06_9CH
|
||||
RAPTORLAKE 06_B7H
|
||||
RAPTORLAKE_P 06_BAH
|
||||
ATOM_GRACEMONT 06_BEH
|
||||
RAPTORLAKE_S 06_BFH
|
||||
=================== ============
|
||||
|
||||
As an exception to this table, Intel Xeon E family parts ALDERLAKE(06_97H) and
|
||||
RAPTORLAKE(06_B7H) codenamed Catlow are not affected. They are reported as
|
||||
vulnerable in Linux because they share the same family/model with an affected
|
||||
part. Unlike their affected counterparts, they do not enumerate RFDS_CLEAR or
|
||||
CPUID.HYBRID. This information could be used to distinguish between the
|
||||
affected and unaffected parts, but it is deemed not worth adding complexity as
|
||||
the reporting is fixed automatically when these parts enumerate RFDS_NO.
|
||||
|
||||
Mitigation
|
||||
==========
|
||||
Intel released a microcode update that enables software to clear sensitive
|
||||
information using the VERW instruction. Like MDS, RFDS deploys the same
|
||||
mitigation strategy to force the CPU to clear the affected buffers before an
|
||||
attacker can extract the secrets. This is achieved by using the otherwise
|
||||
unused and obsolete VERW instruction in combination with a microcode update.
|
||||
The microcode clears the affected CPU buffers when the VERW instruction is
|
||||
executed.
|
||||
|
||||
Mitigation points
|
||||
-----------------
|
||||
VERW is executed by the kernel before returning to user space, and by KVM
|
||||
before VMentry. None of the affected cores support SMT, so VERW is not required
|
||||
at C-state transitions.
|
||||
|
||||
New bits in IA32_ARCH_CAPABILITIES
|
||||
----------------------------------
|
||||
Newer processors and microcode update on existing affected processors added new
|
||||
bits to IA32_ARCH_CAPABILITIES MSR. These bits can be used to enumerate
|
||||
vulnerability and mitigation capability:
|
||||
|
||||
- Bit 27 - RFDS_NO - When set, processor is not affected by RFDS.
|
||||
- Bit 28 - RFDS_CLEAR - When set, processor is affected by RFDS, and has the
|
||||
microcode that clears the affected buffers on VERW execution.
|
||||
|
||||
Mitigation control on the kernel command line
|
||||
---------------------------------------------
|
||||
The kernel command line allows to control RFDS mitigation at boot time with the
|
||||
parameter "reg_file_data_sampling=". The valid arguments are:
|
||||
|
||||
========== =================================================================
|
||||
on If the CPU is vulnerable, enable mitigation; CPU buffer clearing
|
||||
on exit to userspace and before entering a VM.
|
||||
off Disables mitigation.
|
||||
========== =================================================================
|
||||
|
||||
Mitigation default is selected by CONFIG_MITIGATION_RFDS.
|
||||
|
||||
Mitigation status information
|
||||
-----------------------------
|
||||
The Linux kernel provides a sysfs interface to enumerate the current
|
||||
vulnerability status of the system: whether the system is vulnerable, and
|
||||
which mitigations are active. The relevant sysfs file is:
|
||||
|
||||
/sys/devices/system/cpu/vulnerabilities/reg_file_data_sampling
|
||||
|
||||
The possible values in this file are:
|
||||
|
||||
.. list-table::
|
||||
|
||||
* - 'Not affected'
|
||||
- The processor is not vulnerable
|
||||
* - 'Vulnerable'
|
||||
- The processor is vulnerable, but no mitigation enabled
|
||||
* - 'Vulnerable: No microcode'
|
||||
- The processor is vulnerable but microcode is not updated.
|
||||
* - 'Mitigation: Clear Register File'
|
||||
- The processor is vulnerable and the CPU buffer clearing mitigation is
|
||||
enabled.
|
||||
|
||||
References
|
||||
----------
|
||||
.. [#f1] Affected Processors
|
||||
https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/processors-affected-consolidated-product-cpu-model.html
|
||||
|
|
@ -1136,6 +1136,26 @@
|
|||
The filter can be disabled or changed to another
|
||||
driver later using sysfs.
|
||||
|
||||
reg_file_data_sampling=
|
||||
[X86] Controls mitigation for Register File Data
|
||||
Sampling (RFDS) vulnerability. RFDS is a CPU
|
||||
vulnerability which may allow userspace to infer
|
||||
kernel data values previously stored in floating point
|
||||
registers, vector registers, or integer registers.
|
||||
RFDS only affects Intel Atom processors.
|
||||
|
||||
on: Turns ON the mitigation.
|
||||
off: Turns OFF the mitigation.
|
||||
|
||||
This parameter overrides the compile time default set
|
||||
by CONFIG_MITIGATION_RFDS. Mitigation cannot be
|
||||
disabled when other VERW based mitigations (like MDS)
|
||||
are enabled. In order to disable RFDS mitigation all
|
||||
VERW based mitigations need to be disabled.
|
||||
|
||||
For details see:
|
||||
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
|
||||
|
||||
driver_async_probe= [KNL]
|
||||
List of driver names to be probed asynchronously. *
|
||||
matches with all driver names. If * is specified, the
|
||||
|
|
@ -3394,6 +3414,7 @@
|
|||
nospectre_bhb [ARM64]
|
||||
nospectre_v1 [X86,PPC]
|
||||
nospectre_v2 [X86,PPC,S390,ARM64]
|
||||
reg_file_data_sampling=off [X86]
|
||||
retbleed=off [X86]
|
||||
spec_rstack_overflow=off [X86]
|
||||
spec_store_bypass_disable=off [X86,PPC]
|
||||
|
|
|
|||
|
|
@ -2623,6 +2623,17 @@ config MITIGATION_GDS_FORCE
|
|||
|
||||
If in doubt, say N.
|
||||
|
||||
config MITIGATION_RFDS
|
||||
bool "RFDS Mitigation"
|
||||
depends on CPU_SUP_INTEL
|
||||
default y
|
||||
help
|
||||
Enable mitigation for Register File Data Sampling (RFDS) by default.
|
||||
RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
|
||||
allows unprivileged speculative access to stale data previously
|
||||
stored in floating point, vector and integer registers.
|
||||
See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
|
||||
|
||||
endif
|
||||
|
||||
config ARCH_HAS_ADD_PAGES
|
||||
|
|
|
|||
|
|
@ -506,4 +506,5 @@
|
|||
/* BUG word 2 */
|
||||
#define X86_BUG_SRSO X86_BUG(1*32 + 0) /* AMD SRSO bug */
|
||||
#define X86_BUG_DIV0 X86_BUG(1*32 + 1) /* AMD DIV0 speculation bug */
|
||||
#define X86_BUG_RFDS X86_BUG(1*32 + 2) /* CPU is vulnerable to Register File Data Sampling */
|
||||
#endif /* _ASM_X86_CPUFEATURES_H */
|
||||
|
|
|
|||
|
|
@ -176,6 +176,14 @@
|
|||
* CPU is not vulnerable to Gather
|
||||
* Data Sampling (GDS).
|
||||
*/
|
||||
#define ARCH_CAP_RFDS_NO BIT(27) /*
|
||||
* Not susceptible to Register
|
||||
* File Data Sampling.
|
||||
*/
|
||||
#define ARCH_CAP_RFDS_CLEAR BIT(28) /*
|
||||
* VERW clears CPU Register
|
||||
* File.
|
||||
*/
|
||||
|
||||
#define ARCH_CAP_XAPIC_DISABLE BIT(21) /*
|
||||
* IA32_XAPIC_DISABLE_STATUS MSR
|
||||
|
|
|
|||
|
|
@ -422,6 +422,13 @@ static void __init mmio_select_mitigation(void)
|
|||
if (boot_cpu_has_bug(X86_BUG_MDS) || (boot_cpu_has_bug(X86_BUG_TAA) &&
|
||||
boot_cpu_has(X86_FEATURE_RTM)))
|
||||
setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
|
||||
|
||||
/*
|
||||
* X86_FEATURE_CLEAR_CPU_BUF could be enabled by other VERW based
|
||||
* mitigations, disable KVM-only mitigation in that case.
|
||||
*/
|
||||
if (boot_cpu_has(X86_FEATURE_CLEAR_CPU_BUF))
|
||||
static_branch_disable(&mmio_stale_data_clear);
|
||||
else
|
||||
static_branch_enable(&mmio_stale_data_clear);
|
||||
|
||||
|
|
@ -473,6 +480,57 @@ static int __init mmio_stale_data_parse_cmdline(char *str)
|
|||
}
|
||||
early_param("mmio_stale_data", mmio_stale_data_parse_cmdline);
|
||||
|
||||
#undef pr_fmt
|
||||
#define pr_fmt(fmt) "Register File Data Sampling: " fmt
|
||||
|
||||
enum rfds_mitigations {
|
||||
RFDS_MITIGATION_OFF,
|
||||
RFDS_MITIGATION_VERW,
|
||||
RFDS_MITIGATION_UCODE_NEEDED,
|
||||
};
|
||||
|
||||
/* Default mitigation for Register File Data Sampling */
|
||||
static enum rfds_mitigations rfds_mitigation __ro_after_init =
|
||||
IS_ENABLED(CONFIG_MITIGATION_RFDS) ? RFDS_MITIGATION_VERW : RFDS_MITIGATION_OFF;
|
||||
|
||||
static const char * const rfds_strings[] = {
|
||||
[RFDS_MITIGATION_OFF] = "Vulnerable",
|
||||
[RFDS_MITIGATION_VERW] = "Mitigation: Clear Register File",
|
||||
[RFDS_MITIGATION_UCODE_NEEDED] = "Vulnerable: No microcode",
|
||||
};
|
||||
|
||||
static void __init rfds_select_mitigation(void)
|
||||
{
|
||||
if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) {
|
||||
rfds_mitigation = RFDS_MITIGATION_OFF;
|
||||
return;
|
||||
}
|
||||
if (rfds_mitigation == RFDS_MITIGATION_OFF)
|
||||
return;
|
||||
|
||||
if (x86_read_arch_cap_msr() & ARCH_CAP_RFDS_CLEAR)
|
||||
setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF);
|
||||
else
|
||||
rfds_mitigation = RFDS_MITIGATION_UCODE_NEEDED;
|
||||
}
|
||||
|
||||
static __init int rfds_parse_cmdline(char *str)
|
||||
{
|
||||
if (!str)
|
||||
return -EINVAL;
|
||||
|
||||
if (!boot_cpu_has_bug(X86_BUG_RFDS))
|
||||
return 0;
|
||||
|
||||
if (!strcmp(str, "off"))
|
||||
rfds_mitigation = RFDS_MITIGATION_OFF;
|
||||
else if (!strcmp(str, "on"))
|
||||
rfds_mitigation = RFDS_MITIGATION_VERW;
|
||||
|
||||
return 0;
|
||||
}
|
||||
early_param("reg_file_data_sampling", rfds_parse_cmdline);
|
||||
|
||||
#undef pr_fmt
|
||||
#define pr_fmt(fmt) "" fmt
|
||||
|
||||
|
|
@ -498,11 +556,19 @@ static void __init md_clear_update_mitigation(void)
|
|||
taa_mitigation = TAA_MITIGATION_VERW;
|
||||
taa_select_mitigation();
|
||||
}
|
||||
if (mmio_mitigation == MMIO_MITIGATION_OFF &&
|
||||
boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) {
|
||||
/*
|
||||
* MMIO_MITIGATION_OFF is not checked here so that mmio_stale_data_clear
|
||||
* gets updated correctly as per X86_FEATURE_CLEAR_CPU_BUF state.
|
||||
*/
|
||||
if (boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) {
|
||||
mmio_mitigation = MMIO_MITIGATION_VERW;
|
||||
mmio_select_mitigation();
|
||||
}
|
||||
if (rfds_mitigation == RFDS_MITIGATION_OFF &&
|
||||
boot_cpu_has_bug(X86_BUG_RFDS)) {
|
||||
rfds_mitigation = RFDS_MITIGATION_VERW;
|
||||
rfds_select_mitigation();
|
||||
}
|
||||
out:
|
||||
if (boot_cpu_has_bug(X86_BUG_MDS))
|
||||
pr_info("MDS: %s\n", mds_strings[mds_mitigation]);
|
||||
|
|
@ -512,6 +578,8 @@ out:
|
|||
pr_info("MMIO Stale Data: %s\n", mmio_strings[mmio_mitigation]);
|
||||
else if (boot_cpu_has_bug(X86_BUG_MMIO_UNKNOWN))
|
||||
pr_info("MMIO Stale Data: Unknown: No mitigations\n");
|
||||
if (boot_cpu_has_bug(X86_BUG_RFDS))
|
||||
pr_info("Register File Data Sampling: %s\n", rfds_strings[rfds_mitigation]);
|
||||
}
|
||||
|
||||
static void __init md_clear_select_mitigation(void)
|
||||
|
|
@ -519,11 +587,12 @@ static void __init md_clear_select_mitigation(void)
|
|||
mds_select_mitigation();
|
||||
taa_select_mitigation();
|
||||
mmio_select_mitigation();
|
||||
rfds_select_mitigation();
|
||||
|
||||
/*
|
||||
* As MDS, TAA and MMIO Stale Data mitigations are inter-related, update
|
||||
* and print their mitigation after MDS, TAA and MMIO Stale Data
|
||||
* mitigation selection is done.
|
||||
* As these mitigations are inter-related and rely on VERW instruction
|
||||
* to clear the microarchitural buffers, update and print their status
|
||||
* after mitigation selection is done for each of these vulnerabilities.
|
||||
*/
|
||||
md_clear_update_mitigation();
|
||||
}
|
||||
|
|
@ -2613,6 +2682,11 @@ static ssize_t mmio_stale_data_show_state(char *buf)
|
|||
sched_smt_active() ? "vulnerable" : "disabled");
|
||||
}
|
||||
|
||||
static ssize_t rfds_show_state(char *buf)
|
||||
{
|
||||
return sysfs_emit(buf, "%s\n", rfds_strings[rfds_mitigation]);
|
||||
}
|
||||
|
||||
static char *stibp_state(void)
|
||||
{
|
||||
if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) &&
|
||||
|
|
@ -2772,6 +2846,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
|
|||
case X86_BUG_GDS:
|
||||
return gds_show_state(buf);
|
||||
|
||||
case X86_BUG_RFDS:
|
||||
return rfds_show_state(buf);
|
||||
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
|
@ -2846,6 +2923,11 @@ ssize_t cpu_show_gds(struct device *dev, struct device_attribute *attr, char *bu
|
|||
{
|
||||
return cpu_show_common(dev, attr, buf, X86_BUG_GDS);
|
||||
}
|
||||
|
||||
ssize_t cpu_show_reg_file_data_sampling(struct device *dev, struct device_attribute *attr, char *buf)
|
||||
{
|
||||
return cpu_show_common(dev, attr, buf, X86_BUG_RFDS);
|
||||
}
|
||||
#endif
|
||||
|
||||
void __warn_thunk(void)
|
||||
|
|
|
|||
|
|
@ -1224,6 +1224,8 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
|
|||
#define SRSO BIT(5)
|
||||
/* CPU is affected by GDS */
|
||||
#define GDS BIT(6)
|
||||
/* CPU is affected by Register File Data Sampling */
|
||||
#define RFDS BIT(7)
|
||||
|
||||
static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
|
||||
VULNBL_INTEL_STEPPINGS(IVYBRIDGE, X86_STEPPING_ANY, SRBDS),
|
||||
|
|
@ -1251,9 +1253,18 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
|
|||
VULNBL_INTEL_STEPPINGS(TIGERLAKE, X86_STEPPING_ANY, GDS),
|
||||
VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED),
|
||||
VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPING_ANY, MMIO | RETBLEED | GDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPING_ANY, MMIO | MMIO_SBDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS),
|
||||
VULNBL_INTEL_STEPPINGS(ALDERLAKE, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ALDERLAKE_L, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(RAPTORLAKE, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(RAPTORLAKE_P, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(RAPTORLAKE_S, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_GRACEMONT, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO | RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT_D, X86_STEPPING_ANY, RFDS),
|
||||
VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT_PLUS, X86_STEPPING_ANY, RFDS),
|
||||
|
||||
VULNBL_AMD(0x15, RETBLEED),
|
||||
VULNBL_AMD(0x16, RETBLEED),
|
||||
|
|
@ -1287,6 +1298,24 @@ static bool arch_cap_mmio_immune(u64 ia32_cap)
|
|||
ia32_cap & ARCH_CAP_SBDR_SSDP_NO);
|
||||
}
|
||||
|
||||
static bool __init vulnerable_to_rfds(u64 ia32_cap)
|
||||
{
|
||||
/* The "immunity" bit trumps everything else: */
|
||||
if (ia32_cap & ARCH_CAP_RFDS_NO)
|
||||
return false;
|
||||
|
||||
/*
|
||||
* VMMs set ARCH_CAP_RFDS_CLEAR for processors not in the blacklist to
|
||||
* indicate that mitigation is needed because guest is running on a
|
||||
* vulnerable hardware or may migrate to such hardware:
|
||||
*/
|
||||
if (ia32_cap & ARCH_CAP_RFDS_CLEAR)
|
||||
return true;
|
||||
|
||||
/* Only consult the blacklist when there is no enumeration: */
|
||||
return cpu_matches(cpu_vuln_blacklist, RFDS);
|
||||
}
|
||||
|
||||
static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
|
||||
{
|
||||
u64 ia32_cap = x86_read_arch_cap_msr();
|
||||
|
|
@ -1403,6 +1432,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
|
|||
boot_cpu_has(X86_FEATURE_AVX))
|
||||
setup_force_cpu_bug(X86_BUG_GDS);
|
||||
|
||||
if (vulnerable_to_rfds(ia32_cap))
|
||||
setup_force_cpu_bug(X86_BUG_RFDS);
|
||||
|
||||
if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
|
||||
return;
|
||||
|
||||
|
|
|
|||
|
|
@ -1623,7 +1623,8 @@ static bool kvm_is_immutable_feature_msr(u32 msr)
|
|||
ARCH_CAP_SKIP_VMENTRY_L1DFLUSH | ARCH_CAP_SSB_NO | ARCH_CAP_MDS_NO | \
|
||||
ARCH_CAP_PSCHANGE_MC_NO | ARCH_CAP_TSX_CTRL_MSR | ARCH_CAP_TAA_NO | \
|
||||
ARCH_CAP_SBDR_SSDP_NO | ARCH_CAP_FBSDP_NO | ARCH_CAP_PSDP_NO | \
|
||||
ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO | ARCH_CAP_GDS_NO)
|
||||
ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO | ARCH_CAP_GDS_NO | \
|
||||
ARCH_CAP_RFDS_NO | ARCH_CAP_RFDS_CLEAR)
|
||||
|
||||
static u64 kvm_get_arch_capabilities(void)
|
||||
{
|
||||
|
|
@ -1655,6 +1656,8 @@ static u64 kvm_get_arch_capabilities(void)
|
|||
data |= ARCH_CAP_SSB_NO;
|
||||
if (!boot_cpu_has_bug(X86_BUG_MDS))
|
||||
data |= ARCH_CAP_MDS_NO;
|
||||
if (!boot_cpu_has_bug(X86_BUG_RFDS))
|
||||
data |= ARCH_CAP_RFDS_NO;
|
||||
|
||||
if (!boot_cpu_has(X86_FEATURE_RTM)) {
|
||||
/*
|
||||
|
|
|
|||
|
|
@ -588,6 +588,7 @@ CPU_SHOW_VULN_FALLBACK(mmio_stale_data);
|
|||
CPU_SHOW_VULN_FALLBACK(retbleed);
|
||||
CPU_SHOW_VULN_FALLBACK(spec_rstack_overflow);
|
||||
CPU_SHOW_VULN_FALLBACK(gds);
|
||||
CPU_SHOW_VULN_FALLBACK(reg_file_data_sampling);
|
||||
|
||||
static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
|
||||
static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
|
||||
|
|
@ -602,6 +603,7 @@ static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL);
|
|||
static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL);
|
||||
static DEVICE_ATTR(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL);
|
||||
static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL);
|
||||
static DEVICE_ATTR(reg_file_data_sampling, 0444, cpu_show_reg_file_data_sampling, NULL);
|
||||
|
||||
static struct attribute *cpu_root_vulnerabilities_attrs[] = {
|
||||
&dev_attr_meltdown.attr,
|
||||
|
|
@ -617,6 +619,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
|
|||
&dev_attr_retbleed.attr,
|
||||
&dev_attr_spec_rstack_overflow.attr,
|
||||
&dev_attr_gather_data_sampling.attr,
|
||||
&dev_attr_reg_file_data_sampling.attr,
|
||||
NULL
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -75,6 +75,8 @@ extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
|
|||
struct device_attribute *attr, char *buf);
|
||||
extern ssize_t cpu_show_gds(struct device *dev,
|
||||
struct device_attribute *attr, char *buf);
|
||||
extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev,
|
||||
struct device_attribute *attr, char *buf);
|
||||
|
||||
extern __printf(4, 5)
|
||||
struct device *cpu_device_create(struct device *parent, void *drvdata,
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user