From patchwork Thu Feb 2 12:04:21 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: James Hogan X-Patchwork-Id: 9551711 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AD14C60236 for ; Thu, 2 Feb 2017 12:06:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A209826861 for ; Thu, 2 Feb 2017 12:06:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 96E8328425; Thu, 2 Feb 2017 12:06:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1840126861 for ; Thu, 2 Feb 2017 12:06:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751557AbdBBMGJ (ORCPT ); Thu, 2 Feb 2017 07:06:09 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:35261 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751468AbdBBMFB (ORCPT ); Thu, 2 Feb 2017 07:05:01 -0500 Received: from hhmail02.hh.imgtec.org (unknown [10.100.10.20]) by Forcepoint Email with ESMTPS id A3884E944BFCA; Thu, 2 Feb 2017 12:04:55 +0000 (GMT) Received: from jhogan-linux.le.imgtec.org (192.168.154.110) by hhmail02.hh.imgtec.org (10.100.10.21) with Microsoft SMTP Server (TLS) id 14.3.294.0; Thu, 2 Feb 2017 12:04:58 +0000 From: James Hogan To: CC: James Hogan , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Ralf Baechle , Subject: [PATCH v2 8/30] KVM: MIPS/MMU: Move preempt/ASID handling to implementation Date: Thu, 2 Feb 2017 12:04:21 +0000 Message-ID: <341dc04c44b0bdf43044866f9bb1eac091e856ea.1486036366.git-series.james.hogan@imgtec.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 In-Reply-To: References: X-Originating-IP: [192.168.154.110] Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The MIPS KVM host and guest GVA ASIDs may need regenerating when scheduling a process in guest context, which is done from the kvm_arch_vcpu_load() / kvm_arch_vcpu_put() functions in mmu.c. However this is a fairly implementation specific detail. VZ for example may use GuestIDs instead of normal ASIDs to distinguish mappings belonging to different guests, and even on VZ without GuestID the root TLB will be used differently to trap & emulate. Trap & emulate GVA ASIDs only relate to the user part of the full address space, so can be left active during guest exit handling (guest context) to allow guest instructions to be easily read and translated. VZ root ASIDs however are for GPA mappings so can't be left active during normal kernel code. They also aren't useful for accessing guest virtual memory, and we should have CP0_BadInstr[P] registers available to provide encodings of trapping guest instructions anyway. Therefore move the ASID preemption handling into the implementation callback. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/mmu.c | 51 +------------------------------------ arch/mips/kvm/trap_emul.c | 56 ++++++++++++++++++++++++++++++++++++++-- 2 files changed, 54 insertions(+), 53 deletions(-) diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c index ed46528611f4..df013538113f 100644 --- a/arch/mips/kvm/mmu.c +++ b/arch/mips/kvm/mmu.c @@ -235,39 +235,12 @@ static void kvm_mips_migrate_count(struct kvm_vcpu *vcpu) /* Restore ASID once we are scheduled back after preemption */ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { - unsigned long asid_mask = cpu_asid_mask(&cpu_data[cpu]); unsigned long flags; kvm_debug("%s: vcpu %p, cpu: %d\n", __func__, vcpu, cpu); - /* Allocate new kernel and user ASIDs if needed */ - local_irq_save(flags); - if ((vcpu->arch.guest_kernel_asid[cpu] ^ asid_cache(cpu)) & - asid_version_mask(cpu)) { - kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm, cpu, vcpu); - vcpu->arch.guest_kernel_asid[cpu] = - vcpu->arch.guest_kernel_mm.context.asid[cpu]; - - kvm_debug("[%d]: cpu_context: %#lx\n", cpu, - cpu_context(cpu, current->mm)); - kvm_debug("[%d]: Allocated new ASID for Guest Kernel: %#x\n", - cpu, vcpu->arch.guest_kernel_asid[cpu]); - } - - if ((vcpu->arch.guest_user_asid[cpu] ^ asid_cache(cpu)) & - asid_version_mask(cpu)) { - kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu); - vcpu->arch.guest_user_asid[cpu] = - vcpu->arch.guest_user_mm.context.asid[cpu]; - - kvm_debug("[%d]: cpu_context: %#lx\n", cpu, - cpu_context(cpu, current->mm)); - kvm_debug("[%d]: Allocated new ASID for Guest User: %#x\n", cpu, - vcpu->arch.guest_user_asid[cpu]); - } - if (vcpu->arch.last_sched_cpu != cpu) { kvm_debug("[%d->%d]KVM VCPU[%d] switch\n", vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id); @@ -279,25 +252,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_mips_migrate_count(vcpu); } - /* - * If we preempted while the guest was executing, then reload the ASID - * based on the mode of the Guest (Kernel/User) - */ - if (current->flags & PF_VCPU) { - if (KVM_GUEST_KERNEL_MODE(vcpu)) - write_c0_entryhi(vcpu->arch.guest_kernel_asid[cpu] & - asid_mask); - else - write_c0_entryhi(vcpu->arch.guest_user_asid[cpu] & - asid_mask); - ehb(); - } - /* restore guest state to registers */ kvm_mips_callbacks->vcpu_load(vcpu, cpu); local_irq_restore(flags); - } /* ASID can change if another task is scheduled during preemption */ @@ -314,15 +272,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) /* save guest state in registers */ kvm_mips_callbacks->vcpu_put(vcpu, cpu); - if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) & - asid_version_mask(cpu))) { - kvm_debug("%s: Dropping MMU Context: %#lx\n", __func__, - cpu_context(cpu, current->mm)); - drop_mmu_context(current->mm, cpu); - } - write_c0_entryhi(cpu_asid(cpu, current->mm)); - ehb(); - local_irq_restore(flags); } diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index c0ee51465913..494a90221b5e 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -11,9 +11,9 @@ #include #include -#include - #include +#include +#include #include "interrupt.h" @@ -635,6 +635,49 @@ static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu, static int kvm_trap_emul_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { + unsigned long asid_mask = cpu_asid_mask(&cpu_data[cpu]); + + /* Allocate new kernel and user ASIDs if needed */ + + if ((vcpu->arch.guest_kernel_asid[cpu] ^ asid_cache(cpu)) & + asid_version_mask(cpu)) { + kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm, cpu, vcpu); + vcpu->arch.guest_kernel_asid[cpu] = + vcpu->arch.guest_kernel_mm.context.asid[cpu]; + + kvm_debug("[%d]: cpu_context: %#lx\n", cpu, + cpu_context(cpu, current->mm)); + kvm_debug("[%d]: Allocated new ASID for Guest Kernel: %#x\n", + cpu, vcpu->arch.guest_kernel_asid[cpu]); + } + + if ((vcpu->arch.guest_user_asid[cpu] ^ asid_cache(cpu)) & + asid_version_mask(cpu)) { + kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu); + vcpu->arch.guest_user_asid[cpu] = + vcpu->arch.guest_user_mm.context.asid[cpu]; + + kvm_debug("[%d]: cpu_context: %#lx\n", cpu, + cpu_context(cpu, current->mm)); + kvm_debug("[%d]: Allocated new ASID for Guest User: %#x\n", cpu, + vcpu->arch.guest_user_asid[cpu]); + } + + /* + * Were we in guest context? If so then the pre-empted ASID is + * no longer valid, we need to set it to what it should be based + * on the mode of the Guest (Kernel/User) + */ + if (current->flags & PF_VCPU) { + if (KVM_GUEST_KERNEL_MODE(vcpu)) + write_c0_entryhi(vcpu->arch.guest_kernel_asid[cpu] & + asid_mask); + else + write_c0_entryhi(vcpu->arch.guest_user_asid[cpu] & + asid_mask); + ehb(); + } + return 0; } @@ -642,6 +685,15 @@ static int kvm_trap_emul_vcpu_put(struct kvm_vcpu *vcpu, int cpu) { kvm_lose_fpu(vcpu); + if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) & + asid_version_mask(cpu))) { + kvm_debug("%s: Dropping MMU Context: %#lx\n", __func__, + cpu_context(cpu, current->mm)); + drop_mmu_context(current->mm, cpu); + } + write_c0_entryhi(cpu_asid(cpu, current->mm)); + ehb(); + return 0; }