diff options
author | Mark Brown <broonie@kernel.org> | 2024-03-18 17:30:46 +0000 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2024-03-18 17:30:46 +0000 |
commit | 5bd249aec71d75f0088357e4aba27fde0610f823 (patch) | |
tree | ed63b21b48b711430492734564775758a39eb94c /Documentation | |
parent | 7397175cb7b48f7a3fc699083aa46f1234904c7e (diff) | |
parent | e8f897f4afef0031fe618a8e94127a0934896aba (diff) |
spi: Merge up v6.8 release
An i.MX fix depends on other fixes that were sent to v6.8.
Diffstat (limited to 'Documentation')
36 files changed, 571 insertions, 89 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-net-statistics b/Documentation/ABI/testing/sysfs-class-net-statistics index 55db27815361..53e508c6936a 100644 --- a/Documentation/ABI/testing/sysfs-class-net-statistics +++ b/Documentation/ABI/testing/sysfs-class-net-statistics @@ -1,4 +1,4 @@ -What: /sys/class/<iface>/statistics/collisions +What: /sys/class/net/<iface>/statistics/collisions Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -6,7 +6,7 @@ Description: Indicates the number of collisions seen by this network device. This value might not be relevant with all MAC layers. -What: /sys/class/<iface>/statistics/multicast +What: /sys/class/net/<iface>/statistics/multicast Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -14,7 +14,7 @@ Description: Indicates the number of multicast packets received by this network device. -What: /sys/class/<iface>/statistics/rx_bytes +What: /sys/class/net/<iface>/statistics/rx_bytes Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -23,7 +23,7 @@ Description: See the network driver for the exact meaning of when this value is incremented. -What: /sys/class/<iface>/statistics/rx_compressed +What: /sys/class/net/<iface>/statistics/rx_compressed Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -32,7 +32,7 @@ Description: network device. This value might only be relevant for interfaces that support packet compression (e.g: PPP). -What: /sys/class/<iface>/statistics/rx_crc_errors +What: /sys/class/net/<iface>/statistics/rx_crc_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -41,7 +41,7 @@ Description: by this network device. Note that the specific meaning might depend on the MAC layer used by the interface. -What: /sys/class/<iface>/statistics/rx_dropped +What: /sys/class/net/<iface>/statistics/rx_dropped Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -51,7 +51,7 @@ Description: packet processing. See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_errors +What: /sys/class/net/<iface>/statistics/rx_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -59,7 +59,7 @@ Description: Indicates the number of receive errors on this network device. See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_fifo_errors +What: /sys/class/net/<iface>/statistics/rx_fifo_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -68,7 +68,7 @@ Description: network device. See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_frame_errors +What: /sys/class/net/<iface>/statistics/rx_frame_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -78,7 +78,7 @@ Description: on the MAC layer protocol used. See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_length_errors +What: /sys/class/net/<iface>/statistics/rx_length_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -87,7 +87,7 @@ Description: error, oversized or undersized. See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_missed_errors +What: /sys/class/net/<iface>/statistics/rx_missed_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -96,7 +96,7 @@ Description: due to lack of capacity in the receive side. See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_nohandler +What: /sys/class/net/<iface>/statistics/rx_nohandler Date: February 2016 KernelVersion: 4.6 Contact: netdev@vger.kernel.org @@ -104,7 +104,7 @@ Description: Indicates the number of received packets that were dropped on an inactive device by the network core. -What: /sys/class/<iface>/statistics/rx_over_errors +What: /sys/class/net/<iface>/statistics/rx_over_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -114,7 +114,7 @@ Description: (e.g: larger than MTU). See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/rx_packets +What: /sys/class/net/<iface>/statistics/rx_packets Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -122,7 +122,7 @@ Description: Indicates the total number of good packets received by this network device. -What: /sys/class/<iface>/statistics/tx_aborted_errors +What: /sys/class/net/<iface>/statistics/tx_aborted_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -132,7 +132,7 @@ Description: a medium collision). See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/tx_bytes +What: /sys/class/net/<iface>/statistics/tx_bytes Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -143,7 +143,7 @@ Description: transmitted packets or all packets that have been queued for transmission. -What: /sys/class/<iface>/statistics/tx_carrier_errors +What: /sys/class/net/<iface>/statistics/tx_carrier_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -152,7 +152,7 @@ Description: because of carrier errors (e.g: physical link down). See the network driver for the exact meaning of this value. -What: /sys/class/<iface>/statistics/tx_compressed +What: /sys/class/net/<iface>/statistics/tx_compressed Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -161,7 +161,7 @@ Description: this might only be relevant for devices that support compression (e.g: PPP). -What: /sys/class/<iface>/statistics/tx_dropped +What: /sys/class/net/<iface>/statistics/tx_dropped Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -170,7 +170,7 @@ Description: See the driver for the exact reasons as to why the packets were dropped. -What: /sys/class/<iface>/statistics/tx_errors +What: /sys/class/net/<iface>/statistics/tx_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -179,7 +179,7 @@ Description: a network device. See the driver for the exact reasons as to why the packets were dropped. -What: /sys/class/<iface>/statistics/tx_fifo_errors +What: /sys/class/net/<iface>/statistics/tx_fifo_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -188,7 +188,7 @@ Description: FIFO error. See the driver for the exact reasons as to why the packets were dropped. -What: /sys/class/<iface>/statistics/tx_heartbeat_errors +What: /sys/class/net/<iface>/statistics/tx_heartbeat_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -197,7 +197,7 @@ Description: reported as heartbeat errors. See the driver for the exact reasons as to why the packets were dropped. -What: /sys/class/<iface>/statistics/tx_packets +What: /sys/class/net/<iface>/statistics/tx_packets Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org @@ -206,7 +206,7 @@ Description: device. See the driver for whether this reports the number of all attempted or successful transmissions. -What: /sys/class/<iface>/statistics/tx_window_errors +What: /sys/class/net/<iface>/statistics/tx_window_errors Date: April 2005 KernelVersion: 2.6.12 Contact: netdev@vger.kernel.org diff --git a/Documentation/ABI/testing/sysfs-nvmem-cells b/Documentation/ABI/testing/sysfs-nvmem-cells index 7af70adf3690..c7c9444f92a8 100644 --- a/Documentation/ABI/testing/sysfs-nvmem-cells +++ b/Documentation/ABI/testing/sysfs-nvmem-cells @@ -4,18 +4,18 @@ KernelVersion: 6.5 Contact: Miquel Raynal <miquel.raynal@bootlin.com> Description: The "cells" folder contains one file per cell exposed by the - NVMEM device. The name of the file is: <name>@<where>, with - <name> being the cell name and <where> its location in the NVMEM - device, in hexadecimal (without the '0x' prefix, to mimic device - tree node names). The length of the file is the size of the cell - (when known). The content of the file is the binary content of - the cell (may sometimes be ASCII, likely without trailing - character). + NVMEM device. The name of the file is: "<name>@<byte>,<bit>", + with <name> being the cell name and <where> its location in + the NVMEM device, in hexadecimal bytes and bits (without the + '0x' prefix, to mimic device tree node names). The length of + the file is the size of the cell (when known). The content of + the file is the binary content of the cell (may sometimes be + ASCII, likely without trailing character). Note: This file is only present if CONFIG_NVMEM_SYSFS is enabled. Example:: - hexdump -C /sys/bus/nvmem/devices/1-00563/cells/product-name@d + hexdump -C /sys/bus/nvmem/devices/1-00563/cells/product-name@d,0 00000000 54 4e 34 38 4d 2d 50 2d 44 4e |TN48M-P-DN| 0000000a diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index e8c2ce1f9df6..45a7f4932fe0 100644 --- a/Documentation/arch/arm64/silicon-errata.rst +++ b/Documentation/arch/arm64/silicon-errata.rst @@ -243,3 +243,10 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ASR | ASR8601 | #8601001 | N/A | +----------------+-----------------+-----------------+-----------------------------+ ++----------------+-----------------+-----------------+-----------------------------+ +| Microsoft | Azure Cobalt 100| #2139208 | ARM64_ERRATUM_2139208 | ++----------------+-----------------+-----------------+-----------------------------+ +| Microsoft | Azure Cobalt 100| #2067961 | ARM64_ERRATUM_2067961 | ++----------------+-----------------+-----------------+-----------------------------+ +| Microsoft | Azure Cobalt 100| #2253138 | ARM64_ERRATUM_2253138 | ++----------------+-----------------+-----------------+-----------------------------+ diff --git a/Documentation/arch/x86/mds.rst b/Documentation/arch/x86/mds.rst index e73fdff62c0a..c58c72362911 100644 --- a/Documentation/arch/x86/mds.rst +++ b/Documentation/arch/x86/mds.rst @@ -95,6 +95,9 @@ The kernel provides a function to invoke the buffer clearing: mds_clear_cpu_buffers() +Also macro CLEAR_CPU_BUFFERS can be used in ASM late in exit-to-user path. +Other than CFLAGS.ZF, this macro doesn't clobber any registers. + The mitigation is invoked on kernel/userspace, hypervisor/guest and C-state (idle) transitions. @@ -138,17 +141,30 @@ Mitigation points When transitioning from kernel to user space the CPU buffers are flushed on affected CPUs when the mitigation is not disabled on the kernel - command line. The migitation is enabled through the static key - mds_user_clear. - - The mitigation is invoked in prepare_exit_to_usermode() which covers - all but one of the kernel to user space transitions. The exception - is when we return from a Non Maskable Interrupt (NMI), which is - handled directly in do_nmi(). - - (The reason that NMI is special is that prepare_exit_to_usermode() can - enable IRQs. In NMI context, NMIs are blocked, and we don't want to - enable IRQs with NMIs blocked.) + command line. The mitigation is enabled through the feature flag + X86_FEATURE_CLEAR_CPU_BUF. + + The mitigation is invoked just before transitioning to userspace after + user registers are restored. This is done to minimize the window in + which kernel data could be accessed after VERW e.g. via an NMI after + VERW. + + **Corner case not handled** + Interrupts returning to kernel don't clear CPUs buffers since the + exit-to-user path is expected to do that anyways. But, there could be + a case when an NMI is generated in kernel after the exit-to-user path + has cleared the buffers. This case is not handled and NMI returning to + kernel don't clear CPU buffers because: + + 1. It is rare to get an NMI after VERW, but before returning to userspace. + 2. For an unprivileged user, there is no known way to make that NMI + less rare or target it. + 3. It would take a large number of these precisely-timed NMIs to mount + an actual attack. There's presumably not enough bandwidth. + 4. The NMI in question occurs after a VERW, i.e. when user state is + restored and most interesting data is already scrubbed. Whats left + is only the data that NMI touches, and that may or may not be of + any interest. 2. C-State transition diff --git a/Documentation/conf.py b/Documentation/conf.py index 5830b01c5642..da64c9fb7e07 100644 --- a/Documentation/conf.py +++ b/Documentation/conf.py @@ -388,6 +388,12 @@ latex_elements = { verbatimhintsturnover=false, ''', + # + # Some of our authors are fond of deep nesting; tell latex to + # cope. + # + 'maxlistdepth': '10', + # For CJK One-half spacing, need to be in front of hyperref 'extrapackages': r'\usepackage{setspace}', diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile index 2323fd5b7cda..129cf698fa8a 100644 --- a/Documentation/devicetree/bindings/Makefile +++ b/Documentation/devicetree/bindings/Makefile @@ -28,7 +28,10 @@ $(obj)/%.example.dts: $(src)/%.yaml check_dtschema_version FORCE find_all_cmd = find $(srctree)/$(src) \( -name '*.yaml' ! \ -name 'processed-schema*' \) -find_cmd = $(find_all_cmd) | sed 's|^$(srctree)/$(src)/||' | grep -F -e "$(subst :," -e ",$(DT_SCHEMA_FILES))" | sed 's|^|$(srctree)/$(src)/|' +find_cmd = $(find_all_cmd) | \ + sed 's|^$(srctree)/||' | \ + grep -F -e "$(subst :," -e ",$(DT_SCHEMA_FILES))" | \ + sed 's|^|$(srctree)/|' CHK_DT_DOCS := $(shell $(find_cmd)) quiet_cmd_yamllint = LINT $(src) diff --git a/Documentation/devicetree/bindings/ata/ceva,ahci-1v84.yaml b/Documentation/devicetree/bindings/ata/ceva,ahci-1v84.yaml index b29ce598f9aa..9952e0ef7767 100644 --- a/Documentation/devicetree/bindings/ata/ceva,ahci-1v84.yaml +++ b/Documentation/devicetree/bindings/ata/ceva,ahci-1v84.yaml @@ -7,7 +7,8 @@ $schema: http://devicetree.org/meta-schemas/core.yaml# title: Ceva AHCI SATA Controller maintainers: - - Piyush Mehta <piyush.mehta@amd.com> + - Mubin Sayyed <mubin.sayyed@amd.com> + - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> description: | The Ceva SATA controller mostly conforms to the AHCI interface with some diff --git a/Documentation/devicetree/bindings/clock/google,gs101-clock.yaml b/Documentation/devicetree/bindings/clock/google,gs101-clock.yaml index 3eebc03a309b..ca7fdada3ff2 100644 --- a/Documentation/devicetree/bindings/clock/google,gs101-clock.yaml +++ b/Documentation/devicetree/bindings/clock/google,gs101-clock.yaml @@ -85,8 +85,8 @@ allOf: clock-names: items: - - const: dout_cmu_misc_bus - - const: dout_cmu_misc_sss + - const: bus + - const: sss additionalProperties: false diff --git a/Documentation/devicetree/bindings/display/bridge/nxp,tda998x.yaml b/Documentation/devicetree/bindings/display/bridge/nxp,tda998x.yaml index 21d995f29a1e..b8e9cf6ce4e6 100644 --- a/Documentation/devicetree/bindings/display/bridge/nxp,tda998x.yaml +++ b/Documentation/devicetree/bindings/display/bridge/nxp,tda998x.yaml @@ -29,19 +29,22 @@ properties: audio-ports: description: - Array of 8-bit values, 2 values per DAI (Documentation/sound/soc/dai.rst). + Array of 2 values per DAI (Documentation/sound/soc/dai.rst). The implementation allows one or two DAIs. If two DAIs are defined, they must be of different type. $ref: /schemas/types.yaml#/definitions/uint32-matrix + minItems: 1 + maxItems: 2 items: - minItems: 1 items: - description: | The first value defines the DAI type: TDA998x_SPDIF or TDA998x_I2S (see include/dt-bindings/display/tda998x.h). + enum: [ 1, 2 ] - description: The second value defines the tda998x AP_ENA reg content when the DAI in question is used. + maximum: 0xff '#sound-dai-cells': enum: [ 0, 1 ] diff --git a/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml b/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml index b1fd632718d4..bb93baa88879 100644 --- a/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml +++ b/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml @@ -12,7 +12,8 @@ description: PS_MODE). Every pin can be configured as input/output. maintainers: - - Piyush Mehta <piyush.mehta@amd.com> + - Mubin Sayyed <mubin.sayyed@amd.com> + - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> properties: compatible: diff --git a/Documentation/devicetree/bindings/net/marvell,prestera.yaml b/Documentation/devicetree/bindings/net/marvell,prestera.yaml index 5ea8b73663a5..16ff892f7bbd 100644 --- a/Documentation/devicetree/bindings/net/marvell,prestera.yaml +++ b/Documentation/devicetree/bindings/net/marvell,prestera.yaml @@ -78,8 +78,8 @@ examples: pcie@0 { #address-cells = <3>; #size-cells = <2>; - ranges = <0x0 0x0 0x0 0x0 0x0 0x0>; - reg = <0x0 0x0 0x0 0x0 0x0 0x0>; + ranges = <0x02000000 0x0 0x100000 0x10000000 0x0 0x0>; + reg = <0x0 0x1000>; device_type = "pci"; switch@0,0 { diff --git a/Documentation/devicetree/bindings/net/renesas,ethertsn.yaml b/Documentation/devicetree/bindings/net/renesas,ethertsn.yaml index 475aff7714d6..ea35d19be829 100644 --- a/Documentation/devicetree/bindings/net/renesas,ethertsn.yaml +++ b/Documentation/devicetree/bindings/net/renesas,ethertsn.yaml @@ -65,9 +65,11 @@ properties: rx-internal-delay-ps: enum: [0, 1800] + default: 0 tx-internal-delay-ps: enum: [0, 2000] + default: 0 '#address-cells': const: 1 diff --git a/Documentation/devicetree/bindings/reset/xlnx,zynqmp-reset.yaml b/Documentation/devicetree/bindings/reset/xlnx,zynqmp-reset.yaml index 49db66801429..1f1b42dde94d 100644 --- a/Documentation/devicetree/bindings/reset/xlnx,zynqmp-reset.yaml +++ b/Documentation/devicetree/bindings/reset/xlnx,zynqmp-reset.yaml @@ -7,7 +7,8 @@ $schema: http://devicetree.org/meta-schemas/core.yaml# title: Zynq UltraScale+ MPSoC and Versal reset maintainers: - - Piyush Mehta <piyush.mehta@amd.com> + - Mubin Sayyed <mubin.sayyed@amd.com> + - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> description: | The Zynq UltraScale+ MPSoC and Versal has several different resets. diff --git a/Documentation/devicetree/bindings/sound/google,sc7280-herobrine.yaml b/Documentation/devicetree/bindings/sound/google,sc7280-herobrine.yaml index ec4b6e547ca6..cdcd7c6f21eb 100644 --- a/Documentation/devicetree/bindings/sound/google,sc7280-herobrine.yaml +++ b/Documentation/devicetree/bindings/sound/google,sc7280-herobrine.yaml @@ -7,7 +7,6 @@ $schema: http://devicetree.org/meta-schemas/core.yaml# title: Google SC7280-Herobrine ASoC sound card driver maintainers: - - Srinivasa Rao Mandadapu <srivasam@codeaurora.org> - Judy Hsiao <judyhsiao@chromium.org> description: diff --git a/Documentation/devicetree/bindings/sound/nvidia,tegra-audio-max9808x.yaml b/Documentation/devicetree/bindings/sound/nvidia,tegra-audio-max9808x.yaml index c29d7942915c..241d20f3aad0 100644 --- a/Documentation/devicetree/bindings/sound/nvidia,tegra-audio-max9808x.yaml +++ b/Documentation/devicetree/bindings/sound/nvidia,tegra-audio-max9808x.yaml @@ -64,7 +64,7 @@ examples: #include <dt-bindings/clock/tegra30-car.h> #include <dt-bindings/soc/tegra-pmc.h> sound { - compatible = "lge,tegra-audio-max98089-p895", + compatible = "lg,tegra-audio-max98089-p895", "nvidia,tegra-audio-max98089"; nvidia,model = "LG Optimus Vu MAX98089"; diff --git a/Documentation/devicetree/bindings/tpm/tpm-common.yaml b/Documentation/devicetree/bindings/tpm/tpm-common.yaml index 90390624a8be..3c1241b2a43f 100644 --- a/Documentation/devicetree/bindings/tpm/tpm-common.yaml +++ b/Documentation/devicetree/bindings/tpm/tpm-common.yaml @@ -42,7 +42,7 @@ properties: resets: description: Reset controller to reset the TPM - $ref: /schemas/types.yaml#/definitions/phandle + maxItems: 1 reset-gpios: description: Output GPIO pin to reset the TPM diff --git a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml index 88cc1e3a0c88..b2b509b3944d 100644 --- a/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml +++ b/Documentation/devicetree/bindings/ufs/samsung,exynos-ufs.yaml @@ -55,9 +55,12 @@ properties: samsung,sysreg: $ref: /schemas/types.yaml#/definitions/phandle-array - description: Should be phandle/offset pair. The phandle to the syscon node - which indicates the FSYSx sysreg interface and the offset of - the control register for UFS io coherency setting. + items: + - items: + - description: phandle to FSYSx sysreg node + - description: offset of the control register for UFS io coherency setting + description: + Phandle and offset to the FSYSx sysreg for UFS io coherency setting. dma-coherent: true diff --git a/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml b/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml index bb373eb025a5..00f87a558c7d 100644 --- a/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml +++ b/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml @@ -7,7 +7,8 @@ $schema: http://devicetree.org/meta-schemas/core.yaml# title: Xilinx SuperSpeed DWC3 USB SoC controller maintainers: - - Piyush Mehta <piyush.mehta@amd.com> + - Mubin Sayyed <mubin.sayyed@amd.com> + - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> properties: compatible: diff --git a/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml b/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml index 6d4cfd943f58..445183d9d6db 100644 --- a/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml +++ b/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml @@ -16,8 +16,9 @@ description: USB 2.0 traffic. maintainers: - - Piyush Mehta <piyush.mehta@amd.com> - Michal Simek <michal.simek@amd.com> + - Mubin Sayyed <mubin.sayyed@amd.com> + - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> properties: compatible: diff --git a/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml b/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml index 868dffe314bc..a7f75fe36665 100644 --- a/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml +++ b/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml @@ -7,7 +7,8 @@ $schema: http://devicetree.org/meta-schemas/core.yaml# title: Xilinx udc controller maintainers: - - Piyush Mehta <piyush.mehta@amd.com> + - Mubin Sayyed <mubin.sayyed@amd.com> + - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> properties: compatible: diff --git a/Documentation/driver-api/dpll.rst b/Documentation/driver-api/dpll.rst index e3d593841aa7..ea8d16600e16 100644 --- a/Documentation/driver-api/dpll.rst +++ b/Documentation/driver-api/dpll.rst @@ -545,7 +545,7 @@ In such scenario, dpll device input signal shall be also configurable to drive dpll with signal recovered from the PHY netdevice. This is done by exposing a pin to the netdevice - attaching pin to the netdevice itself with -``netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)``. +``dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)``. Exposed pin id handle ``DPLL_A_PIN_ID`` is then identifiable by the user as it is attached to rtnetlink respond to get ``RTM_NEWLINK`` command in nested attribute ``IFLA_DPLL_PIN``. diff --git a/Documentation/kbuild/Kconfig.recursion-issue-01 b/Documentation/kbuild/Kconfig.recursion-issue-01 index e8877db0461f..ac49836d8ecf 100644 --- a/Documentation/kbuild/Kconfig.recursion-issue-01 +++ b/Documentation/kbuild/Kconfig.recursion-issue-01 @@ -16,13 +16,13 @@ # that are possible for CORE. So for example if CORE_BELL_A_ADVANCED is 'y', # CORE must be 'y' too. # -# * What influences CORE_BELL_A_ADVANCED ? +# * What influences CORE_BELL_A_ADVANCED? # # As the name implies CORE_BELL_A_ADVANCED is an advanced feature of # CORE_BELL_A so naturally it depends on CORE_BELL_A. So if CORE_BELL_A is 'y' # we know CORE_BELL_A_ADVANCED can be 'y' too. # -# * What influences CORE_BELL_A ? +# * What influences CORE_BELL_A? # # CORE_BELL_A depends on CORE, so CORE influences CORE_BELL_A. # @@ -34,7 +34,7 @@ # the "recursive dependency detected" error. # # Reading the Documentation/kbuild/Kconfig.recursion-issue-01 file it may be -# obvious that an easy to solution to this problem should just be the removal +# obvious that an easy solution to this problem should just be the removal # of the "select CORE" from CORE_BELL_A_ADVANCED as that is implicit already # since CORE_BELL_A depends on CORE. Recursive dependency issues are not always # so trivial to resolve, we provide another example below of practical diff --git a/Documentation/netlink/specs/dpll.yaml b/Documentation/netlink/specs/dpll.yaml index b14aed18065f..3dcc9ece272a 100644 --- a/Documentation/netlink/specs/dpll.yaml +++ b/Documentation/netlink/specs/dpll.yaml @@ -384,8 +384,6 @@ operations: - type dump: - pre: dpll-lock-dumpit - post: dpll-unlock-dumpit reply: *dev-attrs - @@ -473,8 +471,6 @@ operations: - fractional-frequency-offset dump: - pre: dpll-lock-dumpit - post: dpll-unlock-dumpit request: attributes: - id diff --git a/Documentation/networking/devlink/devlink-port.rst b/Documentation/networking/devlink/devlink-port.rst index e33ad2401ad7..562f46b41274 100644 --- a/Documentation/networking/devlink/devlink-port.rst +++ b/Documentation/networking/devlink/devlink-port.rst @@ -126,7 +126,7 @@ Users may also set the RoCE capability of the function using `devlink port function set roce` command. Users may also set the function as migratable using -'devlink port function set migratable' command. +`devlink port function set migratable` command. Users may also set the IPsec crypto capability of the function using `devlink port function set ipsec_crypto` command. diff --git a/Documentation/networking/net_cachelines/inet_sock.rst b/Documentation/networking/net_cachelines/inet_sock.rst index a2babd0d7954..595d7ef5fc8b 100644 --- a/Documentation/networking/net_cachelines/inet_sock.rst +++ b/Documentation/networking/net_cachelines/inet_sock.rst @@ -1,9 +1,9 @@ .. SPDX-License-Identifier: GPL-2.0 .. Copyright (C) 2023 Google LLC -===================================================== -inet_connection_sock struct fast path usage breakdown -===================================================== +========================================== +inet_sock struct fast path usage breakdown +========================================== Type Name fastpath_tx_access fastpath_rx_access comment ..struct ..inet_sock diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst index e75a53593bb9..dceb49d56a91 100644 --- a/Documentation/networking/net_cachelines/net_device.rst +++ b/Documentation/networking/net_cachelines/net_device.rst @@ -136,8 +136,8 @@ struct_netpoll_info* npinfo - possible_net_t nd_net - read_mostly (dev_net)napi_busy_loop,tcp_v(4/6)_rcv,ip(v6)_rcv,ip(6)_input,ip(6)_input_finish void* ml_priv enum_netdev_ml_priv_type ml_priv_type -struct_pcpu_lstats__percpu* lstats -struct_pcpu_sw_netstats__percpu* tstats +struct_pcpu_lstats__percpu* lstats read_mostly dev_lstats_add() +struct_pcpu_sw_netstats__percpu* tstats read_mostly dev_sw_netstats_tx_add() struct_pcpu_dstats__percpu* dstats struct_garp_port* garp_port struct_mrp_port* mrp_port diff --git a/Documentation/networking/net_cachelines/tcp_sock.rst b/Documentation/networking/net_cachelines/tcp_sock.rst index 97d7a5c8e01c..1c154cbd1848 100644 --- a/Documentation/networking/net_cachelines/tcp_sock.rst +++ b/Documentation/networking/net_cachelines/tcp_sock.rst @@ -38,13 +38,13 @@ u32 max_window read_mostly - u32 mss_cache read_mostly read_mostly tcp_rate_check_app_limited,tcp_current_mss,tcp_sync_mss,tcp_sndbuf_expand,tcp_tso_should_defer(tx);tcp_update_pacing_rate,tcp_clean_rtx_queue(rx) u32 window_clamp read_mostly read_write tcp_rcv_space_adjust,__tcp_select_window u32 rcv_ssthresh read_mostly - __tcp_select_window -u82 scaling_ratio +u8 scaling_ratio read_mostly read_mostly tcp_win_from_space struct tcp_rack u16 advmss - read_mostly tcp_rcv_space_adjust u8 compressed_ack u8:2 dup_ack_counter u8:1 tlp_retrans -u8:1 tcp_usec_ts +u8:1 tcp_usec_ts read_mostly read_mostly u32 chrono_start read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data) u32[3] chrono_stat read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data) u8:2 chrono_type read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data) diff --git a/Documentation/process/cve.rst b/Documentation/process/cve.rst new file mode 100644 index 000000000000..5e2753eff729 --- /dev/null +++ b/Documentation/process/cve.rst @@ -0,0 +1,121 @@ +==== +CVEs +==== + +Common Vulnerabilities and Exposure (CVE®) numbers were developed as an +unambiguous way to identify, define, and catalog publicly disclosed +security vulnerabilities. Over time, their usefulness has declined with +regards to the kernel project, and CVE numbers were very often assigned +in inappropriate ways and for inappropriate reasons. Because of this, +the kernel development community has tended to avoid them. However, the +combination of continuing pressure to assign CVEs and other forms of +security identifiers, and ongoing abuses by individuals and companies +outside of the kernel community has made it clear that the kernel +community should have control over those assignments. + +The Linux kernel developer team does have the ability to assign CVEs for +potential Linux kernel security issues. This assignment is independent +of the :doc:`normal Linux kernel security bug reporting +process<../process/security-bugs>`. + +A list of all assigned CVEs for the Linux kernel can be found in the +archives of the linux-cve mailing list, as seen on +https://lore.kernel.org/linux-cve-announce/. To get notice of the +assigned CVEs, please `subscribe +<https://subspace.kernel.org/subscribing.html>`_ to that mailing list. + +Process +======= + +As part of the normal stable release process, kernel changes that are +potentially security issues are identified by the developers responsible +for CVE number assignments and have CVE numbers automatically assigned +to them. These assignments are published on the linux-cve-announce +mailing list as announcements on a frequent basis. + +Note, due to the layer at which the Linux kernel is in a system, almost +any bug might be exploitable to compromise the security of the kernel, +but the possibility of exploitation is often not evident when the bug is +fixed. Because of this, the CVE assignment team is overly cautious and +assign CVE numbers to any bugfix that they identify. This +explains the seemingly large number of CVEs that are issued by the Linux +kernel team. + +If the CVE assignment team misses a specific fix that any user feels +should have a CVE assigned to it, please email them at <cve@kernel.org> +and the team there will work with you on it. Note that no potential +security issues should be sent to this alias, it is ONLY for assignment +of CVEs for fixes that are already in released kernel trees. If you +feel you have found an unfixed security issue, please follow the +:doc:`normal Linux kernel security bug reporting +process<../process/security-bugs>`. + +No CVEs will be automatically assigned for unfixed security issues in +the Linux kernel; assignment will only automatically happen after a fix +is available and applied to a stable kernel tree, and it will be tracked +that way by the git commit id of the original fix. If anyone wishes to +have a CVE assigned before an issue is resolved with a commit, please +contact the kernel CVE assignment team at <cve@kernel.org> to get an +identifier assigned from their batch of reserved identifiers. + +No CVEs will be assigned for any issue found in a version of the kernel +that is not currently being actively supported by the Stable/LTS kernel +team. A list of the currently supported kernel branches can be found at +https://kernel.org/releases.html + +Disputes of assigned CVEs +========================= + +The authority to dispute or modify an assigned CVE for a specific kernel +change lies solely with the maintainers of the relevant subsystem +affected. This principle ensures a high degree of accuracy and +accountability in vulnerability reporting. Only those individuals with +deep expertise and intimate knowledge of the subsystem can effectively +assess the validity and scope of a reported vulnerability and determine +its appropriate CVE designation. Any attempt to modify or dispute a CVE +outside of this designated authority could lead to confusion, inaccurate +reporting, and ultimately, compromised systems. + +Invalid CVEs +============ + +If a security issue is found in a Linux kernel that is only supported by +a Linux distribution due to the changes that have been made by that +distribution, or due to the distribution supporting a kernel version +that is no longer one of the kernel.org supported releases, then a CVE +can not be assigned by the Linux kernel CVE team, and must be asked for +from that Linux distribution itself. + +Any CVE that is assigned against the Linux kernel for an actively +supported kernel version, by any group other than the kernel assignment +CVE team should not be treated as a valid CVE. Please notify the +kernel CVE assignment team at <cve@kernel.org> so that they can work to +invalidate such entries through the CNA remediation process. + +Applicability of specific CVEs +============================== + +As the Linux kernel can be used in many different ways, with many +different ways of accessing it by external users, or no access at all, +the applicability of any specific CVE is up to the user of Linux to +determine, it is not up to the CVE assignment team. Please do not +contact us to attempt to determine the applicability of any specific +CVE. + +Also, as the source tree is so large, and any one system only uses a +small subset of the source tree, any users of Linux should be aware that +large numbers of assigned CVEs are not relevant for their systems. + +In short, we do not know your use case, and we do not know what portions +of the kernel that you use, so there is no way for us to determine if a +specific CVE is relevant for your system. + +As always, it is best to take all released kernel changes, as they are +tested together in a unified whole by many community members, and not as +individual cherry-picked changes. Also note that for many bugs, the +solution to the overall problem is not found in a single change, but by +the sum of many fixes on top of each other. Ideally CVEs will be +assigned to all fixes for all issues, but sometimes we will fail to +notice fixes, therefore assume that some changes without a CVE assigned +might be relevant to take. + diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst index 6cb732dfcc72..de9cbb7bd7eb 100644 --- a/Documentation/process/index.rst +++ b/Documentation/process/index.rst @@ -81,6 +81,7 @@ of special classes of bugs: regressions and security problems. handling-regressions security-bugs + cve embargoed-hardware-issues Maintainer information diff --git a/Documentation/process/maintainer-netdev.rst b/Documentation/process/maintainer-netdev.rst index 84ee60fceef2..fd96e4a3cef9 100644 --- a/Documentation/process/maintainer-netdev.rst +++ b/Documentation/process/maintainer-netdev.rst @@ -431,7 +431,7 @@ patchwork checks Checks in patchwork are mostly simple wrappers around existing kernel scripts, the sources are available at: -https://github.com/kuba-moo/nipa/tree/master/tests +https://github.com/linux-netdev/nipa/tree/master/tests **Do not** post your patches just to run them through the checks. You must ensure that your patches are ready by testing them locally diff --git a/Documentation/process/security-bugs.rst b/Documentation/process/security-bugs.rst index 692a3ba56cca..56c560a00b37 100644 --- a/Documentation/process/security-bugs.rst +++ b/Documentation/process/security-bugs.rst @@ -99,9 +99,8 @@ CVE assignment The security team does not assign CVEs, nor do we require them for reports or fixes, as this can needlessly complicate the process and may delay the bug handling. If a reporter wishes to have a CVE identifier -assigned, they should find one by themselves, for example by contacting -MITRE directly. However under no circumstances will a patch inclusion -be delayed to wait for a CVE identifier to arrive. +assigned for a confirmed issue, they can contact the :doc:`kernel CVE +assignment team<../process/cve>` to obtain one. Non-disclosure agreements ------------------------- diff --git a/Documentation/sphinx/kernel_feat.py b/Documentation/sphinx/kernel_feat.py index b9df61eb4501..03ace5f01b5c 100644 --- a/Documentation/sphinx/kernel_feat.py +++ b/Documentation/sphinx/kernel_feat.py @@ -109,7 +109,7 @@ class KernelFeat(Directive): else: out_lines += line + "\n" - nodeList = self.nestedParse(out_lines, fname) + nodeList = self.nestedParse(out_lines, self.arguments[0]) return nodeList def nestedParse(self, lines, fname): diff --git a/Documentation/sphinx/translations.py b/Documentation/sphinx/translations.py index 47161e6eba99..32c2b32b2b5e 100644 --- a/Documentation/sphinx/translations.py +++ b/Documentation/sphinx/translations.py @@ -29,10 +29,7 @@ all_languages = { } class LanguagesNode(nodes.Element): - def __init__(self, current_language, *args, **kwargs): - super().__init__(*args, **kwargs) - - self.current_language = current_language + pass class TranslationsTransform(Transform): default_priority = 900 @@ -49,7 +46,8 @@ class TranslationsTransform(Transform): # normalize docname to be the untranslated one docname = os.path.join(*components[2:]) - new_nodes = LanguagesNode(all_languages[this_lang_code]) + new_nodes = LanguagesNode() + new_nodes['current_language'] = all_languages[this_lang_code] for lang_code, lang_name in all_languages.items(): if lang_code == this_lang_code: @@ -84,7 +82,7 @@ def process_languages(app, doctree, docname): html_content = app.builder.templates.render('translations.html', context={ - 'current_language': node.current_language, + 'current_language': node['current_language'], 'languages': languages, }) diff --git a/Documentation/virt/hyperv/index.rst b/Documentation/virt/hyperv/index.rst index 4a7a1b738bbe..de447e11b4a5 100644 --- a/Documentation/virt/hyperv/index.rst +++ b/Documentation/virt/hyperv/index.rst @@ -10,3 +10,4 @@ Hyper-V Enlightenments overview vmbus clocks + vpci diff --git a/Documentation/virt/hyperv/vpci.rst b/Documentation/virt/hyperv/vpci.rst new file mode 100644 index 000000000000..b65b2126ede3 --- /dev/null +++ b/Documentation/virt/hyperv/vpci.rst @@ -0,0 +1,316 @@ +.. SPDX-License-Identifier: GPL-2.0 + +PCI pass-thru devices +========================= +In a Hyper-V guest VM, PCI pass-thru devices (also called +virtual PCI devices, or vPCI devices) are physical PCI devices +that are mapped directly into the VM's physical address space. +Guest device drivers can interact directly with the hardware +without intermediation by the host hypervisor. This approach +provides higher bandwidth access to the device with lower +latency, compared with devices that are virtualized by the +hypervisor. The device should appear to the guest just as it +would when running on bare metal, so no changes are required +to the Linux device drivers for the device. + +Hyper-V terminology for vPCI devices is "Discrete Device +Assignment" (DDA). Public documentation for Hyper-V DDA is +available here: `DDA`_ + +.. _DDA: https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/plan/plan-for-deploying-devices-using-discrete-device-assignment + +DDA is typically used for storage controllers, such as NVMe, +and for GPUs. A similar mechanism for NICs is called SR-IOV +and produces the same benefits by allowing a guest device +driver to interact directly with the hardware. See Hyper-V +public documentation here: `SR-IOV`_ + +.. _SR-IOV: https://learn.microsoft.com/en-us/windows-hardware/drivers/network/overview-of-single-root-i-o-virtualization--sr-iov- + +This discussion of vPCI devices includes DDA and SR-IOV +devices. + +Device Presentation +------------------- +Hyper-V provides full PCI functionality for a vPCI device when +it is operating, so the Linux device driver for the device can +be used unchanged, provided it uses the correct Linux kernel +APIs for accessing PCI config space and for other integration +with Linux. But the initial detection of the PCI device and +its integration with the Linux PCI subsystem must use Hyper-V +specific mechanisms. Consequently, vPCI devices on Hyper-V +have a dual identity. They are initially presented to Linux +guests as VMBus devices via the standard VMBus "offer" +mechanism, so they have a VMBus identity and appear under +/sys/bus/vmbus/devices. The VMBus vPCI driver in Linux at +drivers/pci/controller/pci-hyperv.c handles a newly introduced +vPCI device by fabricating a PCI bus topology and creating all +the normal PCI device data structures in Linux that would +exist if the PCI device were discovered via ACPI on a bare- +metal system. Once those data structures are set up, the +device also has a normal PCI identity in Linux, and the normal +Linux device driver for the vPCI device can function as if it +were running in Linux on bare-metal. Because vPCI devices are +presented dynamically through the VMBus offer mechanism, they +do not appear in the Linux guest's ACPI tables. vPCI devices +may be added to a VM or removed from a VM at any time during +the life of the VM, and not just during initial boot. + +With this approach, the vPCI device is a VMBus device and a +PCI device at the same time. In response to the VMBus offer +message, the hv_pci_probe() function runs and establishes a +VMBus connection to the vPCI VSP on the Hyper-V host. That +connection has a single VMBus channel. The channel is used to +exchange messages with the vPCI VSP for the purpose of setting +up and configuring the vPCI device in Linux. Once the device +is fully configured in Linux as a PCI device, the VMBus +channel is used only if Linux changes the vCPU to be interrupted +in the guest, or if the vPCI device is removed from +the VM while the VM is running. The ongoing operation of the +device happens directly between the Linux device driver for +the device and the hardware, with VMBus and the VMBus channel +playing no role. + +PCI Device Setup +---------------- +PCI device setup follows a sequence that Hyper-V originally +created for Windows guests, and that can be ill-suited for +Linux guests due to differences in the overall structure of +the Linux PCI subsystem compared with Windows. Nonetheless, +with a bit of hackery in the Hyper-V virtual PCI driver for +Linux, the virtual PCI device is setup in Linux so that +generic Linux PCI subsystem code and the Linux driver for the +device "just work". + +Each vPCI device is set up in Linux to be in its own PCI +domain with a host bridge. The PCI domainID is derived from +bytes 4 and 5 of the instance GUID assigned to the VMBus vPCI +device. The Hyper-V host does not guarantee that these bytes +are unique, so hv_pci_probe() has an algorithm to resolve +collisions. The collision resolution is intended to be stable +across reboots of the same VM so that the PCI domainIDs don't +change, as the domainID appears in the user space +configuration of some devices. + +hv_pci_probe() allocates a guest MMIO range to be used as PCI +config space for the device. This MMIO range is communicated +to the Hyper-V host over the VMBus channel as part of telling +the host that the device is ready to enter d0. See +hv_pci_enter_d0(). When the guest subsequently accesses this +MMIO range, the Hyper-V host intercepts the accesses and maps +them to the physical device PCI config space. + +hv_pci_probe() also gets BAR information for the device from +the Hyper-V host, and uses this information to allocate MMIO +space for the BARs. That MMIO space is then setup to be +associated with the host bridge so that it works when generic +PCI subsystem code in Linux processes the BARs. + +Finally, hv_pci_probe() creates the root PCI bus. At this +point the Hyper-V virtual PCI driver hackery is done, and the +normal Linux PCI machinery for scanning the root bus works to +detect the device, to perform driver matching, and to +initialize the driver and device. + +PCI Device Removal +------------------ +A Hyper-V host may initiate removal of a vPCI device from a +guest VM at any time during the life of the VM. The removal +is instigated by an admin action taken on the Hyper-V host and +is not under the control of the guest OS. + +A guest VM is notified of the removal by an unsolicited +"Eject" message sent from the host to the guest over the VMBus +channel associated with the vPCI device. Upon receipt of such +a message, the Hyper-V virtual PCI driver in Linux +asynchronously invokes Linux kernel PCI subsystem calls to +shutdown and remove the device. When those calls are +complete, an "Ejection Complete" message is sent back to +Hyper-V over the VMBus channel indicating that the device has +been removed. At this point, Hyper-V sends a VMBus rescind +message to the Linux guest, which the VMBus driver in Linux +processes by removing the VMBus identity for the device. Once +that processing is complete, all vestiges of the device having +been present are gone from the Linux kernel. The rescind +message also indicates to the guest that Hyper-V has stopped +providing support for the vPCI device in the guest. If the +guest were to attempt to access that device's MMIO space, it +would be an invalid reference. Hypercalls affecting the device +return errors, and any further messages sent in the VMBus +channel are ignored. + +After sending the Eject message, Hyper-V allows the guest VM +60 seconds to cleanly shutdown the device and respond with +Ejection Complete before sending the VMBus rescind +message. If for any reason the Eject steps don't complete +within the allowed 60 seconds, the Hyper-V host forcibly +performs the rescind steps, which will likely result in +cascading errors in the guest because the device is now no +longer present from the guest standpoint and accessing the +device MMIO space will fail. + +Because ejection is asynchronous and can happen at any point +during the guest VM lifecycle, proper synchronization in the +Hyper-V virtual PCI driver is very tricky. Ejection has been +observed even before a newly offered vPCI device has been +fully setup. The Hyper-V virtual PCI driver has been updated +several times over the years to fix race conditions when +ejections happen at inopportune times. Care must be taken when +modifying this code to prevent re-introducing such problems. +See comments in the code. + +Interrupt Assignment +-------------------- +The Hyper-V virtual PCI driver supports vPCI devices using +MSI, multi-MSI, or MSI-X. Assigning the guest vCPU that will +receive the interrupt for a particular MSI or MSI-X message is +complex because of the way the Linux setup of IRQs maps onto +the Hyper-V interfaces. For the single-MSI and MSI-X cases, +Linux calls hv_compse_msi_msg() twice, with the first call +containing a dummy vCPU and the second call containing the +real vCPU. Furthermore, hv_irq_unmask() is finally called +(on x86) or the GICD registers are set (on arm64) to specify +the real vCPU again. Each of these three calls interact +with Hyper-V, which must decide which physical CPU should +receive the interrupt before it is forwarded to the guest VM. +Unfortunately, the Hyper-V decision-making process is a bit +limited, and can result in concentrating the physical +interrupts on a single CPU, causing a performance bottleneck. +See details about how this is resolved in the extensive +comment above the function hv_compose_msi_req_get_cpu(). + +The Hyper-V virtual PCI driver implements the +irq_chip.irq_compose_msi_msg function as hv_compose_msi_msg(). +Unfortunately, on Hyper-V the implementation requires sending +a VMBus message to the Hyper-V host and awaiting an interrupt +indicating receipt of a reply message. Since +irq_chip.irq_compose_msi_msg can be called with IRQ locks +held, it doesn't work to do the normal sleep until awakened by +the interrupt. Instead hv_compose_msi_msg() must send the +VMBus message, and then poll for the completion message. As +further complexity, the vPCI device could be ejected/rescinded +while the polling is in progress, so this scenario must be +detected as well. See comments in the code regarding this +very tricky area. + +Most of the code in the Hyper-V virtual PCI driver (pci- +hyperv.c) applies to Hyper-V and Linux guests running on x86 +and on arm64 architectures. But there are differences in how +interrupt assignments are managed. On x86, the Hyper-V +virtual PCI driver in the guest must make a hypercall to tell +Hyper-V which guest vCPU should be interrupted by each +MSI/MSI-X interrupt, and the x86 interrupt vector number that +the x86_vector IRQ domain has picked for the interrupt. This +hypercall is made by hv_arch_irq_unmask(). On arm64, the +Hyper-V virtual PCI driver manages the allocation of an SPI +for each MSI/MSI-X interrupt. The Hyper-V virtual PCI driver +stores the allocated SPI in the architectural GICD registers, +which Hyper-V emulates, so no hypercall is necessary as with +x86. Hyper-V does not support using LPIs for vPCI devices in +arm64 guest VMs because it does not emulate a GICv3 ITS. + +The Hyper-V virtual PCI driver in Linux supports vPCI devices +whose drivers create managed or unmanaged Linux IRQs. If the +smp_affinity for an unmanaged IRQ is updated via the /proc/irq +interface, the Hyper-V virtual PCI driver is called to tell +the Hyper-V host to change the interrupt targeting and +everything works properly. However, on x86 if the x86_vector +IRQ domain needs to reassign an interrupt vector due to +running out of vectors on a CPU, there's no path to inform the +Hyper-V host of the change, and things break. Fortunately, +guest VMs operate in a constrained device environment where +using all the vectors on a CPU doesn't happen. Since such a +problem is only a theoretical concern rather than a practical +concern, it has been left unaddressed. + +DMA +--- +By default, Hyper-V pins all guest VM memory in the host +when the VM is created, and programs the physical IOMMU to +allow the VM to have DMA access to all its memory. Hence +it is safe to assign PCI devices to the VM, and allow the +guest operating system to program the DMA transfers. The +physical IOMMU prevents a malicious guest from initiating +DMA to memory belonging to the host or to other VMs on the +host. From the Linux guest standpoint, such DMA transfers +are in "direct" mode since Hyper-V does not provide a virtual +IOMMU in the guest. + +Hyper-V assumes that physical PCI devices always perform +cache-coherent DMA. When running on x86, this behavior is +required by the architecture. When running on arm64, the +architecture allows for both cache-coherent and +non-cache-coherent devices, with the behavior of each device +specified in the ACPI DSDT. But when a PCI device is assigned +to a guest VM, that device does not appear in the DSDT, so the +Hyper-V VMBus driver propagates cache-coherency information +from the VMBus node in the ACPI DSDT to all VMBus devices, +including vPCI devices (since they have a dual identity as a VMBus +device and as a PCI device). See vmbus_dma_configure(). +Current Hyper-V versions always indicate that the VMBus is +cache coherent, so vPCI devices on arm64 always get marked as +cache coherent and the CPU does not perform any sync +operations as part of dma_map/unmap_*() calls. + +vPCI protocol versions +---------------------- +As previously described, during vPCI device setup and teardown +messages are passed over a VMBus channel between the Hyper-V +host and the Hyper-v vPCI driver in the Linux guest. Some +messages have been revised in newer versions of Hyper-V, so +the guest and host must agree on the vPCI protocol version to +be used. The version is negotiated when communication over +the VMBus channel is first established. See +hv_pci_protocol_negotiation(). Newer versions of the protocol +extend support to VMs with more than 64 vCPUs, and provide +additional information about the vPCI device, such as the +guest virtual NUMA node to which it is most closely affined in +the underlying hardware. + +Guest NUMA node affinity +------------------------ +When the vPCI protocol version provides it, the guest NUMA +node affinity of the vPCI device is stored as part of the Linux +device information for subsequent use by the Linux driver. See +hv_pci_assign_numa_node(). If the negotiated protocol version +does not support the host providing NUMA affinity information, +the Linux guest defaults the device NUMA node to 0. But even +when the negotiated protocol version includes NUMA affinity +information, the ability of the host to provide such +information depends on certain host configuration options. If +the guest receives NUMA node value "0", it could mean NUMA +node 0, or it could mean "no information is available". +Unfortunately it is not possible to distinguish the two cases +from the guest side. + +PCI config space access in a CoCo VM +------------------------------------ +Linux PCI device drivers access PCI config space using a +standard set of functions provided by the Linux PCI subsystem. +In Hyper-V guests these standard functions map to functions +hv_pcifront_read_config() and hv_pcifront_write_config() +in the Hyper-V virtual PCI driver. In normal VMs, +these hv_pcifront_*() functions directly access the PCI config +space, and the accesses trap to Hyper-V to be handled. +But in CoCo VMs, memory encryption prevents Hyper-V +from reading the guest instruction stream to emulate the +access, so the hv_pcifront_*() functions must invoke +hypercalls with explicit arguments describing the access to be +made. + +Config Block back-channel +------------------------- +The Hyper-V host and Hyper-V virtual PCI driver in Linux +together implement a non-standard back-channel communication +path between the host and guest. The back-channel path uses +messages sent over the VMBus channel associated with the vPCI +device. The functions hyperv_read_cfg_blk() and +hyperv_write_cfg_blk() are the primary interfaces provided to +other parts of the Linux kernel. As of this writing, these +interfaces are used only by the Mellanox mlx5 driver to pass +diagnostic data to a Hyper-V host running in the Azure public +cloud. The functions hyperv_read_cfg_blk() and +hyperv_write_cfg_blk() are implemented in a separate module +(pci-hyperv-intf.c, under CONFIG_PCI_HYPERV_INTERFACE) that +effectively stubs them out when running in non-Hyper-V +environments. diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 3ec0b7a455a0..09c7e585ff58 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8791,6 +8791,11 @@ means the VM type with value @n is supported. Possible values of @n are:: #define KVM_X86_DEFAULT_VM 0 #define KVM_X86_SW_PROTECTED_VM 1 +Note, KVM_X86_SW_PROTECTED_VM is currently only for development and testing. +Do not use KVM_X86_SW_PROTECTED_VM for "real" VMs, and especially not in +production. The behavior and effective ABI for software-protected VMs is +unstable. + 9. Known KVM API problems ========================= |