From patchwork Thu Nov 26 17:32:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 57335 Delivered-To: patch@linaro.org Received: by 10.112.155.196 with SMTP id vy4csp642044lbb; Thu, 26 Nov 2015 09:34:07 -0800 (PST) X-Received: by 10.66.100.135 with SMTP id ey7mr18563925pab.108.1448559247375; Thu, 26 Nov 2015 09:34:07 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id qy7si9989454pab.169.2015.11.26.09.34.07; Thu, 26 Nov 2015 09:34:07 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-pm-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-pm-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752022AbbKZReG (ORCPT + 11 others); Thu, 26 Nov 2015 12:34:06 -0500 Received: from foss.arm.com ([217.140.101.70]:46256 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751995AbbKZReE (ORCPT ); Thu, 26 Nov 2015 12:34:04 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2E9314E7; Thu, 26 Nov 2015 09:33:46 -0800 (PST) Received: from melchizedek.cambridge.arm.com (melchizedek.cambridge.arm.com [10.1.209.158]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4915A3F308; Thu, 26 Nov 2015 09:34:01 -0800 (PST) From: James Morse To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon , Sudeep Holla , Kevin Kang , Geoff Levand , Catalin Marinas , Lorenzo Pieralisi , Mark Rutland , AKASHI Takahiro , wangfei , Marc Zyngier , "Rafael J . Wysocki" , Pavel Machek , linux-pm@vger.kernel.org, James Morse Subject: [PATCH v3 04/10] arm64: kvm: allows kvm cpu hotplug Date: Thu, 26 Nov 2015 17:32:42 +0000 Message-Id: <1448559168-8363-5-git-send-email-james.morse@arm.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1448559168-8363-1-git-send-email-james.morse@arm.com> References: <1448559168-8363-1-git-send-email-james.morse@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org 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 Signed-off-by: James Morse --- arch/arm/include/asm/kvm_host.h | 10 ++++- arch/arm/include/asm/kvm_mmu.h | 1 + arch/arm/kvm/arm.c | 79 ++++++++++++++++++--------------------- arch/arm/kvm/mmu.c | 5 +++ arch/arm64/include/asm/kvm_host.h | 16 +++++++- 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, 138 insertions(+), 48 deletions(-) -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 6692982c9b57..924276571658 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 405aa1883307..dc6fadfd0407 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 eab83b2435b8..a5d9d74f5c75 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; @@ -959,7 +955,7 @@ long kvm_arch_vm_ioctl(struct file *filp, } } -static void cpu_init_hyp_mode(void *dummy) +int kvm_arch_hardware_enable(void) { phys_addr_t boot_pgd_ptr; phys_addr_t pgd_ptr; @@ -967,6 +963,9 @@ static void cpu_init_hyp_mode(void *dummy) unsigned long stack_page; unsigned long vector_ptr; + if (__hyp_get_vectors() != hyp_default_vectors) + return 0; + /* Switch from the HYP stub to our own HYP init vector */ __hyp_set_vectors(kvm_get_idmap_vector()); @@ -979,38 +978,50 @@ static void cpu_init_hyp_mode(void *dummy) __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr); kvm_arm_init_debug(); + + return 0; } -static int hyp_init_cpu_notify(struct notifier_block *self, - unsigned long action, void *cpu) +void kvm_arch_hardware_disable(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; - return NOTIFY_OK; -} + if (__hyp_get_vectors() == hyp_default_vectors) + return; -static struct notifier_block hyp_init_cpu_nb = { - .notifier_call = hyp_init_cpu_notify, -}; + 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); +} #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 (__hyp_get_vectors() != hyp_default_vectors) + __this_cpu_write(kvm_arm_hardware_enabled, 1); + else + __this_cpu_write(kvm_arm_hardware_enabled, 0); + /* + * don't call kvm_arch_hardware_disable() in case of + * CPU_PM_ENTER because it does't actually save any state. + */ + + return NOTIFY_OK; + case CPU_PM_EXIT: + if (__this_cpu_read(kvm_arm_hardware_enabled)) + kvm_arch_hardware_enable(); + return NOTIFY_OK; - } - return NOTIFY_DONE; + default: + return NOTIFY_DONE; + } } static struct notifier_block hyp_init_cpu_pm_nb = { @@ -1108,11 +1119,6 @@ static int init_hyp_mode(void) } /* - * Execute the init code on each CPU. - */ - on_each_cpu(cpu_init_hyp_mode, NULL, 1); - - /* * Init HYP view of VGIC */ err = kvm_vgic_hyp_init(); @@ -1186,26 +1192,15 @@ 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 6984342da13d..69b4a33d232d 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1644,6 +1644,11 @@ 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 a35ce7266aac..0b540f852ec1 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 +248,20 @@ 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); +} + +struct vgic_sr_vectors { + void *save_vgic; + void *restore_vgic; +}; + 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 61505676d085..ff5a08777e11 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 30700961f28c..bca79f90178c 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 2e67a4872c51..192516332e47 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -139,6 +139,39 @@ 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_EL2_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 1bef8db4a13d..aca11d6b996e 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -939,6 +939,11 @@ 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: @@ -982,10 +987,27 @@ 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 /* @@ -999,7 +1021,9 @@ el1_sync: // Guest trapped into EL2 blr lr pop lr, xzr -2: eret + +do_eret: + eret el1_trap: /*