From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- virt/kvm/pfncache.c | 418 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 418 insertions(+) create mode 100644 virt/kvm/pfncache.c (limited to 'virt/kvm/pfncache.c') diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c new file mode 100644 index 000000000..2d6aba677 --- /dev/null +++ b/virt/kvm/pfncache.c @@ -0,0 +1,418 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Kernel-based Virtual Machine driver for Linux + * + * This module enables kernel and guest-mode vCPU access to guest physical + * memory with suitable invalidation mechanisms. + * + * Copyright © 2021 Amazon.com, Inc. or its affiliates. + * + * Authors: + * David Woodhouse + */ + +#include +#include +#include +#include +#include + +#include "kvm_mm.h" + +/* + * MMU notifier 'invalidate_range_start' hook. + */ +void gfn_to_pfn_cache_invalidate_start(struct kvm *kvm, unsigned long start, + unsigned long end, bool may_block) +{ + DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS); + struct gfn_to_pfn_cache *gpc; + bool evict_vcpus = false; + + spin_lock(&kvm->gpc_lock); + list_for_each_entry(gpc, &kvm->gpc_list, list) { + write_lock_irq(&gpc->lock); + + /* Only a single page so no need to care about length */ + if (gpc->valid && !is_error_noslot_pfn(gpc->pfn) && + gpc->uhva >= start && gpc->uhva < end) { + gpc->valid = false; + + /* + * If a guest vCPU could be using the physical address, + * it needs to be forced out of guest mode. + */ + if (gpc->usage & KVM_GUEST_USES_PFN) { + if (!evict_vcpus) { + evict_vcpus = true; + bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS); + } + __set_bit(gpc->vcpu->vcpu_idx, vcpu_bitmap); + } + } + write_unlock_irq(&gpc->lock); + } + spin_unlock(&kvm->gpc_lock); + + if (evict_vcpus) { + /* + * KVM needs to ensure the vCPU is fully out of guest context + * before allowing the invalidation to continue. + */ + unsigned int req = KVM_REQ_OUTSIDE_GUEST_MODE; + bool called; + + /* + * If the OOM reaper is active, then all vCPUs should have + * been stopped already, so perform the request without + * KVM_REQUEST_WAIT and be sad if any needed to be IPI'd. + */ + if (!may_block) + req &= ~KVM_REQUEST_WAIT; + + called = kvm_make_vcpus_request_mask(kvm, req, vcpu_bitmap); + + WARN_ON_ONCE(called && !may_block); + } +} + +bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len) +{ + struct kvm_memslots *slots = kvm_memslots(gpc->kvm); + + if (!gpc->active) + return false; + + if ((gpc->gpa & ~PAGE_MASK) + len > PAGE_SIZE) + return false; + + if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva)) + return false; + + if (!gpc->valid) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(kvm_gpc_check); + +static void gpc_unmap_khva(kvm_pfn_t pfn, void *khva) +{ + /* Unmap the old pfn/page if it was mapped before. */ + if (!is_error_noslot_pfn(pfn) && khva) { + if (pfn_valid(pfn)) + kunmap(pfn_to_page(pfn)); +#ifdef CONFIG_HAS_IOMEM + else + memunmap(khva); +#endif + } +} + +static inline bool mmu_notifier_retry_cache(struct kvm *kvm, unsigned long mmu_seq) +{ + /* + * mn_active_invalidate_count acts for all intents and purposes + * like mmu_invalidate_in_progress here; but the latter cannot + * be used here because the invalidation of caches in the + * mmu_notifier event occurs _before_ mmu_invalidate_in_progress + * is elevated. + * + * Note, it does not matter that mn_active_invalidate_count + * is not protected by gpc->lock. It is guaranteed to + * be elevated before the mmu_notifier acquires gpc->lock, and + * isn't dropped until after mmu_invalidate_seq is updated. + */ + if (kvm->mn_active_invalidate_count) + return true; + + /* + * Ensure mn_active_invalidate_count is read before + * mmu_invalidate_seq. This pairs with the smp_wmb() in + * mmu_notifier_invalidate_range_end() to guarantee either the + * old (non-zero) value of mn_active_invalidate_count or the + * new (incremented) value of mmu_invalidate_seq is observed. + */ + smp_rmb(); + return kvm->mmu_invalidate_seq != mmu_seq; +} + +static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc) +{ + /* Note, the new page offset may be different than the old! */ + void *old_khva = gpc->khva - offset_in_page(gpc->khva); + kvm_pfn_t new_pfn = KVM_PFN_ERR_FAULT; + void *new_khva = NULL; + unsigned long mmu_seq; + + lockdep_assert_held(&gpc->refresh_lock); + + lockdep_assert_held_write(&gpc->lock); + + /* + * Invalidate the cache prior to dropping gpc->lock, the gpa=>uhva + * assets have already been updated and so a concurrent check() from a + * different task may not fail the gpa/uhva/generation checks. + */ + gpc->valid = false; + + do { + mmu_seq = gpc->kvm->mmu_invalidate_seq; + smp_rmb(); + + write_unlock_irq(&gpc->lock); + + /* + * If the previous iteration "failed" due to an mmu_notifier + * event, release the pfn and unmap the kernel virtual address + * from the previous attempt. Unmapping might sleep, so this + * needs to be done after dropping the lock. Opportunistically + * check for resched while the lock isn't held. + */ + if (new_pfn != KVM_PFN_ERR_FAULT) { + /* + * Keep the mapping if the previous iteration reused + * the existing mapping and didn't create a new one. + */ + if (new_khva != old_khva) + gpc_unmap_khva(new_pfn, new_khva); + + kvm_release_pfn_clean(new_pfn); + + cond_resched(); + } + + /* We always request a writeable mapping */ + new_pfn = hva_to_pfn(gpc->uhva, false, false, NULL, true, NULL); + if (is_error_noslot_pfn(new_pfn)) + goto out_error; + + /* + * Obtain a new kernel mapping if KVM itself will access the + * pfn. Note, kmap() and memremap() can both sleep, so this + * too must be done outside of gpc->lock! + */ + if (gpc->usage & KVM_HOST_USES_PFN) { + if (new_pfn == gpc->pfn) { + new_khva = old_khva; + } else if (pfn_valid(new_pfn)) { + new_khva = kmap(pfn_to_page(new_pfn)); +#ifdef CONFIG_HAS_IOMEM + } else { + new_khva = memremap(pfn_to_hpa(new_pfn), PAGE_SIZE, MEMREMAP_WB); +#endif + } + if (!new_khva) { + kvm_release_pfn_clean(new_pfn); + goto out_error; + } + } + + write_lock_irq(&gpc->lock); + + /* + * Other tasks must wait for _this_ refresh to complete before + * attempting to refresh. + */ + WARN_ON_ONCE(gpc->valid); + } while (mmu_notifier_retry_cache(gpc->kvm, mmu_seq)); + + gpc->valid = true; + gpc->pfn = new_pfn; + gpc->khva = new_khva + (gpc->gpa & ~PAGE_MASK); + + /* + * Put the reference to the _new_ pfn. The pfn is now tracked by the + * cache and can be safely migrated, swapped, etc... as the cache will + * invalidate any mappings in response to relevant mmu_notifier events. + */ + kvm_release_pfn_clean(new_pfn); + + return 0; + +out_error: + write_lock_irq(&gpc->lock); + + return -EFAULT; +} + +static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa, + unsigned long len) +{ + struct kvm_memslots *slots = kvm_memslots(gpc->kvm); + unsigned long page_offset = gpa & ~PAGE_MASK; + bool unmap_old = false; + unsigned long old_uhva; + kvm_pfn_t old_pfn; + void *old_khva; + int ret; + + /* + * If must fit within a single page. The 'len' argument is + * only to enforce that. + */ + if (page_offset + len > PAGE_SIZE) + return -EINVAL; + + /* + * If another task is refreshing the cache, wait for it to complete. + * There is no guarantee that concurrent refreshes will see the same + * gpa, memslots generation, etc..., so they must be fully serialized. + */ + mutex_lock(&gpc->refresh_lock); + + write_lock_irq(&gpc->lock); + + if (!gpc->active) { + ret = -EINVAL; + goto out_unlock; + } + + old_pfn = gpc->pfn; + old_khva = gpc->khva - offset_in_page(gpc->khva); + old_uhva = gpc->uhva; + + /* If the userspace HVA is invalid, refresh that first */ + if (gpc->gpa != gpa || gpc->generation != slots->generation || + kvm_is_error_hva(gpc->uhva)) { + gfn_t gfn = gpa_to_gfn(gpa); + + gpc->gpa = gpa; + gpc->generation = slots->generation; + gpc->memslot = __gfn_to_memslot(slots, gfn); + gpc->uhva = gfn_to_hva_memslot(gpc->memslot, gfn); + + if (kvm_is_error_hva(gpc->uhva)) { + ret = -EFAULT; + goto out; + } + } + + /* + * If the userspace HVA changed or the PFN was already invalid, + * drop the lock and do the HVA to PFN lookup again. + */ + if (!gpc->valid || old_uhva != gpc->uhva) { + ret = hva_to_pfn_retry(gpc); + } else { + /* + * If the HVA→PFN mapping was already valid, don't unmap it. + * But do update gpc->khva because the offset within the page + * may have changed. + */ + gpc->khva = old_khva + page_offset; + ret = 0; + goto out_unlock; + } + + out: + /* + * Invalidate the cache and purge the pfn/khva if the refresh failed. + * Some/all of the uhva, gpa, and memslot generation info may still be + * valid, leave it as is. + */ + if (ret) { + gpc->valid = false; + gpc->pfn = KVM_PFN_ERR_FAULT; + gpc->khva = NULL; + } + + /* Detect a pfn change before dropping the lock! */ + unmap_old = (old_pfn != gpc->pfn); + +out_unlock: + write_unlock_irq(&gpc->lock); + + mutex_unlock(&gpc->refresh_lock); + + if (unmap_old) + gpc_unmap_khva(old_pfn, old_khva); + + return ret; +} + +int kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, unsigned long len) +{ + return __kvm_gpc_refresh(gpc, gpc->gpa, len); +} +EXPORT_SYMBOL_GPL(kvm_gpc_refresh); + +void kvm_gpc_init(struct gfn_to_pfn_cache *gpc, struct kvm *kvm, + struct kvm_vcpu *vcpu, enum pfn_cache_usage usage) +{ + WARN_ON_ONCE(!usage || (usage & KVM_GUEST_AND_HOST_USE_PFN) != usage); + WARN_ON_ONCE((usage & KVM_GUEST_USES_PFN) && !vcpu); + + rwlock_init(&gpc->lock); + mutex_init(&gpc->refresh_lock); + + gpc->kvm = kvm; + gpc->vcpu = vcpu; + gpc->usage = usage; + gpc->pfn = KVM_PFN_ERR_FAULT; + gpc->uhva = KVM_HVA_ERR_BAD; +} +EXPORT_SYMBOL_GPL(kvm_gpc_init); + +int kvm_gpc_activate(struct gfn_to_pfn_cache *gpc, gpa_t gpa, unsigned long len) +{ + struct kvm *kvm = gpc->kvm; + + if (!gpc->active) { + if (KVM_BUG_ON(gpc->valid, kvm)) + return -EIO; + + spin_lock(&kvm->gpc_lock); + list_add(&gpc->list, &kvm->gpc_list); + spin_unlock(&kvm->gpc_lock); + + /* + * Activate the cache after adding it to the list, a concurrent + * refresh must not establish a mapping until the cache is + * reachable by mmu_notifier events. + */ + write_lock_irq(&gpc->lock); + gpc->active = true; + write_unlock_irq(&gpc->lock); + } + return __kvm_gpc_refresh(gpc, gpa, len); +} +EXPORT_SYMBOL_GPL(kvm_gpc_activate); + +void kvm_gpc_deactivate(struct gfn_to_pfn_cache *gpc) +{ + struct kvm *kvm = gpc->kvm; + kvm_pfn_t old_pfn; + void *old_khva; + + if (gpc->active) { + /* + * Deactivate the cache before removing it from the list, KVM + * must stall mmu_notifier events until all users go away, i.e. + * until gpc->lock is dropped and refresh is guaranteed to fail. + */ + write_lock_irq(&gpc->lock); + gpc->active = false; + gpc->valid = false; + + /* + * Leave the GPA => uHVA cache intact, it's protected by the + * memslot generation. The PFN lookup needs to be redone every + * time as mmu_notifier protection is lost when the cache is + * removed from the VM's gpc_list. + */ + old_khva = gpc->khva - offset_in_page(gpc->khva); + gpc->khva = NULL; + + old_pfn = gpc->pfn; + gpc->pfn = KVM_PFN_ERR_FAULT; + write_unlock_irq(&gpc->lock); + + spin_lock(&kvm->gpc_lock); + list_del(&gpc->list); + spin_unlock(&kvm->gpc_lock); + + gpc_unmap_khva(old_pfn, old_khva); + } +} +EXPORT_SYMBOL_GPL(kvm_gpc_deactivate); -- cgit v1.2.3