diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/.gitignore | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/Makefile | 72 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/debug-sr.c | 85 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/host.S | 185 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-init.S | 190 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-main.c | 117 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 24 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/switch.c | 283 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/sysreg-sr.c | 46 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/timer-sr.c | 48 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/tlb.c | 159 |
11 files changed, 1211 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/.gitignore b/arch/arm64/kvm/hyp/nvhe/.gitignore new file mode 100644 index 000000000..695d73d02 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +hyp.lds diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile new file mode 100644 index 000000000..230bba1a6 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -0,0 +1,72 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for Kernel-based Virtual Machine module, HYP/nVHE part +# + +asflags-y := -D__KVM_NVHE_HYPERVISOR__ +ccflags-y := -D__KVM_NVHE_HYPERVISOR__ + +lib-objs := clear_page.o copy_page.o memcpy.o memset.o +lib-objs := $(addprefix ../../../lib/, $(lib-objs)) + +obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o hyp-main.o +obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ + ../fpsimd.o ../hyp-entry.o +obj-y += $(lib-objs) + +## +## Build rules for compiling nVHE hyp code +## Output of this folder is `kvm_nvhe.o`, a partially linked object +## file containing all nVHE hyp code and data. +## + +hyp-obj := $(patsubst %.o,%.nvhe.o,$(obj-y)) +obj-y := kvm_nvhe.o +extra-y := $(hyp-obj) kvm_nvhe.tmp.o hyp.lds + +# 1) Compile all source files to `.nvhe.o` object files. The file extension +# avoids file name clashes for files shared with VHE. +$(obj)/%.nvhe.o: $(src)/%.c FORCE + $(call if_changed_rule,cc_o_c) +$(obj)/%.nvhe.o: $(src)/%.S FORCE + $(call if_changed_rule,as_o_S) + +# 2) Compile linker script. +$(obj)/hyp.lds: $(src)/hyp.lds.S FORCE + $(call if_changed_dep,cpp_lds_S) + +# 3) Partially link all '.nvhe.o' files and apply the linker script. +# Prefixes names of ELF sections with '.hyp', eg. '.hyp.text'. +# Note: The following rule assumes that the 'ld' rule puts LDFLAGS before +# the list of dependencies to form '-T $(obj)/hyp.lds'. This is to +# keep the dependency on the target while avoiding an error from +# GNU ld if the linker script is passed to it twice. +LDFLAGS_kvm_nvhe.tmp.o := -r -T +$(obj)/kvm_nvhe.tmp.o: $(obj)/hyp.lds $(addprefix $(obj)/,$(hyp-obj)) FORCE + $(call if_changed,ld) + +# 4) Produce the final 'kvm_nvhe.o', ready to be linked into 'vmlinux'. +# Prefixes names of ELF symbols with '__kvm_nvhe_'. +$(obj)/kvm_nvhe.o: $(obj)/kvm_nvhe.tmp.o FORCE + $(call if_changed,hypcopy) + +# The HYPCOPY command uses `objcopy` to prefix all ELF symbol names +# to avoid clashes with VHE code/data. +quiet_cmd_hypcopy = HYPCOPY $@ + cmd_hypcopy = $(OBJCOPY) --prefix-symbols=__kvm_nvhe_ $< $@ + +# Remove ftrace and Shadow Call Stack CFLAGS. +# This is equivalent to the 'notrace' and '__noscs' annotations. +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS), $(KBUILD_CFLAGS)) + +# KVM nVHE code is run at a different exception code with a different map, so +# compiler instrumentation that inserts callbacks or checks into the code may +# cause crashes. Just disable it. +GCOV_PROFILE := n +KASAN_SANITIZE := n +UBSAN_SANITIZE := n +KCOV_INSTRUMENT := n + +# Skip objtool checking for this directory because nVHE code is compiled with +# non-standard build rules. +OBJECT_FILES_NON_STANDARD := y diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c new file mode 100644 index 000000000..f401724f1 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/debug-sr.h> + +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/debug-monitors.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +static void __debug_save_spe(u64 *pmscr_el1) +{ + u64 reg; + + /* Clear pmscr in case of early return */ + *pmscr_el1 = 0; + + /* SPE present on this CPU? */ + if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1), + ID_AA64DFR0_PMSVER_SHIFT)) + return; + + /* Yes; is it owned by EL3? */ + reg = read_sysreg_s(SYS_PMBIDR_EL1); + if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT)) + return; + + /* No; is the host actually using the thing? */ + reg = read_sysreg_s(SYS_PMBLIMITR_EL1); + if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT))) + return; + + /* Yes; save the control register and disable data generation */ + *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1); + write_sysreg_s(0, SYS_PMSCR_EL1); + isb(); + + /* Now drain all buffered data to memory */ + psb_csync(); + dsb(nsh); +} + +static void __debug_restore_spe(u64 pmscr_el1) +{ + if (!pmscr_el1) + return; + + /* The host page table is installed, but not yet synchronised */ + isb(); + + /* Re-enable data generation */ + write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1); +} + +void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) +{ + /* Disable and flush SPE data generation */ + __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); +} + +void __debug_switch_to_guest(struct kvm_vcpu *vcpu) +{ + __debug_switch_to_guest_common(vcpu); +} + +void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) +{ + __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); +} + +void __debug_switch_to_host(struct kvm_vcpu *vcpu) +{ + __debug_switch_to_host_common(vcpu); +} + +u32 __kvm_get_mdcr_el2(void) +{ + return read_sysreg(mdcr_el2); +} diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S new file mode 100644 index 000000000..4f57a803d --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -0,0 +1,185 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 - Google Inc + * Author: Andrew Scull <ascull@google.com> + */ + +#include <linux/linkage.h> + +#include <asm/assembler.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> + + .text + +SYM_FUNC_START(__host_exit) + stp x0, x1, [sp, #-16]! + + get_host_ctxt x0, x1 + + /* Store the host regs x2 and x3 */ + stp x2, x3, [x0, #CPU_XREG_OFFSET(2)] + + /* Retrieve the host regs x0-x1 from the stack */ + ldp x2, x3, [sp], #16 // x0, x1 + + /* Store the host regs x0-x1 and x4-x17 */ + stp x2, x3, [x0, #CPU_XREG_OFFSET(0)] + stp x4, x5, [x0, #CPU_XREG_OFFSET(4)] + stp x6, x7, [x0, #CPU_XREG_OFFSET(6)] + stp x8, x9, [x0, #CPU_XREG_OFFSET(8)] + stp x10, x11, [x0, #CPU_XREG_OFFSET(10)] + stp x12, x13, [x0, #CPU_XREG_OFFSET(12)] + stp x14, x15, [x0, #CPU_XREG_OFFSET(14)] + stp x16, x17, [x0, #CPU_XREG_OFFSET(16)] + + /* Store the host regs x18-x29, lr */ + save_callee_saved_regs x0 + + /* Save the host context pointer in x29 across the function call */ + mov x29, x0 + bl handle_trap + + /* Restore host regs x0-x17 */ + ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] + + /* x0-7 are use for panic arguments */ +__host_enter_for_panic: + ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] + + /* Restore host regs x18-x29, lr */ + restore_callee_saved_regs x29 + + /* Do not touch any register after this! */ +__host_enter_without_restoring: + eret + sb +SYM_FUNC_END(__host_exit) + +/* + * void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, + * u64 elr, u64 par); + */ +SYM_FUNC_START(__hyp_do_panic) + mov x29, x0 + + /* Load the format string into x0 and arguments into x1-7 */ + ldr x0, =__hyp_panic_string + + mov x6, x3 + get_vcpu_ptr x7, x3 + + mrs x3, esr_el2 + mrs x4, far_el2 + mrs x5, hpfar_el2 + + /* Prepare and exit to the host's panic funciton. */ + mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ + PSR_MODE_EL1h) + msr spsr_el2, lr + ldr lr, =panic + msr elr_el2, lr + + /* Enter the host, conditionally restoring the host context. */ + cbz x29, __host_enter_without_restoring + b __host_enter_for_panic +SYM_FUNC_END(__hyp_do_panic) + +.macro host_el1_sync_vect + .align 7 +.L__vect_start\@: + stp x0, x1, [sp, #-16]! + mrs x0, esr_el2 + ubfx x0, x0, #ESR_ELx_EC_SHIFT, #ESR_ELx_EC_WIDTH + cmp x0, #ESR_ELx_EC_HVC64 + ldp x0, x1, [sp], #16 + b.ne __host_exit + + /* Check for a stub HVC call */ + cmp x0, #HVC_STUB_HCALL_NR + b.hs __host_exit + + /* + * Compute the idmap address of __kvm_handle_stub_hvc and + * jump there. Since we use kimage_voffset, do not use the + * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead + * (by loading it from the constant pool). + * + * Preserve x0-x4, which may contain stub parameters. + */ + ldr x5, =__kvm_handle_stub_hvc + ldr_l x6, kimage_voffset + + /* x5 = __pa(x5) */ + sub x5, x5, x6 + br x5 +.L__vect_end\@: +.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) + .error "host_el1_sync_vect larger than vector entry" +.endif +.endm + +.macro invalid_host_el2_vect + .align 7 + /* If a guest is loaded, panic out of it. */ + stp x0, x1, [sp, #-16]! + get_loaded_vcpu x0, x1 + cbnz x0, __guest_exit_panic + add sp, sp, #16 + + /* + * The panic may not be clean if the exception is taken before the host + * context has been saved by __host_exit or after the hyp context has + * been partially clobbered by __host_enter. + */ + b hyp_panic +.endm + +.macro invalid_host_el1_vect + .align 7 + mov x0, xzr /* host_ctxt = NULL */ + mrs x1, spsr_el2 + mrs x2, elr_el2 + mrs x3, par_el1 + b __hyp_do_panic +.endm + +/* + * The host vector does not use an ESB instruction in order to avoid consuming + * SErrors that should only be consumed by the host. Guest entry is deferred by + * __guest_enter if there are any pending asynchronous exceptions so hyp will + * always return to the host without having consumerd host SErrors. + * + * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the + * host knows about the EL2 vectors already, and there is no point in hiding + * them. + */ + .align 11 +SYM_CODE_START(__kvm_hyp_host_vector) + invalid_host_el2_vect // Synchronous EL2t + invalid_host_el2_vect // IRQ EL2t + invalid_host_el2_vect // FIQ EL2t + invalid_host_el2_vect // Error EL2t + + invalid_host_el2_vect // Synchronous EL2h + invalid_host_el2_vect // IRQ EL2h + invalid_host_el2_vect // FIQ EL2h + invalid_host_el2_vect // Error EL2h + + host_el1_sync_vect // Synchronous 64-bit EL1 + invalid_host_el1_vect // IRQ 64-bit EL1 + invalid_host_el1_vect // FIQ 64-bit EL1 + invalid_host_el1_vect // Error 64-bit EL1 + + invalid_host_el1_vect // Synchronous 32-bit EL1 + invalid_host_el1_vect // IRQ 32-bit EL1 + invalid_host_el1_vect // FIQ 32-bit EL1 + invalid_host_el1_vect // Error 32-bit EL1 +SYM_CODE_END(__kvm_hyp_host_vector) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S new file mode 100644 index 000000000..b11a9d7db --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -0,0 +1,190 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <linux/arm-smccc.h> +#include <linux/linkage.h> + +#include <asm/alternative.h> +#include <asm/assembler.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> +#include <asm/pgtable-hwdef.h> +#include <asm/sysreg.h> +#include <asm/virt.h> + + .text + .pushsection .hyp.idmap.text, "ax" + + .align 11 + +SYM_CODE_START(__kvm_hyp_init) + ventry __invalid // Synchronous EL2t + ventry __invalid // IRQ EL2t + ventry __invalid // FIQ EL2t + ventry __invalid // Error EL2t + + ventry __invalid // Synchronous EL2h + ventry __invalid // IRQ EL2h + ventry __invalid // FIQ EL2h + ventry __invalid // Error EL2h + + ventry __do_hyp_init // Synchronous 64-bit EL1 + ventry __invalid // IRQ 64-bit EL1 + ventry __invalid // FIQ 64-bit EL1 + ventry __invalid // Error 64-bit EL1 + + ventry __invalid // Synchronous 32-bit EL1 + ventry __invalid // IRQ 32-bit EL1 + ventry __invalid // FIQ 32-bit EL1 + ventry __invalid // Error 32-bit EL1 + +__invalid: + b . + + /* + * x0: SMCCC function ID + * x1: HYP pgd + * x2: per-CPU offset + * x3: HYP stack + * x4: HYP vectors + */ +__do_hyp_init: + /* Check for a stub HVC call */ + cmp x0, #HVC_STUB_HCALL_NR + b.lo __kvm_handle_stub_hvc + + // We only actively check bits [24:31], and everything + // else has to be zero, which we check at build time. +#if (KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) & 0xFFFFFFFF00FFFFFF) +#error Unexpected __KVM_HOST_SMCCC_FUNC___kvm_hyp_init value +#endif + + ror x0, x0, #24 + eor x0, x0, #((KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) >> 24) & 0xF) + ror x0, x0, #4 + eor x0, x0, #((KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) >> 28) & 0xF) + cbz x0, 1f + mov x0, #SMCCC_RET_NOT_SUPPORTED + eret + +1: + /* Set tpidr_el2 for use by HYP to free a register */ + msr tpidr_el2, x2 + + phys_to_ttbr x0, x1 +alternative_if ARM64_HAS_CNP + orr x0, x0, #TTBR_CNP_BIT +alternative_else_nop_endif + msr ttbr0_el2, x0 + + mrs x0, tcr_el1 + mov_q x1, TCR_EL2_MASK + and x0, x0, x1 + mov x1, #TCR_EL2_RES1 + orr x0, x0, x1 + + /* + * The ID map may be configured to use an extended virtual address + * range. This is only the case if system RAM is out of range for the + * currently configured page size and VA_BITS, in which case we will + * also need the extended virtual range for the HYP ID map, or we won't + * be able to enable the EL2 MMU. + * + * However, at EL2, there is only one TTBR register, and we can't switch + * between translation tables *and* update TCR_EL2.T0SZ at the same + * time. Bottom line: we need to use the extended range with *both* our + * translation tables. + * + * So use the same T0SZ value we use for the ID map. + */ + ldr_l x1, idmap_t0sz + bfi x0, x1, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH + + /* + * Set the PS bits in TCR_EL2. + */ + tcr_compute_pa_size x0, #TCR_EL2_PS_SHIFT, x1, x2 + + msr tcr_el2, x0 + + mrs x0, mair_el1 + msr mair_el2, x0 + isb + + /* Invalidate the stale TLBs from Bootloader */ + tlbi alle2 + dsb sy + + /* + * Preserve all the RES1 bits while setting the default flags, + * as well as the EE bit on BE. Drop the A flag since the compiler + * is allowed to generate unaligned accesses. + */ + mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) +CPU_BE( orr x0, x0, #SCTLR_ELx_EE) +alternative_if ARM64_HAS_ADDRESS_AUTH + mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ + SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) + orr x0, x0, x1 +alternative_else_nop_endif + msr sctlr_el2, x0 + isb + + /* Set the stack and new vectors */ + mov sp, x3 + msr vbar_el2, x4 + + /* Hello, World! */ + mov x0, #SMCCC_RET_SUCCESS + eret +SYM_CODE_END(__kvm_hyp_init) + +SYM_CODE_START(__kvm_handle_stub_hvc) + cmp x0, #HVC_SOFT_RESTART + b.ne 1f + + /* This is where we're about to jump, staying at EL2 */ + msr elr_el2, x1 + mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) + msr spsr_el2, x0 + + /* Shuffle the arguments, and don't come back */ + mov x0, x2 + mov x1, x3 + mov x2, x4 + b reset + +1: cmp x0, #HVC_RESET_VECTORS + b.ne 1f + + /* + * Set the HVC_RESET_VECTORS return code before entering the common + * path so that we do not clobber x0-x2 in case we are coming via + * HVC_SOFT_RESTART. + */ + mov x0, xzr +reset: + /* Reset kvm back to the hyp stub. */ + mrs x5, sctlr_el2 + mov_q x6, SCTLR_ELx_FLAGS + bic x5, x5, x6 // Clear SCTL_M and etc + pre_disable_mmu_workaround + msr sctlr_el2, x5 + isb + + /* Install stub vectors */ + adr_l x5, __hyp_stub_vectors + msr vbar_el2, x5 + eret + +1: /* Bad stub call */ + mov_q x0, HVC_STUB_ERR + eret + +SYM_CODE_END(__kvm_handle_stub_hvc) + + .popsection diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c new file mode 100644 index 000000000..3df30b459 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 - Google Inc + * Author: Andrew Scull <ascull@google.com> + */ + +#include <hyp/switch.h> + +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_host.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> + +#include <kvm/arm_hypercalls.h> + +static void handle_host_hcall(unsigned long func_id, + struct kvm_cpu_context *host_ctxt) +{ + unsigned long ret = 0; + + switch (func_id) { + case KVM_HOST_SMCCC_FUNC(__kvm_vcpu_run): { + unsigned long r1 = host_ctxt->regs.regs[1]; + struct kvm_vcpu *vcpu = (struct kvm_vcpu *)r1; + + ret = __kvm_vcpu_run(kern_hyp_va(vcpu)); + break; + } + case KVM_HOST_SMCCC_FUNC(__kvm_flush_vm_context): + __kvm_flush_vm_context(); + break; + case KVM_HOST_SMCCC_FUNC(__kvm_tlb_flush_vmid_ipa): { + unsigned long r1 = host_ctxt->regs.regs[1]; + struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1; + phys_addr_t ipa = host_ctxt->regs.regs[2]; + int level = host_ctxt->regs.regs[3]; + + __kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level); + break; + } + case KVM_HOST_SMCCC_FUNC(__kvm_tlb_flush_vmid): { + unsigned long r1 = host_ctxt->regs.regs[1]; + struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1; + + __kvm_tlb_flush_vmid(kern_hyp_va(mmu)); + break; + } + case KVM_HOST_SMCCC_FUNC(__kvm_flush_cpu_context): { + unsigned long r1 = host_ctxt->regs.regs[1]; + struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1; + + __kvm_flush_cpu_context(kern_hyp_va(mmu)); + break; + } + case KVM_HOST_SMCCC_FUNC(__kvm_timer_set_cntvoff): { + u64 cntvoff = host_ctxt->regs.regs[1]; + + __kvm_timer_set_cntvoff(cntvoff); + break; + } + case KVM_HOST_SMCCC_FUNC(__kvm_enable_ssbs): + __kvm_enable_ssbs(); + break; + case KVM_HOST_SMCCC_FUNC(__vgic_v3_get_ich_vtr_el2): + ret = __vgic_v3_get_ich_vtr_el2(); + break; + case KVM_HOST_SMCCC_FUNC(__vgic_v3_read_vmcr): + ret = __vgic_v3_read_vmcr(); + break; + case KVM_HOST_SMCCC_FUNC(__vgic_v3_write_vmcr): { + u32 vmcr = host_ctxt->regs.regs[1]; + + __vgic_v3_write_vmcr(vmcr); + break; + } + case KVM_HOST_SMCCC_FUNC(__vgic_v3_init_lrs): + __vgic_v3_init_lrs(); + break; + case KVM_HOST_SMCCC_FUNC(__kvm_get_mdcr_el2): + ret = __kvm_get_mdcr_el2(); + break; + case KVM_HOST_SMCCC_FUNC(__vgic_v3_save_aprs): { + unsigned long r1 = host_ctxt->regs.regs[1]; + struct vgic_v3_cpu_if *cpu_if = (struct vgic_v3_cpu_if *)r1; + + __vgic_v3_save_aprs(kern_hyp_va(cpu_if)); + break; + } + case KVM_HOST_SMCCC_FUNC(__vgic_v3_restore_aprs): { + unsigned long r1 = host_ctxt->regs.regs[1]; + struct vgic_v3_cpu_if *cpu_if = (struct vgic_v3_cpu_if *)r1; + + __vgic_v3_restore_aprs(kern_hyp_va(cpu_if)); + break; + } + default: + /* Invalid host HVC. */ + host_ctxt->regs.regs[0] = SMCCC_RET_NOT_SUPPORTED; + return; + } + + host_ctxt->regs.regs[0] = SMCCC_RET_SUCCESS; + host_ctxt->regs.regs[1] = ret; +} + +void handle_trap(struct kvm_cpu_context *host_ctxt) +{ + u64 esr = read_sysreg_el2(SYS_ESR); + unsigned long func_id; + + if (ESR_ELx_EC(esr) != ESR_ELx_EC_HVC64) + hyp_panic(); + + func_id = host_ctxt->regs.regs[0]; + handle_host_hcall(func_id, host_ctxt); +} diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S new file mode 100644 index 000000000..a797abace --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020 Google LLC. + * Written by David Brazdil <dbrazdil@google.com> + * + * Linker script used for partial linking of nVHE EL2 object files. + */ + +#include <asm/hyp_image.h> +#include <asm-generic/vmlinux.lds.h> +#include <asm/cache.h> +#include <asm/memory.h> + +SECTIONS { + HYP_SECTION(.text) + /* + * .hyp..data..percpu needs to be page aligned to maintain the same + * alignment for when linking into vmlinux. + */ + . = ALIGN(PAGE_SIZE); + HYP_SECTION_NAME(.data..percpu) : { + PERCPU_INPUT(L1_CACHE_BYTES) + } +} diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c new file mode 100644 index 000000000..2401164c5 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/switch.h> +#include <hyp/sysreg-sr.h> + +#include <linux/arm-smccc.h> +#include <linux/kvm_host.h> +#include <linux/types.h> +#include <linux/jump_label.h> +#include <uapi/linux/psci.h> + +#include <kvm/arm_psci.h> + +#include <asm/barrier.h> +#include <asm/cpufeature.h> +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/fpsimd.h> +#include <asm/debug-monitors.h> +#include <asm/processor.h> +#include <asm/thread_info.h> + +/* Non-VHE specific context */ +DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); +DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); +DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); + +static void __activate_traps(struct kvm_vcpu *vcpu) +{ + u64 val; + + ___activate_traps(vcpu); + __activate_traps_common(vcpu); + + val = CPTR_EL2_DEFAULT; + val |= CPTR_EL2_TTA | CPTR_EL2_TZ | CPTR_EL2_TAM; + if (!update_fp_enabled(vcpu)) { + val |= CPTR_EL2_TFP; + __activate_traps_fpsimd32(vcpu); + } + + write_sysreg(val, cptr_el2); + write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt; + + isb(); + /* + * At this stage, and thanks to the above isb(), S2 is + * configured and enabled. We can now restore the guest's S1 + * configuration: SCTLR, and only then TCR. + */ + write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR_EL1), SYS_SCTLR); + isb(); + write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL1), SYS_TCR); + } +} + +static void __deactivate_traps(struct kvm_vcpu *vcpu) +{ + extern char __kvm_hyp_host_vector[]; + u64 mdcr_el2; + + ___deactivate_traps(vcpu); + + mdcr_el2 = read_sysreg(mdcr_el2); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + u64 val; + + /* + * Set the TCR and SCTLR registers in the exact opposite + * sequence as __activate_traps (first prevent walks, + * then force the MMU on). A generous sprinkling of isb() + * ensure that things happen in this exact order. + */ + val = read_sysreg_el1(SYS_TCR); + write_sysreg_el1(val | TCR_EPD1_MASK | TCR_EPD0_MASK, SYS_TCR); + isb(); + val = read_sysreg_el1(SYS_SCTLR); + write_sysreg_el1(val | SCTLR_ELx_M, SYS_SCTLR); + isb(); + } + + __deactivate_traps_common(); + + mdcr_el2 &= MDCR_EL2_HPMN_MASK; + mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; + + write_sysreg(mdcr_el2, mdcr_el2); + write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2); + write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); + write_sysreg(__kvm_hyp_host_vector, vbar_el2); +} + +static void __load_host_stage2(void) +{ + write_sysreg(0, vttbr_el2); +} + +/* Save VGICv3 state on non-VHE systems */ +static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu) +{ + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { + __vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3); + __vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3); + } +} + +/* Restore VGICv3 state on non_VEH systems */ +static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu) +{ + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { + __vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3); + __vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3); + } +} + +/** + * Disable host events, enable guest events + */ +static bool __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt) +{ + struct kvm_host_data *host; + struct kvm_pmu_events *pmu; + + host = container_of(host_ctxt, struct kvm_host_data, host_ctxt); + pmu = &host->pmu_events; + + if (pmu->events_host) + write_sysreg(pmu->events_host, pmcntenclr_el0); + + if (pmu->events_guest) + write_sysreg(pmu->events_guest, pmcntenset_el0); + + return (pmu->events_host || pmu->events_guest); +} + +/** + * Disable guest events, enable host events + */ +static void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt) +{ + struct kvm_host_data *host; + struct kvm_pmu_events *pmu; + + host = container_of(host_ctxt, struct kvm_host_data, host_ctxt); + pmu = &host->pmu_events; + + if (pmu->events_guest) + write_sysreg(pmu->events_guest, pmcntenclr_el0); + + if (pmu->events_host) + write_sysreg(pmu->events_host, pmcntenset_el0); +} + +/* Switch to the guest for legacy non-VHE systems */ +int __kvm_vcpu_run(struct kvm_vcpu *vcpu) +{ + struct kvm_cpu_context *host_ctxt; + struct kvm_cpu_context *guest_ctxt; + bool pmu_switch_needed; + u64 exit_code; + + /* + * Having IRQs masked via PMR when entering the guest means the GIC + * will not signal the CPU of interrupts of lower priority, and the + * only way to get out will be via guest exceptions. + * Naturally, we want to avoid this. + */ + if (system_uses_irq_prio_masking()) { + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); + pmr_sync(); + } + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + host_ctxt->__hyp_running_vcpu = vcpu; + guest_ctxt = &vcpu->arch.ctxt; + + pmu_switch_needed = __pmu_switch_to_guest(host_ctxt); + + __sysreg_save_state_nvhe(host_ctxt); + /* + * We must flush and disable the SPE buffer for nVHE, as + * the translation regime(EL1&0) is going to be loaded with + * that of the guest. And we must do this before we change the + * translation regime to EL2 (via MDCR_EL2_E2PB == 0) and + * before we load guest Stage1. + */ + __debug_save_host_buffers_nvhe(vcpu); + + /* + * We must restore the 32-bit state before the sysregs, thanks + * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). + * + * Also, and in order to be able to deal with erratum #1319537 (A57) + * and #1319367 (A72), we must ensure that all VM-related sysreg are + * restored before we enable S2 translation. + */ + __sysreg32_restore_state(vcpu); + __sysreg_restore_state_nvhe(guest_ctxt); + + __load_guest_stage2(kern_hyp_va(vcpu->arch.hw_mmu)); + __activate_traps(vcpu); + + __hyp_vgic_restore_state(vcpu); + __timer_enable_traps(vcpu); + + __debug_switch_to_guest(vcpu); + + do { + /* Jump in the fire! */ + exit_code = __guest_enter(vcpu); + + /* And we're baaack! */ + } while (fixup_guest_exit(vcpu, &exit_code)); + + __sysreg_save_state_nvhe(guest_ctxt); + __sysreg32_save_state(vcpu); + __timer_disable_traps(vcpu); + __hyp_vgic_save_state(vcpu); + + __deactivate_traps(vcpu); + __load_host_stage2(); + + __sysreg_restore_state_nvhe(host_ctxt); + + if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) + __fpsimd_save_fpexc32(vcpu); + + __debug_switch_to_host(vcpu); + /* + * This must come after restoring the host sysregs, since a non-VHE + * system may enable SPE here and make use of the TTBRs. + */ + __debug_restore_host_buffers_nvhe(vcpu); + + if (pmu_switch_needed) + __pmu_switch_to_host(host_ctxt); + + /* Returning to host will clear PSR.I, remask PMR if needed */ + if (system_uses_irq_prio_masking()) + gic_write_pmr(GIC_PRIO_IRQOFF); + + host_ctxt->__hyp_running_vcpu = NULL; + + return exit_code; +} + +void __noreturn hyp_panic(void) +{ + u64 spsr = read_sysreg_el2(SYS_SPSR); + u64 elr = read_sysreg_el2(SYS_ELR); + u64 par = read_sysreg_par(); + struct kvm_cpu_context *host_ctxt; + struct kvm_vcpu *vcpu; + + host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; + vcpu = host_ctxt->__hyp_running_vcpu; + + if (vcpu) { + __timer_disable_traps(vcpu); + __deactivate_traps(vcpu); + __load_host_stage2(); + __sysreg_restore_state_nvhe(host_ctxt); + } + + __hyp_do_panic(host_ctxt, spsr, elr, par); + unreachable(); +} + +asmlinkage void kvm_unexpected_el2_exception(void) +{ + __kvm_unexpected_el2_exception(); +} diff --git a/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c new file mode 100644 index 000000000..88a25fc8f --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/sysreg-sr.h> + +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_hyp.h> + +/* + * Non-VHE: Both host and guest must save everything. + */ + +void __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_save_el1_state(ctxt); + __sysreg_save_common_state(ctxt); + __sysreg_save_user_state(ctxt); + __sysreg_save_el2_return_state(ctxt); +} + +void __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt) +{ + __sysreg_restore_el1_state(ctxt); + __sysreg_restore_common_state(ctxt); + __sysreg_restore_user_state(ctxt); + __sysreg_restore_el2_return_state(ctxt); +} + +void __kvm_enable_ssbs(void) +{ + u64 tmp; + + asm volatile( + "mrs %0, sctlr_el2\n" + "orr %0, %0, %1\n" + "msr sctlr_el2, %0" + : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS)); +} diff --git a/arch/arm64/kvm/hyp/nvhe/timer-sr.c b/arch/arm64/kvm/hyp/nvhe/timer-sr.c new file mode 100644 index 000000000..9072e7169 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/timer-sr.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <clocksource/arm_arch_timer.h> +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/kvm_hyp.h> + +void __kvm_timer_set_cntvoff(u64 cntvoff) +{ + write_sysreg(cntvoff, cntvoff_el2); +} + +/* + * Should only be called on non-VHE systems. + * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe(). + */ +void __timer_disable_traps(struct kvm_vcpu *vcpu) +{ + u64 val; + + /* Allow physical timer/counter access for the host */ + val = read_sysreg(cnthctl_el2); + val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN; + write_sysreg(val, cnthctl_el2); +} + +/* + * Should only be called on non-VHE systems. + * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe(). + */ +void __timer_enable_traps(struct kvm_vcpu *vcpu) +{ + u64 val; + + /* + * Disallow physical timer access for the guest + * Physical counter access is allowed + */ + val = read_sysreg(cnthctl_el2); + val &= ~CNTHCTL_EL1PCEN; + val |= CNTHCTL_EL1PCTEN; + write_sysreg(val, cnthctl_el2); +} diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c new file mode 100644 index 000000000..229b06748 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/tlb.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/tlbflush.h> + +struct tlb_inv_context { + u64 tcr; +}; + +static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu, + struct tlb_inv_context *cxt) +{ + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + u64 val; + + /* + * For CPUs that are affected by ARM 1319367, we need to + * avoid a host Stage-1 walk while we have the guest's + * VMID set in the VTTBR in order to invalidate TLBs. + * We're guaranteed that the S1 MMU is enabled, so we can + * simply set the EPD bits to avoid any further TLB fill. + */ + val = cxt->tcr = read_sysreg_el1(SYS_TCR); + val |= TCR_EPD1_MASK | TCR_EPD0_MASK; + write_sysreg_el1(val, SYS_TCR); + isb(); + } + + /* + * __load_guest_stage2() includes an ISB only when the AT + * workaround is applied. Take care of the opposite condition, + * ensuring that we always have an ISB, but not two ISBs back + * to back. + */ + __load_guest_stage2(mmu); + asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT)); +} + +static void __tlb_switch_to_host(struct tlb_inv_context *cxt) +{ + write_sysreg(0, vttbr_el2); + + if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { + /* Ensure write of the host VMID */ + isb(); + /* Restore the host's TCR_EL1 */ + write_sysreg_el1(cxt->tcr, SYS_TCR); + } +} + +void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, + phys_addr_t ipa, int level) +{ + struct tlb_inv_context cxt; + + dsb(ishst); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + /* + * We could do so much better if we had the VA as well. + * Instead, we invalidate Stage-2 for this IPA, and the + * whole of Stage-1. Weep... + */ + ipa >>= 12; + __tlbi_level(ipas2e1is, ipa, level); + + /* + * We have to ensure completion of the invalidation at Stage-2, + * since a table walk on another CPU could refill a TLB with a + * complete (S1 + S2) walk based on the old Stage-2 mapping if + * the Stage-1 invalidation happened first. + */ + dsb(ish); + __tlbi(vmalle1is); + dsb(ish); + isb(); + + /* + * If the host is running at EL1 and we have a VPIPT I-cache, + * then we must perform I-cache maintenance at EL2 in order for + * it to have an effect on the guest. Since the guest cannot hit + * I-cache lines allocated with a different VMID, we don't need + * to worry about junk out of guest reset (we nuke the I-cache on + * VMID rollover), but we do need to be careful when remapping + * executable pages for the same guest. This can happen when KSM + * takes a CoW fault on an executable page, copies the page into + * a page that was previously mapped in the guest and then needs + * to invalidate the guest view of the I-cache for that page + * from EL1. To solve this, we invalidate the entire I-cache when + * unmapping a page from a guest if we have a VPIPT I-cache but + * the host is running at EL1. As above, we could do better if + * we had the VA. + * + * The moral of this story is: if you have a VPIPT I-cache, then + * you should be running with VHE enabled. + */ + if (icache_is_vpipt()) + __flush_icache_all(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + dsb(ishst); + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + __tlbi(vmalls12e1is); + dsb(ish); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu) +{ + struct tlb_inv_context cxt; + + /* Switch to requested VMID */ + __tlb_switch_to_guest(mmu, &cxt); + + __tlbi(vmalle1); + asm volatile("ic iallu"); + dsb(nsh); + isb(); + + __tlb_switch_to_host(&cxt); +} + +void __kvm_flush_vm_context(void) +{ + dsb(ishst); + __tlbi(alle1is); + + /* + * VIPT and PIPT caches are not affected by VMID, so no maintenance + * is necessary across a VMID rollover. + * + * VPIPT caches constrain lookup and maintenance to the active VMID, + * so we need to invalidate lines with a stale VMID to avoid an ABA + * race after multiple rollovers. + * + */ + if (icache_is_vpipt()) + asm volatile("ic ialluis"); + + dsb(ish); +} |