diff options
| -rw-r--r-- | Documentation/virt/hyperv/clocks.rst | 21 | ||||
| -rw-r--r-- | Documentation/virt/hyperv/overview.rst | 22 | ||||
| -rw-r--r-- | Documentation/virt/hyperv/vmbus.rst | 143 | ||||
| -rw-r--r-- | drivers/hv/hv.c | 37 | ||||
| -rw-r--r-- | drivers/hv/hv_balloon.c | 190 | ||||
| -rw-r--r-- | tools/hv/Makefile | 1 |
6 files changed, 208 insertions, 206 deletions
diff --git a/Documentation/virt/hyperv/clocks.rst b/Documentation/virt/hyperv/clocks.rst index a56f4837d443..176043265803 100644 --- a/Documentation/virt/hyperv/clocks.rst +++ b/Documentation/virt/hyperv/clocks.rst @@ -62,12 +62,21 @@ shared page with scale and offset values into user space. User space code performs the same algorithm of reading the TSC and applying the scale and offset to get the constant 10 MHz clock. -Linux clockevents are based on Hyper-V synthetic timer 0. While -Hyper-V offers 4 synthetic timers for each CPU, Linux only uses -timer 0. Interrupts from stimer0 are recorded on the "HVS" line in -/proc/interrupts. Clockevents based on the virtualized PIT and -local APIC timer also work, but the Hyper-V synthetic timer is -preferred. +Linux clockevents are based on Hyper-V synthetic timer 0 (stimer0). +While Hyper-V offers 4 synthetic timers for each CPU, Linux only uses +timer 0. In older versions of Hyper-V, an interrupt from stimer0 +results in a VMBus control message that is demultiplexed by +vmbus_isr() as described in the Documentation/virt/hyperv/vmbus.rst +documentation. In newer versions of Hyper-V, stimer0 interrupts can +be mapped to an architectural interrupt, which is referred to as +"Direct Mode". Linux prefers to use Direct Mode when available. Since +x86/x64 doesn't support per-CPU interrupts, Direct Mode statically +allocates an x86 interrupt vector (HYPERV_STIMER0_VECTOR) across all CPUs +and explicitly codes it to call the stimer0 interrupt handler. Hence +interrupts from stimer0 are recorded on the "HVS" line in /proc/interrupts +rather than being associated with a Linux IRQ. Clockevents based on the +virtualized PIT and local APIC timer also work, but Hyper-V stimer0 +is preferred. The driver for the Hyper-V synthetic system clock and timers is drivers/clocksource/hyperv_timer.c. diff --git a/Documentation/virt/hyperv/overview.rst b/Documentation/virt/hyperv/overview.rst index cd493332c88a..77408a89d1a4 100644 --- a/Documentation/virt/hyperv/overview.rst +++ b/Documentation/virt/hyperv/overview.rst @@ -40,7 +40,7 @@ Linux guests communicate with Hyper-V in four different ways: arm64, these synthetic registers must be accessed using explicit hypercalls. -* VMbus: VMbus is a higher-level software construct that is built on +* VMBus: VMBus is a higher-level software construct that is built on the other 3 mechanisms. It is a message passing interface between the Hyper-V host and the Linux guest. It uses memory that is shared between Hyper-V and the guest, along with various signaling @@ -54,8 +54,8 @@ x86/x64 architecture only. .. _Hyper-V Top Level Functional Spec (TLFS): https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/tlfs -VMbus is not documented. This documentation provides a high-level -overview of VMbus and how it works, but the details can be discerned +VMBus is not documented. This documentation provides a high-level +overview of VMBus and how it works, but the details can be discerned only from the code. Sharing Memory @@ -74,7 +74,7 @@ follows: physical address space. How Hyper-V is told about the GPA or list of GPAs varies. In some cases, a single GPA is written to a synthetic register. In other cases, a GPA or list of GPAs is sent - in a VMbus message. + in a VMBus message. * Hyper-V translates the GPAs into "real" physical memory addresses, and creates a virtual mapping that it can use to access the memory. @@ -133,9 +133,9 @@ only the CPUs actually present in the VM, so Linux does not report any hot-add CPUs. A Linux guest CPU may be taken offline using the normal Linux -mechanisms, provided no VMbus channel interrupts are assigned to -the CPU. See the section on VMbus Interrupts for more details -on how VMbus channel interrupts can be re-assigned to permit +mechanisms, provided no VMBus channel interrupts are assigned to +the CPU. See the section on VMBus Interrupts for more details +on how VMBus channel interrupts can be re-assigned to permit taking a CPU offline. 32-bit and 64-bit @@ -169,14 +169,14 @@ and functionality. Hyper-V indicates feature/function availability via flags in synthetic MSRs that Hyper-V provides to the guest, and the guest code tests these flags. -VMbus has its own protocol version that is negotiated during the -initial VMbus connection from the guest to Hyper-V. This version +VMBus has its own protocol version that is negotiated during the +initial VMBus connection from the guest to Hyper-V. This version number is also output to dmesg during boot. This version number is checked in a few places in the code to determine if specific functionality is present. -Furthermore, each synthetic device on VMbus also has a protocol -version that is separate from the VMbus protocol version. Device +Furthermore, each synthetic device on VMBus also has a protocol +version that is separate from the VMBus protocol version. Device drivers for these synthetic devices typically negotiate the device protocol version, and may test that protocol version to determine if specific device functionality is present. diff --git a/Documentation/virt/hyperv/vmbus.rst b/Documentation/virt/hyperv/vmbus.rst index d2012d9022c5..1dcef6a7fda3 100644 --- a/Documentation/virt/hyperv/vmbus.rst +++ b/Documentation/virt/hyperv/vmbus.rst @@ -1,8 +1,8 @@ .. SPDX-License-Identifier: GPL-2.0 -VMbus +VMBus ===== -VMbus is a software construct provided by Hyper-V to guest VMs. It +VMBus is a software construct provided by Hyper-V to guest VMs. It consists of a control path and common facilities used by synthetic devices that Hyper-V presents to guest VMs. The control path is used to offer synthetic devices to the guest VM and, in some cases, @@ -12,9 +12,9 @@ and the synthetic device implementation that is part of Hyper-V, and signaling primitives to allow Hyper-V and the guest to interrupt each other. -VMbus is modeled in Linux as a bus, with the expected /sys/bus/vmbus -entry in a running Linux guest. The VMbus driver (drivers/hv/vmbus_drv.c) -establishes the VMbus control path with the Hyper-V host, then +VMBus is modeled in Linux as a bus, with the expected /sys/bus/vmbus +entry in a running Linux guest. The VMBus driver (drivers/hv/vmbus_drv.c) +establishes the VMBus control path with the Hyper-V host, then registers itself as a Linux bus driver. It implements the standard bus functions for adding and removing devices to/from the bus. @@ -49,9 +49,9 @@ synthetic NIC is referred to as "netvsc" and the Linux driver for the synthetic SCSI controller is "storvsc". These drivers contain functions with names like "storvsc_connect_to_vsp". -VMbus channels +VMBus channels -------------- -An instance of a synthetic device uses VMbus channels to communicate +An instance of a synthetic device uses VMBus channels to communicate between the VSP and the VSC. Channels are bi-directional and used for passing messages. Most synthetic devices use a single channel, but the synthetic SCSI controller and synthetic NIC may use multiple @@ -73,7 +73,7 @@ write indices and some control flags, followed by the memory for the actual ring. The size of the ring is determined by the VSC in the guest and is specific to each synthetic device. The list of GPAs making up the ring is communicated to the Hyper-V host over the -VMbus control path as a GPA Descriptor List (GPADL). See function +VMBus control path as a GPA Descriptor List (GPADL). See function vmbus_establish_gpadl(). Each ring buffer is mapped into contiguous Linux kernel virtual @@ -102,10 +102,10 @@ resources. For Windows Server 2019 and later, this limit is approximately 1280 Mbytes. For versions prior to Windows Server 2019, the limit is approximately 384 Mbytes. -VMbus messages --------------- -All VMbus messages have a standard header that includes the message -length, the offset of the message payload, some flags, and a +VMBus channel messages +---------------------- +All messages sent in a VMBus channel have a standard header that includes +the message length, the offset of the message payload, some flags, and a transactionID. The portion of the message after the header is unique to each VSP/VSC pair. @@ -137,7 +137,7 @@ control message contains a list of GPAs that describe the data buffer. For example, the storvsc driver uses this approach to specify the data buffers to/from which disk I/O is done. -Three functions exist to send VMbus messages: +Three functions exist to send VMBus channel messages: 1. vmbus_sendpacket(): Control-only messages and messages with embedded data -- no GPAs @@ -154,20 +154,51 @@ Historically, Linux guests have trusted Hyper-V to send well-formed and valid messages, and Linux drivers for synthetic devices did not fully validate messages. With the introduction of processor technologies that fully encrypt guest memory and that allow the -guest to not trust the hypervisor (AMD SNP-SEV, Intel TDX), trusting +guest to not trust the hypervisor (AMD SEV-SNP, Intel TDX), trusting the Hyper-V host is no longer a valid assumption. The drivers for -VMbus synthetic devices are being updated to fully validate any +VMBus synthetic devices are being updated to fully validate any values read from memory that is shared with Hyper-V, which includes -messages from VMbus devices. To facilitate such validation, +messages from VMBus devices. To facilitate such validation, messages read by the guest from the "in" ring buffer are copied to a temporary buffer that is not shared with Hyper-V. Validation is performed in this temporary buffer without the risk of Hyper-V maliciously modifying the message after it is validated but before it is used. -VMbus interrupts +Synthetic Interrupt Controller (synic) +-------------------------------------- +Hyper-V provides each guest CPU with a synthetic interrupt controller +that is used by VMBus for host-guest communication. While each synic +defines 16 synthetic interrupts (SINT), Linux uses only one of the 16 +(VMBUS_MESSAGE_SINT). All interrupts related to communication between +the Hyper-V host and a guest CPU use that SINT. + +The SINT is mapped to a single per-CPU architectural interrupt (i.e, +an 8-bit x86/x64 interrupt vector, or an arm64 PPI INTID). Because +each CPU in the guest has a synic and may receive VMBus interrupts, +they are best modeled in Linux as per-CPU interrupts. This model works +well on arm64 where a single per-CPU Linux IRQ is allocated for +VMBUS_MESSAGE_SINT. This IRQ appears in /proc/interrupts as an IRQ labelled +"Hyper-V VMbus". Since x86/x64 lacks support for per-CPU IRQs, an x86 +interrupt vector is statically allocated (HYPERVISOR_CALLBACK_VECTOR) +across all CPUs and explicitly coded to call vmbus_isr(). In this case, +there's no Linux IRQ, and the interrupts are visible in aggregate in +/proc/interrupts on the "HYP" line. + +The synic provides the means to demultiplex the architectural interrupt into +one or more logical interrupts and route the logical interrupt to the proper +VMBus handler in Linux. This demultiplexing is done by vmbus_isr() and +related functions that access synic data structures. + +The synic is not modeled in Linux as an irq chip or irq domain, +and the demultiplexed logical interrupts are not Linux IRQs. As such, +they don't appear in /proc/interrupts or /proc/irq. The CPU +affinity for one of these logical interrupts is controlled via an +entry under /sys/bus/vmbus as described below. + +VMBus interrupts ---------------- -VMbus provides a mechanism for the guest to interrupt the host when +VMBus provides a mechanism for the guest to interrupt the host when the guest has queued new messages in a ring buffer. The host expects that the guest will send an interrupt only when an "out" ring buffer transitions from empty to non-empty. If the guest sends @@ -176,63 +207,55 @@ unnecessary. If a guest sends an excessive number of unnecessary interrupts, the host may throttle that guest by suspending its execution for a few seconds to prevent a denial-of-service attack. -Similarly, the host will interrupt the guest when it sends a new -message on the VMbus control path, or when a VMbus channel "in" ring -buffer transitions from empty to non-empty. Each CPU in the guest -may receive VMbus interrupts, so they are best modeled as per-CPU -interrupts in Linux. This model works well on arm64 where a single -per-CPU IRQ is allocated for VMbus. Since x86/x64 lacks support for -per-CPU IRQs, an x86 interrupt vector is statically allocated (see -HYPERVISOR_CALLBACK_VECTOR) across all CPUs and explicitly coded to -call the VMbus interrupt service routine. These interrupts are -visible in /proc/interrupts on the "HYP" line. - -The guest CPU that a VMbus channel will interrupt is selected by the +Similarly, the host will interrupt the guest via the synic when +it sends a new message on the VMBus control path, or when a VMBus +channel "in" ring buffer transitions from empty to non-empty due to +the host inserting a new VMBus channel message. The control message stream +and each VMBus channel "in" ring buffer are separate logical interrupts +that are demultiplexed by vmbus_isr(). It demultiplexes by first checking +for channel interrupts by calling vmbus_chan_sched(), which looks at a synic +bitmap to determine which channels have pending interrupts on this CPU. +If multiple channels have pending interrupts for this CPU, they are +processed sequentially. When all channel interrupts have been processed, +vmbus_isr() checks for and processes any messages received on the VMBus +control path. + +The guest CPU that a VMBus channel will interrupt is selected by the guest when the channel is created, and the host is informed of that -selection. VMbus devices are broadly grouped into two categories: +selection. VMBus devices are broadly grouped into two categories: -1. "Slow" devices that need only one VMbus channel. The devices +1. "Slow" devices that need only one VMBus channel. The devices (such as keyboard, mouse, heartbeat, and timesync) generate - relatively few interrupts. Their VMbus channels are all + relatively few interrupts. Their VMBus channels are all assigned to interrupt the VMBUS_CONNECT_CPU, which is always CPU 0. -2. "High speed" devices that may use multiple VMbus channels for +2. "High speed" devices that may use multiple VMBus channels for higher parallelism and performance. These devices include the - synthetic SCSI controller and synthetic NIC. Their VMbus + synthetic SCSI controller and synthetic NIC. Their VMBus channels interrupts are assigned to CPUs that are spread out among the available CPUs in the VM so that interrupts on multiple channels can be processed in parallel. -The assignment of VMbus channel interrupts to CPUs is done in the +The assignment of VMBus channel interrupts to CPUs is done in the function init_vp_index(). This assignment is done outside of the normal Linux interrupt affinity mechanism, so the interrupts are neither "unmanaged" nor "managed" interrupts. -The CPU that a VMbus channel will interrupt can be seen in +The CPU that a VMBus channel will interrupt can be seen in /sys/bus/vmbus/devices/<deviceGUID>/ channels/<channelRelID>/cpu. When running on later versions of Hyper-V, the CPU can be changed -by writing a new value to this sysfs entry. Because the interrupt -assignment is done outside of the normal Linux affinity mechanism, -there are no entries in /proc/irq corresponding to individual -VMbus channel interrupts. +by writing a new value to this sysfs entry. Because VMBus channel +interrupts are not Linux IRQs, there are no entries in /proc/interrupts +or /proc/irq corresponding to individual VMBus channel interrupts. An online CPU in a Linux guest may not be taken offline if it has -VMbus channel interrupts assigned to it. Any such channel +VMBus channel interrupts assigned to it. Any such channel interrupts must first be manually reassigned to another CPU as described above. When no channel interrupts are assigned to the CPU, it can be taken offline. -When a guest CPU receives a VMbus interrupt from the host, the -function vmbus_isr() handles the interrupt. It first checks for -channel interrupts by calling vmbus_chan_sched(), which looks at a -bitmap setup by the host to determine which channels have pending -interrupts on this CPU. If multiple channels have pending -interrupts for this CPU, they are processed sequentially. When all -channel interrupts have been processed, vmbus_isr() checks for and -processes any message received on the VMbus control path. - -The VMbus channel interrupt handling code is designed to work +The VMBus channel interrupt handling code is designed to work correctly even if an interrupt is received on a CPU other than the CPU assigned to the channel. Specifically, the code does not use CPU-based exclusion for correctness. In normal operation, Hyper-V @@ -242,23 +265,23 @@ when Hyper-V will make the transition. The code must work correctly even if there is a time lag before Hyper-V starts interrupting the new CPU. See comments in target_cpu_store(). -VMbus device creation/deletion +VMBus device creation/deletion ------------------------------ Hyper-V and the Linux guest have a separate message-passing path that is used for synthetic device creation and deletion. This -path does not use a VMbus channel. See vmbus_post_msg() and +path does not use a VMBus channel. See vmbus_post_msg() and vmbus_on_msg_dpc(). The first step is for the guest to connect to the generic -Hyper-V VMbus mechanism. As part of establishing this connection, -the guest and Hyper-V agree on a VMbus protocol version they will +Hyper-V VMBus mechanism. As part of establishing this connection, +the guest and Hyper-V agree on a VMBus protocol version they will use. This negotiation allows newer Linux kernels to run on older Hyper-V versions, and vice versa. The guest then tells Hyper-V to "send offers". Hyper-V sends an offer message to the guest for each synthetic device that the VM -is configured to have. Each VMbus device type has a fixed GUID -known as the "class ID", and each VMbus device instance is also +is configured to have. Each VMBus device type has a fixed GUID +known as the "class ID", and each VMBus device instance is also identified by a GUID. The offer message from Hyper-V contains both GUIDs to uniquely (within the VM) identify the device. There is one offer message for each device instance, so a VM with @@ -275,7 +298,7 @@ type based on the class ID, and invokes the correct driver to set up the device. Driver/device matching is performed using the standard Linux mechanism. -The device driver probe function opens the primary VMbus channel to +The device driver probe function opens the primary VMBus channel to the corresponding VSP. It allocates guest memory for the channel ring buffers and shares the ring buffer with the Hyper-V host by giving the host a list of GPAs for the ring buffer memory. See @@ -285,7 +308,7 @@ Once the ring buffer is set up, the device driver and VSP exchange setup messages via the primary channel. These messages may include negotiating the device protocol version to be used between the Linux VSC and the VSP on the Hyper-V host. The setup messages may also -include creating additional VMbus channels, which are somewhat +include creating additional VMBus channels, which are somewhat mis-named as "sub-channels" since they are functionally equivalent to the primary channel once they are created. diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index a8ad728354cb..e0d676c74f14 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -45,8 +45,8 @@ int hv_init(void) * This involves a hypercall. */ int hv_post_message(union hv_connection_id connection_id, - enum hv_message_type message_type, - void *payload, size_t payload_size) + enum hv_message_type message_type, + void *payload, size_t payload_size) { struct hv_input_post_message *aligned_msg; unsigned long flags; @@ -86,7 +86,7 @@ int hv_post_message(union hv_connection_id connection_id, status = HV_STATUS_INVALID_PARAMETER; } else { status = hv_do_hypercall(HVCALL_POST_MESSAGE, - aligned_msg, NULL); + aligned_msg, NULL); } local_irq_restore(flags); @@ -111,7 +111,7 @@ int hv_synic_alloc(void) hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask), GFP_KERNEL); - if (hv_context.hv_numa_map == NULL) { + if (!hv_context.hv_numa_map) { pr_err("Unable to allocate NUMA map\n"); goto err; } @@ -120,11 +120,11 @@ int hv_synic_alloc(void) hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); tasklet_init(&hv_cpu->msg_dpc, - vmbus_on_msg_dpc, (unsigned long) hv_cpu); + vmbus_on_msg_dpc, (unsigned long)hv_cpu); if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) { hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC); - if (hv_cpu->post_msg_page == NULL) { + if (!hv_cpu->post_msg_page) { pr_err("Unable to allocate post msg page\n"); goto err; } @@ -147,14 +147,14 @@ int hv_synic_alloc(void) if (!ms_hyperv.paravisor_present && !hv_root_partition) { hv_cpu->synic_message_page = (void *)get_zeroed_page(GFP_ATOMIC); - if (hv_cpu->synic_message_page == NULL) { + if (!hv_cpu->synic_message_page) { pr_err("Unable to allocate SYNIC message page\n"); goto err; } hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC); - if (hv_cpu->synic_event_page == NULL) { + if (!hv_cpu->synic_event_page) { pr_err("Unable to allocate SYNIC event page\n"); free_page((unsigned long)hv_cpu->synic_message_page); @@ -203,14 +203,13 @@ err: return ret; } - void hv_synic_free(void) { int cpu, ret; for_each_present_cpu(cpu) { - struct hv_per_cpu_context *hv_cpu - = per_cpu_ptr(hv_context.cpu_context, cpu); + struct hv_per_cpu_context *hv_cpu = + per_cpu_ptr(hv_context.cpu_context, cpu); /* It's better to leak the page if the encryption fails. */ if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) { @@ -262,8 +261,8 @@ void hv_synic_free(void) */ void hv_synic_enable_regs(unsigned int cpu) { - struct hv_per_cpu_context *hv_cpu - = per_cpu_ptr(hv_context.cpu_context, cpu); + struct hv_per_cpu_context *hv_cpu = + per_cpu_ptr(hv_context.cpu_context, cpu); union hv_synic_simp simp; union hv_synic_siefp siefp; union hv_synic_sint shared_sint; @@ -277,8 +276,8 @@ void hv_synic_enable_regs(unsigned int cpu) /* Mask out vTOM bit. ioremap_cache() maps decrypted */ u64 base = (simp.base_simp_gpa << HV_HYP_PAGE_SHIFT) & ~ms_hyperv.shared_gpa_boundary; - hv_cpu->synic_message_page - = (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); + hv_cpu->synic_message_page = + (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); if (!hv_cpu->synic_message_page) pr_err("Fail to map synic message page.\n"); } else { @@ -296,8 +295,8 @@ void hv_synic_enable_regs(unsigned int cpu) /* Mask out vTOM bit. ioremap_cache() maps decrypted */ u64 base = (siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT) & ~ms_hyperv.shared_gpa_boundary; - hv_cpu->synic_event_page - = (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); + hv_cpu->synic_event_page = + (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); if (!hv_cpu->synic_event_page) pr_err("Fail to map synic event page.\n"); } else { @@ -348,8 +347,8 @@ int hv_synic_init(unsigned int cpu) */ void hv_synic_disable_regs(unsigned int cpu) { - struct hv_per_cpu_context *hv_cpu - = per_cpu_ptr(hv_context.cpu_context, cpu); + struct hv_per_cpu_context *hv_cpu = + per_cpu_ptr(hv_context.cpu_context, cpu); union hv_synic_sint shared_sint; union hv_synic_simp simp; union hv_synic_siefp siefp; diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index e000fa3b9f97..0e7427c2baf5 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -25,6 +25,7 @@ #include <linux/notifier.h> #include <linux/percpu_counter.h> #include <linux/page_reporting.h> +#include <linux/sizes.h> #include <linux/hyperv.h> #include <asm/hyperv-tlfs.h> @@ -41,8 +42,6 @@ * Begin protocol definitions. */ - - /* * Protocol versions. The low word is the minor version, the high word the major * version. @@ -71,8 +70,6 @@ enum { DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10 }; - - /* * Message Types */ @@ -101,7 +98,6 @@ enum dm_message_type { DM_VERSION_1_MAX = 12 }; - /* * Structures defining the dynamic memory management * protocol. @@ -115,7 +111,6 @@ union dm_version { __u32 version; } __packed; - union dm_caps { struct { __u64 balloon:1; @@ -148,8 +143,6 @@ union dm_mem_page_range { __u64 page_range; } __packed; - - /* * The header for all dynamic memory messages: * @@ -174,7 +167,6 @@ struct dm_message { __u8 data[]; /* enclosed message */ } __packed; - /* * Specific message types supporting the dynamic memory protocol. */ @@ -271,7 +263,6 @@ struct dm_status { __u32 io_diff; } __packed; - /* * Message to ask the guest to allocate memory - balloon up message. * This message is sent from the host to the guest. The guest may not be @@ -286,14 +277,13 @@ struct dm_balloon { __u32 reservedz; } __packed; - /* * Balloon response message; this message is sent from the guest * to the host in response to the balloon message. * * reservedz: Reserved; must be set to zero. * more_pages: If FALSE, this is the last message of the transaction. - * if TRUE there will atleast one more message from the guest. + * if TRUE there will be at least one more message from the guest. * * range_count: The number of ranges in the range array. * @@ -314,7 +304,7 @@ struct dm_balloon_response { * to the guest to give guest more memory. * * more_pages: If FALSE, this is the last message of the transaction. - * if TRUE there will atleast one more message from the guest. + * if TRUE there will be at least one more message from the guest. * * reservedz: Reserved; must be set to zero. * @@ -342,7 +332,6 @@ struct dm_unballoon_response { struct dm_header hdr; } __packed; - /* * Hot add request message. Message sent from the host to the guest. * @@ -390,7 +379,6 @@ enum dm_info_type { MAX_INFO_TYPE }; - /* * Header for the information message. */ @@ -425,11 +413,11 @@ struct dm_info_msg { * The range start_pfn : end_pfn specifies the range * that the host has asked us to hot add. The range * start_pfn : ha_end_pfn specifies the range that we have - * currently hot added. We hot add in multiples of 128M - * chunks; it is possible that we may not be able to bring - * online all the pages in the region. The range + * currently hot added. We hot add in chunks equal to the + * memory block size; it is possible that we may not be able + * to bring online all the pages in the region. The range * covered_start_pfn:covered_end_pfn defines the pages that can - * be brough online. + * be brought online. */ struct hv_hotadd_state { @@ -480,10 +468,10 @@ static unsigned long last_post_time; static int hv_hypercall_multi_failure; -module_param(hot_add, bool, (S_IRUGO | S_IWUSR)); +module_param(hot_add, bool, 0644); MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add"); -module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR)); +module_param(pressure_report_delay, uint, 0644); MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure"); static atomic_t trans_id = ATOMIC_INIT(0); @@ -502,11 +490,13 @@ enum hv_dm_state { DM_INIT_ERROR }; - static __u8 recv_buffer[HV_HYP_PAGE_SIZE]; static __u8 balloon_up_send_buffer[HV_HYP_PAGE_SIZE]; + +static unsigned long ha_pages_in_chunk; +#define HA_BYTES_IN_CHUNK (ha_pages_in_chunk << PAGE_SHIFT) + #define PAGES_IN_2M (2 * 1024 * 1024 / PAGE_SIZE) -#define HA_CHUNK (128 * 1024 * 1024 / PAGE_SIZE) struct hv_dynmem_device { struct hv_device *dev; @@ -595,12 +585,12 @@ static inline bool has_pfn_is_backed(struct hv_hotadd_state *has, struct hv_hotadd_gap *gap; /* The page is not backed. */ - if ((pfn < has->covered_start_pfn) || (pfn >= has->covered_end_pfn)) + if (pfn < has->covered_start_pfn || pfn >= has->covered_end_pfn) return false; /* Check for gaps. */ list_for_each_entry(gap, &has->gap_list, list) { - if ((pfn >= gap->start_pfn) && (pfn < gap->end_pfn)) + if (pfn >= gap->start_pfn && pfn < gap->end_pfn) return false; } @@ -724,28 +714,21 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, unsigned long processed_pfn; unsigned long total_pfn = pfn_count; - for (i = 0; i < (size/HA_CHUNK); i++) { - start_pfn = start + (i * HA_CHUNK); + for (i = 0; i < (size/ha_pages_in_chunk); i++) { + start_pfn = start + (i * ha_pages_in_chunk); scoped_guard(spinlock_irqsave, &dm_device.ha_lock) { - has->ha_end_pfn += HA_CHUNK; - - if (total_pfn > HA_CHUNK) { - processed_pfn = HA_CHUNK; - total_pfn -= HA_CHUNK; - } else { - processed_pfn = total_pfn; - total_pfn = 0; - } - - has->covered_end_pfn += processed_pfn; + has->ha_end_pfn += ha_pages_in_chunk; + processed_pfn = umin(total_pfn, ha_pages_in_chunk); + total_pfn -= processed_pfn; + has->covered_end_pfn += processed_pfn; } reinit_completion(&dm_device.ol_waitevent); nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn)); ret = add_memory(nid, PFN_PHYS((start_pfn)), - (HA_CHUNK << PAGE_SHIFT), MHP_MERGE_RESOURCE); + HA_BYTES_IN_CHUNK, MHP_MERGE_RESOURCE); if (ret) { pr_err("hot_add memory failed error is %d\n", ret); @@ -760,7 +743,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, do_hot_add = false; } scoped_guard(spinlock_irqsave, &dm_device.ha_lock) { - has->ha_end_pfn -= HA_CHUNK; + has->ha_end_pfn -= ha_pages_in_chunk; has->covered_end_pfn -= processed_pfn; } break; @@ -787,8 +770,8 @@ static void hv_online_page(struct page *pg, unsigned int order) guard(spinlock_irqsave)(&dm_device.ha_lock); list_for_each_entry(has, &dm_device.ha_region_list, list) { /* The page belongs to a different HAS. */ - if ((pfn < has->start_pfn) || - (pfn + (1UL << order) > has->end_pfn)) + if (pfn < has->start_pfn || + (pfn + (1UL << order) > has->end_pfn)) continue; hv_bring_pgs_online(has, pfn, 1UL << order); @@ -800,7 +783,7 @@ static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt) { struct hv_hotadd_state *has; struct hv_hotadd_gap *gap; - unsigned long residual, new_inc; + unsigned long residual; int ret = 0; guard(spinlock_irqsave)(&dm_device.ha_lock); @@ -836,15 +819,9 @@ static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt) * our current limit; extend it. */ if ((start_pfn + pfn_cnt) > has->end_pfn) { + /* Extend the region by multiples of ha_pages_in_chunk */ residual = (start_pfn + pfn_cnt - has->end_pfn); - /* - * Extend the region by multiples of HA_CHUNK. - */ - new_inc = (residual / HA_CHUNK) * HA_CHUNK; - if (residual % HA_CHUNK) - new_inc += HA_CHUNK; - - has->end_pfn += new_inc; + has->end_pfn += ALIGN(residual, ha_pages_in_chunk); } ret = 1; @@ -855,7 +832,7 @@ static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt) } static unsigned long handle_pg_range(unsigned long pg_start, - unsigned long pg_count) + unsigned long pg_count) { unsigned long start_pfn = pg_start; unsigned long pfn_cnt = pg_count; @@ -866,7 +843,7 @@ static unsigned long handle_pg_range(unsigned long pg_start, unsigned long res = 0, flags; pr_debug("Hot adding %lu pages starting at pfn 0x%lx.\n", pg_count, - pg_start); + pg_start); spin_lock_irqsave(&dm_device.ha_lock, flags); list_for_each_entry(has, &dm_device.ha_region_list, list) { @@ -902,22 +879,19 @@ static unsigned long handle_pg_range(unsigned long pg_start, if (start_pfn > has->start_pfn && online_section_nr(pfn_to_section_nr(start_pfn))) hv_bring_pgs_online(has, start_pfn, pgs_ol); - } - if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) { + if (has->ha_end_pfn < has->end_pfn && pfn_cnt > 0) { /* * We have some residual hot add range * that needs to be hot added; hot add * it now. Hot add a multiple of - * HA_CHUNK that fully covers the pages + * ha_pages_in_chunk that fully covers the pages * we have. */ size = (has->end_pfn - has->ha_end_pfn); if (pfn_cnt <= size) { - size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK); - if (pfn_cnt % HA_CHUNK) - size += HA_CHUNK; + size = ALIGN(pfn_cnt, ha_pages_in_chunk); } else { pfn_cnt = size; } @@ -1010,10 +984,7 @@ static void hot_add_req(struct work_struct *dummy) rg_start = dm->ha_wrk.ha_region_range.finfo.start_page; rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt; - if ((rg_start == 0) && (!dm->host_specified_ha_region)) { - unsigned long region_size; - unsigned long region_start; - + if (rg_start == 0 && !dm->host_specified_ha_region) { /* * The host has not specified the hot-add region. * Based on the hot-add page range being specified, @@ -1021,19 +992,13 @@ static void hot_add_req(struct work_struct *dummy) * that need to be hot-added while ensuring the alignment * and size requirements of Linux as it relates to hot-add. */ - region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK; - if (pfn_cnt % HA_CHUNK) - region_size += HA_CHUNK; - - region_start = (pg_start / HA_CHUNK) * HA_CHUNK; - - rg_start = region_start; - rg_sz = region_size; + rg_start = ALIGN_DOWN(pg_start, ha_pages_in_chunk); + rg_sz = ALIGN(pfn_cnt, ha_pages_in_chunk); } if (do_hot_add) resp.page_count = process_hot_add(pg_start, pfn_cnt, - rg_start, rg_sz); + rg_start, rg_sz); dm->num_pages_added += resp.page_count; #endif @@ -1211,11 +1176,10 @@ static void post_status(struct hv_dynmem_device *dm) sizeof(struct dm_status), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); - } static void free_balloon_pages(struct hv_dynmem_device *dm, - union dm_mem_page_range *range_array) + union dm_mem_page_range *range_array) { int num_pages = range_array->finfo.page_cnt; __u64 start_frame = range_array->finfo.start_page; @@ -1231,8 +1195,6 @@ static void free_balloon_pages(struct hv_dynmem_device *dm, } } - - static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm, unsigned int num_pages, struct dm_balloon_response *bl_resp, @@ -1278,7 +1240,6 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm, page_to_pfn(pg); bl_resp->range_array[i].finfo.page_cnt = alloc_unit; bl_resp->hdr.size += sizeof(union dm_mem_page_range); - } return i * alloc_unit; @@ -1332,7 +1293,7 @@ static void balloon_up(struct work_struct *dummy) if (num_ballooned == 0 || num_ballooned == num_pages) { pr_debug("Ballooned %u out of %u requested pages.\n", - num_pages, dm_device.balloon_wrk.num_pages); + num_pages, dm_device.balloon_wrk.num_pages); bl_resp->more_pages = 0; done = true; @@ -1366,16 +1327,15 @@ static void balloon_up(struct work_struct *dummy) for (i = 0; i < bl_resp->range_count; i++) free_balloon_pages(&dm_device, - &bl_resp->range_array[i]); + &bl_resp->range_array[i]); done = true; } } - } static void balloon_down(struct hv_dynmem_device *dm, - struct dm_unballoon_request *req) + struct dm_unballoon_request *req) { union dm_mem_page_range *range_array = req->range_array; int range_count = req->range_count; @@ -1389,7 +1349,7 @@ static void balloon_down(struct hv_dynmem_device *dm, } pr_debug("Freed %u ballooned pages.\n", - prev_pages_ballooned - dm->num_pages_ballooned); + prev_pages_ballooned - dm->num_pages_ballooned); if (req->more_pages == 1) return; @@ -1414,8 +1374,7 @@ static int dm_thread_func(void *dm_dev) struct hv_dynmem_device *dm = dm_dev; while (!kthread_should_stop()) { - wait_for_completion_interruptible_timeout( - &dm_device.config_event, 1*HZ); + wait_for_completion_interruptible_timeout(&dm_device.config_event, 1 * HZ); /* * The host expects us to post information on the memory * pressure every second. @@ -1439,9 +1398,8 @@ static int dm_thread_func(void *dm_dev) return 0; } - static void version_resp(struct hv_dynmem_device *dm, - struct dm_version_response *vresp) + struct dm_version_response *vresp) { struct dm_version_request version_req; int ret; @@ -1502,7 +1460,7 @@ version_error: } static void cap_resp(struct hv_dynmem_device *dm, - struct dm_capabilities_resp_msg *cap_resp) + struct dm_capabilities_resp_msg *cap_resp) { if (!cap_resp->is_accepted) { pr_err("Capabilities not accepted by host\n"); @@ -1535,7 +1493,7 @@ static void balloon_onchannelcallback(void *context) switch (dm_hdr->type) { case DM_VERSION_RESPONSE: version_resp(dm, - (struct dm_version_response *)dm_msg); + (struct dm_version_response *)dm_msg); break; case DM_CAPABILITIES_RESPONSE: @@ -1565,7 +1523,7 @@ static void balloon_onchannelcallback(void *context) dm->state = DM_BALLOON_DOWN; balloon_down(dm, - (struct dm_unballoon_request *)recv_buffer); + (struct dm_unballoon_request *)recv_buffer); break; case DM_MEM_HOT_ADD_REQUEST: @@ -1603,17 +1561,15 @@ static void balloon_onchannelcallback(void *context) default: pr_warn_ratelimited("Unhandled message: type: %d\n", dm_hdr->type); - } } - } #define HV_LARGE_REPORTING_ORDER 9 #define HV_LARGE_REPORTING_LEN (HV_HYP_PAGE_SIZE << \ HV_LARGE_REPORTING_ORDER) static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info, - struct scatterlist *sgl, unsigned int nents) + struct scatterlist *sgl, unsigned int nents) { unsigned long flags; struct hv_memory_hint *hint; @@ -1648,7 +1604,7 @@ static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info, */ /* page reporting for pages 2MB or higher */ - if (order >= HV_LARGE_REPORTING_ORDER ) { + if (order >= HV_LARGE_REPORTING_ORDER) { range->page.largepage = 1; range->page_size = HV_GPA_PAGE_RANGE_PAGE_SIZE_2MB; range->base_large_pfn = page_to_hvpfn( @@ -1662,23 +1618,21 @@ static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info, range->page.additional_pages = (sg->length / HV_HYP_PAGE_SIZE) - 1; } - } status = hv_do_rep_hypercall(HV_EXT_CALL_MEMORY_HEAT_HINT, nents, 0, hint, NULL); local_irq_restore(flags); if (!hv_result_success(status)) { - pr_err("Cold memory discard hypercall failed with status %llx\n", - status); + status); if (hv_hypercall_multi_failure > 0) hv_hypercall_multi_failure++; if (hv_result(status) == HV_STATUS_INVALID_PARAMETER) { pr_err("Underlying Hyper-V does not support order less than 9. Hypercall failed\n"); pr_err("Defaulting to page_reporting_order %d\n", - pageblock_order); + pageblock_order); page_reporting_order = pageblock_order; hv_hypercall_multi_failure++; return -EINVAL; @@ -1712,7 +1666,7 @@ static void enable_page_reporting(void) pr_err("Failed to enable cold memory discard: %d\n", ret); } else { pr_info("Cold memory discard hint enabled with order %d\n", - page_reporting_order); + page_reporting_order); } } @@ -1795,7 +1749,7 @@ static int balloon_connect_vsp(struct hv_device *dev) if (ret) goto out; - t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ); + t = wait_for_completion_timeout(&dm_device.host_event, 5 * HZ); if (t == 0) { ret = -ETIMEDOUT; goto out; @@ -1831,10 +1785,13 @@ static int balloon_connect_vsp(struct hv_device *dev) cap_msg.caps.cap_bits.hot_add = hot_add_enabled(); /* - * Specify our alignment requirements as it relates - * memory hot-add. Specify 128MB alignment. + * Specify our alignment requirements for memory hot-add. The value is + * the log base 2 of the number of megabytes in a chunk. For example, + * with 256 MiB chunks, the value is 8. The number of MiB in a chunk + * must be a power of 2. */ - cap_msg.caps.cap_bits.hot_add_alignment = 7; + cap_msg.caps.cap_bits.hot_add_alignment = + ilog2(HA_BYTES_IN_CHUNK / SZ_1M); /* * Currently the host does not use these @@ -1850,7 +1807,7 @@ static int balloon_connect_vsp(struct hv_device *dev) if (ret) goto out; - t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ); + t = wait_for_completion_timeout(&dm_device.host_event, 5 * HZ); if (t == 0) { ret = -ETIMEDOUT; goto out; @@ -1891,8 +1848,8 @@ static int hv_balloon_debug_show(struct seq_file *f, void *offset) char *sname; seq_printf(f, "%-22s: %u.%u\n", "host_version", - DYNMEM_MAJOR_VERSION(dm->version), - DYNMEM_MINOR_VERSION(dm->version)); + DYNMEM_MAJOR_VERSION(dm->version), + DYNMEM_MINOR_VERSION(dm->version)); seq_printf(f, "%-22s:", "capabilities"); if (ballooning_enabled()) @@ -1941,10 +1898,10 @@ static int hv_balloon_debug_show(struct seq_file *f, void *offset) seq_printf(f, "%-22s: %u\n", "pages_ballooned", dm->num_pages_ballooned); seq_printf(f, "%-22s: %lu\n", "total_pages_committed", - get_pages_committed(dm)); + get_pages_committed(dm)); seq_printf(f, "%-22s: %llu\n", "max_dynamic_page_count", - dm->max_dynamic_page_count); + dm->max_dynamic_page_count); return 0; } @@ -1954,7 +1911,7 @@ DEFINE_SHOW_ATTRIBUTE(hv_balloon_debug); static void hv_balloon_debugfs_init(struct hv_dynmem_device *b) { debugfs_create_file("hv-balloon", 0444, NULL, b, - &hv_balloon_debug_fops); + &hv_balloon_debug_fops); } static void hv_balloon_debugfs_exit(struct hv_dynmem_device *b) @@ -1984,8 +1941,23 @@ static int balloon_probe(struct hv_device *dev, hot_add = false; #ifdef CONFIG_MEMORY_HOTPLUG + /* + * Hot-add must operate in chunks that are of size equal to the + * memory block size because that's what the core add_memory() + * interface requires. The Hyper-V interface requires that the memory + * block size be a power of 2, which is guaranteed by the check in + * memory_dev_init(). + */ + ha_pages_in_chunk = memory_block_size_bytes() / PAGE_SIZE; do_hot_add = hot_add; #else + /* + * Without MEMORY_HOTPLUG, the guest returns a failure status for all + * hot add requests from Hyper-V, and the chunk size is used only to + * specify alignment to Hyper-V as required by the host/guest protocol. + * Somewhat arbitrarily, use 128 MiB. + */ + ha_pages_in_chunk = SZ_128M / PAGE_SIZE; do_hot_add = false; #endif dm_device.dev = dev; @@ -2097,7 +2069,6 @@ static int balloon_suspend(struct hv_device *hv_dev) tasklet_enable(&hv_dev->channel->callback_event); return 0; - } static int balloon_resume(struct hv_device *dev) @@ -2156,7 +2127,6 @@ static struct hv_driver balloon_drv = { static int __init init_balloon_drv(void) { - return vmbus_driver_register(&balloon_drv); } diff --git a/tools/hv/Makefile b/tools/hv/Makefile index bb52871da341..2e60e2c212cd 100644 --- a/tools/hv/Makefile +++ b/tools/hv/Makefile @@ -17,6 +17,7 @@ endif MAKEFLAGS += -r override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include +override CFLAGS += -Wno-address-of-packed-member ALL_TARGETS := hv_kvp_daemon hv_vss_daemon ifneq ($(ARCH), aarch64) |