From patchwork Fri Jan 15 19:18:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geoff Levand X-Patchwork-Id: 8044301 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8C65EBEEE5 for ; Fri, 15 Jan 2016 19:26:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3D4DF20384 for ; Fri, 15 Jan 2016 19:26:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DE65D2037E for ; Fri, 15 Jan 2016 19:26:43 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aK9zc-0006xC-EO; Fri, 15 Jan 2016 19:25:04 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aK9tT-0000DT-Sc; Fri, 15 Jan 2016 19:18:44 +0000 Received: from geoff by merlin.infradead.org with local (Exim 4.85 #2 (Red Hat Linux)) id 1aK9tO-0000nC-21; Fri, 15 Jan 2016 19:18:38 +0000 Message-Id: In-Reply-To: References: From: Geoff Levand Patch-Date: Tue, 22 Sep 2015 15:36:29 -0700 Subject: [PATCH 10/19] arm64: kvm: allows kvm cpu hotplug To: Catalin Marinas , Will Deacon Date: Fri, 15 Jan 2016 19:18:38 +0000 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , marc.zyngier@arm.com, kexec@lists.infradead.org, AKASHI Takahiro , James Morse , linux-arm-kernel@lists.infradead.org, christoffer.dall@linaro.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: AKASHI Takahiro The current kvm implementation on arm64 does cpu-specific initialization at system boot, and has no way to gracefully shutdown a core in terms of kvm. This prevents, especially, kexec from rebooting the system on a boot core in EL2. This patch adds a cpu tear-down function and also puts an existing cpu-init code into a separate function, kvm_arch_hardware_disable() and kvm_arch_hardware_enable() respectively. We don't need arm64-specific cpu hotplug hook any more. Since this patch modifies common part of code between arm and arm64, one stub definition, __cpu_reset_hyp_mode(), is added on arm side to avoid compiling errors. Signed-off-by: AKASHI Takahiro --- arch/arm/include/asm/kvm_host.h | 10 ++++- arch/arm/include/asm/kvm_mmu.h | 1 + arch/arm/kvm/arm.c | 93 +++++++++++++++++++++++---------------- arch/arm/kvm/mmu.c | 5 +++ arch/arm64/include/asm/kvm_host.h | 11 ++++- arch/arm64/include/asm/kvm_mmu.h | 1 + arch/arm64/include/asm/virt.h | 9 ++++ arch/arm64/kvm/hyp-init.S | 33 ++++++++++++++ arch/arm64/kvm/hyp.S | 32 ++++++++++++-- 9 files changed, 151 insertions(+), 44 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 6692982..9242765 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -214,6 +214,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr, kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr); } +static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr, + phys_addr_t phys_idmap_start) +{ + /* + * TODO + * kvm_call_reset(boot_pgd_ptr, phys_idmap_start); + */ +} + static inline int kvm_arch_dev_ioctl_check_extension(long ext) { return 0; @@ -226,7 +235,6 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); -static inline void kvm_arch_hardware_disable(void) {} static inline void kvm_arch_hardware_unsetup(void) {} static inline void kvm_arch_sync_events(struct kvm *kvm) {} static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 405aa18..dc6fadf 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -66,6 +66,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); phys_addr_t kvm_mmu_get_httbr(void); phys_addr_t kvm_mmu_get_boot_httbr(void); phys_addr_t kvm_get_idmap_vector(void); +phys_addr_t kvm_get_idmap_start(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index e06fd29..e91f80e 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -16,7 +16,6 @@ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ -#include #include #include #include @@ -61,6 +60,8 @@ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1); static u8 kvm_next_vmid; static DEFINE_SPINLOCK(kvm_vmid_lock); +static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled); + static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu) { BUG_ON(preemptible()); @@ -85,11 +86,6 @@ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void) return &kvm_arm_running_vcpu; } -int kvm_arch_hardware_enable(void) -{ - return 0; -} - int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) { return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; @@ -577,7 +573,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) /* * Re-check atomic conditions */ - if (signal_pending(current)) { + if (unlikely(!__this_cpu_read(kvm_arm_hardware_enabled))) { + /* cpu has been torn down */ + ret = 0; + run->exit_reason = KVM_EXIT_FAIL_ENTRY; + run->fail_entry.hardware_entry_failure_reason + = (u64)-ENOEXEC; + } else if (signal_pending(current)) { ret = -EINTR; run->exit_reason = KVM_EXIT_INTR; } @@ -954,7 +956,7 @@ long kvm_arch_vm_ioctl(struct file *filp, } } -static void cpu_init_hyp_mode(void *dummy) +static void cpu_init_hyp_mode(void) { phys_addr_t boot_pgd_ptr; phys_addr_t pgd_ptr; @@ -976,36 +978,56 @@ static void cpu_init_hyp_mode(void *dummy) kvm_arm_init_debug(); } -static int hyp_init_cpu_notify(struct notifier_block *self, - unsigned long action, void *cpu) +static void cpu_reset_hyp_mode(void) { - switch (action) { - case CPU_STARTING: - case CPU_STARTING_FROZEN: - if (__hyp_get_vectors() == hyp_default_vectors) - cpu_init_hyp_mode(NULL); - break; + phys_addr_t boot_pgd_ptr; + phys_addr_t phys_idmap_start; + + boot_pgd_ptr = kvm_mmu_get_boot_httbr(); + phys_idmap_start = kvm_get_idmap_start(); + + __cpu_reset_hyp_mode(boot_pgd_ptr, phys_idmap_start); +} + +int kvm_arch_hardware_enable(void) +{ + if (!__this_cpu_read(kvm_arm_hardware_enabled)) { + cpu_init_hyp_mode(); + __this_cpu_write(kvm_arm_hardware_enabled, 1); } - return NOTIFY_OK; + return 0; } -static struct notifier_block hyp_init_cpu_nb = { - .notifier_call = hyp_init_cpu_notify, -}; +void kvm_arch_hardware_disable(void) +{ + if (!__this_cpu_read(kvm_arm_hardware_enabled)) + return; + + cpu_reset_hyp_mode(); + __this_cpu_write(kvm_arm_hardware_enabled, 0); +} #ifdef CONFIG_CPU_PM static int hyp_init_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, void *v) { - if (cmd == CPU_PM_EXIT && - __hyp_get_vectors() == hyp_default_vectors) { - cpu_init_hyp_mode(NULL); + switch (cmd) { + case CPU_PM_ENTER: + if (__this_cpu_read(kvm_arm_hardware_enabled)) + cpu_reset_hyp_mode(); + return NOTIFY_OK; - } + case CPU_PM_EXIT: + if (__this_cpu_read(kvm_arm_hardware_enabled)) + cpu_init_hyp_mode(); - return NOTIFY_DONE; + return NOTIFY_OK; + + default: + return NOTIFY_DONE; + } } static struct notifier_block hyp_init_cpu_pm_nb = { @@ -1103,14 +1125,20 @@ static int init_hyp_mode(void) } /* - * Execute the init code on each CPU. + * Init this CPU temporarily to execute kvm_hyp_call() + * during kvm_vgic_hyp_init(). */ - on_each_cpu(cpu_init_hyp_mode, NULL, 1); + preempt_disable(); + cpu_init_hyp_mode(); /* * Init HYP view of VGIC */ err = kvm_vgic_hyp_init(); + + cpu_reset_hyp_mode(); + preempt_enable(); + if (err) goto out_free_context; @@ -1181,26 +1209,15 @@ int kvm_arch_init(void *opaque) } } - cpu_notifier_register_begin(); - err = init_hyp_mode(); if (err) goto out_err; - err = __register_cpu_notifier(&hyp_init_cpu_nb); - if (err) { - kvm_err("Cannot register HYP init CPU notifier (%d)\n", err); - goto out_err; - } - - cpu_notifier_register_done(); - hyp_cpu_pm_init(); kvm_coproc_table_init(); return 0; out_err: - cpu_notifier_register_done(); return err; } diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 61d96a6..e6651dd 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1643,6 +1643,11 @@ phys_addr_t kvm_get_idmap_vector(void) return hyp_idmap_vector; } +phys_addr_t kvm_get_idmap_start(void) +{ + return hyp_idmap_start; +} + int kvm_mmu_init(void) { int err; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a35ce72..de08e4c 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -223,6 +223,7 @@ struct kvm_vcpu *kvm_arm_get_running_vcpu(void); struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void); u64 kvm_call_hyp(void *hypfn, ...); +void kvm_call_reset(phys_addr_t boot_pgd_ptr, phys_addr_t phys_idmap_start); void force_vm_exit(const cpumask_t *mask); void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); @@ -247,7 +248,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr, hyp_stack_ptr, vector_ptr); } -static inline void kvm_arch_hardware_disable(void) {} +static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr, + phys_addr_t phys_idmap_start) +{ + /* + * Call reset code, and switch back to stub hyp vectors. + */ + kvm_call_reset(boot_pgd_ptr, phys_idmap_start); +} + static inline void kvm_arch_hardware_unsetup(void) {} static inline void kvm_arch_sync_events(struct kvm *kvm) {} static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 6150567..ff5a087 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -98,6 +98,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); phys_addr_t kvm_mmu_get_httbr(void); phys_addr_t kvm_mmu_get_boot_httbr(void); phys_addr_t kvm_get_idmap_vector(void); +phys_addr_t kvm_get_idmap_start(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 3070096..bca79f9 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -58,9 +58,18 @@ #define HVC_CALL_FUNC 3 +/* + * HVC_RESET_CPU - Reset cpu in EL2 to initial state. + * + * @x0: entry address in trampoline code in va + * @x1: identical mapping page table in pa + */ + #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) +#define HVC_RESET_CPU 4 + #ifndef __ASSEMBLY__ /* diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S index 1d7e502..d909ce2 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -140,6 +140,39 @@ merged: eret ENDPROC(__kvm_hyp_init) + /* + * 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 + + /* Invalidate the old TLBs */ + tlbi alle2 + dsb sy + + /* 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 + + /* Install stub vectors */ + adrp x0, __hyp_stub_vectors + add x0, x0, #:lo12:__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 15b1ef9..ed82dc2 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -943,6 +943,11 @@ ENTRY(kvm_call_hyp) ret ENDPROC(kvm_call_hyp) +ENTRY(kvm_call_reset) + hvc #HVC_RESET_CPU + ret +ENDPROC(kvm_call_reset) + .macro invalid_vector label, target .align 2 \label: @@ -986,10 +991,27 @@ el1_sync: // Guest trapped into EL2 cmp x18, #HVC_GET_VECTORS b.ne 1f mrs x0, vbar_el2 - b 2f - -1: /* Default to HVC_CALL_HYP. */ + b do_eret + /* jump into trampoline code */ +1: cmp x18, #HVC_RESET_CPU + b.ne 2f + /* + * Entry point is: + * TRAMPOLINE_VA + * + (__kvm_hyp_reset - (__hyp_idmap_text_start & PAGE_MASK)) + */ + adrp x2, __kvm_hyp_reset + add x2, x2, #:lo12:__kvm_hyp_reset + adrp x3, __hyp_idmap_text_start + add x3, x3, #:lo12:__hyp_idmap_text_start + and x3, x3, PAGE_MASK + sub x2, x2, x3 + ldr x3, =TRAMPOLINE_VA + add x2, x2, x3 + br x2 // no return + +2: /* Default to HVC_CALL_HYP. */ push lr, xzr /* @@ -1003,7 +1025,9 @@ el1_sync: // Guest trapped into EL2 blr lr pop lr, xzr -2: eret + +do_eret: + eret el1_trap: /*