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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/x86/hyperv/hv_init.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'arch/x86/hyperv/hv_init.c')
-rw-r--r--arch/x86/hyperv/hv_init.c614
1 files changed, 614 insertions, 0 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
new file mode 100644
index 000000000..41ef036eb
--- /dev/null
+++ b/arch/x86/hyperv/hv_init.c
@@ -0,0 +1,614 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * X86 specific Hyper-V initialization code.
+ *
+ * Copyright (C) 2016, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/efi.h>
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <asm/apic.h>
+#include <asm/desc.h>
+#include <asm/sev.h>
+#include <asm/hypervisor.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
+#include <asm/idtentry.h>
+#include <linux/kexec.h>
+#include <linux/version.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/hyperv.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/cpuhotplug.h>
+#include <linux/syscore_ops.h>
+#include <clocksource/hyperv_timer.h>
+#include <linux/highmem.h>
+#include <linux/swiotlb.h>
+
+int hyperv_init_cpuhp;
+u64 hv_current_partition_id = ~0ull;
+EXPORT_SYMBOL_GPL(hv_current_partition_id);
+
+void *hv_hypercall_pg;
+EXPORT_SYMBOL_GPL(hv_hypercall_pg);
+
+union hv_ghcb * __percpu *hv_ghcb_pg;
+
+/* Storage to save the hypercall page temporarily for hibernation */
+static void *hv_hypercall_pg_saved;
+
+struct hv_vp_assist_page **hv_vp_assist_page;
+EXPORT_SYMBOL_GPL(hv_vp_assist_page);
+
+static int hyperv_init_ghcb(void)
+{
+ u64 ghcb_gpa;
+ void *ghcb_va;
+ void **ghcb_base;
+
+ if (!hv_isolation_type_snp())
+ return 0;
+
+ if (!hv_ghcb_pg)
+ return -EINVAL;
+
+ /*
+ * GHCB page is allocated by paravisor. The address
+ * returned by MSR_AMD64_SEV_ES_GHCB is above shared
+ * memory boundary and map it here.
+ */
+ rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa);
+ ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+ if (!ghcb_va)
+ return -ENOMEM;
+
+ ghcb_base = (void **)this_cpu_ptr(hv_ghcb_pg);
+ *ghcb_base = ghcb_va;
+
+ return 0;
+}
+
+static int hv_cpu_init(unsigned int cpu)
+{
+ union hv_vp_assist_msr_contents msr = { 0 };
+ struct hv_vp_assist_page **hvp = &hv_vp_assist_page[cpu];
+ int ret;
+
+ ret = hv_common_cpu_init(cpu);
+ if (ret)
+ return ret;
+
+ if (!hv_vp_assist_page)
+ return 0;
+
+ if (hv_root_partition) {
+ /*
+ * For root partition we get the hypervisor provided VP assist
+ * page, instead of allocating a new page.
+ */
+ rdmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
+ *hvp = memremap(msr.pfn << HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT,
+ PAGE_SIZE, MEMREMAP_WB);
+ } else {
+ /*
+ * The VP assist page is an "overlay" page (see Hyper-V TLFS's
+ * Section 5.2.1 "GPA Overlay Pages"). Here it must be zeroed
+ * out to make sure we always write the EOI MSR in
+ * hv_apic_eoi_write() *after* the EOI optimization is disabled
+ * in hv_cpu_die(), otherwise a CPU may not be stopped in the
+ * case of CPU offlining and the VM will hang.
+ */
+ if (!*hvp)
+ *hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO);
+ if (*hvp)
+ msr.pfn = vmalloc_to_pfn(*hvp);
+
+ }
+ if (!WARN_ON(!(*hvp))) {
+ msr.enable = 1;
+ wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
+ }
+
+ return hyperv_init_ghcb();
+}
+
+static void (*hv_reenlightenment_cb)(void);
+
+static void hv_reenlightenment_notify(struct work_struct *dummy)
+{
+ struct hv_tsc_emulation_status emu_status;
+
+ rdmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status);
+
+ /* Don't issue the callback if TSC accesses are not emulated */
+ if (hv_reenlightenment_cb && emu_status.inprogress)
+ hv_reenlightenment_cb();
+}
+static DECLARE_DELAYED_WORK(hv_reenlightenment_work, hv_reenlightenment_notify);
+
+void hyperv_stop_tsc_emulation(void)
+{
+ u64 freq;
+ struct hv_tsc_emulation_status emu_status;
+
+ rdmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status);
+ emu_status.inprogress = 0;
+ wrmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status);
+
+ rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
+ tsc_khz = div64_u64(freq, 1000);
+}
+EXPORT_SYMBOL_GPL(hyperv_stop_tsc_emulation);
+
+static inline bool hv_reenlightenment_available(void)
+{
+ /*
+ * Check for required features and privileges to make TSC frequency
+ * change notifications work.
+ */
+ return ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
+ ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE &&
+ ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT;
+}
+
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_reenlightenment)
+{
+ ack_APIC_irq();
+ inc_irq_stat(irq_hv_reenlightenment_count);
+ schedule_delayed_work(&hv_reenlightenment_work, HZ/10);
+}
+
+void set_hv_tscchange_cb(void (*cb)(void))
+{
+ struct hv_reenlightenment_control re_ctrl = {
+ .vector = HYPERV_REENLIGHTENMENT_VECTOR,
+ .enabled = 1,
+ };
+ struct hv_tsc_emulation_control emu_ctrl = {.enabled = 1};
+
+ if (!hv_reenlightenment_available()) {
+ pr_warn("Hyper-V: reenlightenment support is unavailable\n");
+ return;
+ }
+
+ if (!hv_vp_index)
+ return;
+
+ hv_reenlightenment_cb = cb;
+
+ /* Make sure callback is registered before we write to MSRs */
+ wmb();
+
+ re_ctrl.target_vp = hv_vp_index[get_cpu()];
+
+ wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
+ wrmsrl(HV_X64_MSR_TSC_EMULATION_CONTROL, *((u64 *)&emu_ctrl));
+
+ put_cpu();
+}
+EXPORT_SYMBOL_GPL(set_hv_tscchange_cb);
+
+void clear_hv_tscchange_cb(void)
+{
+ struct hv_reenlightenment_control re_ctrl;
+
+ if (!hv_reenlightenment_available())
+ return;
+
+ rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *(u64 *)&re_ctrl);
+ re_ctrl.enabled = 0;
+ wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *(u64 *)&re_ctrl);
+
+ hv_reenlightenment_cb = NULL;
+}
+EXPORT_SYMBOL_GPL(clear_hv_tscchange_cb);
+
+static int hv_cpu_die(unsigned int cpu)
+{
+ struct hv_reenlightenment_control re_ctrl;
+ unsigned int new_cpu;
+ void **ghcb_va;
+
+ if (hv_ghcb_pg) {
+ ghcb_va = (void **)this_cpu_ptr(hv_ghcb_pg);
+ if (*ghcb_va)
+ memunmap(*ghcb_va);
+ *ghcb_va = NULL;
+ }
+
+ hv_common_cpu_die(cpu);
+
+ if (hv_vp_assist_page && hv_vp_assist_page[cpu]) {
+ union hv_vp_assist_msr_contents msr = { 0 };
+ if (hv_root_partition) {
+ /*
+ * For root partition the VP assist page is mapped to
+ * hypervisor provided page, and thus we unmap the
+ * page here and nullify it, so that in future we have
+ * correct page address mapped in hv_cpu_init.
+ */
+ memunmap(hv_vp_assist_page[cpu]);
+ hv_vp_assist_page[cpu] = NULL;
+ rdmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
+ msr.enable = 0;
+ }
+ wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
+ }
+
+ if (hv_reenlightenment_cb == NULL)
+ return 0;
+
+ rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
+ if (re_ctrl.target_vp == hv_vp_index[cpu]) {
+ /*
+ * Reassign reenlightenment notifications to some other online
+ * CPU or just disable the feature if there are no online CPUs
+ * left (happens on hibernation).
+ */
+ new_cpu = cpumask_any_but(cpu_online_mask, cpu);
+
+ if (new_cpu < nr_cpu_ids)
+ re_ctrl.target_vp = hv_vp_index[new_cpu];
+ else
+ re_ctrl.enabled = 0;
+
+ wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
+ }
+
+ return 0;
+}
+
+static int __init hv_pci_init(void)
+{
+ int gen2vm = efi_enabled(EFI_BOOT);
+
+ /*
+ * For Generation-2 VM, we exit from pci_arch_init() by returning 0.
+ * The purpose is to suppress the harmless warning:
+ * "PCI: Fatal: No config space access function found"
+ */
+ if (gen2vm)
+ return 0;
+
+ /* For Generation-1 VM, we'll proceed in pci_arch_init(). */
+ return 1;
+}
+
+static int hv_suspend(void)
+{
+ union hv_x64_msr_hypercall_contents hypercall_msr;
+ int ret;
+
+ if (hv_root_partition)
+ return -EPERM;
+
+ /*
+ * Reset the hypercall page as it is going to be invalidated
+ * across hibernation. Setting hv_hypercall_pg to NULL ensures
+ * that any subsequent hypercall operation fails safely instead of
+ * crashing due to an access of an invalid page. The hypercall page
+ * pointer is restored on resume.
+ */
+ hv_hypercall_pg_saved = hv_hypercall_pg;
+ hv_hypercall_pg = NULL;
+
+ /* Disable the hypercall page in the hypervisor */
+ rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+ hypercall_msr.enable = 0;
+ wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ ret = hv_cpu_die(0);
+ return ret;
+}
+
+static void hv_resume(void)
+{
+ union hv_x64_msr_hypercall_contents hypercall_msr;
+ int ret;
+
+ ret = hv_cpu_init(0);
+ WARN_ON(ret);
+
+ /* Re-enable the hypercall page */
+ rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+ hypercall_msr.enable = 1;
+ hypercall_msr.guest_physical_address =
+ vmalloc_to_pfn(hv_hypercall_pg_saved);
+ wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ hv_hypercall_pg = hv_hypercall_pg_saved;
+ hv_hypercall_pg_saved = NULL;
+
+ /*
+ * Reenlightenment notifications are disabled by hv_cpu_die(0),
+ * reenable them here if hv_reenlightenment_cb was previously set.
+ */
+ if (hv_reenlightenment_cb)
+ set_hv_tscchange_cb(hv_reenlightenment_cb);
+}
+
+/* Note: when the ops are called, only CPU0 is online and IRQs are disabled. */
+static struct syscore_ops hv_syscore_ops = {
+ .suspend = hv_suspend,
+ .resume = hv_resume,
+};
+
+static void (* __initdata old_setup_percpu_clockev)(void);
+
+static void __init hv_stimer_setup_percpu_clockev(void)
+{
+ /*
+ * Ignore any errors in setting up stimer clockevents
+ * as we can run with the LAPIC timer as a fallback.
+ */
+ (void)hv_stimer_alloc(false);
+
+ /*
+ * Still register the LAPIC timer, because the direct-mode STIMER is
+ * not supported by old versions of Hyper-V. This also allows users
+ * to switch to LAPIC timer via /sys, if they want to.
+ */
+ if (old_setup_percpu_clockev)
+ old_setup_percpu_clockev();
+}
+
+static void __init hv_get_partition_id(void)
+{
+ struct hv_get_partition_id *output_page;
+ u64 status;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
+ status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page);
+ if (!hv_result_success(status)) {
+ /* No point in proceeding if this failed */
+ pr_err("Failed to get partition ID: %lld\n", status);
+ BUG();
+ }
+ hv_current_partition_id = output_page->partition_id;
+ local_irq_restore(flags);
+}
+
+/*
+ * This function is to be invoked early in the boot sequence after the
+ * hypervisor has been detected.
+ *
+ * 1. Setup the hypercall page.
+ * 2. Register Hyper-V specific clocksource.
+ * 3. Setup Hyper-V specific APIC entry points.
+ */
+void __init hyperv_init(void)
+{
+ u64 guest_id;
+ union hv_x64_msr_hypercall_contents hypercall_msr;
+ int cpuhp;
+
+ if (x86_hyper_type != X86_HYPER_MS_HYPERV)
+ return;
+
+ if (hv_common_init())
+ return;
+
+ hv_vp_assist_page = kcalloc(num_possible_cpus(),
+ sizeof(*hv_vp_assist_page), GFP_KERNEL);
+ if (!hv_vp_assist_page) {
+ ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
+ goto common_free;
+ }
+
+ if (hv_isolation_type_snp()) {
+ /* Negotiate GHCB Version. */
+ if (!hv_ghcb_negotiate_protocol())
+ hv_ghcb_terminate(SEV_TERM_SET_GEN,
+ GHCB_SEV_ES_PROT_UNSUPPORTED);
+
+ hv_ghcb_pg = alloc_percpu(union hv_ghcb *);
+ if (!hv_ghcb_pg)
+ goto free_vp_assist_page;
+ }
+
+ cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
+ hv_cpu_init, hv_cpu_die);
+ if (cpuhp < 0)
+ goto free_ghcb_page;
+
+ /*
+ * Setup the hypercall page and enable hypercalls.
+ * 1. Register the guest ID
+ * 2. Enable the hypercall and register the hypercall page
+ */
+ guest_id = hv_generate_guest_id(LINUX_VERSION_CODE);
+ wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+ /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+ hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
+ VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
+ VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
+ __builtin_return_address(0));
+ if (hv_hypercall_pg == NULL)
+ goto clean_guest_os_id;
+
+ rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+ hypercall_msr.enable = 1;
+
+ if (hv_root_partition) {
+ struct page *pg;
+ void *src;
+
+ /*
+ * For the root partition, the hypervisor will set up its
+ * hypercall page. The hypervisor guarantees it will not show
+ * up in the root's address space. The root can't change the
+ * location of the hypercall page.
+ *
+ * Order is important here. We must enable the hypercall page
+ * so it is populated with code, then copy the code to an
+ * executable page.
+ */
+ wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ pg = vmalloc_to_page(hv_hypercall_pg);
+ src = memremap(hypercall_msr.guest_physical_address << PAGE_SHIFT, PAGE_SIZE,
+ MEMREMAP_WB);
+ BUG_ON(!src);
+ memcpy_to_page(pg, 0, src, HV_HYP_PAGE_SIZE);
+ memunmap(src);
+
+ hv_remap_tsc_clocksource();
+ } else {
+ hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
+ wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+ }
+
+ /*
+ * hyperv_init() is called before LAPIC is initialized: see
+ * apic_intr_mode_init() -> x86_platform.apic_post_init() and
+ * apic_bsp_setup() -> setup_local_APIC(). The direct-mode STIMER
+ * depends on LAPIC, so hv_stimer_alloc() should be called from
+ * x86_init.timers.setup_percpu_clockev.
+ */
+ old_setup_percpu_clockev = x86_init.timers.setup_percpu_clockev;
+ x86_init.timers.setup_percpu_clockev = hv_stimer_setup_percpu_clockev;
+
+ hv_apic_init();
+
+ x86_init.pci.arch_init = hv_pci_init;
+
+ register_syscore_ops(&hv_syscore_ops);
+
+ hyperv_init_cpuhp = cpuhp;
+
+ if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_ACCESS_PARTITION_ID)
+ hv_get_partition_id();
+
+ BUG_ON(hv_root_partition && hv_current_partition_id == ~0ull);
+
+#ifdef CONFIG_PCI_MSI
+ /*
+ * If we're running as root, we want to create our own PCI MSI domain.
+ * We can't set this in hv_pci_init because that would be too late.
+ */
+ if (hv_root_partition)
+ x86_init.irqs.create_pci_msi_domain = hv_create_pci_msi_domain;
+#endif
+
+ /* Query the VMs extended capability once, so that it can be cached. */
+ hv_query_ext_cap(0);
+
+#ifdef CONFIG_SWIOTLB
+ /*
+ * Swiotlb bounce buffer needs to be mapped in extra address
+ * space. Map function doesn't work in the early place and so
+ * call swiotlb_update_mem_attributes() here.
+ */
+ if (hv_is_isolation_supported())
+ swiotlb_update_mem_attributes();
+#endif
+
+ return;
+
+clean_guest_os_id:
+ wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
+ cpuhp_remove_state(cpuhp);
+free_ghcb_page:
+ free_percpu(hv_ghcb_pg);
+free_vp_assist_page:
+ kfree(hv_vp_assist_page);
+ hv_vp_assist_page = NULL;
+common_free:
+ hv_common_free();
+}
+
+/*
+ * This routine is called before kexec/kdump, it does the required cleanup.
+ */
+void hyperv_cleanup(void)
+{
+ union hv_x64_msr_hypercall_contents hypercall_msr;
+ union hv_reference_tsc_msr tsc_msr;
+
+ /* Reset our OS id */
+ wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+ hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
+
+ /*
+ * Reset hypercall page reference before reset the page,
+ * let hypercall operations fail safely rather than
+ * panic the kernel for using invalid hypercall page
+ */
+ hv_hypercall_pg = NULL;
+
+ /* Reset the hypercall page */
+ hypercall_msr.as_uint64 = hv_get_register(HV_X64_MSR_HYPERCALL);
+ hypercall_msr.enable = 0;
+ hv_set_register(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ /* Reset the TSC page */
+ tsc_msr.as_uint64 = hv_get_register(HV_X64_MSR_REFERENCE_TSC);
+ tsc_msr.enable = 0;
+ hv_set_register(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
+}
+
+void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
+{
+ static bool panic_reported;
+ u64 guest_id;
+
+ if (in_die && !panic_on_oops)
+ return;
+
+ /*
+ * We prefer to report panic on 'die' chain as we have proper
+ * registers to report, but if we miss it (e.g. on BUG()) we need
+ * to report it on 'panic'.
+ */
+ if (panic_reported)
+ return;
+ panic_reported = true;
+
+ rdmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+ wrmsrl(HV_X64_MSR_CRASH_P0, err);
+ wrmsrl(HV_X64_MSR_CRASH_P1, guest_id);
+ wrmsrl(HV_X64_MSR_CRASH_P2, regs->ip);
+ wrmsrl(HV_X64_MSR_CRASH_P3, regs->ax);
+ wrmsrl(HV_X64_MSR_CRASH_P4, regs->sp);
+
+ /*
+ * Let Hyper-V know there is crash data available
+ */
+ wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
+}
+EXPORT_SYMBOL_GPL(hyperv_report_panic);
+
+bool hv_is_hyperv_initialized(void)
+{
+ union hv_x64_msr_hypercall_contents hypercall_msr;
+
+ /*
+ * Ensure that we're really on Hyper-V, and not a KVM or Xen
+ * emulation of Hyper-V
+ */
+ if (x86_hyper_type != X86_HYPER_MS_HYPERV)
+ return false;
+
+ /*
+ * Verify that earlier initialization succeeded by checking
+ * that the hypercall page is setup
+ */
+ hypercall_msr.as_uint64 = 0;
+ rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ return hypercall_msr.enable;
+}
+EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);