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().
  ...

1 files changed, 1230 insertions, 0 deletions

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
new file mode 100644
index 000000000..552653fa1
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -0,0 +1,1230 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Google LLC
+ * Author: Quentin Perret <qperret@google.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+#include <asm/kvm_pgtable.h>
+#include <asm/kvm_pkvm.h>
+#include <asm/stage2_pgtable.h>
+
+#include <hyp/fault.h>
+
+#include <nvhe/gfp.h>
+#include <nvhe/memory.h>
+#include <nvhe/mem_protect.h>
+#include <nvhe/mm.h>
+
+#define KVM_HOST_S2_FLAGS (KVM_PGTABLE_S2_NOFWB | KVM_PGTABLE_S2_IDMAP)
+
+struct host_mmu host_mmu;
+
+static struct hyp_pool host_s2_pool;
+
+static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm);
+#define current_vm (*this_cpu_ptr(&__current_vm))
+
+static void guest_lock_component(struct pkvm_hyp_vm *vm)
+{
+	hyp_spin_lock(&vm->lock);
+	current_vm = vm;
+}
+
+static void guest_unlock_component(struct pkvm_hyp_vm *vm)
+{
+	current_vm = NULL;
+	hyp_spin_unlock(&vm->lock);
+}
+
+static void host_lock_component(void)
+{
+	hyp_spin_lock(&host_mmu.lock);
+}
+
+static void host_unlock_component(void)
+{
+	hyp_spin_unlock(&host_mmu.lock);
+}
+
+static void hyp_lock_component(void)
+{
+	hyp_spin_lock(&pkvm_pgd_lock);
+}
+
+static void hyp_unlock_component(void)
+{
+	hyp_spin_unlock(&pkvm_pgd_lock);
+}
+
+static void *host_s2_zalloc_pages_exact(size_t size)
+{
+	void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size));
+
+	hyp_split_page(hyp_virt_to_page(addr));
+
+	/*
+	 * The size of concatenated PGDs is always a power of two of PAGE_SIZE,
+	 * so there should be no need to free any of the tail pages to make the
+	 * allocation exact.
+	 */
+	WARN_ON(size != (PAGE_SIZE << get_order(size)));
+
+	return addr;
+}
+
+static void *host_s2_zalloc_page(void *pool)
+{
+	return hyp_alloc_pages(pool, 0);
+}
+
+static void host_s2_get_page(void *addr)
+{
+	hyp_get_page(&host_s2_pool, addr);
+}
+
+static void host_s2_put_page(void *addr)
+{
+	hyp_put_page(&host_s2_pool, addr);
+}
+
+static void host_s2_free_removed_table(void *addr, u32 level)
+{
+	kvm_pgtable_stage2_free_removed(&host_mmu.mm_ops, addr, level);
+}
+
+static int prepare_s2_pool(void *pgt_pool_base)
+{
+	unsigned long nr_pages, pfn;
+	int ret;
+
+	pfn = hyp_virt_to_pfn(pgt_pool_base);
+	nr_pages = host_s2_pgtable_pages();
+	ret = hyp_pool_init(&host_s2_pool, pfn, nr_pages, 0);
+	if (ret)
+		return ret;
+
+	host_mmu.mm_ops = (struct kvm_pgtable_mm_ops) {
+		.zalloc_pages_exact = host_s2_zalloc_pages_exact,
+		.zalloc_page = host_s2_zalloc_page,
+		.free_removed_table = host_s2_free_removed_table,
+		.phys_to_virt = hyp_phys_to_virt,
+		.virt_to_phys = hyp_virt_to_phys,
+		.page_count = hyp_page_count,
+		.get_page = host_s2_get_page,
+		.put_page = host_s2_put_page,
+	};
+
+	return 0;
+}
+
+static void prepare_host_vtcr(void)
+{
+	u32 parange, phys_shift;
+
+	/* The host stage 2 is id-mapped, so use parange for T0SZ */
+	parange = kvm_get_parange(id_aa64mmfr0_el1_sys_val);
+	phys_shift = id_aa64mmfr0_parange_to_phys_shift(parange);
+
+	host_mmu.arch.vtcr = kvm_get_vtcr(id_aa64mmfr0_el1_sys_val,
+					  id_aa64mmfr1_el1_sys_val, phys_shift);
+}
+
+static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot);
+
+int kvm_host_prepare_stage2(void *pgt_pool_base)
+{
+	struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu;
+	int ret;
+
+	prepare_host_vtcr();
+	hyp_spin_lock_init(&host_mmu.lock);
+	mmu->arch = &host_mmu.arch;
+
+	ret = prepare_s2_pool(pgt_pool_base);
+	if (ret)
+		return ret;
+
+	ret = __kvm_pgtable_stage2_init(&host_mmu.pgt, mmu,
+					&host_mmu.mm_ops, KVM_HOST_S2_FLAGS,
+					host_stage2_force_pte_cb);
+	if (ret)
+		return ret;
+
+	mmu->pgd_phys = __hyp_pa(host_mmu.pgt.pgd);
+	mmu->pgt = &host_mmu.pgt;
+	atomic64_set(&mmu->vmid.id, 0);
+
+	return 0;
+}
+
+static bool guest_stage2_force_pte_cb(u64 addr, u64 end,
+				      enum kvm_pgtable_prot prot)
+{
+	return true;
+}
+
+static void *guest_s2_zalloc_pages_exact(size_t size)
+{
+	void *addr = hyp_alloc_pages(&current_vm->pool, get_order(size));
+
+	WARN_ON(size != (PAGE_SIZE << get_order(size)));
+	hyp_split_page(hyp_virt_to_page(addr));
+
+	return addr;
+}
+
+static void guest_s2_free_pages_exact(void *addr, unsigned long size)
+{
+	u8 order = get_order(size);
+	unsigned int i;
+
+	for (i = 0; i < (1 << order); i++)
+		hyp_put_page(&current_vm->pool, addr + (i * PAGE_SIZE));
+}
+
+static void *guest_s2_zalloc_page(void *mc)
+{
+	struct hyp_page *p;
+	void *addr;
+
+	addr = hyp_alloc_pages(&current_vm->pool, 0);
+	if (addr)
+		return addr;
+
+	addr = pop_hyp_memcache(mc, hyp_phys_to_virt);
+	if (!addr)
+		return addr;
+
+	memset(addr, 0, PAGE_SIZE);
+	p = hyp_virt_to_page(addr);
+	memset(p, 0, sizeof(*p));
+	p->refcount = 1;
+
+	return addr;
+}
+
+static void guest_s2_get_page(void *addr)
+{
+	hyp_get_page(&current_vm->pool, addr);
+}
+
+static void guest_s2_put_page(void *addr)
+{
+	hyp_put_page(&current_vm->pool, addr);
+}
+
+static void clean_dcache_guest_page(void *va, size_t size)
+{
+	__clean_dcache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size);
+	hyp_fixmap_unmap();
+}
+
+static void invalidate_icache_guest_page(void *va, size_t size)
+{
+	__invalidate_icache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size);
+	hyp_fixmap_unmap();
+}
+
+int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd)
+{
+	struct kvm_s2_mmu *mmu = &vm->kvm.arch.mmu;
+	unsigned long nr_pages;
+	int ret;
+
+	nr_pages = kvm_pgtable_stage2_pgd_size(vm->kvm.arch.vtcr) >> PAGE_SHIFT;
+	ret = hyp_pool_init(&vm->pool, hyp_virt_to_pfn(pgd), nr_pages, 0);
+	if (ret)
+		return ret;
+
+	hyp_spin_lock_init(&vm->lock);
+	vm->mm_ops = (struct kvm_pgtable_mm_ops) {
+		.zalloc_pages_exact	= guest_s2_zalloc_pages_exact,
+		.free_pages_exact	= guest_s2_free_pages_exact,
+		.zalloc_page		= guest_s2_zalloc_page,
+		.phys_to_virt		= hyp_phys_to_virt,
+		.virt_to_phys		= hyp_virt_to_phys,
+		.page_count		= hyp_page_count,
+		.get_page		= guest_s2_get_page,
+		.put_page		= guest_s2_put_page,
+		.dcache_clean_inval_poc	= clean_dcache_guest_page,
+		.icache_inval_pou	= invalidate_icache_guest_page,
+	};
+
+	guest_lock_component(vm);
+	ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0,
+					guest_stage2_force_pte_cb);
+	guest_unlock_component(vm);
+	if (ret)
+		return ret;
+
+	vm->kvm.arch.mmu.pgd_phys = __hyp_pa(vm->pgt.pgd);
+
+	return 0;
+}
+
+void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc)
+{
+	void *addr;
+
+	/* Dump all pgtable pages in the hyp_pool */
+	guest_lock_component(vm);
+	kvm_pgtable_stage2_destroy(&vm->pgt);
+	vm->kvm.arch.mmu.pgd_phys = 0ULL;
+	guest_unlock_component(vm);
+
+	/* Drain the hyp_pool into the memcache */
+	addr = hyp_alloc_pages(&vm->pool, 0);
+	while (addr) {
+		memset(hyp_virt_to_page(addr), 0, sizeof(struct hyp_page));
+		push_hyp_memcache(mc, addr, hyp_virt_to_phys);
+		WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(addr), 1));
+		addr = hyp_alloc_pages(&vm->pool, 0);
+	}
+}
+
+int __pkvm_prot_finalize(void)
+{
+	struct kvm_s2_mmu *mmu = &host_mmu.arch.mmu;
+	struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
+
+	if (params->hcr_el2 & HCR_VM)
+		return -EPERM;
+
+	params->vttbr = kvm_get_vttbr(mmu);
+	params->vtcr = host_mmu.arch.vtcr;
+	params->hcr_el2 |= HCR_VM;
+	kvm_flush_dcache_to_poc(params, sizeof(*params));
+
+	write_sysreg(params->hcr_el2, hcr_el2);
+	__load_stage2(&host_mmu.arch.mmu, &host_mmu.arch);
+
+	/*
+	 * Make sure to have an ISB before the TLB maintenance below but only
+	 * when __load_stage2() doesn't include one already.
+	 */
+	asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT));
+
+	/* Invalidate stale HCR bits that may be cached in TLBs */
+	__tlbi(vmalls12e1);
+	dsb(nsh);
+	isb();
+
+	return 0;
+}
+
+static int host_stage2_unmap_dev_all(void)
+{
+	struct kvm_pgtable *pgt = &host_mmu.pgt;
+	struct memblock_region *reg;
+	u64 addr = 0;
+	int i, ret;
+
+	/* Unmap all non-memory regions to recycle the pages */
+	for (i = 0; i < hyp_memblock_nr; i++, addr = reg->base + reg->size) {
+		reg = &hyp_memory[i];
+		ret = kvm_pgtable_stage2_unmap(pgt, addr, reg->base - addr);
+		if (ret)
+			return ret;
+	}
+	return kvm_pgtable_stage2_unmap(pgt, addr, BIT(pgt->ia_bits) - addr);
+}
+
+struct kvm_mem_range {
+	u64 start;
+	u64 end;
+};
+
+static struct memblock_region *find_mem_range(phys_addr_t addr, struct kvm_mem_range *range)
+{
+	int cur, left = 0, right = hyp_memblock_nr;
+	struct memblock_region *reg;
+	phys_addr_t end;
+
+	range->start = 0;
+	range->end = ULONG_MAX;
+
+	/* The list of memblock regions is sorted, binary search it */
+	while (left < right) {
+		cur = (left + right) >> 1;
+		reg = &hyp_memory[cur];
+		end = reg->base + reg->size;
+		if (addr < reg->base) {
+			right = cur;
+			range->end = reg->base;
+		} else if (addr >= end) {
+			left = cur + 1;
+			range->start = end;
+		} else {
+			range->start = reg->base;
+			range->end = end;
+			return reg;
+		}
+	}
+
+	return NULL;
+}
+
+bool addr_is_memory(phys_addr_t phys)
+{
+	struct kvm_mem_range range;
+
+	return !!find_mem_range(phys, &range);
+}
+
+static bool addr_is_allowed_memory(phys_addr_t phys)
+{
+	struct memblock_region *reg;
+	struct kvm_mem_range range;
+
+	reg = find_mem_range(phys, &range);
+
+	return reg && !(reg->flags & MEMBLOCK_NOMAP);
+}
+
+static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range)
+{
+	return range->start <= addr && addr < range->end;
+}
+
+static bool range_is_memory(u64 start, u64 end)
+{
+	struct kvm_mem_range r;
+
+	if (!find_mem_range(start, &r))
+		return false;
+
+	return is_in_mem_range(end - 1, &r);
+}
+
+static inline int __host_stage2_idmap(u64 start, u64 end,
+				      enum kvm_pgtable_prot prot)
+{
+	return kvm_pgtable_stage2_map(&host_mmu.pgt, start, end - start, start,
+				      prot, &host_s2_pool, 0);
+}
+
+/*
+ * The pool has been provided with enough pages to cover all of memory with
+ * page granularity, but it is difficult to know how much of the MMIO range
+ * we will need to cover upfront, so we may need to 'recycle' the pages if we
+ * run out.
+ */
+#define host_stage2_try(fn, ...)					\
+	({								\
+		int __ret;						\
+		hyp_assert_lock_held(&host_mmu.lock);			\
+		__ret = fn(__VA_ARGS__);				\
+		if (__ret == -ENOMEM) {					\
+			__ret = host_stage2_unmap_dev_all();		\
+			if (!__ret)					\
+				__ret = fn(__VA_ARGS__);		\
+		}							\
+		__ret;							\
+	 })
+
+static inline bool range_included(struct kvm_mem_range *child,
+				  struct kvm_mem_range *parent)
+{
+	return parent->start <= child->start && child->end <= parent->end;
+}
+
+static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)
+{
+	struct kvm_mem_range cur;
+	kvm_pte_t pte;
+	u32 level;
+	int ret;
+
+	hyp_assert_lock_held(&host_mmu.lock);
+	ret = kvm_pgtable_get_leaf(&host_mmu.pgt, addr, &pte, &level);
+	if (ret)
+		return ret;
+
+	if (kvm_pte_valid(pte))
+		return -EAGAIN;
+
+	if (pte)
+		return -EPERM;
+
+	do {
+		u64 granule = kvm_granule_size(level);
+		cur.start = ALIGN_DOWN(addr, granule);
+		cur.end = cur.start + granule;
+		level++;
+	} while ((level < KVM_PGTABLE_MAX_LEVELS) &&
+			!(kvm_level_supports_block_mapping(level) &&
+			  range_included(&cur, range)));
+
+	*range = cur;
+
+	return 0;
+}
+
+int host_stage2_idmap_locked(phys_addr_t addr, u64 size,
+			     enum kvm_pgtable_prot prot)
+{
+	return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot);
+}
+
+int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
+{
+	return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt,
+			       addr, size, &host_s2_pool, owner_id);
+}
+
+static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot)
+{
+	/*
+	 * Block mappings must be used with care in the host stage-2 as a
+	 * kvm_pgtable_stage2_map() operation targeting a page in the range of
+	 * an existing block will delete the block under the assumption that
+	 * mappings in the rest of the block range can always be rebuilt lazily.
+	 * That assumption is correct for the host stage-2 with RWX mappings
+	 * targeting memory or RW mappings targeting MMIO ranges (see
+	 * host_stage2_idmap() below which implements some of the host memory
+	 * abort logic). However, this is not safe for any other mappings where
+	 * the host stage-2 page-table is in fact the only place where this
+	 * state is stored. In all those cases, it is safer to use page-level
+	 * mappings, hence avoiding to lose the state because of side-effects in
+	 * kvm_pgtable_stage2_map().
+	 */
+	if (range_is_memory(addr, end))
+		return prot != PKVM_HOST_MEM_PROT;
+	else
+		return prot != PKVM_HOST_MMIO_PROT;
+}
+
+static int host_stage2_idmap(u64 addr)
+{
+	struct kvm_mem_range range;
+	bool is_memory = !!find_mem_range(addr, &range);
+	enum kvm_pgtable_prot prot;
+	int ret;
+
+	prot = is_memory ? PKVM_HOST_MEM_PROT : PKVM_HOST_MMIO_PROT;
+
+	host_lock_component();
+	ret = host_stage2_adjust_range(addr, &range);
+	if (ret)
+		goto unlock;
+
+	ret = host_stage2_idmap_locked(range.start, range.end - range.start, prot);
+unlock:
+	host_unlock_component();
+
+	return ret;
+}
+
+void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
+{
+	struct kvm_vcpu_fault_info fault;
+	u64 esr, addr;
+	int ret = 0;
+
+	esr = read_sysreg_el2(SYS_ESR);
+	BUG_ON(!__get_fault_info(esr, &fault));
+
+	addr = (fault.hpfar_el2 & HPFAR_MASK) << 8;
+	ret = host_stage2_idmap(addr);
+	BUG_ON(ret && ret != -EAGAIN);
+}
+
+struct pkvm_mem_transition {
+	u64				nr_pages;
+
+	struct {
+		enum pkvm_component_id	id;
+		/* Address in the initiator's address space */
+		u64			addr;
+
+		union {
+			struct {
+				/* Address in the completer's address space */
+				u64	completer_addr;
+			} host;
+			struct {
+				u64	completer_addr;
+			} hyp;
+		};
+	} initiator;
+
+	struct {
+		enum pkvm_component_id	id;
+	} completer;
+};
+
+struct pkvm_mem_share {
+	const struct pkvm_mem_transition	tx;
+	const enum kvm_pgtable_prot		completer_prot;
+};
+
+struct pkvm_mem_donation {
+	const struct pkvm_mem_transition	tx;
+};
+
+struct check_walk_data {
+	enum pkvm_page_state	desired;
+	enum pkvm_page_state	(*get_page_state)(kvm_pte_t pte);
+};
+
+static int __check_page_state_visitor(const struct kvm_pgtable_visit_ctx *ctx,
+				      enum kvm_pgtable_walk_flags visit)
+{
+	struct check_walk_data *d = ctx->arg;
+
+	if (kvm_pte_valid(ctx->old) && !addr_is_allowed_memory(kvm_pte_to_phys(ctx->old)))
+		return -EINVAL;
+
+	return d->get_page_state(ctx->old) == d->desired ? 0 : -EPERM;
+}
+
+static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size,
+				  struct check_walk_data *data)
+{
+	struct kvm_pgtable_walker walker = {
+		.cb	= __check_page_state_visitor,
+		.arg	= data,
+		.flags	= KVM_PGTABLE_WALK_LEAF,
+	};
+
+	return kvm_pgtable_walk(pgt, addr, size, &walker);
+}
+
+static enum pkvm_page_state host_get_page_state(kvm_pte_t pte)
+{
+	if (!kvm_pte_valid(pte) && pte)
+		return PKVM_NOPAGE;
+
+	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
+}
+
+static int __host_check_page_state_range(u64 addr, u64 size,
+					 enum pkvm_page_state state)
+{
+	struct check_walk_data d = {
+		.desired	= state,
+		.get_page_state	= host_get_page_state,
+	};
+
+	hyp_assert_lock_held(&host_mmu.lock);
+	return check_page_state_range(&host_mmu.pgt, addr, size, &d);
+}
+
+static int __host_set_page_state_range(u64 addr, u64 size,
+				       enum pkvm_page_state state)
+{
+	enum kvm_pgtable_prot prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, state);
+
+	return host_stage2_idmap_locked(addr, size, prot);
+}
+
+static int host_request_owned_transition(u64 *completer_addr,
+					 const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	u64 addr = tx->initiator.addr;
+
+	*completer_addr = tx->initiator.host.completer_addr;
+	return __host_check_page_state_range(addr, size, PKVM_PAGE_OWNED);
+}
+
+static int host_request_unshare(u64 *completer_addr,
+				const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	u64 addr = tx->initiator.addr;
+
+	*completer_addr = tx->initiator.host.completer_addr;
+	return __host_check_page_state_range(addr, size, PKVM_PAGE_SHARED_OWNED);
+}
+
+static int host_initiate_share(u64 *completer_addr,
+			       const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	u64 addr = tx->initiator.addr;
+
+	*completer_addr = tx->initiator.host.completer_addr;
+	return __host_set_page_state_range(addr, size, PKVM_PAGE_SHARED_OWNED);
+}
+
+static int host_initiate_unshare(u64 *completer_addr,
+				 const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	u64 addr = tx->initiator.addr;
+
+	*completer_addr = tx->initiator.host.completer_addr;
+	return __host_set_page_state_range(addr, size, PKVM_PAGE_OWNED);
+}
+
+static int host_initiate_donation(u64 *completer_addr,
+				  const struct pkvm_mem_transition *tx)
+{
+	u8 owner_id = tx->completer.id;
+	u64 size = tx->nr_pages * PAGE_SIZE;
+
+	*completer_addr = tx->initiator.host.completer_addr;
+	return host_stage2_set_owner_locked(tx->initiator.addr, size, owner_id);
+}
+
+static bool __host_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx)
+{
+	return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) ||
+		 tx->initiator.id != PKVM_ID_HYP);
+}
+
+static int __host_ack_transition(u64 addr, const struct pkvm_mem_transition *tx,
+				 enum pkvm_page_state state)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+
+	if (__host_ack_skip_pgtable_check(tx))
+		return 0;
+
+	return __host_check_page_state_range(addr, size, state);
+}
+
+static int host_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
+{
+	return __host_ack_transition(addr, tx, PKVM_NOPAGE);
+}
+
+static int host_complete_donation(u64 addr, const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	u8 host_id = tx->completer.id;
+
+	return host_stage2_set_owner_locked(addr, size, host_id);
+}
+
+static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte)
+{
+	if (!kvm_pte_valid(pte))
+		return PKVM_NOPAGE;
+
+	return pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte));
+}
+
+static int __hyp_check_page_state_range(u64 addr, u64 size,
+					enum pkvm_page_state state)
+{
+	struct check_walk_data d = {
+		.desired	= state,
+		.get_page_state	= hyp_get_page_state,
+	};
+
+	hyp_assert_lock_held(&pkvm_pgd_lock);
+	return check_page_state_range(&pkvm_pgtable, addr, size, &d);
+}
+
+static int hyp_request_donation(u64 *completer_addr,
+				const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	u64 addr = tx->initiator.addr;
+
+	*completer_addr = tx->initiator.hyp.completer_addr;
+	return __hyp_check_page_state_range(addr, size, PKVM_PAGE_OWNED);
+}
+
+static int hyp_initiate_donation(u64 *completer_addr,
+				 const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	int ret;
+
+	*completer_addr = tx->initiator.hyp.completer_addr;
+	ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, tx->initiator.addr, size);
+	return (ret != size) ? -EFAULT : 0;
+}
+
+static bool __hyp_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx)
+{
+	return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) ||
+		 tx->initiator.id != PKVM_ID_HOST);
+}
+
+static int hyp_ack_share(u64 addr, const struct pkvm_mem_transition *tx,
+			 enum kvm_pgtable_prot perms)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+
+	if (perms != PAGE_HYP)
+		return -EPERM;
+
+	if (__hyp_ack_skip_pgtable_check(tx))
+		return 0;
+
+	return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE);
+}
+
+static int hyp_ack_unshare(u64 addr, const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+
+	if (tx->initiator.id == PKVM_ID_HOST && hyp_page_count((void *)addr))
+		return -EBUSY;
+
+	if (__hyp_ack_skip_pgtable_check(tx))
+		return 0;
+
+	return __hyp_check_page_state_range(addr, size,
+					    PKVM_PAGE_SHARED_BORROWED);
+}
+
+static int hyp_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+
+	if (__hyp_ack_skip_pgtable_check(tx))
+		return 0;
+
+	return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE);
+}
+
+static int hyp_complete_share(u64 addr, const struct pkvm_mem_transition *tx,
+			      enum kvm_pgtable_prot perms)
+{
+	void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE);
+	enum kvm_pgtable_prot prot;
+
+	prot = pkvm_mkstate(perms, PKVM_PAGE_SHARED_BORROWED);
+	return pkvm_create_mappings_locked(start, end, prot);
+}
+
+static int hyp_complete_unshare(u64 addr, const struct pkvm_mem_transition *tx)
+{
+	u64 size = tx->nr_pages * PAGE_SIZE;
+	int ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, addr, size);
+
+	return (ret != size) ? -EFAULT : 0;
+}
+
+static int hyp_complete_donation(u64 addr,
+				 const struct pkvm_mem_transition *tx)
+{
+	void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE);
+	enum kvm_pgtable_prot prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_OWNED);
+
+	return pkvm_create_mappings_locked(start, end, prot);
+}
+
+static int check_share(struct pkvm_mem_share *share)
+{
+	const struct pkvm_mem_transition *tx = &share->tx;
+	u64 completer_addr;
+	int ret;
+
+	switch (tx->initiator.id) {
+	case PKVM_ID_HOST:
+		ret = host_request_owned_transition(&completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	switch (tx->completer.id) {
+	case PKVM_ID_HYP:
+		ret = hyp_ack_share(completer_addr, tx, share->completer_prot);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int __do_share(struct pkvm_mem_share *share)
+{
+	const struct pkvm_mem_transition *tx = &share->tx;
+	u64 completer_addr;
+	int ret;
+
+	switch (tx->initiator.id) {
+	case PKVM_ID_HOST:
+		ret = host_initiate_share(&completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	switch (tx->completer.id) {
+	case PKVM_ID_HYP:
+		ret = hyp_complete_share(completer_addr, tx, share->completer_prot);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/*
+ * do_share():
+ *
+ * The page owner grants access to another component with a given set
+ * of permissions.
+ *
+ * Initiator: OWNED	=> SHARED_OWNED
+ * Completer: NOPAGE	=> SHARED_BORROWED
+ */
+static int do_share(struct pkvm_mem_share *share)
+{
+	int ret;
+
+	ret = check_share(share);
+	if (ret)
+		return ret;
+
+	return WARN_ON(__do_share(share));
+}
+
+static int check_unshare(struct pkvm_mem_share *share)
+{
+	const struct pkvm_mem_transition *tx = &share->tx;
+	u64 completer_addr;
+	int ret;
+
+	switch (tx->initiator.id) {
+	case PKVM_ID_HOST:
+		ret = host_request_unshare(&completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	switch (tx->completer.id) {
+	case PKVM_ID_HYP:
+		ret = hyp_ack_unshare(completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int __do_unshare(struct pkvm_mem_share *share)
+{
+	const struct pkvm_mem_transition *tx = &share->tx;
+	u64 completer_addr;
+	int ret;
+
+	switch (tx->initiator.id) {
+	case PKVM_ID_HOST:
+		ret = host_initiate_unshare(&completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	switch (tx->completer.id) {
+	case PKVM_ID_HYP:
+		ret = hyp_complete_unshare(completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/*
+ * do_unshare():
+ *
+ * The page owner revokes access from another component for a range of
+ * pages which were previously shared using do_share().
+ *
+ * Initiator: SHARED_OWNED	=> OWNED
+ * Completer: SHARED_BORROWED	=> NOPAGE
+ */
+static int do_unshare(struct pkvm_mem_share *share)
+{
+	int ret;
+
+	ret = check_unshare(share);
+	if (ret)
+		return ret;
+
+	return WARN_ON(__do_unshare(share));
+}
+
+static int check_donation(struct pkvm_mem_donation *donation)
+{
+	const struct pkvm_mem_transition *tx = &donation->tx;
+	u64 completer_addr;
+	int ret;
+
+	switch (tx->initiator.id) {
+	case PKVM_ID_HOST:
+		ret = host_request_owned_transition(&completer_addr, tx);
+		break;
+	case PKVM_ID_HYP:
+		ret = hyp_request_donation(&completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	switch (tx->completer.id) {
+	case PKVM_ID_HOST:
+		ret = host_ack_donation(completer_addr, tx);
+		break;
+	case PKVM_ID_HYP:
+		ret = hyp_ack_donation(completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int __do_donate(struct pkvm_mem_donation *donation)
+{
+	const struct pkvm_mem_transition *tx = &donation->tx;
+	u64 completer_addr;
+	int ret;
+
+	switch (tx->initiator.id) {
+	case PKVM_ID_HOST:
+		ret = host_initiate_donation(&completer_addr, tx);
+		break;
+	case PKVM_ID_HYP:
+		ret = hyp_initiate_donation(&completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	switch (tx->completer.id) {
+	case PKVM_ID_HOST:
+		ret = host_complete_donation(completer_addr, tx);
+		break;
+	case PKVM_ID_HYP:
+		ret = hyp_complete_donation(completer_addr, tx);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/*
+ * do_donate():
+ *
+ * The page owner transfers ownership to another component, losing access
+ * as a consequence.
+ *
+ * Initiator: OWNED	=> NOPAGE
+ * Completer: NOPAGE	=> OWNED
+ */
+static int do_donate(struct pkvm_mem_donation *donation)
+{
+	int ret;
+
+	ret = check_donation(donation);
+	if (ret)
+		return ret;
+
+	return WARN_ON(__do_donate(donation));
+}
+
+int __pkvm_host_share_hyp(u64 pfn)
+{
+	int ret;
+	u64 host_addr = hyp_pfn_to_phys(pfn);
+	u64 hyp_addr = (u64)__hyp_va(host_addr);
+	struct pkvm_mem_share share = {
+		.tx	= {
+			.nr_pages	= 1,
+			.initiator	= {
+				.id	= PKVM_ID_HOST,
+				.addr	= host_addr,
+				.host	= {
+					.completer_addr = hyp_addr,
+				},
+			},
+			.completer	= {
+				.id	= PKVM_ID_HYP,
+			},
+		},
+		.completer_prot	= PAGE_HYP,
+	};
+
+	host_lock_component();
+	hyp_lock_component();
+
+	ret = do_share(&share);
+
+	hyp_unlock_component();
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_unshare_hyp(u64 pfn)
+{
+	int ret;
+	u64 host_addr = hyp_pfn_to_phys(pfn);
+	u64 hyp_addr = (u64)__hyp_va(host_addr);
+	struct pkvm_mem_share share = {
+		.tx	= {
+			.nr_pages	= 1,
+			.initiator	= {
+				.id	= PKVM_ID_HOST,
+				.addr	= host_addr,
+				.host	= {
+					.completer_addr = hyp_addr,
+				},
+			},
+			.completer	= {
+				.id	= PKVM_ID_HYP,
+			},
+		},
+		.completer_prot	= PAGE_HYP,
+	};
+
+	host_lock_component();
+	hyp_lock_component();
+
+	ret = do_unshare(&share);
+
+	hyp_unlock_component();
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages)
+{
+	int ret;
+	u64 host_addr = hyp_pfn_to_phys(pfn);
+	u64 hyp_addr = (u64)__hyp_va(host_addr);
+	struct pkvm_mem_donation donation = {
+		.tx	= {
+			.nr_pages	= nr_pages,
+			.initiator	= {
+				.id	= PKVM_ID_HOST,
+				.addr	= host_addr,
+				.host	= {
+					.completer_addr = hyp_addr,
+				},
+			},
+			.completer	= {
+				.id	= PKVM_ID_HYP,
+			},
+		},
+	};
+
+	host_lock_component();
+	hyp_lock_component();
+
+	ret = do_donate(&donation);
+
+	hyp_unlock_component();
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages)
+{
+	int ret;
+	u64 host_addr = hyp_pfn_to_phys(pfn);
+	u64 hyp_addr = (u64)__hyp_va(host_addr);
+	struct pkvm_mem_donation donation = {
+		.tx	= {
+			.nr_pages	= nr_pages,
+			.initiator	= {
+				.id	= PKVM_ID_HYP,
+				.addr	= hyp_addr,
+				.hyp	= {
+					.completer_addr = host_addr,
+				},
+			},
+			.completer	= {
+				.id	= PKVM_ID_HOST,
+			},
+		},
+	};
+
+	host_lock_component();
+	hyp_lock_component();
+
+	ret = do_donate(&donation);
+
+	hyp_unlock_component();
+	host_unlock_component();
+
+	return ret;
+}
+
+int hyp_pin_shared_mem(void *from, void *to)
+{
+	u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE);
+	u64 end = PAGE_ALIGN((u64)to);
+	u64 size = end - start;
+	int ret;
+
+	host_lock_component();
+	hyp_lock_component();
+
+	ret = __host_check_page_state_range(__hyp_pa(start), size,
+					    PKVM_PAGE_SHARED_OWNED);
+	if (ret)
+		goto unlock;
+
+	ret = __hyp_check_page_state_range(start, size,
+					   PKVM_PAGE_SHARED_BORROWED);
+	if (ret)
+		goto unlock;
+
+	for (cur = start; cur < end; cur += PAGE_SIZE)
+		hyp_page_ref_inc(hyp_virt_to_page(cur));
+
+unlock:
+	hyp_unlock_component();
+	host_unlock_component();
+
+	return ret;
+}
+
+void hyp_unpin_shared_mem(void *from, void *to)
+{
+	u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE);
+	u64 end = PAGE_ALIGN((u64)to);
+
+	host_lock_component();
+	hyp_lock_component();
+
+	for (cur = start; cur < end; cur += PAGE_SIZE)
+		hyp_page_ref_dec(hyp_virt_to_page(cur));
+
+	hyp_unlock_component();
+	host_unlock_component();
+}