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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/mips/kvm/entry.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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/mips/kvm/entry.c')
-rw-r--r--arch/mips/kvm/entry.c916
1 files changed, 916 insertions, 0 deletions
diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
new file mode 100644
index 000000000..aceed14aa
--- /dev/null
+++ b/arch/mips/kvm/entry.c
@@ -0,0 +1,916 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Generation of main entry point for the guest, exception handling.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ *
+ * Copyright (C) 2016 Imagination Technologies Ltd.
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/log2.h>
+#include <asm/mmu_context.h>
+#include <asm/msa.h>
+#include <asm/setup.h>
+#include <asm/tlbex.h>
+#include <asm/uasm.h>
+
+/* Register names */
+#define ZERO 0
+#define AT 1
+#define V0 2
+#define V1 3
+#define A0 4
+#define A1 5
+
+#if _MIPS_SIM == _MIPS_SIM_ABI32
+#define T0 8
+#define T1 9
+#define T2 10
+#define T3 11
+#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
+
+#if _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32
+#define T0 12
+#define T1 13
+#define T2 14
+#define T3 15
+#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32 */
+
+#define S0 16
+#define S1 17
+#define T9 25
+#define K0 26
+#define K1 27
+#define GP 28
+#define SP 29
+#define RA 31
+
+/* Some CP0 registers */
+#define C0_PWBASE 5, 5
+#define C0_HWRENA 7, 0
+#define C0_BADVADDR 8, 0
+#define C0_BADINSTR 8, 1
+#define C0_BADINSTRP 8, 2
+#define C0_PGD 9, 7
+#define C0_ENTRYHI 10, 0
+#define C0_GUESTCTL1 10, 4
+#define C0_STATUS 12, 0
+#define C0_GUESTCTL0 12, 6
+#define C0_CAUSE 13, 0
+#define C0_EPC 14, 0
+#define C0_EBASE 15, 1
+#define C0_CONFIG5 16, 5
+#define C0_DDATA_LO 28, 3
+#define C0_ERROREPC 30, 0
+
+#define CALLFRAME_SIZ 32
+
+#ifdef CONFIG_64BIT
+#define ST0_KX_IF_64 ST0_KX
+#else
+#define ST0_KX_IF_64 0
+#endif
+
+static unsigned int scratch_vcpu[2] = { C0_DDATA_LO };
+static unsigned int scratch_tmp[2] = { C0_ERROREPC };
+
+enum label_id {
+ label_fpu_1 = 1,
+ label_msa_1,
+ label_return_to_host,
+ label_kernel_asid,
+ label_exit_common,
+};
+
+UASM_L_LA(_fpu_1)
+UASM_L_LA(_msa_1)
+UASM_L_LA(_return_to_host)
+UASM_L_LA(_kernel_asid)
+UASM_L_LA(_exit_common)
+
+static void *kvm_mips_build_enter_guest(void *addr);
+static void *kvm_mips_build_ret_from_exit(void *addr);
+static void *kvm_mips_build_ret_to_guest(void *addr);
+static void *kvm_mips_build_ret_to_host(void *addr);
+
+/*
+ * The version of this function in tlbex.c uses current_cpu_type(), but for KVM
+ * we assume symmetry.
+ */
+static int c0_kscratch(void)
+{
+ return 31;
+}
+
+/**
+ * kvm_mips_entry_setup() - Perform global setup for entry code.
+ *
+ * Perform global setup for entry code, such as choosing a scratch register.
+ *
+ * Returns: 0 on success.
+ * -errno on failure.
+ */
+int kvm_mips_entry_setup(void)
+{
+ /*
+ * We prefer to use KScratchN registers if they are available over the
+ * defaults above, which may not work on all cores.
+ */
+ unsigned int kscratch_mask = cpu_data[0].kscratch_mask;
+
+ if (pgd_reg != -1)
+ kscratch_mask &= ~BIT(pgd_reg);
+
+ /* Pick a scratch register for storing VCPU */
+ if (kscratch_mask) {
+ scratch_vcpu[0] = c0_kscratch();
+ scratch_vcpu[1] = ffs(kscratch_mask) - 1;
+ kscratch_mask &= ~BIT(scratch_vcpu[1]);
+ }
+
+ /* Pick a scratch register to use as a temp for saving state */
+ if (kscratch_mask) {
+ scratch_tmp[0] = c0_kscratch();
+ scratch_tmp[1] = ffs(kscratch_mask) - 1;
+ kscratch_mask &= ~BIT(scratch_tmp[1]);
+ }
+
+ return 0;
+}
+
+static void kvm_mips_build_save_scratch(u32 **p, unsigned int tmp,
+ unsigned int frame)
+{
+ /* Save the VCPU scratch register value in cp0_epc of the stack frame */
+ UASM_i_MFC0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]);
+ UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame);
+
+ /* Save the temp scratch register value in cp0_cause of stack frame */
+ if (scratch_tmp[0] == c0_kscratch()) {
+ UASM_i_MFC0(p, tmp, scratch_tmp[0], scratch_tmp[1]);
+ UASM_i_SW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame);
+ }
+}
+
+static void kvm_mips_build_restore_scratch(u32 **p, unsigned int tmp,
+ unsigned int frame)
+{
+ /*
+ * Restore host scratch register values saved by
+ * kvm_mips_build_save_scratch().
+ */
+ UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_epc), frame);
+ UASM_i_MTC0(p, tmp, scratch_vcpu[0], scratch_vcpu[1]);
+
+ if (scratch_tmp[0] == c0_kscratch()) {
+ UASM_i_LW(p, tmp, offsetof(struct pt_regs, cp0_cause), frame);
+ UASM_i_MTC0(p, tmp, scratch_tmp[0], scratch_tmp[1]);
+ }
+}
+
+/**
+ * build_set_exc_base() - Assemble code to write exception base address.
+ * @p: Code buffer pointer.
+ * @reg: Source register (generated code may set WG bit in @reg).
+ *
+ * Assemble code to modify the exception base address in the EBase register,
+ * using the appropriately sized access and setting the WG bit if necessary.
+ */
+static inline void build_set_exc_base(u32 **p, unsigned int reg)
+{
+ if (cpu_has_ebase_wg) {
+ /* Set WG so that all the bits get written */
+ uasm_i_ori(p, reg, reg, MIPS_EBASE_WG);
+ UASM_i_MTC0(p, reg, C0_EBASE);
+ } else {
+ uasm_i_mtc0(p, reg, C0_EBASE);
+ }
+}
+
+/**
+ * kvm_mips_build_vcpu_run() - Assemble function to start running a guest VCPU.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the start of the vcpu_run function to run a guest VCPU. The function
+ * conforms to the following prototype:
+ *
+ * int vcpu_run(struct kvm_vcpu *vcpu);
+ *
+ * The exit from the guest and return to the caller is handled by the code
+ * generated by kvm_mips_build_ret_to_host().
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_vcpu_run(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+
+ /*
+ * A0: vcpu
+ */
+
+ /* k0/k1 not being used in host kernel context */
+ UASM_i_ADDIU(&p, K1, SP, -(int)sizeof(struct pt_regs));
+ for (i = 16; i < 32; ++i) {
+ if (i == 24)
+ i = 28;
+ UASM_i_SW(&p, i, offsetof(struct pt_regs, regs[i]), K1);
+ }
+
+ /* Save host status */
+ uasm_i_mfc0(&p, V0, C0_STATUS);
+ UASM_i_SW(&p, V0, offsetof(struct pt_regs, cp0_status), K1);
+
+ /* Save scratch registers, will be used to store pointer to vcpu etc */
+ kvm_mips_build_save_scratch(&p, V1, K1);
+
+ /* VCPU scratch register has pointer to vcpu */
+ UASM_i_MTC0(&p, A0, scratch_vcpu[0], scratch_vcpu[1]);
+
+ /* Offset into vcpu->arch */
+ UASM_i_ADDIU(&p, K1, A0, offsetof(struct kvm_vcpu, arch));
+
+ /*
+ * Save the host stack to VCPU, used for exception processing
+ * when we exit from the Guest
+ */
+ UASM_i_SW(&p, SP, offsetof(struct kvm_vcpu_arch, host_stack), K1);
+
+ /* Save the kernel gp as well */
+ UASM_i_SW(&p, GP, offsetof(struct kvm_vcpu_arch, host_gp), K1);
+
+ /*
+ * Setup status register for running the guest in UM, interrupts
+ * are disabled
+ */
+ UASM_i_LA(&p, K0, ST0_EXL | KSU_USER | ST0_BEV | ST0_KX_IF_64);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ /* load up the new EBASE */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1);
+ build_set_exc_base(&p, K0);
+
+ /*
+ * Now that the new EBASE has been loaded, unset BEV, set
+ * interrupt mask as it was but make sure that timer interrupts
+ * are enabled
+ */
+ uasm_i_addiu(&p, K0, ZERO, ST0_EXL | KSU_USER | ST0_IE | ST0_KX_IF_64);
+ uasm_i_andi(&p, V0, V0, ST0_IM);
+ uasm_i_or(&p, K0, K0, V0);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ p = kvm_mips_build_enter_guest(p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_enter_guest() - Assemble code to resume guest execution.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to resume guest execution. This code is common between the
+ * initial entry into the guest from the host, and returning from the exit
+ * handler back to the guest.
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_enter_guest(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+ struct uasm_label __maybe_unused *l = labels;
+ struct uasm_reloc __maybe_unused *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /* Set Guest EPC */
+ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, pc), K1);
+ UASM_i_MTC0(&p, T0, C0_EPC);
+
+ /* Save normal linux process pgd (VZ guarantees pgd_reg is set) */
+ if (cpu_has_ldpte)
+ UASM_i_MFC0(&p, K0, C0_PWBASE);
+ else
+ UASM_i_MFC0(&p, K0, c0_kscratch(), pgd_reg);
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, host_pgd), K1);
+
+ /*
+ * Set up KVM GPA pgd.
+ * This does roughly the same as TLBMISS_HANDLER_SETUP_PGD():
+ * - call tlbmiss_handler_setup_pgd(mm->pgd)
+ * - write mm->pgd into CP0_PWBase
+ *
+ * We keep S0 pointing at struct kvm so we can load the ASID below.
+ */
+ UASM_i_LW(&p, S0, (int)offsetof(struct kvm_vcpu, kvm) -
+ (int)offsetof(struct kvm_vcpu, arch), K1);
+ UASM_i_LW(&p, A0, offsetof(struct kvm, arch.gpa_mm.pgd), S0);
+ UASM_i_LA(&p, T9, (unsigned long)tlbmiss_handler_setup_pgd);
+ uasm_i_jalr(&p, RA, T9);
+ /* delay slot */
+ if (cpu_has_htw)
+ UASM_i_MTC0(&p, A0, C0_PWBASE);
+ else
+ uasm_i_nop(&p);
+
+ /* Set GM bit to setup eret to VZ guest context */
+ uasm_i_addiu(&p, V1, ZERO, 1);
+ uasm_i_mfc0(&p, K0, C0_GUESTCTL0);
+ uasm_i_ins(&p, K0, V1, MIPS_GCTL0_GM_SHIFT, 1);
+ uasm_i_mtc0(&p, K0, C0_GUESTCTL0);
+
+ if (cpu_has_guestid) {
+ /*
+ * Set root mode GuestID, so that root TLB refill handler can
+ * use the correct GuestID in the root TLB.
+ */
+
+ /* Get current GuestID */
+ uasm_i_mfc0(&p, T0, C0_GUESTCTL1);
+ /* Set GuestCtl1.RID = GuestCtl1.ID */
+ uasm_i_ext(&p, T1, T0, MIPS_GCTL1_ID_SHIFT,
+ MIPS_GCTL1_ID_WIDTH);
+ uasm_i_ins(&p, T0, T1, MIPS_GCTL1_RID_SHIFT,
+ MIPS_GCTL1_RID_WIDTH);
+ uasm_i_mtc0(&p, T0, C0_GUESTCTL1);
+
+ /* GuestID handles dealiasing so we don't need to touch ASID */
+ goto skip_asid_restore;
+ }
+
+ /* Root ASID Dealias (RAD) */
+
+ /* Save host ASID */
+ UASM_i_MFC0(&p, K0, C0_ENTRYHI);
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, host_entryhi),
+ K1);
+
+ /* Set the root ASID for the Guest */
+ UASM_i_ADDIU(&p, T1, S0,
+ offsetof(struct kvm, arch.gpa_mm.context.asid));
+
+ /* t1: contains the base of the ASID array, need to get the cpu id */
+ /* smp_processor_id */
+ uasm_i_lw(&p, T2, offsetof(struct thread_info, cpu), GP);
+ /* index the ASID array */
+ uasm_i_sll(&p, T2, T2, ilog2(sizeof(long)));
+ UASM_i_ADDU(&p, T3, T1, T2);
+ UASM_i_LW(&p, K0, 0, T3);
+#ifdef CONFIG_MIPS_ASID_BITS_VARIABLE
+ /*
+ * reuse ASID array offset
+ * cpuinfo_mips is a multiple of sizeof(long)
+ */
+ uasm_i_addiu(&p, T3, ZERO, sizeof(struct cpuinfo_mips)/sizeof(long));
+ uasm_i_mul(&p, T2, T2, T3);
+
+ UASM_i_LA_mostly(&p, AT, (long)&cpu_data[0].asid_mask);
+ UASM_i_ADDU(&p, AT, AT, T2);
+ UASM_i_LW(&p, T2, uasm_rel_lo((long)&cpu_data[0].asid_mask), AT);
+ uasm_i_and(&p, K0, K0, T2);
+#else
+ uasm_i_andi(&p, K0, K0, MIPS_ENTRYHI_ASID);
+#endif
+
+ /* Set up KVM VZ root ASID (!guestid) */
+ uasm_i_mtc0(&p, K0, C0_ENTRYHI);
+skip_asid_restore:
+ uasm_i_ehb(&p);
+
+ /* Disable RDHWR access */
+ uasm_i_mtc0(&p, ZERO, C0_HWRENA);
+
+ /* load the guest context from VCPU and return */
+ for (i = 1; i < 32; ++i) {
+ /* Guest k0/k1 loaded later */
+ if (i == K0 || i == K1)
+ continue;
+ UASM_i_LW(&p, i, offsetof(struct kvm_vcpu_arch, gprs[i]), K1);
+ }
+
+#ifndef CONFIG_CPU_MIPSR6
+ /* Restore hi/lo */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, hi), K1);
+ uasm_i_mthi(&p, K0);
+
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, lo), K1);
+ uasm_i_mtlo(&p, K0);
+#endif
+
+ /* Restore the guest's k0/k1 registers */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, gprs[K0]), K1);
+ UASM_i_LW(&p, K1, offsetof(struct kvm_vcpu_arch, gprs[K1]), K1);
+
+ /* Jump to guest */
+ uasm_i_eret(&p);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_tlb_refill_exception() - Assemble TLB refill handler.
+ * @addr: Address to start writing code.
+ * @handler: Address of common handler (within range of @addr).
+ *
+ * Assemble TLB refill exception fast path handler for guest execution.
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_tlb_refill_exception(void *addr, void *handler)
+{
+ u32 *p = addr;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+#ifndef CONFIG_CPU_LOONGSON64
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+#endif
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /* Save guest k1 into scratch register */
+ UASM_i_MTC0(&p, K1, scratch_tmp[0], scratch_tmp[1]);
+
+ /* Get the VCPU pointer from the VCPU scratch register */
+ UASM_i_MFC0(&p, K1, scratch_vcpu[0], scratch_vcpu[1]);
+
+ /* Save guest k0 into VCPU structure */
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu, arch.gprs[K0]), K1);
+
+ /*
+ * Some of the common tlbex code uses current_cpu_type(). For KVM we
+ * assume symmetry and just disable preemption to silence the warning.
+ */
+ preempt_disable();
+
+#ifdef CONFIG_CPU_LOONGSON64
+ UASM_i_MFC0(&p, K1, C0_PGD);
+ uasm_i_lddir(&p, K0, K1, 3); /* global page dir */
+#ifndef __PAGETABLE_PMD_FOLDED
+ uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */
+#endif
+ uasm_i_ldpte(&p, K1, 0); /* even */
+ uasm_i_ldpte(&p, K1, 1); /* odd */
+ uasm_i_tlbwr(&p);
+#else
+ /*
+ * Now for the actual refill bit. A lot of this can be common with the
+ * Linux TLB refill handler, however we don't need to handle so many
+ * cases. We only need to handle user mode refills, and user mode runs
+ * with 32-bit addressing.
+ *
+ * Therefore the branch to label_vmalloc generated by build_get_pmde64()
+ * that isn't resolved should never actually get taken and is harmless
+ * to leave in place for now.
+ */
+
+#ifdef CONFIG_64BIT
+ build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
+#else
+ build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
+#endif
+
+ /* we don't support huge pages yet */
+
+ build_get_ptep(&p, K0, K1);
+ build_update_entries(&p, K0, K1);
+ build_tlb_write_entry(&p, &l, &r, tlb_random);
+#endif
+
+ preempt_enable();
+
+ /* Get the VCPU pointer from the VCPU scratch register again */
+ UASM_i_MFC0(&p, K1, scratch_vcpu[0], scratch_vcpu[1]);
+
+ /* Restore the guest's k0/k1 registers */
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu, arch.gprs[K0]), K1);
+ uasm_i_ehb(&p);
+ UASM_i_MFC0(&p, K1, scratch_tmp[0], scratch_tmp[1]);
+
+ /* Jump to guest */
+ uasm_i_eret(&p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_exception() - Assemble first level guest exception handler.
+ * @addr: Address to start writing code.
+ * @handler: Address of common handler (within range of @addr).
+ *
+ * Assemble exception vector code for guest execution. The generated vector will
+ * branch to the common exception handler generated by kvm_mips_build_exit().
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_exception(void *addr, void *handler)
+{
+ u32 *p = addr;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /* Save guest k1 into scratch register */
+ UASM_i_MTC0(&p, K1, scratch_tmp[0], scratch_tmp[1]);
+
+ /* Get the VCPU pointer from the VCPU scratch register */
+ UASM_i_MFC0(&p, K1, scratch_vcpu[0], scratch_vcpu[1]);
+ UASM_i_ADDIU(&p, K1, K1, offsetof(struct kvm_vcpu, arch));
+
+ /* Save guest k0 into VCPU structure */
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, gprs[K0]), K1);
+
+ /* Branch to the common handler */
+ uasm_il_b(&p, &r, label_exit_common);
+ uasm_i_nop(&p);
+
+ uasm_l_exit_common(&l, handler);
+ uasm_resolve_relocs(relocs, labels);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_exit() - Assemble common guest exit handler.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the generic guest exit handling code. This is called by the
+ * exception vectors (generated by kvm_mips_build_exception()), and calls
+ * kvm_mips_handle_exit(), then either resumes the guest or returns to the host
+ * depending on the return value.
+ *
+ * Returns: Next address after end of written function.
+ */
+void *kvm_mips_build_exit(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+ struct uasm_label labels[3];
+ struct uasm_reloc relocs[3];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /*
+ * Generic Guest exception handler. We end up here when the guest
+ * does something that causes a trap to kernel mode.
+ *
+ * Both k0/k1 registers will have already been saved (k0 into the vcpu
+ * structure, and k1 into the scratch_tmp register).
+ *
+ * The k1 register will already contain the kvm_vcpu_arch pointer.
+ */
+
+ /* Start saving Guest context to VCPU */
+ for (i = 0; i < 32; ++i) {
+ /* Guest k0/k1 saved later */
+ if (i == K0 || i == K1)
+ continue;
+ UASM_i_SW(&p, i, offsetof(struct kvm_vcpu_arch, gprs[i]), K1);
+ }
+
+#ifndef CONFIG_CPU_MIPSR6
+ /* We need to save hi/lo and restore them on the way out */
+ uasm_i_mfhi(&p, T0);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, hi), K1);
+
+ uasm_i_mflo(&p, T0);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, lo), K1);
+#endif
+
+ /* Finally save guest k1 to VCPU */
+ uasm_i_ehb(&p);
+ UASM_i_MFC0(&p, T0, scratch_tmp[0], scratch_tmp[1]);
+ UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, gprs[K1]), K1);
+
+ /* Now that context has been saved, we can use other registers */
+
+ /* Restore vcpu */
+ UASM_i_MFC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);
+
+ /*
+ * Save Host level EPC, BadVaddr and Cause to VCPU, useful to process
+ * the exception
+ */
+ UASM_i_MFC0(&p, K0, C0_EPC);
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, pc), K1);
+
+ UASM_i_MFC0(&p, K0, C0_BADVADDR);
+ UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, host_cp0_badvaddr),
+ K1);
+
+ uasm_i_mfc0(&p, K0, C0_CAUSE);
+ uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch, host_cp0_cause), K1);
+
+ if (cpu_has_badinstr) {
+ uasm_i_mfc0(&p, K0, C0_BADINSTR);
+ uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch,
+ host_cp0_badinstr), K1);
+ }
+
+ if (cpu_has_badinstrp) {
+ uasm_i_mfc0(&p, K0, C0_BADINSTRP);
+ uasm_i_sw(&p, K0, offsetof(struct kvm_vcpu_arch,
+ host_cp0_badinstrp), K1);
+ }
+
+ /* Now restore the host state just enough to run the handlers */
+
+ /* Switch EBASE to the one used by Linux */
+ /* load up the host EBASE */
+ uasm_i_mfc0(&p, V0, C0_STATUS);
+
+ uasm_i_lui(&p, AT, ST0_BEV >> 16);
+ uasm_i_or(&p, K0, V0, AT);
+
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ UASM_i_LA_mostly(&p, K0, (long)&ebase);
+ UASM_i_LW(&p, K0, uasm_rel_lo((long)&ebase), K0);
+ build_set_exc_base(&p, K0);
+
+ if (raw_cpu_has_fpu) {
+ /*
+ * If FPU is enabled, save FCR31 and clear it so that later
+ * ctc1's don't trigger FPE for pending exceptions.
+ */
+ uasm_i_lui(&p, AT, ST0_CU1 >> 16);
+ uasm_i_and(&p, V1, V0, AT);
+ uasm_il_beqz(&p, &r, V1, label_fpu_1);
+ uasm_i_nop(&p);
+ uasm_i_cfc1(&p, T0, 31);
+ uasm_i_sw(&p, T0, offsetof(struct kvm_vcpu_arch, fpu.fcr31),
+ K1);
+ uasm_i_ctc1(&p, ZERO, 31);
+ uasm_l_fpu_1(&l, p);
+ }
+
+ if (cpu_has_msa) {
+ /*
+ * If MSA is enabled, save MSACSR and clear it so that later
+ * instructions don't trigger MSAFPE for pending exceptions.
+ */
+ uasm_i_mfc0(&p, T0, C0_CONFIG5);
+ uasm_i_ext(&p, T0, T0, 27, 1); /* MIPS_CONF5_MSAEN */
+ uasm_il_beqz(&p, &r, T0, label_msa_1);
+ uasm_i_nop(&p);
+ uasm_i_cfcmsa(&p, T0, MSA_CSR);
+ uasm_i_sw(&p, T0, offsetof(struct kvm_vcpu_arch, fpu.msacsr),
+ K1);
+ uasm_i_ctcmsa(&p, MSA_CSR, ZERO);
+ uasm_l_msa_1(&l, p);
+ }
+
+ /* Restore host ASID */
+ if (!cpu_has_guestid) {
+ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, host_entryhi),
+ K1);
+ UASM_i_MTC0(&p, K0, C0_ENTRYHI);
+ }
+
+ /*
+ * Set up normal Linux process pgd.
+ * This does roughly the same as TLBMISS_HANDLER_SETUP_PGD():
+ * - call tlbmiss_handler_setup_pgd(mm->pgd)
+ * - write mm->pgd into CP0_PWBase
+ */
+ UASM_i_LW(&p, A0,
+ offsetof(struct kvm_vcpu_arch, host_pgd), K1);
+ UASM_i_LA(&p, T9, (unsigned long)tlbmiss_handler_setup_pgd);
+ uasm_i_jalr(&p, RA, T9);
+ /* delay slot */
+ if (cpu_has_htw)
+ UASM_i_MTC0(&p, A0, C0_PWBASE);
+ else
+ uasm_i_nop(&p);
+
+ /* Clear GM bit so we don't enter guest mode when EXL is cleared */
+ uasm_i_mfc0(&p, K0, C0_GUESTCTL0);
+ uasm_i_ins(&p, K0, ZERO, MIPS_GCTL0_GM_SHIFT, 1);
+ uasm_i_mtc0(&p, K0, C0_GUESTCTL0);
+
+ /* Save GuestCtl0 so we can access GExcCode after CPU migration */
+ uasm_i_sw(&p, K0,
+ offsetof(struct kvm_vcpu_arch, host_cp0_guestctl0), K1);
+
+ if (cpu_has_guestid) {
+ /*
+ * Clear root mode GuestID, so that root TLB operations use the
+ * root GuestID in the root TLB.
+ */
+ uasm_i_mfc0(&p, T0, C0_GUESTCTL1);
+ /* Set GuestCtl1.RID = MIPS_GCTL1_ROOT_GUESTID (i.e. 0) */
+ uasm_i_ins(&p, T0, ZERO, MIPS_GCTL1_RID_SHIFT,
+ MIPS_GCTL1_RID_WIDTH);
+ uasm_i_mtc0(&p, T0, C0_GUESTCTL1);
+ }
+
+ /* Now that the new EBASE has been loaded, unset BEV and KSU_USER */
+ uasm_i_addiu(&p, AT, ZERO, ~(ST0_EXL | KSU_USER | ST0_IE));
+ uasm_i_and(&p, V0, V0, AT);
+ uasm_i_lui(&p, AT, ST0_CU0 >> 16);
+ uasm_i_or(&p, V0, V0, AT);
+#ifdef CONFIG_64BIT
+ uasm_i_ori(&p, V0, V0, ST0_SX | ST0_UX);
+#endif
+ uasm_i_mtc0(&p, V0, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ /* Load up host GP */
+ UASM_i_LW(&p, GP, offsetof(struct kvm_vcpu_arch, host_gp), K1);
+
+ /* Need a stack before we can jump to "C" */
+ UASM_i_LW(&p, SP, offsetof(struct kvm_vcpu_arch, host_stack), K1);
+
+ /* Saved host state */
+ UASM_i_ADDIU(&p, SP, SP, -(int)sizeof(struct pt_regs));
+
+ /*
+ * XXXKYMA do we need to load the host ASID, maybe not because the
+ * kernel entries are marked GLOBAL, need to verify
+ */
+
+ /* Restore host scratch registers, as we'll have clobbered them */
+ kvm_mips_build_restore_scratch(&p, K0, SP);
+
+ /* Restore RDHWR access */
+ UASM_i_LA_mostly(&p, K0, (long)&hwrena);
+ uasm_i_lw(&p, K0, uasm_rel_lo((long)&hwrena), K0);
+ uasm_i_mtc0(&p, K0, C0_HWRENA);
+
+ /* Jump to handler */
+ /*
+ * XXXKYMA: not sure if this is safe, how large is the stack??
+ * Now jump to the kvm_mips_handle_exit() to see if we can deal
+ * with this in the kernel
+ */
+ uasm_i_move(&p, A0, S0);
+ UASM_i_LA(&p, T9, (unsigned long)kvm_mips_handle_exit);
+ uasm_i_jalr(&p, RA, T9);
+ UASM_i_ADDIU(&p, SP, SP, -CALLFRAME_SIZ);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ p = kvm_mips_build_ret_from_exit(p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_ret_from_exit() - Assemble guest exit return handler.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to handle the return from kvm_mips_handle_exit(), either
+ * resuming the guest or returning to the host depending on the return value.
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_ret_from_exit(void *addr)
+{
+ u32 *p = addr;
+ struct uasm_label labels[2];
+ struct uasm_reloc relocs[2];
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ /* Return from handler Make sure interrupts are disabled */
+ uasm_i_di(&p, ZERO);
+ uasm_i_ehb(&p);
+
+ /*
+ * XXXKYMA: k0/k1 could have been blown away if we processed
+ * an exception while we were handling the exception from the
+ * guest, reload k1
+ */
+
+ uasm_i_move(&p, K1, S0);
+ UASM_i_ADDIU(&p, K1, K1, offsetof(struct kvm_vcpu, arch));
+
+ /*
+ * Check return value, should tell us if we are returning to the
+ * host (handle I/O etc)or resuming the guest
+ */
+ uasm_i_andi(&p, T0, V0, RESUME_HOST);
+ uasm_il_bnez(&p, &r, T0, label_return_to_host);
+ uasm_i_nop(&p);
+
+ p = kvm_mips_build_ret_to_guest(p);
+
+ uasm_l_return_to_host(&l, p);
+ p = kvm_mips_build_ret_to_host(p);
+
+ uasm_resolve_relocs(relocs, labels);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_ret_to_guest() - Assemble code to return to the guest.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to handle return from the guest exit handler
+ * (kvm_mips_handle_exit()) back to the guest.
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_ret_to_guest(void *addr)
+{
+ u32 *p = addr;
+
+ /* Put the saved pointer to vcpu (s0) back into the scratch register */
+ UASM_i_MTC0(&p, S0, scratch_vcpu[0], scratch_vcpu[1]);
+
+ /* Load up the Guest EBASE to minimize the window where BEV is set */
+ UASM_i_LW(&p, T0, offsetof(struct kvm_vcpu_arch, guest_ebase), K1);
+
+ /* Switch EBASE back to the one used by KVM */
+ uasm_i_mfc0(&p, V1, C0_STATUS);
+ uasm_i_lui(&p, AT, ST0_BEV >> 16);
+ uasm_i_or(&p, K0, V1, AT);
+ uasm_i_mtc0(&p, K0, C0_STATUS);
+ uasm_i_ehb(&p);
+ build_set_exc_base(&p, T0);
+
+ /* Setup status register for running guest in UM */
+ uasm_i_ori(&p, V1, V1, ST0_EXL | KSU_USER | ST0_IE);
+ UASM_i_LA(&p, AT, ~(ST0_CU0 | ST0_MX | ST0_SX | ST0_UX));
+ uasm_i_and(&p, V1, V1, AT);
+ uasm_i_mtc0(&p, V1, C0_STATUS);
+ uasm_i_ehb(&p);
+
+ p = kvm_mips_build_enter_guest(p);
+
+ return p;
+}
+
+/**
+ * kvm_mips_build_ret_to_host() - Assemble code to return to the host.
+ * @addr: Address to start writing code.
+ *
+ * Assemble the code to handle return from the guest exit handler
+ * (kvm_mips_handle_exit()) back to the host, i.e. to the caller of the vcpu_run
+ * function generated by kvm_mips_build_vcpu_run().
+ *
+ * Returns: Next address after end of written function.
+ */
+static void *kvm_mips_build_ret_to_host(void *addr)
+{
+ u32 *p = addr;
+ unsigned int i;
+
+ /* EBASE is already pointing to Linux */
+ UASM_i_LW(&p, K1, offsetof(struct kvm_vcpu_arch, host_stack), K1);
+ UASM_i_ADDIU(&p, K1, K1, -(int)sizeof(struct pt_regs));
+
+ /*
+ * r2/v0 is the return code, shift it down by 2 (arithmetic)
+ * to recover the err code
+ */
+ uasm_i_sra(&p, K0, V0, 2);
+ uasm_i_move(&p, V0, K0);
+
+ /* Load context saved on the host stack */
+ for (i = 16; i < 31; ++i) {
+ if (i == 24)
+ i = 28;
+ UASM_i_LW(&p, i, offsetof(struct pt_regs, regs[i]), K1);
+ }
+
+ /* Restore RDHWR access */
+ UASM_i_LA_mostly(&p, K0, (long)&hwrena);
+ uasm_i_lw(&p, K0, uasm_rel_lo((long)&hwrena), K0);
+ uasm_i_mtc0(&p, K0, C0_HWRENA);
+
+ /* Restore RA, which is the address we will return to */
+ UASM_i_LW(&p, RA, offsetof(struct pt_regs, regs[RA]), K1);
+ uasm_i_jr(&p, RA);
+ uasm_i_nop(&p);
+
+ return p;
+}
+