From patchwork Thu Mar 26 08:25:22 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 6096821 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 22AD7BF90F for ; Thu, 26 Mar 2015 08:31:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 59498203F7 for ; Thu, 26 Mar 2015 08:31:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3508D203F1 for ; Thu, 26 Mar 2015 08:31:22 +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 1Yb39T-0002JW-EA; Thu, 26 Mar 2015 08:28:31 +0000 Received: from mail-pa0-f42.google.com ([209.85.220.42]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Yb380-0001WD-Eu for linux-arm-kernel@lists.infradead.org; Thu, 26 Mar 2015 08:27:04 +0000 Received: by padcy3 with SMTP id cy3so56277773pad.3 for ; Thu, 26 Mar 2015 01:26:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+pL7k8KXZDb93y1X/4UomYrU2R4Df86kOZa0VYRduZo=; b=BaE+K0l33gsPHqhhp+ufTebICflhcMYs/cgpYq/OTkIqnV3tICATckFRAC+OiHWYJC nJdwFd1EGtL22V9JrCRtWsJO+oeG8ZW8GGgVkBHR9ZGB/v0nglUUUiK9MFP5Vswe0a0l wHA8yv+ufsS57Sl0AEImIULN6f3ZgtuB6tLXASxsmuqZlW8AIaYRIRI803BCwSzx4eHi UrdWScYPNO/8RL+I8MoY/D28Fs3CucdmVfXL6MNhAubtlEJRRvQNZ+Fe1upwXabU51mU +Kp1W9A9UcyoDlpLseEOxPf3qplixGrqAmcP6x59BIkixZTUT1aQQ/lWq2J34OYXrfUt Gz0Q== X-Gm-Message-State: ALoCoQl0KQzqan7+jdFl3TEpmrT6q7sj1C7rjRfgBu1mrqeJ8FF3DhGBklapY/J+zD8KnmfUa1N9 X-Received: by 10.70.65.39 with SMTP id u7mr24642648pds.11.1427358399074; Thu, 26 Mar 2015 01:26:39 -0700 (PDT) Received: from localhost.localdomain (61-205-2-129m5.grp1.mineo.jp. [61.205.2.129]) by mx.google.com with ESMTPSA id xz1sm4722152pbb.47.2015.03.26.01.26.32 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 26 Mar 2015 01:26:37 -0700 (PDT) From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, mark.rutland@arm.com Subject: [RFC v2 1/5] arm64: kvm: add a cpu tear-down function Date: Thu, 26 Mar 2015 17:25:22 +0900 Message-Id: <1427358326-3708-2-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1427358326-3708-1-git-send-email-takahiro.akashi@linaro.org> References: <1427358326-3708-1-git-send-email-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150326_012700_621462_4FF72C78 X-CRM114-Status: GOOD ( 17.45 ) X-Spam-Score: -0.7 (/) Cc: linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, geoff@infradead.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro , broonie@kernel.org, david.griego@linaro.org, christoffer.dall@linaro.org, freddy77@gmail.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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, T_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 Cpu must be put back into its initial state, at least, in the following cases in order to shutdown the system and/or re-initialize cpus later on: 1) kexec/kdump 2) cpu hotplug (offline) 3) removing kvm as a module To address those issues in later patches, this patch adds a tear-down function, kvm_cpu_reset(), that disables D-cache & MMU and restore a vector table to the initial stub at EL2. Signed-off-by: AKASHI Takahiro --- arch/arm/kvm/arm.c | 15 +++++++++++++++ arch/arm/kvm/mmu.c | 5 +++++ arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_host.h | 11 +++++++++++ arch/arm64/include/asm/kvm_mmu.h | 5 +++++ arch/arm64/include/asm/virt.h | 11 +++++++++++ arch/arm64/kvm/hyp-init.S | 35 +++++++++++++++++++++++++++++++++++ arch/arm64/kvm/hyp.S | 16 +++++++++++++--- 8 files changed, 96 insertions(+), 3 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 5560f74..39df694 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -897,6 +897,21 @@ static void cpu_init_hyp_mode(void *dummy) __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr); } +static void kvm_cpu_reset(void *dummy) +{ + phys_addr_t boot_pgd_ptr; + phys_addr_t phys_idmap_start; + + if (__hyp_get_vectors() == hyp_default_vectors) + return; + + 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, + hyp_default_vectors, + kvm_virt_to_trampoline(__kvm_hyp_reset)); +} + static int hyp_init_cpu_notify(struct notifier_block *self, unsigned long action, void *cpu) { diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 3e6859b..3631a37 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1490,6 +1490,11 @@ 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_asm.h b/arch/arm64/include/asm/kvm_asm.h index 4f7310f..f1c16e2 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -118,6 +118,7 @@ struct kvm_vcpu; extern char __kvm_hyp_init[]; extern char __kvm_hyp_init_end[]; +extern char __kvm_hyp_reset[]; extern char __kvm_hyp_vector[]; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8ac3c70..6a8da9c 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -199,6 +199,8 @@ 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, + unsigned long stub_vector_ptr, unsigned long reset_func); void force_vm_exit(const cpumask_t *mask); void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); @@ -223,6 +225,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr, hyp_stack_ptr, vector_ptr); } +static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr, + phys_addr_t phys_idmap_start, + unsigned long stub_vector_ptr, + unsigned long reset_func) +{ + kvm_call_reset(boot_pgd_ptr, phys_idmap_start, stub_vector_ptr, + reset_func); +} + struct vgic_sr_vectors { void *save_vgic; void *restore_vgic; diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 6458b53..c191432 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -96,6 +96,7 @@ 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); @@ -305,5 +306,9 @@ static inline void __kvm_flush_dcache_pud(pud_t pud) void kvm_set_way_flush(struct kvm_vcpu *vcpu); void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled); +extern char __hyp_idmap_text_start[]; +#define kvm_virt_to_trampoline(x) \ + (TRAMPOLINE_VA + ((x) - __hyp_idmap_text_start)) + #endif /* __ASSEMBLY__ */ #endif /* __ARM64_KVM_MMU_H__ */ diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 3070096..7fcd087 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -61,6 +61,17 @@ #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) +/* + * HVC_RESET - Reset cpu in EL2 to initial state. + * + * @x0: entry address in trampoline code in va + * @x1: identical mapping page table in pa + * @x2: start address of identical mapping in pa + * @x3: initial stub vector in pa + */ + +#define HVC_RESET 5 + #ifndef __ASSEMBLY__ /* diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S index c319116..d212990 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -115,6 +115,41 @@ target: /* We're now in the trampoline code, switch page tables */ eret ENDPROC(__kvm_hyp_init) + /* + * x0: HYP boot pgd + * x1: HYP phys_idmap_start + * x2: HYP stub vectors + */ +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 + and x1, x0, #SCTLR_EL2_EE + orr x0, x0, x1 // preserve endianness of EL2 + ldr x1, =SCTLR_EL2_FLAGS + eor x1, x1, xzr + bic x0, x0, x1 // Clear SCTL_M and etc + msr sctlr_el2, x0 + isb + + /* Install stub vectors */ + msr vbar_el2, x2 + + eret +ENDPROC(__kvm_hyp_reset) + .ltorg .popsection diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index fd085ec..7c3bdee 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -1136,6 +1136,11 @@ ENTRY(kvm_call_hyp) ret ENDPROC(kvm_call_hyp) +ENTRY(kvm_call_reset) + hvc #HVC_RESET + ret +ENDPROC(kvm_call_reset) + .macro invalid_vector label, target .align 2 \label: @@ -1179,10 +1184,14 @@ el1_sync: // Guest trapped into EL2 cmp x18, #HVC_GET_VECTORS b.ne 1f mrs x0, vbar_el2 - b 2f + b 3f -1: /* Default to HVC_CALL_HYP. */ + /* jump into trampoline code */ +1: cmp x18, #HVC_RESET + b.ne 2f + br x3 // no return +2: /* Default to HVC_CALL_HYP. */ push lr, xzr /* @@ -1196,7 +1205,8 @@ el1_sync: // Guest trapped into EL2 blr lr pop lr, xzr -2: eret + +3: eret el1_trap: /*