Merge/sound upstream 20230825

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -513,17 +513,18 @@ Description:	information about CPUs heterogeneity.
 		cpu_capacity: capacity of cpuX.
 
 What:		/sys/devices/system/cpu/vulnerabilities
+		/sys/devices/system/cpu/vulnerabilities/gather_data_sampling
+		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
+		/sys/devices/system/cpu/vulnerabilities/l1tf
+		/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/retbleed
+		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
 		/sys/devices/system/cpu/vulnerabilities/spectre_v1
 		/sys/devices/system/cpu/vulnerabilities/spectre_v2
-		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
-		/sys/devices/system/cpu/vulnerabilities/l1tf
-		/sys/devices/system/cpu/vulnerabilities/mds
 		/sys/devices/system/cpu/vulnerabilities/srbds
 		/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
-		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
-		/sys/devices/system/cpu/vulnerabilities/mmio_stale_data
-		/sys/devices/system/cpu/vulnerabilities/retbleed
 Date:		January 2018
 Contact:	Linux kernel mailing list <[email protected]>
 Description:	Information about CPU vulnerabilities

Documentation/ABI/testing/sysfs-platform-hidma

@@ -2,7 +2,7 @@ What:		/sys/devices/platform/hidma-*/chid
 		/sys/devices/platform/QCOM8061:*/chid
 Date:		Dec 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains the ID of the channel within the HIDMA instance.
 		It is used to associate a given HIDMA channel with the

Documentation/ABI/testing/sysfs-platform-hidma-mgmt

@@ -2,7 +2,7 @@ What:		/sys/devices/platform/hidma-mgmt*/chanops/chan*/priority
 		/sys/devices/platform/QCOM8060:*/chanops/chan*/priority
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains either 0 or 1 and indicates if the DMA channel is a
 		low priority (0) or high priority (1) channel.
@@ -11,7 +11,7 @@ What:		/sys/devices/platform/hidma-mgmt*/chanops/chan*/weight
 		/sys/devices/platform/QCOM8060:*/chanops/chan*/weight
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains 0..15 and indicates the weight of the channel among
 		equal priority channels during round robin scheduling.
@@ -20,7 +20,7 @@ What:		/sys/devices/platform/hidma-mgmt*/chreset_timeout_cycles
 		/sys/devices/platform/QCOM8060:*/chreset_timeout_cycles
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains the platform specific cycle value to wait after a
 		reset command is issued. If the value is chosen too short,
@@ -32,7 +32,7 @@ What:		/sys/devices/platform/hidma-mgmt*/dma_channels
 		/sys/devices/platform/QCOM8060:*/dma_channels
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains the number of dma channels supported by one instance
 		of HIDMA hardware. The value may change from chip to chip.
@@ -41,23 +41,23 @@ What:		/sys/devices/platform/hidma-mgmt*/hw_version_major
 		/sys/devices/platform/QCOM8060:*/hw_version_major
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Version number major for the hardware.
 
 What:		/sys/devices/platform/hidma-mgmt*/hw_version_minor
 		/sys/devices/platform/QCOM8060:*/hw_version_minor
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Version number minor for the hardware.
 
 What:		/sys/devices/platform/hidma-mgmt*/max_rd_xactions
 		/sys/devices/platform/QCOM8060:*/max_rd_xactions
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains a value between 0 and 31. Maximum number of
 		read transactions that can be issued back to back.
@@ -69,7 +69,7 @@ What:		/sys/devices/platform/hidma-mgmt*/max_read_request
 		/sys/devices/platform/QCOM8060:*/max_read_request
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Size of each read request. The value needs to be a power
 		of two and can be between 128 and 1024.
@@ -78,7 +78,7 @@ What:		/sys/devices/platform/hidma-mgmt*/max_wr_xactions
 		/sys/devices/platform/QCOM8060:*/max_wr_xactions
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Contains a value between 0 and 31. Maximum number of
 		write transactions that can be issued back to back.
@@ -91,7 +91,7 @@ What:		/sys/devices/platform/hidma-mgmt*/max_write_request
 		/sys/devices/platform/QCOM8060:*/max_write_request
 Date:		Nov 2015
 KernelVersion:	4.4
-Contact:	"Sinan Kaya <okaya@codeaurora.org>"
+Contact:	"Sinan Kaya <okaya@kernel.org>"
 Description:
 		Size of each write request. The value needs to be a power
 		of two and can be between 128 and 1024.

Documentation/admin-guide/hw-vuln/gather_data_sampling.rst

@@ -0,0 +1,109 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+GDS - Gather Data Sampling
+==========================
+
+Gather Data Sampling is a hardware vulnerability which allows unprivileged
+speculative access to data which was previously stored in vector registers.
+
+Problem
+-------
+When a gather instruction performs loads from memory, different data elements
+are merged into the destination vector register. However, when a gather
+instruction that is transiently executed encounters a fault, stale data from
+architectural or internal vector registers may get transiently forwarded to the
+destination vector register instead. This will allow a malicious attacker to
+infer stale data using typical side channel techniques like cache timing
+attacks. GDS is a purely sampling-based attack.
+
+The attacker uses gather instructions to infer the stale vector register data.
+The victim does not need to do anything special other than use the vector
+registers. The victim does not need to use gather instructions to be
+vulnerable.
+
+Because the buffers are shared between Hyper-Threads cross Hyper-Thread attacks
+are possible.
+
+Attack scenarios
+----------------
+Without mitigation, GDS can infer stale data across virtually all
+permission boundaries:
+
+	Non-enclaves can infer SGX enclave data
+	Userspace can infer kernel data
+	Guests can infer data from hosts
+	Guest can infer guest from other guests
+	Users can infer data from other users
+
+Because of this, it is important to ensure that the mitigation stays enabled in
+lower-privilege contexts like guests and when running outside SGX enclaves.
+
+The hardware enforces the mitigation for SGX. Likewise, VMMs should  ensure
+that guests are not allowed to disable the GDS mitigation. If a host erred and
+allowed this, a guest could theoretically disable GDS mitigation, mount an
+attack, and re-enable it.
+
+Mitigation mechanism
+--------------------
+This issue is mitigated in microcode. The microcode defines the following new
+bits:
+
+ ================================   ===   ============================
+ IA32_ARCH_CAPABILITIES[GDS_CTRL]   R/O   Enumerates GDS vulnerability
+                                          and mitigation support.
+ IA32_ARCH_CAPABILITIES[GDS_NO]     R/O   Processor is not vulnerable.
+ IA32_MCU_OPT_CTRL[GDS_MITG_DIS]    R/W   Disables the mitigation
+                                          0 by default.
+ IA32_MCU_OPT_CTRL[GDS_MITG_LOCK]   R/W   Locks GDS_MITG_DIS=0. Writes
+                                          to GDS_MITG_DIS are ignored
+                                          Can't be cleared once set.
+ ================================   ===   ============================
+
+GDS can also be mitigated on systems that don't have updated microcode by
+disabling AVX. This can be done by setting gather_data_sampling="force" or
+"clearcpuid=avx" on the kernel command-line.
+
+If used, these options will disable AVX use by turning off XSAVE YMM support.
+However, the processor will still enumerate AVX support.  Userspace that
+does not follow proper AVX enumeration to check both AVX *and* XSAVE YMM
+support will break.
+
+Mitigation control on the kernel command line
+---------------------------------------------
+The mitigation can be disabled by setting "gather_data_sampling=off" or
+"mitigations=off" on the kernel command line. Not specifying either will default
+to the mitigation being enabled. Specifying "gather_data_sampling=force" will
+use the microcode mitigation when available or disable AVX on affected systems
+where the microcode hasn't been updated to include the mitigation.
+
+GDS System Information
+------------------------
+The kernel provides vulnerability status information through sysfs. For
+GDS this can be accessed by the following sysfs file:
+
+/sys/devices/system/cpu/vulnerabilities/gather_data_sampling
+
+The possible values contained in this file are:
+
+ ============================== =============================================
+ Not affected                   Processor not vulnerable.
+ Vulnerable                     Processor vulnerable and mitigation disabled.
+ Vulnerable: No microcode       Processor vulnerable and microcode is missing
+                                mitigation.
+ Mitigation: AVX disabled,
+ no microcode                   Processor is vulnerable and microcode is missing
+                                mitigation. AVX disabled as mitigation.
+ Mitigation: Microcode          Processor is vulnerable and mitigation is in
+                                effect.
+ Mitigation: Microcode (locked) Processor is vulnerable and mitigation is in
+                                effect and cannot be disabled.
+ Unknown: Dependent on
+ hypervisor status              Running on a virtual guest processor that is
+                                affected but with no way to know if host
+                                processor is mitigated or vulnerable.
+ ============================== =============================================
+
+GDS Default mitigation
+----------------------
+The updated microcode will enable the mitigation by default. The kernel's
+default action is to leave the mitigation enabled.

Documentation/admin-guide/hw-vuln/index.rst

@@ -13,9 +13,11 @@ are configurable at compile, boot or run time.
    l1tf
    mds
    tsx_async_abort
-   multihit.rst
-   special-register-buffer-data-sampling.rst
-   core-scheduling.rst
-   l1d_flush.rst
-   processor_mmio_stale_data.rst
-   cross-thread-rsb.rst
+   multihit
+   special-register-buffer-data-sampling
+   core-scheduling
+   l1d_flush
+   processor_mmio_stale_data
+   cross-thread-rsb
+   srso
+   gather_data_sampling