diff options
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/handle_exit.c | 7 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp-init.S | 48 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp.S | 11 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 19 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 10 | ||||
| -rw-r--r-- | arch/arm64/kvm/reset.c | 30 |
6 files changed, 114 insertions, 11 deletions
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index eba89e42f0ed..3246c4aba5b1 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -186,6 +186,13 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, exit_handler = kvm_get_exit_handler(vcpu); return exit_handler(vcpu, run); + case ARM_EXCEPTION_HYP_GONE: + /* + * EL2 has been reset to the hyp-stub. This happens when a guest + * is pre-empted by kvm_reboot()'s shutdown call. + */ + run->exit_reason = KVM_EXIT_FAIL_ENTRY; + return 0; default: kvm_pr_unimpl("Unsupported exception type: %d", exception_index); diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S index 7d8747c6427c..a873a6d8be90 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -21,6 +21,7 @@ #include <asm/kvm_arm.h> #include <asm/kvm_mmu.h> #include <asm/pgtable-hwdef.h> +#include <asm/sysreg.h> .text .pushsection .hyp.idmap.text, "ax" @@ -103,8 +104,8 @@ __do_hyp_init: dsb sy mrs x4, sctlr_el2 - and x4, x4, #SCTLR_EL2_EE // preserve endianness of EL2 - ldr x5, =SCTLR_EL2_FLAGS + and x4, x4, #SCTLR_ELx_EE // preserve endianness of EL2 + ldr x5, =SCTLR_ELx_FLAGS orr x4, x4, x5 msr sctlr_el2, x4 isb @@ -138,6 +139,49 @@ merged: eret ENDPROC(__kvm_hyp_init) + /* + * Reset kvm back to the hyp stub. This is the trampoline dance in + * reverse. If kvm used an extended idmap, __extended_idmap_trampoline + * calls this code directly in the idmap. In this case switching to the + * boot tables is a no-op. + * + * x0: HYP boot pgd + * x1: HYP phys_idmap_start + */ +ENTRY(__kvm_hyp_reset) + /* We're in trampoline code in VA, switch back to boot page tables */ + msr ttbr0_el2, x0 + isb + + /* Ensure the PA branch doesn't find a stale tlb entry or stale code. */ + ic iallu + tlbi alle2 + dsb sy + isb + + /* Branch into PA space */ + adr x0, 1f + bfi x1, x0, #0, #PAGE_SHIFT + br x1 + + /* We're now in idmap, disable MMU */ +1: mrs x0, sctlr_el2 + ldr x1, =SCTLR_ELx_FLAGS + bic x0, x0, x1 // Clear SCTL_M and etc + msr sctlr_el2, x0 + isb + + /* Invalidate the old TLBs */ + tlbi alle2 + dsb sy + + /* Install stub vectors */ + adr_l x0, __hyp_stub_vectors + msr vbar_el2, x0 + + eret +ENDPROC(__kvm_hyp_reset) + .ltorg .popsection diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 48f19a37b3df..7ce931565151 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -35,16 +35,21 @@ * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are * passed in x0. * - * A function pointer with a value of 0 has a special meaning, and is - * used to implement __hyp_get_vectors in the same way as in + * A function pointer with a value less than 0xfff has a special meaning, + * and is used to implement __hyp_get_vectors in the same way as in * arch/arm64/kernel/hyp_stub.S. + * HVC behaves as a 'bl' call and will clobber lr. */ ENTRY(__kvm_call_hyp) -alternative_if_not ARM64_HAS_VIRT_HOST_EXTN +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN + str lr, [sp, #-16]! hvc #0 + ldr lr, [sp], #16 ret alternative_else b __vhe_hyp_call nop + nop + nop alternative_endif ENDPROC(__kvm_call_hyp) diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index ce9e5e5f28cf..70254a65bd5b 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -164,3 +164,22 @@ alternative_endif eret ENDPROC(__fpsimd_guest_restore) + +/* + * When using the extended idmap, we don't have a trampoline page we can use + * while we switch pages tables during __kvm_hyp_reset. Accessing the idmap + * directly would be ideal, but if we're using the extended idmap then the + * idmap is located above HYP_PAGE_OFFSET, and the address will be masked by + * kvm_call_hyp using kern_hyp_va. + * + * x0: HYP boot pgd + * x1: HYP phys_idmap_start + */ +ENTRY(__extended_idmap_trampoline) + mov x4, x1 + adr_l x3, __kvm_hyp_reset + + /* insert __kvm_hyp_reset()s offset into phys_idmap_start */ + bfi x4, x3, #0, #PAGE_SHIFT + br x4 +ENDPROC(__extended_idmap_trampoline) diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 3488894397ff..2d87f36d5cb4 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -42,19 +42,17 @@ * Shuffle the parameters before calling the function * pointed to in x0. Assumes parameters in x[1,2,3]. */ - sub sp, sp, #16 - str lr, [sp] mov lr, x0 mov x0, x1 mov x1, x2 mov x2, x3 blr lr - ldr lr, [sp] - add sp, sp, #16 .endm ENTRY(__vhe_hyp_call) + str lr, [sp, #-16]! do_el2_call + ldr lr, [sp], #16 /* * We used to rely on having an exception return to get * an implicit isb. In the E2H case, we don't have it anymore. @@ -84,8 +82,8 @@ alternative_endif /* Here, we're pretty sure the host called HVC. */ restore_x0_to_x3 - /* Check for __hyp_get_vectors */ - cbnz x0, 1f + cmp x0, #HVC_GET_VECTORS + b.ne 1f mrs x0, vbar_el2 b 2f diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 9677bf069bcc..b1ad730e1567 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -29,7 +29,9 @@ #include <asm/cputype.h> #include <asm/ptrace.h> #include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> #include <asm/kvm_coproc.h> +#include <asm/kvm_mmu.h> /* * ARMv8 Reset Values @@ -130,3 +132,31 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) /* Reset timer */ return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq); } + +extern char __hyp_idmap_text_start[]; + +unsigned long kvm_hyp_reset_entry(void) +{ + if (!__kvm_cpu_uses_extended_idmap()) { + unsigned long offset; + + /* + * Find the address of __kvm_hyp_reset() in the trampoline page. + * This is present in the running page tables, and the boot page + * tables, so we call the code here to start the trampoline + * dance in reverse. + */ + offset = (unsigned long)__kvm_hyp_reset + - ((unsigned long)__hyp_idmap_text_start & PAGE_MASK); + + return TRAMPOLINE_VA + offset; + } else { + /* + * KVM is running with merged page tables, which don't have the + * trampoline page mapped. We know the idmap is still mapped, + * but can't be called into directly. Use + * __extended_idmap_trampoline to do the call. + */ + return (unsigned long)kvm_ksym_ref(__extended_idmap_trampoline); + } +} |